diff mbox series

[RESEND,v4] iommu/mediatek: check 4GB mode by reading infracfg

Message ID 20200826085618.2889-1-miles.chen@mediatek.com (mailing list archive)
State New, archived
Headers show
Series [RESEND,v4] iommu/mediatek: check 4GB mode by reading infracfg | expand

Commit Message

Miles Chen Aug. 26, 2020, 8:56 a.m. UTC
In previous discussion [1] and [2], we found that it is risky to
use max_pfn or totalram_pages to tell if 4GB mode is enabled.

Check 4GB mode by reading infracfg register, remove the usage
of the un-exported symbol max_pfn.

This is a step towards building mtk_iommu as a kernel module.

[1] https://lore.kernel.org/lkml/20200603161132.2441-1-miles.chen@mediatek.com/
[2] https://lore.kernel.org/lkml/20200604080120.2628-1-miles.chen@mediatek.com/
[3] https://lore.kernel.org/lkml/20200715205120.GA778876@bogus/

Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Yong Wu <yong.wu@mediatek.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Miles Chen <miles.chen@mediatek.com>

---

Change since v3
- use lore.kernel.org links
- move "change since..." after "---"

Change since v2:
- determine compatible string by m4u_plat
- rebase to next-20200720
- add "---"

Change since v1:
- remove the phandle usage, search for infracfg instead [3]
- use infracfg instead of infracfg_regmap
- move infracfg definitaions to linux/soc/mediatek/infracfg.h
- update enable_4GB only when has_4gb_mode
---
 drivers/iommu/mtk_iommu.c             | 34 +++++++++++++++++++++++----
 include/linux/soc/mediatek/infracfg.h |  3 +++
 2 files changed, 32 insertions(+), 5 deletions(-)

Comments

Yong Wu (吴勇) Aug. 27, 2020, 5:31 a.m. UTC | #1
On Wed, 2020-08-26 at 16:56 +0800, Miles Chen wrote:
> In previous discussion [1] and [2], we found that it is risky to
> use max_pfn or totalram_pages to tell if 4GB mode is enabled.
> 
> Check 4GB mode by reading infracfg register, remove the usage
> of the un-exported symbol max_pfn.
> 
> This is a step towards building mtk_iommu as a kernel module.
> 
> [1] https://lore.kernel.org/lkml/20200603161132.2441-1-miles.chen@mediatek.com/
> [2] https://lore.kernel.org/lkml/20200604080120.2628-1-miles.chen@mediatek.com/
> [3] https://lore.kernel.org/lkml/20200715205120.GA778876@bogus/
> 
> Cc: Mike Rapoport <rppt@linux.ibm.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Yong Wu <yong.wu@mediatek.com>
> Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Matthias Brugger <matthias.bgg@gmail.com>
> Signed-off-by: Miles Chen <miles.chen@mediatek.com>
> 
> ---
> 
> Change since v3
> - use lore.kernel.org links
> - move "change since..." after "---"
> 
> Change since v2:
> - determine compatible string by m4u_plat
> - rebase to next-20200720
> - add "---"
> 
> Change since v1:
> - remove the phandle usage, search for infracfg instead [3]
> - use infracfg instead of infracfg_regmap
> - move infracfg definitaions to linux/soc/mediatek/infracfg.h
> - update enable_4GB only when has_4gb_mode
> ---
>  drivers/iommu/mtk_iommu.c             | 34 +++++++++++++++++++++++----
>  include/linux/soc/mediatek/infracfg.h |  3 +++
>  2 files changed, 32 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 785b228d39a6..adc350150492 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -3,7 +3,6 @@
>   * Copyright (c) 2015-2016 MediaTek Inc.
>   * Author: Yong Wu <yong.wu@mediatek.com>
>   */
> -#include <linux/memblock.h>
>  #include <linux/bug.h>
>  #include <linux/clk.h>
>  #include <linux/component.h>
> @@ -15,13 +14,16 @@
>  #include <linux/iommu.h>
>  #include <linux/iopoll.h>
>  #include <linux/list.h>
> +#include <linux/mfd/syscon.h>
>  #include <linux/of_address.h>
>  #include <linux/of_iommu.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> +#include <linux/regmap.h>
>  #include <linux/slab.h>
>  #include <linux/spinlock.h>
> +#include <linux/soc/mediatek/infracfg.h>
>  #include <asm/barrier.h>
>  #include <soc/mediatek/smi.h>
>  
> @@ -640,8 +642,11 @@ static int mtk_iommu_probe(struct platform_device *pdev)
>  	struct resource         *res;
>  	resource_size_t		ioaddr;
>  	struct component_match  *match = NULL;
> +	struct regmap		*infracfg;
>  	void                    *protect;
>  	int                     i, larb_nr, ret;
> +	u32			val;
> +	char                    *p;
>  
>  	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>  	if (!data)
> @@ -655,10 +660,29 @@ static int mtk_iommu_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
>  
> -	/* Whether the current dram is over 4GB */
> -	data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
> -	if (!MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE))
> -		data->enable_4GB = false;
> +	data->enable_4GB = false;
> +	if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE)) {
> +		switch (data->plat_data->m4u_plat) {
> +		case M4U_MT2712:
> +			p = "mediatek,mt2712-infracfg";
> +			break;
> +		case M4U_MT8173:
> +			p = "mediatek,mt8173-infracfg";
> +			break;
> +		default:
> +			p = NULL;
> +		}
> +

