diff mbox series

[V3,8/8] iommu/arm: Add Renesas IPMMU-VMSA support

Message ID 1566324587-3442-9-git-send-email-olekstysh@gmail.com (mailing list archive)
State Superseded
Headers show
Series iommu/arm: Add Renesas IPMMU-VMSA support + Linux's iommu_fwspec | expand

Commit Message

Oleksandr Tyshchenko Aug. 20, 2019, 6:09 p.m. UTC
From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>

The IPMMU-VMSA is VMSA-compatible I/O Memory Management Unit (IOMMU)
which provides address translation and access protection functionalities
to processing units and interconnect networks.

Please note, current driver is supposed to work only with newest
Gen3 SoCs revisions which IPMMU hardware supports stage 2 translation
table format and is able to use CPU's P2M table as is if one is
3-level page table (up to 40 bit IPA).

The major differences compare to the Linux driver are:

1. Stage 1/Stage 2 translation. Linux driver supports Stage 1
translation only (with Stage 1 translation table format). It manages
page table by itself. But Xen driver supports Stage 2 translation
(with Stage 2 translation table format) to be able to share the P2M
with the CPU. Stage 1 translation is always bypassed in Xen driver.

So, Xen driver is supposed to be used with newest R-Car Gen3 SoC revisions
only (H3 ES3.0, M3-W+, etc.) which IPMMU H/W supports stage 2 translation
table format.

2. AArch64 support. Linux driver uses VMSAv8-32 mode, while Xen driver
enables Armv8 VMSAv8-64 mode to cover up to 40 bit input address.

3. Context bank (sets of page table) usage. In Xen, each context bank is
mapped to one Xen domain. So, all devices being pass throughed to the
same Xen domain share the same context bank.

4. IPMMU device tracking. In Xen, all IOMMU devices are managed
by single driver instance. So, driver uses global list to keep track
of registered IPMMU devices.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
CC: Julien Grall <julien.grall@arm.com>
CC: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

---
Changes V2 -> V3:
    - added Copyright from Linux
    - included <xen/iommu.h> and <asm/iommu_fwspec.h> directly
    - removed pointless spin_lock from ipmmu_iommu_domain_teardown()
    - changed "Gen3" to "R-Car Gen3", "M3 ES3.0" to "M3-W+"
    - changed RCAR_PRODUCT_M3 to RCAR_PRODUCT_M3W
    - clarified IMTTBCR_TSZ1_MASK
    - removed TLB flush from ipmmu_domain_irq() until clarified the purpose
    - returned -ENODEV in ipmmu_init() if P2M sharing or P2M IPA size
      is not supported to show that IOMMU device is not usable in Xen
    - implemented new callback "of_xlate" to parse DT IOMMU specifier
      and add device IDs to "iommu_fwspec"
    - reworked "add_device" callback
    - updated patch description

Changes V1 -> V2:
    - rewrited driver to use iommu_fwspec
    - removed DT parsing code for micro-TLBs
    - removed struct ipmmu_vmsa_master_cfg, dev_archdata macro
    - added ipmmu_find_mmu_by_dev(), various helpers to access
      fwspec->iommu_priv
    - implemented new callback "add_device" to add master device to IPMMU
    - removed ipmmu_protect_masters()
    - removed code to locate Root device in the first place,
      used EAGAIN to request deferred probing
    - used printk_once for the system wide error messages in ipmmu_init()
      which don't need to be shown for every device being probed
    - removed map_page/unmap_page implementation, reused them
      from iommu_helpers.c
    - used %pd for printing domaid id
    - performed various cosmetic fixes
    - changed u32 -> uint32_t, u64 -> uint64_t,
      unsigned int -> uint32_t where needed
    - clarified TODOs
    - clafiried supported SoC versions in config IPMMU_VMSA,
      set default to "n"
    - updated comments in code, provided more accurate description,
      added new comments where needed
    - updated patch description by providing differences between
      Linux/Xen implementations
    - removed fields for cache snoop transaction when configuring IMTTBCR
      (update from Renesas BSP)
---
 xen/arch/arm/platforms/Kconfig           |    1 +
 xen/drivers/passthrough/Kconfig          |   13 +
 xen/drivers/passthrough/arm/Makefile     |    1 +
 xen/drivers/passthrough/arm/ipmmu-vmsa.c | 1359 ++++++++++++++++++++++++++++++
 4 files changed, 1374 insertions(+)
 create mode 100644 xen/drivers/passthrough/arm/ipmmu-vmsa.c

Comments

Yoshihiro Shimoda Aug. 29, 2019, 8:37 a.m. UTC | #1
Hi Oleksandr-san,

> From: Oleksandr Tyshchenko, Sent: Wednesday, August 21, 2019 3:10 AM
> 
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
> 
> The IPMMU-VMSA is VMSA-compatible I/O Memory Management Unit (IOMMU)
> which provides address translation and access protection functionalities
> to processing units and interconnect networks.
> 
> Please note, current driver is supposed to work only with newest
> Gen3 SoCs revisions which IPMMU hardware supports stage 2 translation

This is still "Gen3", so that please replace it with "R-Car Gen3"...

> table format and is able to use CPU's P2M table as is if one is
> 3-level page table (up to 40 bit IPA).
> 
> The major differences compare to the Linux driver are:
> 
> 1. Stage 1/Stage 2 translation. Linux driver supports Stage 1
> translation only (with Stage 1 translation table format). It manages
> page table by itself. But Xen driver supports Stage 2 translation
> (with Stage 2 translation table format) to be able to share the P2M
> with the CPU. Stage 1 translation is always bypassed in Xen driver.
> 
> So, Xen driver is supposed to be used with newest R-Car Gen3 SoC revisions
> only (H3 ES3.0, M3-W+, etc.) which IPMMU H/W supports stage 2 translation
> table format.
> 
> 2. AArch64 support. Linux driver uses VMSAv8-32 mode, while Xen driver
> enables Armv8 VMSAv8-64 mode to cover up to 40 bit input address.
> 
> 3. Context bank (sets of page table) usage. In Xen, each context bank is
> mapped to one Xen domain. So, all devices being pass throughed to the
> same Xen domain share the same context bank.
> 
> 4. IPMMU device tracking. In Xen, all IOMMU devices are managed
> by single driver instance. So, driver uses global list to keep track
> of registered IPMMU devices.
> 
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
> CC: Julien Grall <julien.grall@arm.com>
> CC: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

About this hardware handling, this patch seems good to me. But, since
I'm not familiar about Xen passthrough framework, I think I cannot
add my Reviewed-by tag into this patch. What do you think?

Best regards,
Yoshihiro Shimoda
Oleksandr Tyshchenko Aug. 29, 2019, 10:56 a.m. UTC | #2
On 29.08.19 11:37, Yoshihiro Shimoda wrote:
> Hi Oleksandr-san,

Hi Shimoda-san.


>
>> From: Oleksandr Tyshchenko, Sent: Wednesday, August 21, 2019 3:10 AM
>>
>> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
>>
>> The IPMMU-VMSA is VMSA-compatible I/O Memory Management Unit (IOMMU)
>> which provides address translation and access protection functionalities
>> to processing units and interconnect networks.
>>
>> Please note, current driver is supposed to work only with newest
>> Gen3 SoCs revisions which IPMMU hardware supports stage 2 translation
> This is still "Gen3", so that please replace it with "R-Car Gen3"...

Will do.


>
>> table format and is able to use CPU's P2M table as is if one is
>> 3-level page table (up to 40 bit IPA).
>>
>> The major differences compare to the Linux driver are:
>>
>> 1. Stage 1/Stage 2 translation. Linux driver supports Stage 1
>> translation only (with Stage 1 translation table format). It manages
>> page table by itself. But Xen driver supports Stage 2 translation
>> (with Stage 2 translation table format) to be able to share the P2M
>> with the CPU. Stage 1 translation is always bypassed in Xen driver.
>>
>> So, Xen driver is supposed to be used with newest R-Car Gen3 SoC revisions
>> only (H3 ES3.0, M3-W+, etc.) which IPMMU H/W supports stage 2 translation
>> table format.
>>
>> 2. AArch64 support. Linux driver uses VMSAv8-32 mode, while Xen driver
>> enables Armv8 VMSAv8-64 mode to cover up to 40 bit input address.
>>
>> 3. Context bank (sets of page table) usage. In Xen, each context bank is
>> mapped to one Xen domain. So, all devices being pass throughed to the
>> same Xen domain share the same context bank.
>>
>> 4. IPMMU device tracking. In Xen, all IOMMU devices are managed
>> by single driver instance. So, driver uses global list to keep track
>> of registered IPMMU devices.
>>
>> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
>> CC: Julien Grall <julien.grall@arm.com>
>> CC: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> About this hardware handling, this patch seems good to me. But, since
> I'm not familiar about Xen passthrough framework, I think I cannot
> add my Reviewed-by tag into this patch. What do you think?

I am not completely sure regarding that, but I have seen cases when the 
people give their R-b not for the entire patch, but for a part of it.

Especially, when patch touches many sub-systems/archs. Would you mind if 
I specify what your R-b covers? -> [for the IPMMU H/W bits]


Thank you for the review.

>
> Best regards,
> Yoshihiro Shimoda
>
Oleksandr Tyshchenko Aug. 29, 2019, 11:19 a.m. UTC | #3
Hi, all


> +
> +static __init int ipmmu_init(struct dt_device_node *node, const void *data)
> +{
> +    int ret;
> +
> +    /*
> +     * Even if the device can't be initialized, we don't want to give
> +     * the IPMMU device to dom0.
> +     */
> +    dt_device_set_used_by(node, DOMID_XEN);
> +
> +    if ( !iommu_hap_pt_share )
> +    {
> +        printk_once(XENLOG_ERR "ipmmu: P2M table must always be shared between the CPU and the IPMMU\n");
> +        return -EINVAL;
> +    }
> +
> +    if ( !ipmmu_stage2_supported() )
> +    {
> +        printk_once(XENLOG_ERR "ipmmu: P2M sharing is not supported in current SoC revision\n");
> +        return -ENODEV;
> +    }
> +    else
> +    {
> +        /*
> +         * As 4-level translation table is not supported in IPMMU, we need
> +         * to check IPA size used for P2M table beforehand to be sure it is
> +         * 3-level and the IPMMU will be able to use it.
> +         *
> +         * TODO: First initialize the IOMMU and gather the requirements and
> +         * then initialize the P2M. In the P2M code, take into the account
> +         * the IOMMU requirements and restrict "pa_range" if necessary.
> +         */
> +        if ( IPMMU_MAX_P2M_IPA_BITS < p2m_ipa_bits )
> +        {
> +            printk_once(XENLOG_ERR "ipmmu: P2M IPA size is not supported (P2M=%u IPMMU=%u)!\n",
> +                        p2m_ipa_bits, IPMMU_MAX_P2M_IPA_BITS);
> +            return -ENODEV;
> +        }


There is a patch in ML which is intended to address this TODO:

https://lists.xenproject.org/archives/html/xen-devel/2019-08/msg02237.html
Yoshihiro Shimoda Sept. 2, 2019, 7:04 a.m. UTC | #4
Hi Oleksandr-san,

> From: Oleksandr, Sent: Thursday, August 29, 2019 7:56 PM
<snip>
> > About this hardware handling, this patch seems good to me. But, since
> > I'm not familiar about Xen passthrough framework, I think I cannot
> > add my Reviewed-by tag into this patch. What do you think?
> 
> I am not completely sure regarding that, but I have seen cases when the
> people give their R-b not for the entire patch, but for a part of it.
> 
> Especially, when patch touches many sub-systems/archs. Would you mind if
> I specify what your R-b covers? -> [for the IPMMU H/W bits]

I got it. When you submit v4 patch, I'll review and send such a tag.

Best regards,
Yoshihiro Shimoda
Oleksandr Tyshchenko Sept. 9, 2019, 2:33 p.m. UTC | #5
On 02.09.19 10:04, Yoshihiro Shimoda wrote:
> Hi Oleksandr-san,

Hi, Shimoda-san


>
>> From: Oleksandr, Sent: Thursday, August 29, 2019 7:56 PM
> <snip>
>>> About this hardware handling, this patch seems good to me. But, since
>>> I'm not familiar about Xen passthrough framework, I think I cannot
>>> add my Reviewed-by tag into this patch. What do you think?
>> I am not completely sure regarding that, but I have seen cases when the
>> people give their R-b not for the entire patch, but for a part of it.
>>
>> Especially, when patch touches many sub-systems/archs. Would you mind if
>> I specify what your R-b covers? -> [for the IPMMU H/W bits]
> I got it. When you submit v4 patch, I'll review and send such a tag.

Thank you.
Julien Grall Sept. 9, 2019, 9:24 p.m. UTC | #6
Hi Oleksandr,

On 8/20/19 7:09 PM, Oleksandr Tyshchenko wrote:
> diff --git a/xen/arch/arm/platforms/Kconfig b/xen/arch/arm/platforms/Kconfig
> index bc0e9cd..c93a6b2 100644
> --- a/xen/arch/arm/platforms/Kconfig
> +++ b/xen/arch/arm/platforms/Kconfig
> @@ -25,6 +25,7 @@ config RCAR3
>   	bool "Renesas RCar3 support"
>   	depends on ARM_64
>   	select HAS_SCIF
> +	select IPMMU_VMSA

As discussed previously, I think the IPMMU driver should be merged as 
tech preview for a couple of release to allow more users to test before 
we mark it as supported.

Based on this, I would not advise to select IPMMU_VMSA by default as 
user may not want to use tech preview code by default. Instead I would 
only select if EXPERT is set.

>   	---help---
>   	Enable all the required drivers for Renesas RCar3
>   
> diff --git a/xen/drivers/passthrough/Kconfig b/xen/drivers/passthrough/Kconfig
> index a3c0649..47eadb4 100644
> --- a/xen/drivers/passthrough/Kconfig
> +++ b/xen/drivers/passthrough/Kconfig
> @@ -12,4 +12,17 @@ config ARM_SMMU
>   
>   	  Say Y here if your SoC includes an IOMMU device implementing the
>   	  ARM SMMU architecture.
> +
> +config IPMMU_VMSA
> +	bool "Renesas IPMMU-VMSA found in R-Car Gen3 SoCs"
> +	default n
> +	depends on ARM_64
> +	---help---
> +	  Support for implementations of the Renesas IPMMU-VMSA found
> +	  in R-Car Gen3 SoCs.
> +
> +	  Say Y here if you are using newest R-Car Gen3 SoCs revisions
> +	  (H3 ES3.0, M3-W+, etc) which IPMMU hardware supports stage 2
> +	  translation table format and is able to use CPU's P2M table as is.
> +
>   endif

[...]

> +    /* Wait until the Root device has been registered for sure. */
> +    if ( !mmu->root )
> +    {
> +        dev_err(&node->dev, "Root IPMMU hasn't been registered yet\n");

This is a bit odd to throw an error if we are going to defer the probe.

> +        ret = -EAGAIN;
> +        goto out;
> +    }

[...]

> +static __init bool ipmmu_stage2_supported(void)
> +{
> +    struct dt_device_node *np;
> +    uint64_t addr, size;
> +    void __iomem *base;
> +    uint32_t product, cut;
> +    static enum
> +    {
> +        UNKNOWN,
> +        SUPPORTED,
> +        NOTSUPPORTED
> +    } stage2_supported = UNKNOWN;
> +
> +    /* Use the flag to avoid checking for the compatibility more then once. */

There are only one IOMMU root that will always be initialized first. So 
can't you move this code in the root IOMMU path?

> +    switch ( stage2_supported )
> +    {
> +    case SUPPORTED:
> +        return true;
> +
> +    case NOTSUPPORTED:
> +        return false;
> +
> +    case UNKNOWN:
> +    default:
> +        stage2_supported = NOTSUPPORTED;
> +        break;
> +    }
> +
> +    np = dt_find_compatible_node(NULL, NULL, "renesas,prr");
> +    if ( !np )
> +    {
> +        printk(XENLOG_ERR "ipmmu: Failed to find PRR node\n");
> +        return false;
> +    }
> +
> +    if ( dt_device_get_address(np, 0, &addr, &size) )
> +    {
> +        printk(XENLOG_ERR "ipmmu: Failed to get PRR MMIO\n");
> +        return false;
> +    }
> +
> +    base = ioremap_nocache(addr, size);
> +    if ( !base )
> +    {
> +        printk(XENLOG_ERR "ipmmu: Failed to ioremap PRR MMIO\n");
> +        return false;
> +    }
> +
> +    product = readl(base);
> +    cut = product & RCAR_CUT_MASK;
> +    product &= RCAR_PRODUCT_MASK;
> +
> +    switch ( product )
> +    {
> +    case RCAR_PRODUCT_H3:
> +    case RCAR_PRODUCT_M3W:
> +        if ( cut >= RCAR_CUT_VER30 )
> +            stage2_supported = SUPPORTED;
> +        break;
> +
> +    case RCAR_PRODUCT_M3N:
> +        stage2_supported = SUPPORTED;
> +        break;
> +
> +    default:
> +        printk(XENLOG_ERR "ipmmu: Unsupported SoC version\n");
> +        break;
> +    }
> +
> +    iounmap(base);
> +
> +    return stage2_supported == SUPPORTED;
> +}
> +
> +static const struct dt_device_match ipmmu_dt_match[] __initconst =
> +{
> +    DT_MATCH_COMPATIBLE("renesas,ipmmu-r8a7795"),
> +    DT_MATCH_COMPATIBLE("renesas,ipmmu-r8a77965"),
> +    DT_MATCH_COMPATIBLE("renesas,ipmmu-r8a7796"),
> +    { /* sentinel */ },
> +};
> +
> +static __init int ipmmu_init(struct dt_device_node *node, const void *data)
> +{
> +    int ret;
> +
> +    /*
> +     * Even if the device can't be initialized, we don't want to give
> +     * the IPMMU device to dom0.
> +     */
> +    dt_device_set_used_by(node, DOMID_XEN);
> +
> +    if ( !iommu_hap_pt_share )

iommu_hap_pt_share will soon be hardcoded to true on Arm (see [1]). Even 
without the patch, the value of iommu_hap_pt_share should be ignored as 
done by the SMMU.

> +    {
> +        printk_once(XENLOG_ERR "ipmmu: P2M table must always be shared between the CPU and the IPMMU\n");
> +        return -EINVAL;
> +    }
> +
> +    if ( !ipmmu_stage2_supported() )
> +    {
> +        printk_once(XENLOG_ERR "ipmmu: P2M sharing is not supported in current SoC revision\n");
> +        return -ENODEV;

The if part is returning so...

> +    }
> +    else

... the else part is not necessary removing one layer of indentation.