This can be simplified:

        if (data->plat_data->m4u_plat == M4U_MT2712)
		p = "mediatek,mt2712-infracfg";
	else if(data->plat_data->m4u_plat == M4U_MT8173)
		p = "mediatek,mt8173-infracfg";
	else
		return -EINVAL;

Then,
Reviewed-by: Yong Wu <yong.wu@mediatek.com>
	

> +		infracfg = syscon_regmap_lookup_by_compatible(p);
> +
> +		if (IS_ERR(infracfg))
> +			return PTR_ERR(infracfg);
> +
> +		ret = regmap_read(infracfg, REG_INFRA_MISC, &val);
> +		if (ret)
> +			return ret;
> +		data->enable_4GB = !!(val & F_DDR_4GB_SUPPORT_EN);
> +	}
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	data->base = devm_ioremap_resource(dev, res);
> diff --git a/include/linux/soc/mediatek/infracfg.h b/include/linux/soc/mediatek/infracfg.h
> index fd25f0148566..233463d789c6 100644
> --- a/include/linux/soc/mediatek/infracfg.h
> +++ b/include/linux/soc/mediatek/infracfg.h
> @@ -32,6 +32,9 @@
>  #define MT7622_TOP_AXI_PROT_EN_WB		(BIT(2) | BIT(6) | \
>  						 BIT(7) | BIT(8))
>  
> +#define REG_INFRA_MISC				0xf00
> +#define F_DDR_4GB_SUPPORT_EN			BIT(13)
> +
>  int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
>  		bool reg_update);
>  int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
Matthias Brugger Aug. 27, 2020, 9:53 a.m. UTC | #2
On 26/08/2020 10:56, Miles Chen wrote:
> In previous discussion [1] and [2], we found that it is risky to
> use max_pfn or totalram_pages to tell if 4GB mode is enabled.
> 
> Check 4GB mode by reading infracfg register, remove the usage
> of the un-exported symbol max_pfn.
> 
> This is a step towards building mtk_iommu as a kernel module.
> 
> [1] https://lore.kernel.org/lkml/20200603161132.2441-1-miles.chen@mediatek.com/
> [2] https://lore.kernel.org/lkml/20200604080120.2628-1-miles.chen@mediatek.com/
> [3] https://lore.kernel.org/lkml/20200715205120.GA778876@bogus/
> 
> Cc: Mike Rapoport <rppt@linux.ibm.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Yong Wu <yong.wu@mediatek.com>
> Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Matthias Brugger <matthias.bgg@gmail.com>
> Signed-off-by: Miles Chen <miles.chen@mediatek.com>

Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>

> 
> ---
> 
> Change since v3
> - use lore.kernel.org links
> - move "change since..." after "---"
> 
> Change since v2:
> - determine compatible string by m4u_plat
> - rebase to next-20200720
> - add "---"
> 
> Change since v1:
> - remove the phandle usage, search for infracfg instead [3]
> - use infracfg instead of infracfg_regmap
> - move infracfg definitaions to linux/soc/mediatek/infracfg.h
> - update enable_4GB only when has_4gb_mode
> ---
>   drivers/iommu/mtk_iommu.c             | 34 +++++++++++++++++++++++----
>   include/linux/soc/mediatek/infracfg.h |  3 +++
>   2 files changed, 32 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 785b228d39a6..adc350150492 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -3,7 +3,6 @@
>    * Copyright (c) 2015-2016 MediaTek Inc.
>    * Author: Yong Wu <yong.wu@mediatek.com>
>    */
> -#include <linux/memblock.h>
>   #include <linux/bug.h>
>   #include <linux/clk.h>
>   #include <linux/component.h>
> @@ -15,13 +14,16 @@
>   #include <linux/iommu.h>
>   #include <linux/iopoll.h>
>   #include <linux/list.h>
> +#include <linux/mfd/syscon.h>
>   #include <linux/of_address.h>
>   #include <linux/of_iommu.h>
>   #include <linux/of_irq.h>
>   #include <linux/of_platform.h>
>   #include <linux/platform_device.h>
> +#include <linux/regmap.h>
>   #include <linux/slab.h>
>   #include <linux/spinlock.h>
> +#include <linux/soc/mediatek/infracfg.h>
>   #include <asm/barrier.h>
>   #include <soc/mediatek/smi.h>
>   
> @@ -640,8 +642,11 @@ static int mtk_iommu_probe(struct platform_device *pdev)
>   	struct resource         *res;
>   	resource_size_t		ioaddr;
>   	struct component_match  *match = NULL;
> +	struct regmap		*infracfg;
>   	void                    *protect;
>   	int                     i, larb_nr, ret;
> +	u32			val;
> +	char                    *p;
>   
>   	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>   	if (!data)
> @@ -655,10 +660,29 @@ static int mtk_iommu_probe(struct platform_device *pdev)
>   		return -ENOMEM;
>   	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
>   
> -	/* Whether the current dram is over 4GB */
> -	data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
> -	if (!MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE))
> -		data->enable_4GB = false;
> +	data->enable_4GB = false;
> +	if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE)) {
> +		switch (data->plat_data->m4u_plat) {
> +		case M4U_MT2712:
> +			p = "mediatek,mt2712-infracfg";
> +			break;
> +		case M4U_MT8173:
> +			p = "mediatek,mt8173-infracfg";
> +			break;
> +		default:
> +			p = NULL;
> +		}
> +
> +		infracfg = syscon_regmap_lookup_by_compatible(p);
> +
> +		if (IS_ERR(infracfg))
> +			return PTR_ERR(infracfg);
> +
> +		ret = regmap_read(infracfg, REG_INFRA_MISC, &val);
> +		if (ret)
> +			return ret;
> +		data->enable_4GB = !!(val & F_DDR_4GB_SUPPORT_EN);
> +	}
>   
>   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>   	data->base = devm_ioremap_resource(dev, res);
> diff --git a/include/linux/soc/mediatek/infracfg.h b/include/linux/soc/mediatek/infracfg.h
> index fd25f0148566..233463d789c6 100644
> --- a/include/linux/soc/mediatek/infracfg.h
> +++ b/include/linux/soc/mediatek/infracfg.h
> @@ -32,6 +32,9 @@
>   #define MT7622_TOP_AXI_PROT_EN_WB		(BIT(2) | BIT(6) | \
>   						 BIT(7) | BIT(8))
>   
> +#define REG_INFRA_MISC				0xf00
> +#define F_DDR_4GB_SUPPORT_EN			BIT(13)
> +
>   int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