> +    {
> +        /*
> +         * As 4-level translation table is not supported in IPMMU, we need
> +         * to check IPA size used for P2M table beforehand to be sure it is
> +         * 3-level and the IPMMU will be able to use it.
> +         *
> +         * TODO: First initialize the IOMMU and gather the requirements and
> +         * then initialize the P2M. In the P2M code, take into the account
> +         * the IOMMU requirements and restrict "pa_range" if necessary.
> +         */
> +        if ( IPMMU_MAX_P2M_IPA_BITS < p2m_ipa_bits )
> +        {
> +            printk_once(XENLOG_ERR "ipmmu: P2M IPA size is not supported (P2M=%u IPMMU=%u)!\n",
> +                        p2m_ipa_bits, IPMMU_MAX_P2M_IPA_BITS);
> +            return -ENODEV;
> +        }
> +    }
> +
> +    ret = ipmmu_probe(node);
> +    if ( ret )
> +    {
> +        dev_err(&node->dev, "Failed to init IPMMU (%d)\n", ret);
> +        return ret;
> +    }
> +
> +    iommu_set_ops(&ipmmu_iommu_ops);
> +
> +    return 0;
> +}
> +
> +DT_DEVICE_START(ipmmu, "Renesas IPMMU-VMSA", DEVICE_IOMMU)
> +    .dt_match = ipmmu_dt_match,
> +    .init = ipmmu_init,
> +DT_DEVICE_END
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> 

[1] <20190902145014.36442-6-paul.durrant@citrix.com>
Oleksandr Tyshchenko Sept. 10, 2019, 11:04 a.m. UTC | #7
On 10.09.19 00:24, Julien Grall wrote:
> Hi Oleksandr,

Hi Julien


>
> On 8/20/19 7:09 PM, Oleksandr Tyshchenko wrote:
>> diff --git a/xen/arch/arm/platforms/Kconfig 
>> b/xen/arch/arm/platforms/Kconfig
>> index bc0e9cd..c93a6b2 100644
>> --- a/xen/arch/arm/platforms/Kconfig
>> +++ b/xen/arch/arm/platforms/Kconfig
>> @@ -25,6 +25,7 @@ config RCAR3
>>       bool "Renesas RCar3 support"
>>       depends on ARM_64
>>       select HAS_SCIF
>> +    select IPMMU_VMSA
>
> As discussed previously, I think the IPMMU driver should be merged as 
> tech preview for a couple of release to allow more users to test 
> before we mark it as supported.

Yes


>
> Based on this, I would not advise to select IPMMU_VMSA by default as 
> user may not want to use tech preview code by default. Instead I would 
> only select if EXPERT is set.

Agree. Will do.


>
>>       ---help---
>>       Enable all the required drivers for Renesas RCar3
>>   diff --git a/xen/drivers/passthrough/Kconfig 
>> b/xen/drivers/passthrough/Kconfig
>> index a3c0649..47eadb4 100644
>> --- a/xen/drivers/passthrough/Kconfig
>> +++ b/xen/drivers/passthrough/Kconfig
>> @@ -12,4 +12,17 @@ config ARM_SMMU
>>           Say Y here if your SoC includes an IOMMU device 
>> implementing the
>>         ARM SMMU architecture.
>> +
>> +config IPMMU_VMSA
>> +    bool "Renesas IPMMU-VMSA found in R-Car Gen3 SoCs"

Shall I add EXPERT here also?

bool "Renesas IPMMU-VMSA found in R-Car Gen3 SoCs" if EXPERT = "y"


>> +    default n
>> +    depends on ARM_64
>> +    ---help---
>> +      Support for implementations of the Renesas IPMMU-VMSA found
>> +      in R-Car Gen3 SoCs.
>> +
>> +      Say Y here if you are using newest R-Car Gen3 SoCs revisions
>> +      (H3 ES3.0, M3-W+, etc) which IPMMU hardware supports stage 2
>> +      translation table format and is able to use CPU's P2M table as 
>> is.
>> +
>>   endif
>
> [...]
>
>> +    /* Wait until the Root device has been registered for sure. */
>> +    if ( !mmu->root )
>> +    {
>> +        dev_err(&node->dev, "Root IPMMU hasn't been registered yet\n");
>
> This is a bit odd to throw an error if we are going to defer the probe.

Agree. Will remove.


>
>> +static __init bool ipmmu_stage2_supported(void)
>> +{
>> +    struct dt_device_node *np;
>> +    uint64_t addr, size;
>> +    void __iomem *base;
>> +    uint32_t product, cut;
>> +    static enum
>> +    {
>> +        UNKNOWN,
>> +        SUPPORTED,
>> +        NOTSUPPORTED
>> +    } stage2_supported = UNKNOWN;
>> +
>> +    /* Use the flag to avoid checking for the compatibility more 
>> then once. */
>
> There are only one IOMMU root that will always be initialized first. 
> So can't you move this code in the root IOMMU path?

Actually, I can. Good point.


>
>
>> +    switch ( stage2_supported )
>> +    {
>> +    case SUPPORTED:
>> +        return true;
>> +
>> +    case NOTSUPPORTED:
>> +        return false;
>> +
>> +    case UNKNOWN:
>> +    default:
>> +        stage2_supported = NOTSUPPORTED;
>> +        break;
>> +    }
>> +
>> +    np = dt_find_compatible_node(NULL, NULL, "renesas,prr");
>> +    if ( !np )
>> +    {
>> +        printk(XENLOG_ERR "ipmmu: Failed to find PRR node\n");
>> +        return false;
>> +    }
>> +
>> +    if ( dt_device_get_address(np, 0, &addr, &size) )
>> +    {
>> +        printk(XENLOG_ERR "ipmmu: Failed to get PRR MMIO\n");
>> +        return false;
>> +    }
>> +
>> +    base = ioremap_nocache(addr, size);
>> +    if ( !base )
>> +    {
>> +        printk(XENLOG_ERR "ipmmu: Failed to ioremap PRR MMIO\n");
>> +        return false;
>> +    }
>> +
>> +    product = readl(base);
>> +    cut = product & RCAR_CUT_MASK;
>> +    product &= RCAR_PRODUCT_MASK;
>> +
>> +    switch ( product )
>> +    {
>> +    case RCAR_PRODUCT_H3:
>> +    case RCAR_PRODUCT_M3W:
>> +        if ( cut >= RCAR_CUT_VER30 )
>> +            stage2_supported = SUPPORTED;
>> +        break;
>> +
>> +    case RCAR_PRODUCT_M3N:
>> +        stage2_supported = SUPPORTED;
>> +        break;
>> +
>> +    default:
>> +        printk(XENLOG_ERR "ipmmu: Unsupported SoC version\n");
>> +        break;
>> +    }
>> +
>> +    iounmap(base);
>> +
>> +    return stage2_supported == SUPPORTED;
>> +}
>> +
>> +static const struct dt_device_match ipmmu_dt_match[] __initconst =
>> +{
>> +    DT_MATCH_COMPATIBLE("renesas,ipmmu-r8a7795"),
>> +    DT_MATCH_COMPATIBLE("renesas,ipmmu-r8a77965"),
>> +    DT_MATCH_COMPATIBLE("renesas,ipmmu-r8a7796"),
>> +    { /* sentinel */ },
>> +};
>> +
>> +static __init int ipmmu_init(struct dt_device_node *node, const void 
>> *data)
>> +{
>> +    int ret;
>> +
>> +    /*
>> +     * Even if the device can't be initialized, we don't want to give
>> +     * the IPMMU device to dom0.
>> +     */
>> +    dt_device_set_used_by(node, DOMID_XEN);
>> +
>> +    if ( !iommu_hap_pt_share )
>
> iommu_hap_pt_share will soon be hardcoded to true on Arm (see [1]). 
> Even without the patch, the value of iommu_hap_pt_share should be 
> ignored as done by the SMMU.

I got it. Will ignore.


>
>
>> +    {
>> +        printk_once(XENLOG_ERR "ipmmu: P2M table must always be 
>> shared between the CPU and the IPMMU\n");
>> +        return -EINVAL;
>> +    }
>> +
>> +    if ( !ipmmu_stage2_supported() )
>> +    {
>> +        printk_once(XENLOG_ERR "ipmmu: P2M sharing is not supported 
>> in current SoC revision\n");
>> +        return -ENODEV;
>
> The if part is returning so...
>
>> +    }
>> +    else
>
> ... the else part is not necessary removing one layer of indentation.

ok
Julien Grall Sept. 10, 2019, 2:31 p.m. UTC | #8
Hi,

On 9/10/19 12:04 PM, Oleksandr wrote:
> On 10.09.19 00:24, Julien Grall wrote:
>>>       ---help---
>>>       Enable all the required drivers for Renesas RCar3
>>>   diff --git a/xen/drivers/passthrough/Kconfig 
>>> b/xen/drivers/passthrough/Kconfig
>>> index a3c0649..47eadb4 100644
>>> --- a/xen/drivers/passthrough/Kconfig
>>> +++ b/xen/drivers/passthrough/Kconfig
>>> @@ -12,4 +12,17 @@ config ARM_SMMU
>>>           Say Y here if your SoC includes an IOMMU device 
>>> implementing the
>>>         ARM SMMU architecture.
>>> +
>>> +config IPMMU_VMSA
>>> +    bool "Renesas IPMMU-VMSA found in R-Car Gen3 SoCs"
> 
> Shall I add EXPERT here also?

Good question. Probably, but then I am wondering if the EXPERT = "y" 
would actually be sufficient.

Cheers,
Oleksandr Tyshchenko Sept. 11, 2019, 3:29 p.m. UTC | #9
On 10.09.19 17:31, Julien Grall wrote:
> Hi,

Hi Julien


>
> On 9/10/19 12:04 PM, Oleksandr wrote:
>> On 10.09.19 00:24, Julien Grall wrote:
>>>>       ---help---
>>>>       Enable all the required drivers for Renesas RCar3
>>>>   diff --git a/xen/drivers/passthrough/Kconfig 
>>>> b/xen/drivers/passthrough/Kconfig
>>>> index a3c0649..47eadb4 100644
>>>> --- a/xen/drivers/passthrough/Kconfig
>>>> +++ b/xen/drivers/passthrough/Kconfig
>>>> @@ -12,4 +12,17 @@ config ARM_SMMU
>>>>           Say Y here if your SoC includes an IOMMU device 
>>>> implementing the
>>>>         ARM SMMU architecture.
>>>> +
>>>> +config IPMMU_VMSA
>>>> +    bool "Renesas IPMMU-VMSA found in R-Car Gen3 SoCs"
>>
>> Shall I add EXPERT here also?
>
> Good question. Probably, but then I am wondering if the EXPERT = "y" 
> would actually be sufficient.

Should be in both places, here and where you pointed (config RCAR3).
diff mbox series

Patch

diff --git a/xen/arch/arm/platforms/Kconfig b/xen/arch/arm/platforms/Kconfig
index bc0e9cd..c93a6b2 100644
--- a/xen/arch/arm/platforms/Kconfig
+++ b/xen/arch/arm/platforms/Kconfig
@@ -25,6 +25,7 @@  config RCAR3
 	bool "Renesas RCar3 support"
 	depends on ARM_64
 	select HAS_SCIF
+	select IPMMU_VMSA
 	---help---
 	Enable all the required drivers for Renesas RCar3
 
diff --git a/xen/drivers/passthrough/Kconfig b/xen/drivers/passthrough/Kconfig
index a3c0649..47eadb4 100644
--- a/xen/drivers/passthrough/Kconfig
+++ b/xen/drivers/passthrough/Kconfig
@@ -12,4 +12,17 @@  config ARM_SMMU
 
 	  Say Y here if your SoC includes an IOMMU device implementing the
 	  ARM SMMU architecture.
+
+config IPMMU_VMSA
+	bool "Renesas IPMMU-VMSA found in R-Car Gen3 SoCs"
+	default n
+	depends on ARM_64
+	---help---
+	  Support for implementations of the Renesas IPMMU-VMSA found
+	  in R-Car Gen3 SoCs.
+
+	  Say Y here if you are using newest R-Car Gen3 SoCs revisions
+	  (H3 ES3.0, M3-W+, etc) which IPMMU hardware supports stage 2
+	  translation table format and is able to use CPU's P2M table as is.
+
 endif
diff --git a/xen/drivers/passthrough/arm/Makefile b/xen/drivers/passthrough/arm/Makefile
index 5fbad45..fcd918e 100644
--- a/xen/drivers/passthrough/arm/Makefile
+++ b/xen/drivers/passthrough/arm/Makefile
@@ -1,2 +1,3 @@ 
 obj-y += iommu.o iommu_helpers.o iommu_fwspec.o
 obj-$(CONFIG_ARM_SMMU) += smmu.o
+obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
diff --git a/xen/drivers/passthrough/arm/ipmmu-vmsa.c b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
new file mode 100644
index 0000000..ec543c3
--- /dev/null
+++ b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
@@ -0,0 +1,1359 @@ 
+/*
+ * xen/drivers/passthrough/arm/ipmmu-vmsa.c
+ *
+ * Driver for the Renesas IPMMU-VMSA found in R-Car Gen3 SoCs.
+ *
+ * The IPMMU-VMSA is VMSA-compatible I/O Memory Management Unit (IOMMU)
+ * which provides address translation and access protection functionalities
+ * to processing units and interconnect networks.
+ *
+ * Please note, current driver is supposed to work only with newest
+ * R-Car Gen3 SoCs revisions which IPMMU hardware supports stage 2 translation
+ * table format and is able to use CPU's P2M table as is.
+ *
+ * Based on Linux's IPMMU-VMSA driver from Renesas BSP:
+ *    drivers/iommu/ipmmu-vmsa.c
+ * you can found at:
+ *    url: git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas-bsp.git
+ *    branch: v4.14.75-ltsi/rcar-3.9.6
+ *    commit: e206eb5b81a60e64c35fbc3a999b1a0db2b98044
+ * and Xen's SMMU driver:
+ *    xen/drivers/passthrough/arm/smmu.c
+ *
+ * Copyright (C) 2014-2019 Renesas Electronics Corporation
+ *
+ * Copyright (C) 2016-2019 EPAM Systems Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms and conditions of the GNU General Public
+ * License, version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <xen/delay.h>
+#include <xen/err.h>
+#include <xen/iommu.h>
+#include <xen/irq.h>
+#include <xen/lib.h>
+#include <xen/list.h>
+#include <xen/mm.h>
+#include <xen/sched.h>
+#include <xen/vmap.h>
+
+#include <asm/atomic.h>
+#include <asm/device.h>
+#include <asm/io.h>
+#include <asm/iommu_fwspec.h>
+
+#define dev_name(dev) dt_node_full_name(dev_to_dt(dev))
+
+/* Device logger functions */
+#define dev_print(dev, lvl, fmt, ...)    \
+    printk(lvl "ipmmu: %s: " fmt, dev_name(dev), ## __VA_ARGS__)
+
+#define dev_info(dev, fmt, ...)    \
+    dev_print(dev, XENLOG_INFO, fmt, ## __VA_ARGS__)
+#define dev_warn(dev, fmt, ...)    \
+    dev_print(dev, XENLOG_WARNING, fmt, ## __VA_ARGS__)
+#define dev_err(dev, fmt, ...)     \
+    dev_print(dev, XENLOG_ERR, fmt, ## __VA_ARGS__)
+#define dev_err_ratelimited(dev, fmt, ...)    \
+    dev_print(dev, XENLOG_ERR, fmt, ## __VA_ARGS__)
+
+/*
+ * R-Car Gen3 SoCs make use of up to 8 IPMMU contexts (sets of page table) and
+ * these can be managed independently. Each context is mapped to one Xen domain.
+ */
+#define IPMMU_CTX_MAX     8
+/* R-Car Gen3 SoCs make use of up to 48 micro-TLBs per IPMMU device. */
+#define IPMMU_UTLB_MAX    48
+
+/* IPMMU context supports IPA size up to 40 bit. */
+#define IPMMU_MAX_P2M_IPA_BITS    40
+
+/*
+ * Xen's domain IPMMU information stored in dom_iommu(d)->arch.priv
+ *
+ * As each context (set of page table) is mapped to one Xen domain,
+ * all associated IPMMU domains use the same context mapped to this Xen domain.
+ * This makes all master devices being attached to the same Xen domain share
+ * the same context (P2M table).
+ */
+struct ipmmu_vmsa_xen_domain {
+    /*
+     * Used to protect everything which belongs to this Xen domain:
+     * device assignment, domain init/destroy, flush ops, etc
+     */
+    spinlock_t lock;
+    /* One or more Cache IPMMU domains associated with this Xen domain */
+    struct list_head cache_domains;
+    /* Root IPMMU domain associated with this Xen domain */
+    struct ipmmu_vmsa_domain *root_domain;
+};
+
+/* Xen master device's IPMMU information stored in fwspec->iommu_priv */
+struct ipmmu_vmsa_xen_device {
+    /* Cache IPMMU domain this master device is logically attached to */
+    struct ipmmu_vmsa_domain *domain;
+    /* Cache IPMMU this master device is physically connected to */
+    struct ipmmu_vmsa_device *mmu;
+};
+
+/* Root/Cache IPMMU device's information */
+struct ipmmu_vmsa_device {
+    struct device *dev;
+    void __iomem *base;
+    struct ipmmu_vmsa_device *root;
+    struct list_head list;
+    unsigned int num_utlbs;
+    unsigned int num_ctx;
+    spinlock_t lock;    /* Protects ctx and domains[] */
+    DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
+    struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
+};
+
+/*
+ * Root/Cache IPMMU domain's information
+ *
+ * Root IPMMU device is assigned to Root IPMMU domain while Cache IPMMU device
+ * is assigned to Cache IPMMU domain. Master devices are connected to Cache
+ * IPMMU devices through specific ports called micro-TLBs.
+ * All Cache IPMMU devices, in turn, are connected to Root IPMMU device
+ * which manages IPMMU context.
+ */
+struct ipmmu_vmsa_domain {
+    /*
+     * IPMMU device assigned to this IPMMU domain.
+     * Either Root device which is located at the main memory bus domain or
+     * Cache device which is located at each hierarchy bus domain.
+     */
+    struct ipmmu_vmsa_device *mmu;
+
+    /* Context used for this IPMMU domain */
+    unsigned int context_id;
+
+    /* Xen domain associated with this IPMMU domain */
+    struct domain *d;
+
+    /* The fields below are used for Cache IPMMU domain only */
+
+    /*
+     * Used to keep track of the master devices which are attached to this
+     * IPMMU domain (domain users). Master devices behind the same IPMMU device
+     * are grouped together by putting into the same IPMMU domain.
+     * Only when the refcount reaches 0 this IPMMU domain can be destroyed.
+     */
+    unsigned int refcount;
+    /* Used to link this IPMMU domain for the same Xen domain */
+    struct list_head list;
+};
+
+/* Used to keep track of registered IPMMU devices */
+static LIST_HEAD(ipmmu_devices);
+static DEFINE_SPINLOCK(ipmmu_devices_lock);
+
+#define TLB_LOOP_TIMEOUT    100 /* 100us */
+
+/* Registers Definition */
+#define IM_CTX_SIZE    0x40
+
+#define IMCTR                0x0000
+/*
+ * These fields are implemented in IPMMU-MM only. So, can be set for
+ * Root IPMMU only.
+ */
+#define IMCTR_VA64           (1 << 29)
+#define IMCTR_TRE            (1 << 17)
+#define IMCTR_AFE            (1 << 16)
+#define IMCTR_RTSEL_MASK     (3 << 4)
+#define IMCTR_RTSEL_SHIFT    4
+#define IMCTR_TREN           (1 << 3)
+/*
+ * These fields are common for all IPMMU devices. So, can be set for
+ * Cache IPMMUs as well.
+ */
+#define IMCTR_INTEN          (1 << 2)
+#define IMCTR_FLUSH          (1 << 1)
+#define IMCTR_MMUEN          (1 << 0)
+#define IMCTR_COMMON_MASK    (7 << 0)
+
+#define IMCAAR               0x0004
+
+#define IMTTBCR                        0x0008
+#define IMTTBCR_EAE                    (1 << 31)
+#define IMTTBCR_PMB                    (1 << 30)
+#define IMTTBCR_SH1_NON_SHAREABLE      (0 << 28)
+#define IMTTBCR_SH1_OUTER_SHAREABLE    (2 << 28)
+#define IMTTBCR_SH1_INNER_SHAREABLE    (3 << 28)
+#define IMTTBCR_SH1_MASK               (3 << 28)
+#define IMTTBCR_ORGN1_NC               (0 << 26)
+#define IMTTBCR_ORGN1_WB_WA            (1 << 26)