>   		bool reg_update);
>   int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
>
Robin Murphy Aug. 27, 2020, 7:27 p.m. UTC | #3
On 2020-08-27 06:31, Yong Wu wrote:
> On Wed, 2020-08-26 at 16:56 +0800, Miles Chen wrote:
>> In previous discussion [1] and [2], we found that it is risky to
>> use max_pfn or totalram_pages to tell if 4GB mode is enabled.
>>
>> Check 4GB mode by reading infracfg register, remove the usage
>> of the un-exported symbol max_pfn.
>>
>> This is a step towards building mtk_iommu as a kernel module.
>>
>> [1] https://lore.kernel.org/lkml/20200603161132.2441-1-miles.chen@mediatek.com/
>> [2] https://lore.kernel.org/lkml/20200604080120.2628-1-miles.chen@mediatek.com/
>> [3] https://lore.kernel.org/lkml/20200715205120.GA778876@bogus/
>>
>> Cc: Mike Rapoport <rppt@linux.ibm.com>
>> Cc: David Hildenbrand <david@redhat.com>
>> Cc: Yong Wu <yong.wu@mediatek.com>
>> Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
>> Cc: Christoph Hellwig <hch@lst.de>
>> Cc: Rob Herring <robh@kernel.org>
>> Cc: Matthias Brugger <matthias.bgg@gmail.com>
>> Signed-off-by: Miles Chen <miles.chen@mediatek.com>
>>
>> ---
>>
>> Change since v3
>> - use lore.kernel.org links
>> - move "change since..." after "---"
>>
>> Change since v2:
>> - determine compatible string by m4u_plat
>> - rebase to next-20200720
>> - add "---"
>>
>> Change since v1:
>> - remove the phandle usage, search for infracfg instead [3]
>> - use infracfg instead of infracfg_regmap
>> - move infracfg definitaions to linux/soc/mediatek/infracfg.h
>> - update enable_4GB only when has_4gb_mode
>> ---
>>   drivers/iommu/mtk_iommu.c             | 34 +++++++++++++++++++++++----
>>   include/linux/soc/mediatek/infracfg.h |  3 +++
>>   2 files changed, 32 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
>> index 785b228d39a6..adc350150492 100644
>> --- a/drivers/iommu/mtk_iommu.c
>> +++ b/drivers/iommu/mtk_iommu.c
>> @@ -3,7 +3,6 @@
>>    * Copyright (c) 2015-2016 MediaTek Inc.
>>    * Author: Yong Wu <yong.wu@mediatek.com>
>>    */
>> -#include <linux/memblock.h>
>>   #include <linux/bug.h>
>>   #include <linux/clk.h>
>>   #include <linux/component.h>
>> @@ -15,13 +14,16 @@
>>   #include <linux/iommu.h>
>>   #include <linux/iopoll.h>
>>   #include <linux/list.h>
>> +#include <linux/mfd/syscon.h>
>>   #include <linux/of_address.h>
>>   #include <linux/of_iommu.h>
>>   #include <linux/of_irq.h>
>>   #include <linux/of_platform.h>
>>   #include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>>   #include <linux/slab.h>
>>   #include <linux/spinlock.h>
>> +#include <linux/soc/mediatek/infracfg.h>
>>   #include <asm/barrier.h>
>>   #include <soc/mediatek/smi.h>
>>   
>> @@ -640,8 +642,11 @@ static int mtk_iommu_probe(struct platform_device *pdev)
>>   	struct resource         *res;
>>   	resource_size_t		ioaddr;
>>   	struct component_match  *match = NULL;
>> +	struct regmap		*infracfg;
>>   	void                    *protect;
>>   	int                     i, larb_nr, ret;
>> +	u32			val;
>> +	char                    *p;
>>   
>>   	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>>   	if (!data)
>> @@ -655,10 +660,29 @@ static int mtk_iommu_probe(struct platform_device *pdev)
>>   		return -ENOMEM;
>>   	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
>>   
>> -	/* Whether the current dram is over 4GB */
>> -	data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
>> -	if (!MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE))
>> -		data->enable_4GB = false;
>> +	data->enable_4GB = false;