+#define IMTTBCR_ORGN1_WT               (2 << 26)
+#define IMTTBCR_ORGN1_WB               (3 << 26)
+#define IMTTBCR_ORGN1_MASK             (3 << 26)
+#define IMTTBCR_IRGN1_NC               (0 << 24)
+#define IMTTBCR_IRGN1_WB_WA            (1 << 24)
+#define IMTTBCR_IRGN1_WT               (2 << 24)
+#define IMTTBCR_IRGN1_WB               (3 << 24)
+#define IMTTBCR_IRGN1_MASK             (3 << 24)
+#define IMTTBCR_TSZ1_MASK              (0x1f << 16)
+#define IMTTBCR_TSZ1_SHIFT             16
+#define IMTTBCR_SH0_NON_SHAREABLE      (0 << 12)
+#define IMTTBCR_SH0_OUTER_SHAREABLE    (2 << 12)
+#define IMTTBCR_SH0_INNER_SHAREABLE    (3 << 12)
+#define IMTTBCR_SH0_MASK               (3 << 12)
+#define IMTTBCR_ORGN0_NC               (0 << 10)
+#define IMTTBCR_ORGN0_WB_WA            (1 << 10)
+#define IMTTBCR_ORGN0_WT               (2 << 10)
+#define IMTTBCR_ORGN0_WB               (3 << 10)
+#define IMTTBCR_ORGN0_MASK             (3 << 10)
+#define IMTTBCR_IRGN0_NC               (0 << 8)
+#define IMTTBCR_IRGN0_WB_WA            (1 << 8)
+#define IMTTBCR_IRGN0_WT               (2 << 8)
+#define IMTTBCR_IRGN0_WB               (3 << 8)
+#define IMTTBCR_IRGN0_MASK             (3 << 8)
+#define IMTTBCR_SL0_LVL_2              (0 << 6)
+#define IMTTBCR_SL0_LVL_1              (1 << 6)
+#define IMTTBCR_TSZ0_MASK              (0x1f << 0)
+#define IMTTBCR_TSZ0_SHIFT             0
+
+#define IMTTLBR0              0x0010
+#define IMTTLBR0_TTBR_MASK    (0xfffff << 12)
+#define IMTTUBR0              0x0014
+#define IMTTUBR0_TTBR_MASK    (0xff << 0)
+#define IMTTLBR1              0x0018
+#define IMTTLBR1_TTBR_MASK    (0xfffff << 12)
+#define IMTTUBR1              0x001c
+#define IMTTUBR1_TTBR_MASK    (0xff << 0)
+
+#define IMSTR                          0x0020
+#define IMSTR_ERRLVL_MASK              (3 << 12)
+#define IMSTR_ERRLVL_SHIFT             12
+#define IMSTR_ERRCODE_TLB_FORMAT       (1 << 8)
+#define IMSTR_ERRCODE_ACCESS_PERM      (4 << 8)
+#define IMSTR_ERRCODE_SECURE_ACCESS    (5 << 8)
+#define IMSTR_ERRCODE_MASK             (7 << 8)
+#define IMSTR_MHIT                     (1 << 4)
+#define IMSTR_ABORT                    (1 << 2)
+#define IMSTR_PF                       (1 << 1)
+#define IMSTR_TF                       (1 << 0)
+
+#define IMELAR    0x0030
+#define IMEUAR    0x0034
+
+#define IMUCTR(n)              ((n) < 32 ? IMUCTR0(n) : IMUCTR32(n))
+#define IMUCTR0(n)             (0x0300 + ((n) * 16))
+#define IMUCTR32(n)            (0x0600 + (((n) - 32) * 16))
+#define IMUCTR_FIXADDEN        (1 << 31)
+#define IMUCTR_FIXADD_MASK     (0xff << 16)
+#define IMUCTR_FIXADD_SHIFT    16
+#define IMUCTR_TTSEL_MMU(n)    ((n) << 4)
+#define IMUCTR_TTSEL_PMB       (8 << 4)
+#define IMUCTR_TTSEL_MASK      (15 << 4)
+#define IMUCTR_FLUSH           (1 << 1)
+#define IMUCTR_MMUEN           (1 << 0)
+
+#define IMUASID(n)             ((n) < 32 ? IMUASID0(n) : IMUASID32(n))
+#define IMUASID0(n)            (0x0308 + ((n) * 16))
+#define IMUASID32(n)           (0x0608 + (((n) - 32) * 16))
+#define IMUASID_ASID8_MASK     (0xff << 8)
+#define IMUASID_ASID8_SHIFT    8
+#define IMUASID_ASID0_MASK     (0xff << 0)
+#define IMUASID_ASID0_SHIFT    0
+
+#define IMSAUXCTLR          0x0504
+#define IMSAUXCTLR_S2PTE    (1 << 3)
+
+static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
+{
+    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+    return fwspec && fwspec->iommu_priv ?
+        ((struct ipmmu_vmsa_xen_device *)fwspec->iommu_priv)->mmu : NULL;
+}
+
+static void set_ipmmu(struct device *dev, struct ipmmu_vmsa_device *mmu)
+{
+    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+    ((struct ipmmu_vmsa_xen_device *)fwspec->iommu_priv)->mmu = mmu;
+}
+
+static struct ipmmu_vmsa_domain *to_domain(struct device *dev)
+{
+    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+    return fwspec && fwspec->iommu_priv ?
+        ((struct ipmmu_vmsa_xen_device *)fwspec->iommu_priv)->domain : NULL;
+}
+
+static void set_domain(struct device *dev, struct ipmmu_vmsa_domain *domain)
+{
+    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+    ((struct ipmmu_vmsa_xen_device *)fwspec->iommu_priv)->domain = domain;
+}
+
+static struct ipmmu_vmsa_device *ipmmu_find_mmu_by_dev(struct device *dev)
+{
+    struct ipmmu_vmsa_device *mmu = NULL;
+    bool found = false;
+
+    spin_lock(&ipmmu_devices_lock);
+
+    list_for_each_entry ( mmu, &ipmmu_devices, list )
+    {
+        if ( mmu->dev == dev )
+        {
+            found = true;
+            break;
+        }
+    }
+
+    spin_unlock(&ipmmu_devices_lock);
+
+    return found ? mmu : NULL;
+}
+
+/* Root device handling */
+static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
+{
+    return mmu->root == mmu;
+}
+
+static struct ipmmu_vmsa_device *ipmmu_find_root(void)
+{
+    struct ipmmu_vmsa_device *mmu = NULL;
+    bool found = false;
+
+    spin_lock(&ipmmu_devices_lock);
+
+    list_for_each_entry( mmu, &ipmmu_devices, list )
+    {
+        if ( ipmmu_is_root(mmu) )
+        {
+            found = true;
+            break;
+        }
+    }
+
+    spin_unlock(&ipmmu_devices_lock);
+
+    return found ? mmu : NULL;
+}
+
+/* Read/Write Access */
+static uint32_t ipmmu_read(struct ipmmu_vmsa_device *mmu, uint32_t offset)
+{
+    return readl(mmu->base + offset);
+}
+
+static void ipmmu_write(struct ipmmu_vmsa_device *mmu, uint32_t offset,
+                        uint32_t data)
+{
+    writel(data, mmu->base + offset);
+}
+
+static uint32_t ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
+                                    uint32_t reg)
+{
+    return ipmmu_read(domain->mmu->root,
+                      domain->context_id * IM_CTX_SIZE + reg);
+}
+
+static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
+                                 uint32_t reg, uint32_t data)
+{
+    ipmmu_write(domain->mmu->root,
+                domain->context_id * IM_CTX_SIZE + reg, data);
+}
+
+static void ipmmu_ctx_write_cache(struct ipmmu_vmsa_domain *domain,
+                                  uint32_t reg, uint32_t data)
+{
+    /* We expect only IMCTR value to be passed as a reg. */
+    ASSERT(reg == IMCTR);
+
+    /* Mask fields which are implemented in IPMMU-MM only. */
+    if ( !ipmmu_is_root(domain->mmu) )
+        ipmmu_write(domain->mmu, domain->context_id * IM_CTX_SIZE + reg,
+                    data & IMCTR_COMMON_MASK);
+}
+
+/*
+ * Write the context to both Root IPMMU and all Cache IPMMUs assigned
+ * to this Xen domain.
+ */
+static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
+                                uint32_t reg, uint32_t data)
+{
+    struct ipmmu_vmsa_xen_domain *xen_domain = dom_iommu(domain->d)->arch.priv;
+    struct ipmmu_vmsa_domain *cache_domain;
+
+    list_for_each_entry( cache_domain, &xen_domain->cache_domains, list )
+        ipmmu_ctx_write_cache(cache_domain, reg, data);
+
+    ipmmu_ctx_write_root(domain, reg, data);
+}
+
+/* TLB and micro-TLB Management */
+
+/* Wait for any pending TLB invalidations to complete. */
+static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
+{
+    unsigned int count = 0;
+
+    while ( ipmmu_ctx_read_root(domain, IMCTR) & IMCTR_FLUSH )
+    {
+        cpu_relax();
+        if ( ++count == TLB_LOOP_TIMEOUT )
+        {
+            dev_err_ratelimited(domain->mmu->dev, "TLB sync timed out -- MMU may be deadlocked\n");
+            return;
+        }
+        udelay(1);
+    }
+}
+
+static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
+{
+    uint32_t data;
+
+    data = ipmmu_ctx_read_root(domain, IMCTR);
+    data |= IMCTR_FLUSH;
+    ipmmu_ctx_write_all(domain, IMCTR, data);
+
+    ipmmu_tlb_sync(domain);
+}
+
+/* Enable MMU translation for the micro-TLB. */
+static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
+                              unsigned int utlb)
+{
+    struct ipmmu_vmsa_device *mmu = domain->mmu;
+
+    /*
+     * TODO: Reference-count the micro-TLB as several bus masters can be
+     * connected to the same micro-TLB. Prevent the use cases where
+     * the same micro-TLB could be shared between multiple Xen domains.
+     */
+    ipmmu_write(mmu, IMUASID(utlb), 0);
+    ipmmu_write(mmu, IMUCTR(utlb), ipmmu_read(mmu, IMUCTR(utlb)) |
+                IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_MMUEN);
+}
+
+/* Disable MMU translation for the micro-TLB. */
+static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
+                               unsigned int utlb)
+{
+    struct ipmmu_vmsa_device *mmu = domain->mmu;
+
+    ipmmu_write(mmu, IMUCTR(utlb), 0);
+}
+
+/* Domain/Context Management */
+static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
+                                         struct ipmmu_vmsa_domain *domain)
+{
+    unsigned long flags;
+    int ret;
+
+    spin_lock_irqsave(&mmu->lock, flags);
+
+    ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
+    if ( ret != mmu->num_ctx )
+    {
+        mmu->domains[ret] = domain;
+        set_bit(ret, mmu->ctx);
+    }
+    else
+        ret = -EBUSY;
+
+    spin_unlock_irqrestore(&mmu->lock, flags);
+
+    return ret;
+}
+
+static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
+                                      unsigned int context_id)
+{
+    unsigned long flags;
+
+    spin_lock_irqsave(&mmu->lock, flags);
+
+    clear_bit(context_id, mmu->ctx);
+    mmu->domains[context_id] = NULL;
+
+    spin_unlock_irqrestore(&mmu->lock, flags);
+}
+
+static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
+{
+    uint64_t ttbr;
+    uint32_t tsz0;
+    int ret;
+
+    /* Find an unused context. */
+    ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
+    if ( ret < 0 )
+        return ret;
+
+    domain->context_id = ret;
+
+    /*
+     * TTBR0
+     * Use P2M table for this Xen domain.
+     */
+    ASSERT(domain->d != NULL);
+    ttbr = page_to_maddr(domain->d->arch.p2m.root);
+
+    dev_info(domain->mmu->root->dev, "%pd: Set IPMMU context %u (pgd 0x%"PRIx64")\n",
+             domain->d, domain->context_id, ttbr);
+
+    ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr & IMTTLBR0_TTBR_MASK);
+    ipmmu_ctx_write_root(domain, IMTTUBR0, (ttbr >> 32) & IMTTUBR0_TTBR_MASK);
+
+    /*
+     * TTBCR
+     * We use long descriptors and allocate the whole "p2m_ipa_bits" IPA space
+     * to TTBR0. Use 4KB page granule. Start page table walks at first level.
+     * Always bypass stage 1 translation.
+     */
+    tsz0 = (64 - p2m_ipa_bits) << IMTTBCR_TSZ0_SHIFT;
+    ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE | IMTTBCR_PMB |
+                         IMTTBCR_SL0_LVL_1 | tsz0);
+
+    /*
+     * IMSTR
+     * Clear all interrupt flags.
+     */
+    ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
+
+    /*
+     * IMCTR
+     * Enable the MMU and interrupt generation. The long-descriptor
+     * translation table format doesn't use TEX remapping. Don't enable AF
+     * software management as we have no use for it. Use VMSAv8-64 mode.
+     * Enable the context for Root IPMMU only. Flush the TLB as required
+     * when modifying the context registers.
+     */
+    ipmmu_ctx_write_root(domain, IMCTR,
+                         IMCTR_VA64 | IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
+
+    return 0;
+}
+
+static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
+{
+    if ( !domain->mmu )
+        return;
+
+    /*
+     * Disable the context for Root IPMMU only. Flush the TLB as required
+     * when modifying the context registers.
+     */
+    ipmmu_ctx_write_root(domain, IMCTR, IMCTR_FLUSH);
+    ipmmu_tlb_sync(domain);
+
+    ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
+}
+
+/* Fault Handling */
+static void ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
+{
+    const uint32_t err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
+    struct ipmmu_vmsa_device *mmu = domain->mmu;
+    uint32_t status;
+    uint64_t iova;
+
+    status = ipmmu_ctx_read_root(domain, IMSTR);
+    if ( !(status & err_mask) )
+        return;
+
+    iova = ipmmu_ctx_read_root(domain, IMELAR) |
+        ((uint64_t)ipmmu_ctx_read_root(domain, IMEUAR) << 32);
+
+    /*
+     * Clear the error status flags. Unlike traditional interrupt flag
+     * registers that must be cleared by writing 1, this status register
+     * seems to require 0. The error address register must be read before,
+     * otherwise its value will be 0.
+     */
+    ipmmu_ctx_write_root(domain, IMSTR, 0);
+
+    /* Log fatal errors. */
+    if ( status & IMSTR_MHIT )
+        dev_err_ratelimited(mmu->dev, "%pd: Multiple TLB hits @0x%"PRIx64"\n",
+                            domain->d, iova);
+    if ( status & IMSTR_ABORT )
+        dev_err_ratelimited(mmu->dev, "%pd: Page Table Walk Abort @0x%"PRIx64"\n",
+                            domain->d, iova);
+
+    /* Return if it is neither Permission Fault nor Translation Fault. */
+    if ( !(status & (IMSTR_PF | IMSTR_TF)) )
+        return;
+
+    dev_err_ratelimited(mmu->dev, "%pd: Unhandled fault: status 0x%08x iova 0x%"PRIx64"\n",
+                        domain->d, status, iova);
+}
+
+static void ipmmu_irq(int irq, void *dev, struct cpu_user_regs *regs)
+{
+    struct ipmmu_vmsa_device *mmu = dev;
+    unsigned int i;
+    unsigned long flags;
+
+    spin_lock_irqsave(&mmu->lock, flags);
+
+    /*
+     * When interrupt arrives, we don't know the context it is related to.
+     * So, check interrupts for all active contexts to locate a context
+     * with status bits set.
+    */
+    for ( i = 0; i < mmu->num_ctx; i++ )
+    {
+        if ( !mmu->domains[i] )
+            continue;
+        ipmmu_domain_irq(mmu->domains[i]);
+    }
+
+    spin_unlock_irqrestore(&mmu->lock, flags);
+}
+
+/* Master devices management */
+static int ipmmu_attach_device(struct ipmmu_vmsa_domain *domain,
+                               struct device *dev)
+{
+    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+    struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
+    unsigned int i;
+
+    if ( !mmu )
+    {
+        dev_err(dev, "Cannot attach to IPMMU\n");
+        return -ENXIO;
+    }
+
+    if ( !domain->mmu )
+    {
+        /* The domain hasn't been used yet, initialize it. */
+        domain->mmu = mmu;
+
+        /*
+         * We have already enabled context for Root IPMMU assigned to this
+         * Xen domain in ipmmu_domain_init_context().
+         * Enable the context for Cache IPMMU only. Flush the TLB as required
+         * when modifying the context registers.
+         */
+        ipmmu_ctx_write_cache(domain, IMCTR,
+                              ipmmu_ctx_read_root(domain, IMCTR) | IMCTR_FLUSH);
+
+        dev_info(dev, "Using IPMMU context %u\n", domain->context_id);
+    }
+    else if ( domain->mmu != mmu )
+    {
+        /*
+         * Something is wrong, we can't attach two master devices using
+         * different IOMMUs to the same IPMMU domain.
+         */
+        dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
+                dev_name(mmu->dev), dev_name(domain->mmu->dev));
+        return -EINVAL;
+    }
+    else
+        dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
+
+    for ( i = 0; i < fwspec->num_ids; ++i )
+        ipmmu_utlb_enable(domain, fwspec->ids[i]);
+
+    return 0;
+}
+
+static void ipmmu_detach_device(struct ipmmu_vmsa_domain *domain,
+                                struct device *dev)
+{
+    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+    unsigned int i;
+
+    for ( i = 0; i < fwspec->num_ids; ++i )
+        ipmmu_utlb_disable(domain, fwspec->ids[i]);
+}
+
+static int ipmmu_init_platform_device(struct device *dev,
+                                      struct dt_phandle_args *args)
+{
+    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+    struct ipmmu_vmsa_device *mmu;
+
+    mmu = ipmmu_find_mmu_by_dev(dt_to_dev(args->np));
+    if ( !mmu )
+        return -ENODEV;
+
+    fwspec->iommu_priv = xzalloc(struct ipmmu_vmsa_xen_device);
+    if ( !fwspec->iommu_priv )
+        return -ENOMEM;
+
+    set_ipmmu(dev, mmu);
+
+    return 0;
+}
+
+static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
+{
+    unsigned int i;
+
+    /* Disable all contexts. */
+    for ( i = 0; i < mmu->num_ctx; ++i )
+        ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
+}
+
+/*
+ * This function relies on the fact that Root IPMMU device is being probed
+ * the first. If not the case, it denies further Cache IPMMU device probes
+ * (returns the -EAGAIN) until the Root IPMMU device has been registered
+ * for sure.
+ */
+static int ipmmu_probe(struct dt_device_node *node)
+{
+    struct ipmmu_vmsa_device *mmu;
+    uint64_t addr, size;
+    int irq, ret;
+
+    mmu = xzalloc(struct ipmmu_vmsa_device);
+    if ( !mmu )
+    {
+        dev_err(&node->dev, "Cannot allocate device data\n");
+        return -ENOMEM;
+    }
+
+    mmu->dev = &node->dev;
+    mmu->num_utlbs = IPMMU_UTLB_MAX;
+    mmu->num_ctx = IPMMU_CTX_MAX;