Nit: this isn't really necessary, since the structure is kzalloc()ed.

>> +	if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE)) {
>> +		switch (data->plat_data->m4u_plat) {
>> +		case M4U_MT2712:
>> +			p = "mediatek,mt2712-infracfg";
>> +			break;
>> +		case M4U_MT8173:
>> +			p = "mediatek,mt8173-infracfg";
>> +			break;
>> +		default:
>> +			p = NULL;
>> +		}
>> +
> 
> This can be simplified:
> 
>          if (data->plat_data->m4u_plat == M4U_MT2712)
> 		p = "mediatek,mt2712-infracfg";
> 	else if(data->plat_data->m4u_plat == M4U_MT8173)
> 		p = "mediatek,mt8173-infracfg";
> 	else
> 		return -EINVAL;

Right, at this point the HAS_4GB_MODE flag is entirely redundant and 
should be removed. FWIW I still think your suggestion of putting the 
infracfg names into plat_data would be even better and cleaner - there's 
plenty of precedent for that sort of thing (see "git grep '\.clk_name'" 
for example).

Robin.

> 
> Then,
> Reviewed-by: Yong Wu <yong.wu@mediatek.com>
> 	
> 
>> +		infracfg = syscon_regmap_lookup_by_compatible(p);
>> +
>> +		if (IS_ERR(infracfg))
>> +			return PTR_ERR(infracfg);
>> +
>> +		ret = regmap_read(infracfg, REG_INFRA_MISC, &val);
>> +		if (ret)
>> +			return ret;
>> +		data->enable_4GB = !!(val & F_DDR_4GB_SUPPORT_EN);
>> +	}
>>   
>>   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>   	data->base = devm_ioremap_resource(dev, res);
>> diff --git a/include/linux/soc/mediatek/infracfg.h b/include/linux/soc/mediatek/infracfg.h
>> index fd25f0148566..233463d789c6 100644
>> --- a/include/linux/soc/mediatek/infracfg.h
>> +++ b/include/linux/soc/mediatek/infracfg.h
>> @@ -32,6 +32,9 @@
>>   #define MT7622_TOP_AXI_PROT_EN_WB		(BIT(2) | BIT(6) | \
>>   						 BIT(7) | BIT(8))
>>   
>> +#define REG_INFRA_MISC				0xf00
>> +#define F_DDR_4GB_SUPPORT_EN			BIT(13)
>> +
>>   int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
>>   		bool reg_update);
>>   int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
Miles Chen Aug. 29, 2020, 8:51 a.m. UTC | #4
On Thu, 2020-08-27 at 20:27 +0100, Robin Murphy wrote:
> On 2020-08-27 06:31, Yong Wu wrote:
> > On Wed, 2020-08-26 at 16:56 +0800, Miles Chen wrote:
> >> In previous discussion [1] and [2], we found that it is risky to
> >> use max_pfn or totalram_pages to tell if 4GB mode is enabled.
> >>
> >> Check 4GB mode by reading infracfg register, remove the usage
> >> of the un-exported symbol max_pfn.
> >>
> >> This is a step towards building mtk_iommu as a kernel module.
> >>
> >> [1] https://lore.kernel.org/lkml/20200603161132.2441-1-miles.chen@mediatek.com/
> >> [2] https://lore.kernel.org/lkml/20200604080120.2628-1-miles.chen@mediatek.com/
> >> [3] https://lore.kernel.org/lkml/20200715205120.GA778876@bogus/
> >>
> >> Cc: Mike Rapoport <rppt@linux.ibm.com>
> >> Cc: David Hildenbrand <david@redhat.com>
> >> Cc: Yong Wu <yong.wu@mediatek.com>
> >> Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
> >> Cc: Christoph Hellwig <hch@lst.de>
> >> Cc: Rob Herring <robh@kernel.org>
> >> Cc: Matthias Brugger <matthias.bgg@gmail.com>
> >> Signed-off-by: Miles Chen <miles.chen@mediatek.com>
> >>
> >> ---
> >>
> >> Change since v3
> >> - use lore.kernel.org links
> >> - move "change since..." after "---"
> >>
> >> Change since v2:
> >> - determine compatible string by m4u_plat
> >> - rebase to next-20200720
> >> - add "---"
> >>
> >> Change since v1:
> >> - remove the phandle usage, search for infracfg instead [3]
> >> - use infracfg instead of infracfg_regmap
> >> - move infracfg definitaions to linux/soc/mediatek/infracfg.h
> >> - update enable_4GB only when has_4gb_mode
> >> ---
> >>   drivers/iommu/mtk_iommu.c             | 34 +++++++++++++++++++++++----
> >>   include/linux/soc/mediatek/infracfg.h |  3 +++
> >>   2 files changed, 32 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> >> index 785b228d39a6..adc350150492 100644
> >> --- a/drivers/iommu/mtk_iommu.c
> >> +++ b/drivers/iommu/mtk_iommu.c
> >> @@ -3,7 +3,6 @@
> >>    * Copyright (c) 2015-2016 MediaTek Inc.
> >>    * Author: Yong Wu <yong.wu@mediatek.com>
> >>    */
> >> -#include <linux/memblock.h>
> >>   #include <linux/bug.h>
> >>   #include <linux/clk.h>
> >>   #include <linux/component.h>
> >> @@ -15,13 +14,16 @@
> >>   #include <linux/iommu.h>
> >>   #include <linux/iopoll.h>
> >>   #include <linux/list.h>
> >> +#include <linux/mfd/syscon.h>
> >>   #include <linux/of_address.h>
> >>   #include <linux/of_iommu.h>
> >>   #include <linux/of_irq.h>
> >>   #include <linux/of_platform.h>
> >>   #include <linux/platform_device.h>
> >> +#include <linux/regmap.h>
> >>   #include <linux/slab.h>
> >>   #include <linux/spinlock.h>
> >> +#include <linux/soc/mediatek/infracfg.h>
> >>   #include <asm/barrier.h>
> >>   #include <soc/mediatek/smi.h>
> >>   
> >> @@ -640,8 +642,11 @@ static int mtk_iommu_probe(struct platform_device *pdev)
> >>   	struct resource         *res;
> >>   	resource_size_t		ioaddr;
> >>   	struct component_match  *match = NULL;
> >> +	struct regmap		*infracfg;
> >>   	void                    *protect;
> >>   	int                     i, larb_nr, ret;
> >> +	u32			val;
> >> +	char                    *p;
> >>   
> >>   	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> >>   	if (!data)
> >> @@ -655,10 +660,29 @@ static int mtk_iommu_probe(struct platform_device *pdev)
> >>   		return -ENOMEM;
> >>   	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
> >>   
> >> -	/* Whether the current dram is over 4GB */
> >> -	data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
> >> -	if (!MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE))
> >> -		data->enable_4GB = false;
> >> +	data->enable_4GB = false;
> 
> Nit: this isn't really necessary, since the structure is kzalloc()ed.