+    spin_lock_init(&mmu->lock);
+    bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
+
+    /* Map I/O memory and request IRQ. */
+    ret = dt_device_get_address(node, 0, &addr, &size);
+    if ( ret )
+    {
+        dev_err(&node->dev, "Failed to get MMIO\n");
+        goto out;
+    }
+
+    mmu->base = ioremap_nocache(addr, size);
+    if ( !mmu->base )
+    {
+        dev_err(&node->dev, "Failed to ioremap MMIO (addr 0x%"PRIx64" size 0x%"PRIx64")\n",
+                addr, size);
+        ret = -ENOMEM;
+        goto out;
+    }
+
+    /*
+     * Determine if this IPMMU node is a Root device by checking for
+     * the lack of renesas,ipmmu-main property.
+     */
+    if ( !dt_find_property(node, "renesas,ipmmu-main", NULL) )
+        mmu->root = mmu;
+    else
+        mmu->root = ipmmu_find_root();
+
+    /* Wait until the Root device has been registered for sure. */
+    if ( !mmu->root )
+    {
+        dev_err(&node->dev, "Root IPMMU hasn't been registered yet\n");
+        ret = -EAGAIN;
+        goto out;
+    }
+
+    /* Root devices have mandatory IRQs. */
+    if ( ipmmu_is_root(mmu) )
+    {
+        irq = platform_get_irq(node, 0);
+        if ( irq < 0 )
+        {
+            dev_err(&node->dev, "No IRQ found\n");
+            ret = irq;
+            goto out;
+        }
+
+        ret = request_irq(irq, 0, ipmmu_irq, dev_name(&node->dev), mmu);
+        if ( ret < 0 )
+        {
+            dev_err(&node->dev, "Failed to request IRQ %d\n", irq);
+            goto out;
+        }
+
+        ipmmu_device_reset(mmu);
+
+        /*
+         * Use stage 2 translation table format when stage 2 translation
+         * enabled.
+         */
+        ipmmu_write(mmu, IMSAUXCTLR,
+                    ipmmu_read(mmu, IMSAUXCTLR) | IMSAUXCTLR_S2PTE);
+
+        dev_info(&node->dev, "IPMMU context 0 is reserved\n");
+        set_bit(0, mmu->ctx);
+    }
+
+    spin_lock(&ipmmu_devices_lock);
+    list_add(&mmu->list, &ipmmu_devices);
+    spin_unlock(&ipmmu_devices_lock);
+
+    dev_info(&node->dev, "Registered %s IPMMU\n",
+             ipmmu_is_root(mmu) ? "Root" : "Cache");
+
+    return 0;
+
+out:
+    if ( mmu->base )
+        iounmap(mmu->base);
+    xfree(mmu);
+
+    return ret;
+}
+
+/* Xen IOMMU ops */
+static int __must_check ipmmu_iotlb_flush_all(struct domain *d)
+{
+    struct ipmmu_vmsa_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
+
+    if ( !xen_domain || !xen_domain->root_domain )
+        return 0;
+
+    spin_lock(&xen_domain->lock);
+    ipmmu_tlb_invalidate(xen_domain->root_domain);
+    spin_unlock(&xen_domain->lock);
+
+    return 0;
+}
+
+static int __must_check ipmmu_iotlb_flush(struct domain *d, dfn_t dfn,
+                                          unsigned int page_count,
+                                          unsigned int flush_flags)
+{
+    ASSERT(flush_flags);
+
+    /* The hardware doesn't support selective TLB flush. */
+    return ipmmu_iotlb_flush_all(d);
+}
+
+static struct ipmmu_vmsa_domain *ipmmu_get_cache_domain(struct domain *d,
+                                                        struct device *dev)
+{
+    struct ipmmu_vmsa_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
+    struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
+    struct ipmmu_vmsa_domain *domain;
+
+    if ( !mmu )
+        return NULL;
+
+    /*
+     * Loop through all Cache IPMMU domains associated with this Xen domain
+     * to locate an IPMMU domain this IPMMU device is assigned to.
+     */
+    list_for_each_entry( domain, &xen_domain->cache_domains, list )
+    {
+        if ( domain->mmu == mmu )
+            return domain;
+    }
+
+    return NULL;
+}
+
+static struct ipmmu_vmsa_domain *ipmmu_alloc_cache_domain(struct domain *d)
+{
+    struct ipmmu_vmsa_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
+    struct ipmmu_vmsa_domain *domain;
+
+    domain = xzalloc(struct ipmmu_vmsa_domain);
+    if ( !domain )
+        return ERR_PTR(-ENOMEM);
+
+    /*
+     * We don't assign the Cache IPMMU device here, it will be assigned when
+     * attaching master device to this domain in ipmmu_attach_device().
+     * domain->mmu = NULL;
+     */
+
+    domain->d = d;
+    /* Use the same context mapped to this Xen domain. */
+    domain->context_id = xen_domain->root_domain->context_id;
+
+    return domain;
+}
+
+static void ipmmu_free_cache_domain(struct ipmmu_vmsa_domain *domain)
+{
+    list_del(&domain->list);
+    /*
+     * Disable the context for Cache IPMMU only. Flush the TLB as required
+     * when modifying the context registers.
+     */
+    ipmmu_ctx_write_cache(domain, IMCTR, IMCTR_FLUSH);
+    xfree(domain);
+}
+
+static struct ipmmu_vmsa_domain *ipmmu_alloc_root_domain(struct domain *d)
+{
+    struct ipmmu_vmsa_domain *domain;
+    struct ipmmu_vmsa_device *root;
+    int ret;
+
+    /* If we are here then Root device must has been registered. */
+    root = ipmmu_find_root();
+    if ( !root )
+    {
+        printk(XENLOG_ERR "ipmmu: Unable to locate Root IPMMU\n");
+        return ERR_PTR(-ENODEV);
+    }
+
+    domain = xzalloc(struct ipmmu_vmsa_domain);
+    if ( !domain )
+        return ERR_PTR(-ENOMEM);
+
+    domain->mmu = root;
+    domain->d = d;
+
+    /* Initialize the context to be mapped to this Xen domain. */
+    ret = ipmmu_domain_init_context(domain);
+    if ( ret < 0 )
+    {
+        dev_err(root->dev, "%pd: Unable to initialize IPMMU context\n", d);
+        xfree(domain);
+        return ERR_PTR(ret);
+    }
+
+    return domain;
+}
+
+static void ipmmu_free_root_domain(struct ipmmu_vmsa_domain *domain)
+{
+    ipmmu_domain_destroy_context(domain);
+    xfree(domain);
+}
+
+static int ipmmu_assign_device(struct domain *d, u8 devfn, struct device *dev,
+                               uint32_t flag)
+{
+    struct ipmmu_vmsa_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
+    struct ipmmu_vmsa_domain *domain;
+    int ret;
+
+    if ( !xen_domain )
+        return -EINVAL;
+
+    if ( !to_ipmmu(dev) )
+        return -ENODEV;
+
+    spin_lock(&xen_domain->lock);
+
+    /*
+     * The IPMMU context for the Xen domain is not allocated beforehand
+     * (at the Xen domain creation time), but on demand only, when the first
+     * master device being attached to it.
+     * Create Root IPMMU domain which context will be mapped to this Xen domain
+     * if not exits yet.
+     */
+    if ( !xen_domain->root_domain )
+    {
+        domain = ipmmu_alloc_root_domain(d);
+        if ( IS_ERR(domain) )
+        {
+            ret = PTR_ERR(domain);
+            goto out;
+        }
+
+        xen_domain->root_domain = domain;
+    }
+
+    if ( to_domain(dev) )
+    {
+        dev_err(dev, "Already attached to IPMMU domain\n");
+        ret = -EEXIST;
+        goto out;
+    }
+
+    /*
+     * Master devices behind the same Cache IPMMU can be attached to the same
+     * Cache IPMMU domain.
+     * Before creating new IPMMU domain check to see if the required one
+     * already exists for this Xen domain.
+     */
+    domain = ipmmu_get_cache_domain(d, dev);
+    if ( !domain )
+    {
+        /* Create new IPMMU domain this master device will be attached to. */
+        domain = ipmmu_alloc_cache_domain(d);
+        if ( IS_ERR(domain) )
+        {
+            ret = PTR_ERR(domain);
+            goto out;
+        }
+
+        /* Chain new IPMMU domain to the Xen domain. */
+        list_add(&domain->list, &xen_domain->cache_domains);
+    }
+
+    ret = ipmmu_attach_device(domain, dev);
+    if ( ret )
+    {
+        /*
+         * Destroy Cache IPMMU domain only if there are no master devices
+         * attached to it.
+         */
+        if ( !domain->refcount )
+            ipmmu_free_cache_domain(domain);
+    }
+    else
+    {
+        domain->refcount++;
+        set_domain(dev, domain);
+    }
+
+out:
+    spin_unlock(&xen_domain->lock);
+
+    return ret;
+}
+
+static int ipmmu_deassign_device(struct domain *d, struct device *dev)
+{
+    struct ipmmu_vmsa_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
+    struct ipmmu_vmsa_domain *domain = to_domain(dev);
+
+    if ( !domain || domain->d != d )
+    {
+        dev_err(dev, "Not attached to %pd\n", d);
+        return -ESRCH;
+    }
+
+    spin_lock(&xen_domain->lock);
+
+    ipmmu_detach_device(domain, dev);
+    set_domain(dev, NULL);
+    domain->refcount--;
+
+    /*
+     * Destroy Cache IPMMU domain only if there are no master devices
+     * attached to it.