Thanks for the comment, I will remove this this in v5.
> 
> >> +	if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE)) {
> >> +		switch (data->plat_data->m4u_plat) {
> >> +		case M4U_MT2712:
> >> +			p = "mediatek,mt2712-infracfg";
> >> +			break;
> >> +		case M4U_MT8173:
> >> +			p = "mediatek,mt8173-infracfg";
> >> +			break;
> >> +		default:
> >> +			p = NULL;
> >> +		}
> >> +
> > 
> > This can be simplified:
> > 
> >          if (data->plat_data->m4u_plat == M4U_MT2712)
> > 		p = "mediatek,mt2712-infracfg";
> > 	else if(data->plat_data->m4u_plat == M4U_MT8173)
> > 		p = "mediatek,mt8173-infracfg";
> > 	else
> > 		return -EINVAL;
> 
> Right, at this point the HAS_4GB_MODE flag is entirely redundant and 
> should be removed. FWIW I still think your suggestion of putting the 
> infracfg names into plat_data would be even better and cleaner - there's 
> plenty of precedent for that sort of thing (see "git grep '\.clk_name'" 
> for example).
> 
> Robin.

hmm, I have no strong opinion about this. We have discussed this
approach before and built this patch based on the discussion.
https://lore.kernel.org/patchwork/patch/1276801/



Miles
> 
> > 
> > Then,
> > Reviewed-by: Yong Wu <yong.wu@mediatek.com>
> > 	
> > 
> >> +		infracfg = syscon_regmap_lookup_by_compatible(p);
> >> +
> >> +		if (IS_ERR(infracfg))
> >> +			return PTR_ERR(infracfg);
> >> +
> >> +		ret = regmap_read(infracfg, REG_INFRA_MISC, &val);
> >> +		if (ret)
> >> +			return ret;
> >> +		data->enable_4GB = !!(val & F_DDR_4GB_SUPPORT_EN);
> >> +	}
> >>   
> >>   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >>   	data->base = devm_ioremap_resource(dev, res);
> >> diff --git a/include/linux/soc/mediatek/infracfg.h b/include/linux/soc/mediatek/infracfg.h
> >> index fd25f0148566..233463d789c6 100644
> >> --- a/include/linux/soc/mediatek/infracfg.h
> >> +++ b/include/linux/soc/mediatek/infracfg.h
> >> @@ -32,6 +32,9 @@
> >>   #define MT7622_TOP_AXI_PROT_EN_WB		(BIT(2) | BIT(6) | \
> >>   						 BIT(7) | BIT(8))
> >>   
> >> +#define REG_INFRA_MISC				0xf00
> >> +#define F_DDR_4GB_SUPPORT_EN			BIT(13)
> >> +
> >>   int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
> >>   		bool reg_update);
> >>   int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
> > 
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >
diff mbox series

Patch

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 785b228d39a6..adc350150492 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -3,7 +3,6 @@ 
  * Copyright (c) 2015-2016 MediaTek Inc.
  * Author: Yong Wu <yong.wu@mediatek.com>
  */
-#include <linux/memblock.h>
 #include <linux/bug.h>
 #include <linux/clk.h>
 #include <linux/component.h>
@@ -15,13 +14,16 @@ 
 #include <linux/iommu.h>
 #include <linux/iopoll.h>
 #include <linux/list.h>
+#include <linux/mfd/syscon.h>
 #include <linux/of_address.h>
 #include <linux/of_iommu.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <linux/soc/mediatek/infracfg.h>
 #include <asm/barrier.h>
 #include <soc/mediatek/smi.h>
 
@@ -640,8 +642,11 @@  static int mtk_iommu_probe(struct platform_device *pdev)
 	struct resource         *res;
 	resource_size_t		ioaddr;
 	struct component_match  *match = NULL;
+	struct regmap		*infracfg;
 	void                    *protect;
 	int                     i, larb_nr, ret;
+	u32			val;
+	char                    *p;
 
 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
@@ -655,10 +660,29 @@  static int mtk_iommu_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
 
-	/* Whether the current dram is over 4GB */
-	data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
-	if (!MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE))
-		data->enable_4GB = false;
+	data->enable_4GB = false;
+	if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE)) {
+		switch (data->plat_data->m4u_plat) {
+		case M4U_MT2712:
+			p = "mediatek,mt2712-infracfg";
+			break;
+		case M4U_MT8173:
+			p = "mediatek,mt8173-infracfg";
+			break;
+		default:
+			p = NULL;
+		}
+
+		infracfg = syscon_regmap_lookup_by_compatible(p);
+
+		if (IS_ERR(infracfg))
+			return PTR_ERR(infracfg);
+
+		ret = regmap_read(infracfg, REG_INFRA_MISC, &val);
+		if (ret)
+			return ret;
+		data->enable_4GB = !!(val & F_DDR_4GB_SUPPORT_EN);
+	}
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	data->base = devm_ioremap_resource(dev, res);
diff --git a/include/linux/soc/mediatek/infracfg.h b/include/linux/soc/mediatek/infracfg.h
index fd25f0148566..233463d789c6 100644
--- a/include/linux/soc/mediatek/infracfg.h
+++ b/include/linux/soc/mediatek/infracfg.h
@@ -32,6 +32,9 @@ 
 #define MT7622_TOP_AXI_PROT_EN_WB		(BIT(2) | BIT(6) | \
 						 BIT(7) | BIT(8))
 
+#define REG_INFRA_MISC				0xf00
+#define F_DDR_4GB_SUPPORT_EN			BIT(13)
+
 int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
 		bool reg_update);
 int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,