+     */
+    if ( !domain->refcount )
+        ipmmu_free_cache_domain(domain);
+
+    spin_unlock(&xen_domain->lock);
+
+    return 0;
+}
+
+static int ipmmu_reassign_device(struct domain *s, struct domain *t,
+                                 u8 devfn,  struct device *dev)
+{
+    int ret = 0;
+
+    /* Don't allow remapping on other domain than hwdom */
+    if ( t && t != hardware_domain )
+        return -EPERM;
+
+    if ( t == s )
+        return 0;
+
+    ret = ipmmu_deassign_device(s, dev);
+    if ( ret )
+        return ret;
+
+    if ( t )
+    {
+        /* No flags are defined for ARM. */
+        ret = ipmmu_assign_device(t, devfn, dev, 0);
+        if ( ret )
+            return ret;
+    }
+
+    return 0;
+}
+
+static int ipmmu_of_xlate(struct device *dev, struct dt_phandle_args *spec)
+{
+    int ret;
+
+    /*
+     * Perform sanity check of passed DT IOMMU specifier. Each master device
+     * gets micro-TLB (device ID) assignment via the "iommus" property
+     * in DT. We expect #iommu-cells to be 1 (Multiple-master IOMMU) and
+     * this cell for the micro-TLB (device ID).
+     */
+    if ( spec->args_count != 1 || spec->args[0] >= IPMMU_UTLB_MAX )
+        return -EINVAL;
+
+    ret = iommu_fwspec_add_ids(dev, spec->args, 1);
+    if ( ret )
+        return ret;
+
+    /* Initialize once - xlate() will call multiple times. */
+    if ( to_ipmmu(dev) )
+        return 0;
+
+    return ipmmu_init_platform_device(dev, spec);
+}
+
+static int ipmmu_add_device(u8 devfn, struct device *dev)
+{
+    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+    /* Only let through devices that have been verified in xlate(). */
+    if ( !to_ipmmu(dev) )
+        return -ENODEV;
+
+    if ( dt_device_is_protected(dev_to_dt(dev)) )
+    {
+        dev_err(dev, "Already added to IPMMU\n");
+        return -EEXIST;
+    }
+
+    /* Let Xen know that the master device is protected by an IOMMU. */
+    dt_device_set_protected(dev_to_dt(dev));
+
+    dev_info(dev, "Added master device (IPMMU %s micro-TLBs %u)\n",
+             dev_name(fwspec->iommu_dev), fwspec->num_ids);
+
+    return 0;
+}
+
+static int ipmmu_iommu_domain_init(struct domain *d)
+{
+    struct ipmmu_vmsa_xen_domain *xen_domain;
+
+    xen_domain = xzalloc(struct ipmmu_vmsa_xen_domain);
+    if ( !xen_domain )
+        return -ENOMEM;
+
+    spin_lock_init(&xen_domain->lock);
+    INIT_LIST_HEAD(&xen_domain->cache_domains);
+    /*
+     * We don't create Root IPMMU domain here, it will be created on demand
+     * only, when attaching the first master device to this Xen domain in
+     * ipmmu_assign_device().
+     * xen_domain->root_domain = NULL;
+    */
+
+    dom_iommu(d)->arch.priv = xen_domain;
+
+    return 0;
+}
+
+static void __hwdom_init ipmmu_iommu_hwdom_init(struct domain *d)
+{
+    /* Set to false options not supported on ARM. */
+    if ( iommu_hwdom_inclusive )
+        printk(XENLOG_WARNING "ipmmu: map-inclusive dom0-iommu option is not supported on ARM\n");
+    iommu_hwdom_inclusive = false;
+    if ( iommu_hwdom_reserved == 1 )
+        printk(XENLOG_WARNING "ipmmu: map-reserved dom0-iommu option is not supported on ARM\n");
+    iommu_hwdom_reserved = 0;
+
+    arch_iommu_hwdom_init(d);
+}
+
+static void ipmmu_iommu_domain_teardown(struct domain *d)
+{
+    struct ipmmu_vmsa_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
+
+    if ( !xen_domain )
+        return;
+
+    /*
+     * Destroy Root IPMMU domain which context is mapped to this Xen domain
+     * if exits.
+     */
+    if ( xen_domain->root_domain )
+        ipmmu_free_root_domain(xen_domain->root_domain);
+
+    /*
+     * We assume that all master devices have already been detached from
+     * this Xen domain and there must be no associated Cache IPMMU domains
+     * in use.
+     */
+    ASSERT(list_empty(&xen_domain->cache_domains));
+    xfree(xen_domain);
+    dom_iommu(d)->arch.priv = NULL;
+}
+
+static const struct iommu_ops ipmmu_iommu_ops =
+{
+    .init            = ipmmu_iommu_domain_init,
+    .hwdom_init      = ipmmu_iommu_hwdom_init,
+    .teardown        = ipmmu_iommu_domain_teardown,
+    .iotlb_flush     = ipmmu_iotlb_flush,
+    .iotlb_flush_all = ipmmu_iotlb_flush_all,
+    .assign_device   = ipmmu_assign_device,
+    .reassign_device = ipmmu_reassign_device,
+    .map_page        = arm_iommu_map_page,
+    .unmap_page      = arm_iommu_unmap_page,
+    .of_xlate        = ipmmu_of_xlate,
+    .add_device      = ipmmu_add_device,
+};
+
+/* R-Car Gen3 SoCs product and cut information. */
+#define RCAR_PRODUCT_MASK    0x00007F00
+#define RCAR_PRODUCT_H3      0x00004F00
+#define RCAR_PRODUCT_M3W     0x00005200
+#define RCAR_PRODUCT_M3N     0x00005500
+#define RCAR_CUT_MASK        0x000000FF
+#define RCAR_CUT_VER30       0x00000020
+
+static __init bool ipmmu_stage2_supported(void)
+{
+    struct dt_device_node *np;
+    uint64_t addr, size;
+    void __iomem *base;
+    uint32_t product, cut;
+    static enum
+    {
+        UNKNOWN,
+        SUPPORTED,
+        NOTSUPPORTED
+    } stage2_supported = UNKNOWN;
+
+    /* Use the flag to avoid checking for the compatibility more then once. */
+    switch ( stage2_supported )
+    {
+    case SUPPORTED:
+        return true;
+
+    case NOTSUPPORTED:
+        return false;
+
+    case UNKNOWN:
+    default:
+        stage2_supported = NOTSUPPORTED;
+        break;
+    }
+
+    np = dt_find_compatible_node(NULL, NULL, "renesas,prr");
+    if ( !np )
+    {
+        printk(XENLOG_ERR "ipmmu: Failed to find PRR node\n");
+        return false;
+    }
+
+    if ( dt_device_get_address(np, 0, &addr, &size) )
+    {
+        printk(XENLOG_ERR "ipmmu: Failed to get PRR MMIO\n");
+        return false;
+    }
+
+    base = ioremap_nocache(addr, size);
+    if ( !base )
+    {
+        printk(XENLOG_ERR "ipmmu: Failed to ioremap PRR MMIO\n");
+        return false;
+    }
+
+    product = readl(base);
+    cut = product & RCAR_CUT_MASK;
+    product &= RCAR_PRODUCT_MASK;
+
+    switch ( product )
+    {
+    case RCAR_PRODUCT_H3:
+    case RCAR_PRODUCT_M3W:
+        if ( cut >= RCAR_CUT_VER30 )
+            stage2_supported = SUPPORTED;
+        break;
+
+    case RCAR_PRODUCT_M3N:
+        stage2_supported = SUPPORTED;
+        break;
+
+    default:
+        printk(XENLOG_ERR "ipmmu: Unsupported SoC version\n");
+        break;
+    }
+
+    iounmap(base);
+
+    return stage2_supported == SUPPORTED;
+}
+
+static const struct dt_device_match ipmmu_dt_match[] __initconst =
+{
+    DT_MATCH_COMPATIBLE("renesas,ipmmu-r8a7795"),
+    DT_MATCH_COMPATIBLE("renesas,ipmmu-r8a77965"),
+    DT_MATCH_COMPATIBLE("renesas,ipmmu-r8a7796"),
+    { /* sentinel */ },
+};
+
+static __init int ipmmu_init(struct dt_device_node *node, const void *data)
+{
+    int ret;
+
+    /*
+     * Even if the device can't be initialized, we don't want to give
+     * the IPMMU device to dom0.
+     */
+    dt_device_set_used_by(node, DOMID_XEN);
+
+    if ( !iommu_hap_pt_share )
+    {
+        printk_once(XENLOG_ERR "ipmmu: P2M table must always be shared between the CPU and the IPMMU\n");
+        return -EINVAL;
+    }
+
+    if ( !ipmmu_stage2_supported() )
+    {
+        printk_once(XENLOG_ERR "ipmmu: P2M sharing is not supported in current SoC revision\n");
+        return -ENODEV;
+    }
+    else
+    {
+        /*
+         * As 4-level translation table is not supported in IPMMU, we need
+         * to check IPA size used for P2M table beforehand to be sure it is
+         * 3-level and the IPMMU will be able to use it.
+         *
+         * TODO: First initialize the IOMMU and gather the requirements and
+         * then initialize the P2M. In the P2M code, take into the account
+         * the IOMMU requirements and restrict "pa_range" if necessary.
+         */
+        if ( IPMMU_MAX_P2M_IPA_BITS < p2m_ipa_bits )
+        {
+            printk_once(XENLOG_ERR "ipmmu: P2M IPA size is not supported (P2M=%u IPMMU=%u)!\n",
+                        p2m_ipa_bits, IPMMU_MAX_P2M_IPA_BITS);
+            return -ENODEV;
+        }
+    }
+
+    ret = ipmmu_probe(node);
+    if ( ret )
+    {
+        dev_err(&node->dev, "Failed to init IPMMU (%d)\n", ret);
+        return ret;
+    }
+
+    iommu_set_ops(&ipmmu_iommu_ops);
+
+    return 0;
+}
+
+DT_DEVICE_START(ipmmu, "Renesas IPMMU-VMSA", DEVICE_IOMMU)
+    .dt_match = ipmmu_dt_match,
+    .init = ipmmu_init,
+DT_DEVICE_END
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */