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[RFC,08/16] PCI: Introduce pci_scan_host_bridge() and pci_host_info

Message ID 1416219710-26088-9-git-send-email-wangyijing@huawei.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Yijing Wang Nov. 17, 2014, 10:21 a.m. UTC
From: Yijing Wang <wangyijing0307@gmail.com>

Now pci_host_bridge has been ripped out from pci root
bus creation. Currently pci_scan_root_bus() lacks
scalability, so platform host drivers have no proper
way to configure pci_host_bridge. E.g we should assign
msi_controller to pci_host_bridge, add argument for
pci_scan_root_bus() is not a good idea, it has already
five, so introudce struct pci_host_info to make
pci scan interfaces more scalable. Because almost
all host drivers need to configure host resources,
so we put .init_res() in it first, and add other
hooks when need.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
 drivers/pci/host-bridge.c |   27 +++++++++-------
 drivers/pci/probe.c       |   73 ++++++++++++++++++++++++++++++++++++++++++--
 include/linux/pci.h       |   20 ++++++++++++-
 3 files changed, 103 insertions(+), 17 deletions(-)

Comments

Liviu Dudau Nov. 18, 2014, 3:42 p.m. UTC | #1
On Mon, Nov 17, 2014 at 10:21:42AM +0000, Yijing Wang wrote:
> From: Yijing Wang <wangyijing0307@gmail.com>
> 
> Now pci_host_bridge has been ripped out from pci root
> bus creation. Currently pci_scan_root_bus() lacks
> scalability, so platform host drivers have no proper
> way to configure pci_host_bridge. E.g we should assign
> msi_controller to pci_host_bridge, add argument for
> pci_scan_root_bus() is not a good idea, it has already
> five, so introudce struct pci_host_info to make
> pci scan interfaces more scalable. Because almost
> all host drivers need to configure host resources,
> so we put .init_res() in it first, and add other
> hooks when need.
> 
> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> ---
>  drivers/pci/host-bridge.c |   27 +++++++++-------
>  drivers/pci/probe.c       |   73 ++++++++++++++++++++++++++++++++++++++++++--
>  include/linux/pci.h       |   20 ++++++++++++-
>  3 files changed, 103 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
> index e31604f..49b6c21 100644
> --- a/drivers/pci/host-bridge.c
> +++ b/drivers/pci/host-bridge.c
> @@ -8,9 +8,6 @@
>  
>  #include "pci.h"
>  
> -LIST_HEAD(pci_host_bridge_list);
> -DECLARE_RWSEM(pci_host_bridge_sem);
> -
>  static struct resource busn_resource = {
>  	.name	= "PCI busn",
>  	.start	= 0,
> @@ -18,6 +15,9 @@ static struct resource busn_resource = {
>  	.flags	= IORESOURCE_BUS,
>  };
>  
> +LIST_HEAD(pci_host_bridge_list);
> +DECLARE_RWSEM(pci_host_bridge_sem);
> +
>  static void pci_release_host_bridge_dev(struct device *dev)
>  {
>  	struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
> @@ -29,14 +29,12 @@ static void pci_release_host_bridge_dev(struct device *dev)
>  }
>  
>  struct pci_host_bridge *pci_create_host_bridge(
> -		struct device *parent, u32 db, 
> -		struct pci_ops *ops, void *sysdata, 
> -		struct list_head *resources)
> +		struct device *parent, u32 db, struct pci_ops *ops, 
> +		struct pci_host_info *info)
>  {
>  	int error;
>  	struct pci_bus *b;
>  	struct pci_host_bridge *host, *h;
> -	struct pci_host_bridge_window *window, *n;
>  
>  	down_read(&pci_host_bridge_sem);
>  	list_for_each_entry(h, &pci_host_bridge_list, list) {
> @@ -53,7 +51,7 @@ struct pci_host_bridge *pci_create_host_bridge(
>  	if (!host)
>  		return NULL;
>  
> -	host->sysdata = sysdata;
> +	host->sysdata = info->arg;
>  	host->busnum = PCI_BUSNUM(db);
>  	host->domain = PCI_DOMAIN(db);
>  	host->ops = ops;
> @@ -63,18 +61,23 @@ struct pci_host_bridge *pci_create_host_bridge(
>  
>  	/* this is hack, just for build, will be removed later*/

Why do you need this hack? Just for calling pci_domain_nr() ?

>  	b = kzalloc(sizeof(*b), GFP_KERNEL);
> -	b->sysdata = sysdata;
> +	b->sysdata = host->sysdata;
>  	pci_bus_assign_domain_nr(b, parent);
>  	host->domain = pci_domain_nr(b);
> +	kfree(b);
>  
> -	if (!resources) {
> +	if (info->res_type == PCI_HOST_RES_DEFAULT) {
>  		/* Use default IO/MEM/BUS resources*/
>  		pci_add_resource(&host->windows, &ioport_resource);
>  		pci_add_resource(&host->windows, &iomem_resource);
>  		pci_add_resource(&host->windows, &busn_resource);
>  	} else {
> -		list_for_each_entry_safe(window, n, resources, list)
> -			list_move_tail(&window->list, &host->windows);
> +		if (!info->init_res || info->init_res(host, info)) {
> +			pr_err("pci host %04x:%02x init resources fail\n",
> +					host->domain, host->busnum);
> +			kfree(host);
> +			return NULL;
> +		}
>  	}
>  
>  	dev_set_name(&host->dev, "pci%04x:%02x", host->domain, 
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index d472da4..42158fd 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1863,6 +1863,21 @@ void __weak pcibios_remove_bus(struct pci_bus *bus)
>  {
>  }
>  
> +static int pci_default_init_res(struct pci_host_bridge *host,
> +		struct pci_host_info *info)
> +{
> +	struct pci_host_bridge_window *window, *n;
> +
> +	if (info->res_type != PCI_HOST_RES_DEFAULT) 
> +		list_for_each_entry_safe(window, n, info->resources,
> +				list)
> +			list_move_tail(&window->list, &host->windows);
> +	else
> +		info->res_type = PCI_HOST_RES_DEFAULT;

I'm confused about this assignment. Isn't this a nop as the else part
means info->res_type *is* PCI_HOST_RES_DEFAULT?

> +
> +	return 0;
> +}
> +
>  struct pci_bus *__pci_create_root_bus(struct pci_host_bridge *bridge)
>  {
>  	int error;
> @@ -1949,13 +1964,17 @@ err_out:
>  	return NULL;
>  }
>  
> -struct pci_bus *pci_create_root_bus(struct device *parent, u32 bus,
> +struct pci_bus *pci_create_root_bus(struct device *parent, u32 db,
>  		struct pci_ops *ops, void *sysdata, struct list_head *resources)
>  {
>  	struct pci_host_bridge *host;
> +	struct pci_host_info info;
> +	
> +	info.arg= sysdata;
> +	info.resources = resources;
> +	info.init_res = pci_default_init_res;
>  
> -	host = pci_create_host_bridge(parent, bus, ops, 
> -			sysdata ,resources);
> +	host = pci_create_host_bridge(parent, db, ops, &info);
>  	if (!host)
>  		return NULL;
>  
> @@ -2038,8 +2057,13 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
>  	bool found = false;
>  	struct pci_host_bridge *host;
>  	int max;
> +	struct pci_host_info info;
> +	
> +	info.arg = sysdata;
> +	info.resources = resources;
> +	info.init_res = pci_default_init_res;

I have mixed feelings about this patch. While it is heading in the right direction
of moving pci_host_bridge relevant information towards the right user, I don't think
you picked up the right set to move. The resource list is going to be copied into
internal pci_host_bridge list anyway, keeping another copy is not helpful *and*
you have increased the code size.

I think for now we should aim to get the *missing* data into pci_host_bridge: MSI
controllers and PCI domain/segment. Then we can do more cleanup.

>  
> -	host = pci_create_host_bridge(parent, db, ops, sysdata, resources);
> +	host = pci_create_host_bridge(parent, db, ops, &info);
>  	if (!host)
>  		return NULL;
>  
> @@ -2070,6 +2094,47 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
>  }
>  EXPORT_SYMBOL(pci_scan_root_bus);
>  
> +struct pci_host_bridge *pci_scan_host_bridge(
> +		struct device *parent, u32 db, struct pci_ops *ops,
> +		struct pci_host_info *info)
> +{
> +	struct pci_host_bridge_window *window;
> +	bool found = false;
> +	struct pci_host_bridge *host;
> +	int max;
> +
> +	host = pci_create_host_bridge(parent, db, ops, info);
> +	if (!host)
> +		return NULL;
> +
> +	list_for_each_entry(window, &host->windows, list)
> +		if (window->res->flags & IORESOURCE_BUS) {
> +			found = true;
> +			break;
> +		}
> +
> +	host->bus = __pci_create_root_bus(host);
> +	if (!host->bus) {
> +		pci_free_host_bridge(host);
> +		return NULL;
> +	}
> +
> +	if (!found) {
> +		dev_info(&host->bus->dev,
> +		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
> +			host->busnum);
> +		pci_bus_insert_busn_res(host->bus, host->busnum, 255);
> +	}
> +
> +	max = pci_scan_child_bus(host->bus);
> +	if (!found)
> +		pci_bus_update_busn_res_end(host->bus, max);
> +
> +	return host;
> +
> +}
> +EXPORT_SYMBOL(pci_scan_host_bridge);
> +
>  /**
>   * pci_rescan_bus_bridge_resize - scan a PCI bus for devices.
>   * @bridge: PCI bridge for the bus to scan
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index daa7f40..a51f5f5 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -412,6 +412,21 @@ struct pci_host_bridge {
>  	void *release_data;
>  };
>  
> +struct pci_host_info {
> +	u8 res_type;
> +	void *arg;
> +	struct list_head *resources; /*just for build, will clean up later */
> +	int (*init_res)(struct pci_host_bridge *host, 
> +			struct pci_host_info *info);
> +};
> +
> +static inline void init_pci_host_info(struct pci_host_info *info)
> +{
> +	memset(info, 0 , sizeof(*info));
> +}

Where is this used?

> +
> +#define PCI_HOST_RES_DEFAULT	0x2
> +

Magic number?

Best regards,
Liviu

>  #define	to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev)
>  void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
>  		     void (*release_fn)(struct pci_host_bridge *),
> @@ -420,7 +435,7 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
>  int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge);
>  struct pci_host_bridge *pci_create_host_bridge(
>  		struct device *parent, u32 db, struct pci_ops *ops, 
> -		void *sys, struct list_head *resources);
> +		struct pci_host_info *info);
>  /*
>   * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond
>   * to P2P or CardBus bridge windows) go in a table.  Additional ones (for
> @@ -785,6 +800,9 @@ void pci_bus_release_busn_res(struct pci_bus *b);
>  struct pci_bus *pci_scan_root_bus(struct device *parent, u32 bus,
>  					     struct pci_ops *ops, void *sysdata,
>  					     struct list_head *resources);
> +struct pci_host_bridge *pci_scan_host_bridge(struct device *parent,
> +		u32 db, struct pci_ops *ops,
> +		struct pci_host_info *info);
>  struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
>  				int busnr);
>  void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
> -- 
> 1.7.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
Yijing Wang Nov. 19, 2014, 2:09 a.m. UTC | #2
>>  struct pci_host_bridge *pci_create_host_bridge(
>> -		struct device *parent, u32 db, 
>> -		struct pci_ops *ops, void *sysdata, 
>> -		struct list_head *resources)
>> +		struct device *parent, u32 db, struct pci_ops *ops, 
>> +		struct pci_host_info *info)
>>  {
>>  	int error;
>>  	struct pci_bus *b;
>>  	struct pci_host_bridge *host, *h;
>> -	struct pci_host_bridge_window *window, *n;
>>  
>>  	down_read(&pci_host_bridge_sem);
>>  	list_for_each_entry(h, &pci_host_bridge_list, list) {
>> @@ -53,7 +51,7 @@ struct pci_host_bridge *pci_create_host_bridge(
>>  	if (!host)
>>  		return NULL;
>>  
>> -	host->sysdata = sysdata;
>> +	host->sysdata = info->arg;
>>  	host->busnum = PCI_BUSNUM(db);
>>  	host->domain = PCI_DOMAIN(db);
>>  	host->ops = ops;
>> @@ -63,18 +61,23 @@ struct pci_host_bridge *pci_create_host_bridge(
>>  
>>  	/* this is hack, just for build, will be removed later*/
> 
> Why do you need this hack? Just for calling pci_domain_nr() ?

Yes, it's temporary code, we need domain number here for pci host bridge register.

> 
>>  	b = kzalloc(sizeof(*b), GFP_KERNEL);
>> -	b->sysdata = sysdata;
>> +	b->sysdata = host->sysdata;
>>  	pci_bus_assign_domain_nr(b, parent);
>>  	host->domain = pci_domain_nr(b);
>> +	kfree(b);
>>  
...
>> +static int pci_default_init_res(struct pci_host_bridge *host,
>> +		struct pci_host_info *info)
>> +{
>> +	struct pci_host_bridge_window *window, *n;
>> +
>> +	if (info->res_type != PCI_HOST_RES_DEFAULT) 
>> +		list_for_each_entry_safe(window, n, info->resources,
>> +				list)
>> +			list_move_tail(&window->list, &host->windows);
>> +	else
>> +		info->res_type = PCI_HOST_RES_DEFAULT;
> 
> I'm confused about this assignment. Isn't this a nop as the else part
> means info->res_type *is* PCI_HOST_RES_DEFAULT?

No, in this patch, host drivers pass a pci host bridge resources init hook
in pci_host_info *info, and we call this info->init_res() in pci_create_host_bridge().

+struct pci_host_info {
+	u8 res_type;
+	void *arg;
+	struct list_head *resources; /*just for build, will clean up later */
+	int (*init_res)(struct pci_host_bridge *host,
+			struct pci_host_info *info);
+};
+

> 
>> +
>> +	return 0;
>> +}
...
>> @@ -2038,8 +2057,13 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
>>  	bool found = false;
>>  	struct pci_host_bridge *host;
>>  	int max;
>> +	struct pci_host_info info;
>> +	
>> +	info.arg = sysdata;
>> +	info.resources = resources;
>> +	info.init_res = pci_default_init_res;
> 
> I have mixed feelings about this patch. While it is heading in the right direction
> of moving pci_host_bridge relevant information towards the right user, I don't think
> you picked up the right set to move. The resource list is going to be copied into
> internal pci_host_bridge list anyway, keeping another copy is not helpful *and*
> you have increased the code size.
> 
> I think for now we should aim to get the *missing* data into pci_host_bridge: MSI
> controllers and PCI domain/segment. Then we can do more cleanup.

Hi Liviu, I agree with you here, the changes to resources stuff seems not a perfect
solution. In my patch 6, we could pass pci domain nr by u32 PCI_DOMBUS(domain, bus) argument,
and store it in pci_host_bridge. For msi controller, we couldn't save the msi_controller
in pci_host_bridge. Before we assume one pci host bridge only had one msi_controller,
but now something changes, Jiang introduce hierarchy irq domain in x86, and now
one pci host bridge may has more than one msi_controller. So I prefer to add a
function to pci_host_bridge something like

struct msi_controller *pci_get_msi_controller(struct pci_dev *dev)

> 
>>  
>> -	host = pci_create_host_bridge(parent, db, ops, sysdata, resources);
>> +	host = pci_create_host_bridge(parent, db, ops, &info);
>>  	if (!host)
>>  		return NULL;
>>  
>> @@ -2070,6 +2094,47 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
>>  }
>>  EXPORT_SYMBOL(pci_scan_root_bus);
>>  
>> +struct pci_host_bridge *pci_scan_host_bridge(
>> +		struct device *parent, u32 db, struct pci_ops *ops,
>> +		struct pci_host_info *info)
>> +{
>> +	struct pci_host_bridge_window *window;
>> +	bool found = false;
>> +	struct pci_host_bridge *host;
>> +	int max;
>> +
>> +	host = pci_create_host_bridge(parent, db, ops, info);
>> +	if (!host)
>> +		return NULL;
>> +
>> +	list_for_each_entry(window, &host->windows, list)
>> +		if (window->res->flags & IORESOURCE_BUS) {
>> +			found = true;
>> +			break;
>> +		}
>> +
>> +	host->bus = __pci_create_root_bus(host);
>> +	if (!host->bus) {
>> +		pci_free_host_bridge(host);
>> +		return NULL;
>> +	}
>> +
>> +	if (!found) {
>> +		dev_info(&host->bus->dev,
>> +		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
>> +			host->busnum);
>> +		pci_bus_insert_busn_res(host->bus, host->busnum, 255);
>> +	}
>> +
>> +	max = pci_scan_child_bus(host->bus);
>> +	if (!found)
>> +		pci_bus_update_busn_res_end(host->bus, max);
>> +
>> +	return host;
>> +
>> +}
>> +EXPORT_SYMBOL(pci_scan_host_bridge);
>> +
>>  /**
>>   * pci_rescan_bus_bridge_resize - scan a PCI bus for devices.
>>   * @bridge: PCI bridge for the bus to scan
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index daa7f40..a51f5f5 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -412,6 +412,21 @@ struct pci_host_bridge {
>>  	void *release_data;
>>  };
>>  
>> +struct pci_host_info {
>> +	u8 res_type;
>> +	void *arg;
>> +	struct list_head *resources; /*just for build, will clean up later */
>> +	int (*init_res)(struct pci_host_bridge *host, 
>> +			struct pci_host_info *info);
>> +};
>> +
>> +static inline void init_pci_host_info(struct pci_host_info *info)
>> +{
>> +	memset(info, 0 , sizeof(*info));
>> +}
> 
> Where is this used?

Host driver uses it to init pci_host_info.

> 
>> +
>> +#define PCI_HOST_RES_DEFAULT	0x2
>> +
> 
> Magic number?

Hmmm, I will rework pci host bridge resources stuff.

> 
> Best regards,
> Liviu
> 
>>  #define	to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev)
>>  void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
>>  		     void (*release_fn)(struct pci_host_bridge *),
>> @@ -420,7 +435,7 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
>>  int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge);
>>  struct pci_host_bridge *pci_create_host_bridge(
>>  		struct device *parent, u32 db, struct pci_ops *ops, 
>> -		void *sys, struct list_head *resources);
>> +		struct pci_host_info *info);
>>  /*
>>   * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond
>>   * to P2P or CardBus bridge windows) go in a table.  Additional ones (for
>> @@ -785,6 +800,9 @@ void pci_bus_release_busn_res(struct pci_bus *b);
>>  struct pci_bus *pci_scan_root_bus(struct device *parent, u32 bus,
>>  					     struct pci_ops *ops, void *sysdata,
>>  					     struct list_head *resources);
>> +struct pci_host_bridge *pci_scan_host_bridge(struct device *parent,
>> +		u32 db, struct pci_ops *ops,
>> +		struct pci_host_info *info);
>>  struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
>>  				int busnr);
>>  void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
>> -- 
>> 1.7.1
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>
Liviu Dudau Nov. 19, 2014, 4:41 p.m. UTC | #3
On Wed, Nov 19, 2014 at 02:09:12AM +0000, Yijing Wang wrote:
> >>  struct pci_host_bridge *pci_create_host_bridge(
> >> -		struct device *parent, u32 db, 
> >> -		struct pci_ops *ops, void *sysdata, 
> >> -		struct list_head *resources)
> >> +		struct device *parent, u32 db, struct pci_ops *ops, 
> >> +		struct pci_host_info *info)
> >>  {
> >>  	int error;
> >>  	struct pci_bus *b;
> >>  	struct pci_host_bridge *host, *h;
> >> -	struct pci_host_bridge_window *window, *n;
> >>  
> >>  	down_read(&pci_host_bridge_sem);
> >>  	list_for_each_entry(h, &pci_host_bridge_list, list) {
> >> @@ -53,7 +51,7 @@ struct pci_host_bridge *pci_create_host_bridge(
> >>  	if (!host)
> >>  		return NULL;
> >>  
> >> -	host->sysdata = sysdata;
> >> +	host->sysdata = info->arg;
> >>  	host->busnum = PCI_BUSNUM(db);
> >>  	host->domain = PCI_DOMAIN(db);
> >>  	host->ops = ops;
> >> @@ -63,18 +61,23 @@ struct pci_host_bridge *pci_create_host_bridge(
> >>  
> >>  	/* this is hack, just for build, will be removed later*/
> > 
> > Why do you need this hack? Just for calling pci_domain_nr() ?
> 
> Yes, it's temporary code, we need domain number here for pci host bridge register.
> 
> > 
> >>  	b = kzalloc(sizeof(*b), GFP_KERNEL);
> >> -	b->sysdata = sysdata;
> >> +	b->sysdata = host->sysdata;
> >>  	pci_bus_assign_domain_nr(b, parent);
> >>  	host->domain = pci_domain_nr(b);
> >> +	kfree(b);
> >>  
> ...
> >> +static int pci_default_init_res(struct pci_host_bridge *host,
> >> +		struct pci_host_info *info)
> >> +{
> >> +	struct pci_host_bridge_window *window, *n;
> >> +
> >> +	if (info->res_type != PCI_HOST_RES_DEFAULT) 
> >> +		list_for_each_entry_safe(window, n, info->resources,
> >> +				list)
> >> +			list_move_tail(&window->list, &host->windows);
> >> +	else
> >> +		info->res_type = PCI_HOST_RES_DEFAULT;
> > 
> > I'm confused about this assignment. Isn't this a nop as the else part
> > means info->res_type *is* PCI_HOST_RES_DEFAULT?
> 
> No, in this patch, host drivers pass a pci host bridge resources init hook
> in pci_host_info *info, and we call this info->init_res() in pci_create_host_bridge().
> 
> +struct pci_host_info {
> +	u8 res_type;
> +	void *arg;
> +	struct list_head *resources; /*just for build, will clean up later */
> +	int (*init_res)(struct pci_host_bridge *host,
> +			struct pci_host_info *info);
> +};
> +

That's not what I've asked! Your code does:

	if (info->res_type != PCI_HOST_RES_DEFAULT)
		....
	else /* info->res_type == PCI_HOST_RES_DEFAULT)
		info->res_type = PCI_HOST_RES_DEFAULT;

info->res_type is already == PCI_HOST_RES_DEFAULT in the else side, assignment is a NOP?


> 
> > 
> >> +
> >> +	return 0;
> >> +}
> ...
> >> @@ -2038,8 +2057,13 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
> >>  	bool found = false;
> >>  	struct pci_host_bridge *host;
> >>  	int max;
> >> +	struct pci_host_info info;
> >> +	
> >> +	info.arg = sysdata;
> >> +	info.resources = resources;
> >> +	info.init_res = pci_default_init_res;
> > 
> > I have mixed feelings about this patch. While it is heading in the right direction
> > of moving pci_host_bridge relevant information towards the right user, I don't think
> > you picked up the right set to move. The resource list is going to be copied into
> > internal pci_host_bridge list anyway, keeping another copy is not helpful *and*
> > you have increased the code size.
> > 
> > I think for now we should aim to get the *missing* data into pci_host_bridge: MSI
> > controllers and PCI domain/segment. Then we can do more cleanup.
> 
> Hi Liviu, I agree with you here, the changes to resources stuff seems not a perfect
> solution. In my patch 6, we could pass pci domain nr by u32 PCI_DOMBUS(domain, bus) argument,
> and store it in pci_host_bridge. For msi controller, we couldn't save the msi_controller
> in pci_host_bridge. Before we assume one pci host bridge only had one msi_controller,
> but now something changes, Jiang introduce hierarchy irq domain in x86, and now
> one pci host bridge may has more than one msi_controller. So I prefer to add a
> function to pci_host_bridge something like
> 
> struct msi_controller *pci_get_msi_controller(struct pci_dev *dev)

Yes, good idea.

> 
> > 
> >>  
> >> -	host = pci_create_host_bridge(parent, db, ops, sysdata, resources);
> >> +	host = pci_create_host_bridge(parent, db, ops, &info);
> >>  	if (!host)
> >>  		return NULL;
> >>  
> >> @@ -2070,6 +2094,47 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
> >>  }
> >>  EXPORT_SYMBOL(pci_scan_root_bus);
> >>  
> >> +struct pci_host_bridge *pci_scan_host_bridge(
> >> +		struct device *parent, u32 db, struct pci_ops *ops,
> >> +		struct pci_host_info *info)
> >> +{
> >> +	struct pci_host_bridge_window *window;
> >> +	bool found = false;
> >> +	struct pci_host_bridge *host;
> >> +	int max;
> >> +
> >> +	host = pci_create_host_bridge(parent, db, ops, info);
> >> +	if (!host)
> >> +		return NULL;
> >> +
> >> +	list_for_each_entry(window, &host->windows, list)
> >> +		if (window->res->flags & IORESOURCE_BUS) {
> >> +			found = true;
> >> +			break;
> >> +		}
> >> +
> >> +	host->bus = __pci_create_root_bus(host);
> >> +	if (!host->bus) {
> >> +		pci_free_host_bridge(host);
> >> +		return NULL;
> >> +	}
> >> +
> >> +	if (!found) {
> >> +		dev_info(&host->bus->dev,
> >> +		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
> >> +			host->busnum);
> >> +		pci_bus_insert_busn_res(host->bus, host->busnum, 255);
> >> +	}
> >> +
> >> +	max = pci_scan_child_bus(host->bus);
> >> +	if (!found)
> >> +		pci_bus_update_busn_res_end(host->bus, max);
> >> +
> >> +	return host;
> >> +
> >> +}
> >> +EXPORT_SYMBOL(pci_scan_host_bridge);
> >> +
> >>  /**
> >>   * pci_rescan_bus_bridge_resize - scan a PCI bus for devices.
> >>   * @bridge: PCI bridge for the bus to scan
> >> diff --git a/include/linux/pci.h b/include/linux/pci.h
> >> index daa7f40..a51f5f5 100644
> >> --- a/include/linux/pci.h
> >> +++ b/include/linux/pci.h
> >> @@ -412,6 +412,21 @@ struct pci_host_bridge {
> >>  	void *release_data;
> >>  };
> >>  
> >> +struct pci_host_info {
> >> +	u8 res_type;
> >> +	void *arg;
> >> +	struct list_head *resources; /*just for build, will clean up later */
> >> +	int (*init_res)(struct pci_host_bridge *host, 
> >> +			struct pci_host_info *info);
> >> +};
> >> +
> >> +static inline void init_pci_host_info(struct pci_host_info *info)
> >> +{
> >> +	memset(info, 0 , sizeof(*info));
> >> +}
> > 
> > Where is this used?
> 
> Host driver uses it to init pci_host_info.

Might be worth adding it that patch rather than here.

Best regards,
Liviu

> 
> > 
> >> +
> >> +#define PCI_HOST_RES_DEFAULT	0x2
> >> +
> > 
> > Magic number?
> 
> Hmmm, I will rework pci host bridge resources stuff.
> 
> > 
> > Best regards,
> > Liviu
> > 
> >>  #define	to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev)
> >>  void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
> >>  		     void (*release_fn)(struct pci_host_bridge *),
> >> @@ -420,7 +435,7 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
> >>  int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge);
> >>  struct pci_host_bridge *pci_create_host_bridge(
> >>  		struct device *parent, u32 db, struct pci_ops *ops, 
> >> -		void *sys, struct list_head *resources);
> >> +		struct pci_host_info *info);
> >>  /*
> >>   * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond
> >>   * to P2P or CardBus bridge windows) go in a table.  Additional ones (for
> >> @@ -785,6 +800,9 @@ void pci_bus_release_busn_res(struct pci_bus *b);
> >>  struct pci_bus *pci_scan_root_bus(struct device *parent, u32 bus,
> >>  					     struct pci_ops *ops, void *sysdata,
> >>  					     struct list_head *resources);
> >> +struct pci_host_bridge *pci_scan_host_bridge(struct device *parent,
> >> +		u32 db, struct pci_ops *ops,
> >> +		struct pci_host_info *info);
> >>  struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
> >>  				int busnr);
> >>  void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
> >> -- 
> >> 1.7.1
> >>
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> >> the body of a message to majordomo@vger.kernel.org
> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>
> > 
> 
> 
> -- 
> Thanks!
> Yijing
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
Yijing Wang Nov. 20, 2014, 2:54 a.m. UTC | #4
>> No, in this patch, host drivers pass a pci host bridge resources init hook
>> in pci_host_info *info, and we call this info->init_res() in pci_create_host_bridge().
>>
>> +struct pci_host_info {
>> +	u8 res_type;
>> +	void *arg;
>> +	struct list_head *resources; /*just for build, will clean up later */
>> +	int (*init_res)(struct pci_host_bridge *host,
>> +			struct pci_host_info *info);
>> +};
>> +
> 
> That's not what I've asked! Your code does:
> 
> 	if (info->res_type != PCI_HOST_RES_DEFAULT)
> 		....
> 	else /* info->res_type == PCI_HOST_RES_DEFAULT)
> 		info->res_type = PCI_HOST_RES_DEFAULT;
> 
> info->res_type is already == PCI_HOST_RES_DEFAULT in the else side, assignment is a NOP?

Hmmm, I wanted pci_create_host_bridge() to process the default res later(add default res),
It's ugly code, I will rework it.

> 
> 
>>
>>>
>>>> +
>>>> +	return 0;
>>>> +}
>> ...
>>>> @@ -2038,8 +2057,13 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
>>>>  	bool found = false;
>>>>  	struct pci_host_bridge *host;
>>>>  	int max;
>>>> +	struct pci_host_info info;
>>>> +	
>>>> +	info.arg = sysdata;
>>>> +	info.resources = resources;
>>>> +	info.init_res = pci_default_init_res;
>>>
>>> I have mixed feelings about this patch. While it is heading in the right direction
>>> of moving pci_host_bridge relevant information towards the right user, I don't think
>>> you picked up the right set to move. The resource list is going to be copied into
>>> internal pci_host_bridge list anyway, keeping another copy is not helpful *and*
>>> you have increased the code size.
>>>
>>> I think for now we should aim to get the *missing* data into pci_host_bridge: MSI
>>> controllers and PCI domain/segment. Then we can do more cleanup.
>>
>> Hi Liviu, I agree with you here, the changes to resources stuff seems not a perfect
>> solution. In my patch 6, we could pass pci domain nr by u32 PCI_DOMBUS(domain, bus) argument,
>> and store it in pci_host_bridge. For msi controller, we couldn't save the msi_controller
>> in pci_host_bridge. Before we assume one pci host bridge only had one msi_controller,
>> but now something changes, Jiang introduce hierarchy irq domain in x86, and now
>> one pci host bridge may has more than one msi_controller. So I prefer to add a
>> function to pci_host_bridge something like
>>
>> struct msi_controller *pci_get_msi_controller(struct pci_dev *dev)
> 
> Yes, good idea.
> 
>>
>>>
>>>>  
>>>> -	host = pci_create_host_bridge(parent, db, ops, sysdata, resources);
>>>> +	host = pci_create_host_bridge(parent, db, ops, &info);
>>>>  	if (!host)
>>>>  		return NULL;
>>>>  
>>>> @@ -2070,6 +2094,47 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
>>>>  }
>>>>  EXPORT_SYMBOL(pci_scan_root_bus);
>>>>  
>>>> +struct pci_host_bridge *pci_scan_host_bridge(
>>>> +		struct device *parent, u32 db, struct pci_ops *ops,
>>>> +		struct pci_host_info *info)
>>>> +{
>>>> +	struct pci_host_bridge_window *window;
>>>> +	bool found = false;
>>>> +	struct pci_host_bridge *host;
>>>> +	int max;
>>>> +
>>>> +	host = pci_create_host_bridge(parent, db, ops, info);
>>>> +	if (!host)
>>>> +		return NULL;
>>>> +
>>>> +	list_for_each_entry(window, &host->windows, list)
>>>> +		if (window->res->flags & IORESOURCE_BUS) {
>>>> +			found = true;
>>>> +			break;
>>>> +		}
>>>> +
>>>> +	host->bus = __pci_create_root_bus(host);
>>>> +	if (!host->bus) {
>>>> +		pci_free_host_bridge(host);
>>>> +		return NULL;
>>>> +	}
>>>> +
>>>> +	if (!found) {
>>>> +		dev_info(&host->bus->dev,
>>>> +		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
>>>> +			host->busnum);
>>>> +		pci_bus_insert_busn_res(host->bus, host->busnum, 255);
>>>> +	}
>>>> +
>>>> +	max = pci_scan_child_bus(host->bus);
>>>> +	if (!found)
>>>> +		pci_bus_update_busn_res_end(host->bus, max);
>>>> +
>>>> +	return host;
>>>> +
>>>> +}
>>>> +EXPORT_SYMBOL(pci_scan_host_bridge);
>>>> +
>>>>  /**
>>>>   * pci_rescan_bus_bridge_resize - scan a PCI bus for devices.
>>>>   * @bridge: PCI bridge for the bus to scan
>>>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>>>> index daa7f40..a51f5f5 100644
>>>> --- a/include/linux/pci.h
>>>> +++ b/include/linux/pci.h
>>>> @@ -412,6 +412,21 @@ struct pci_host_bridge {
>>>>  	void *release_data;
>>>>  };
>>>>  
>>>> +struct pci_host_info {
>>>> +	u8 res_type;
>>>> +	void *arg;
>>>> +	struct list_head *resources; /*just for build, will clean up later */
>>>> +	int (*init_res)(struct pci_host_bridge *host, 
>>>> +			struct pci_host_info *info);
>>>> +};
>>>> +
>>>> +static inline void init_pci_host_info(struct pci_host_info *info)
>>>> +{
>>>> +	memset(info, 0 , sizeof(*info));
>>>> +}
>>>
>>> Where is this used?
>>
>> Host driver uses it to init pci_host_info.
> 
> Might be worth adding it that patch rather than here.

OK

> 
> Best regards,
> Liviu
> 
>>
>>>
>>>> +
>>>> +#define PCI_HOST_RES_DEFAULT	0x2
>>>> +
>>>
>>> Magic number?
>>
>> Hmmm, I will rework pci host bridge resources stuff.
>>
>>>
>>> Best regards,
>>> Liviu
>>>
>>>>  #define	to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev)
>>>>  void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
>>>>  		     void (*release_fn)(struct pci_host_bridge *),
>>>> @@ -420,7 +435,7 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
>>>>  int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge);
>>>>  struct pci_host_bridge *pci_create_host_bridge(
>>>>  		struct device *parent, u32 db, struct pci_ops *ops, 
>>>> -		void *sys, struct list_head *resources);
>>>> +		struct pci_host_info *info);
>>>>  /*
>>>>   * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond
>>>>   * to P2P or CardBus bridge windows) go in a table.  Additional ones (for
>>>> @@ -785,6 +800,9 @@ void pci_bus_release_busn_res(struct pci_bus *b);
>>>>  struct pci_bus *pci_scan_root_bus(struct device *parent, u32 bus,
>>>>  					     struct pci_ops *ops, void *sysdata,
>>>>  					     struct list_head *resources);
>>>> +struct pci_host_bridge *pci_scan_host_bridge(struct device *parent,
>>>> +		u32 db, struct pci_ops *ops,
>>>> +		struct pci_host_info *info);
>>>>  struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
>>>>  				int busnr);
>>>>  void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
>>>> -- 
>>>> 1.7.1
>>>>
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>>
>>>
>>
>>
>> -- 
>> Thanks!
>> Yijing
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>
diff mbox

Patch

diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index e31604f..49b6c21 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -8,9 +8,6 @@ 
 
 #include "pci.h"
 
-LIST_HEAD(pci_host_bridge_list);
-DECLARE_RWSEM(pci_host_bridge_sem);
-
 static struct resource busn_resource = {
 	.name	= "PCI busn",
 	.start	= 0,
@@ -18,6 +15,9 @@  static struct resource busn_resource = {
 	.flags	= IORESOURCE_BUS,
 };
 
+LIST_HEAD(pci_host_bridge_list);
+DECLARE_RWSEM(pci_host_bridge_sem);
+
 static void pci_release_host_bridge_dev(struct device *dev)
 {
 	struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
@@ -29,14 +29,12 @@  static void pci_release_host_bridge_dev(struct device *dev)
 }
 
 struct pci_host_bridge *pci_create_host_bridge(
-		struct device *parent, u32 db, 
-		struct pci_ops *ops, void *sysdata, 
-		struct list_head *resources)
+		struct device *parent, u32 db, struct pci_ops *ops, 
+		struct pci_host_info *info)
 {
 	int error;
 	struct pci_bus *b;
 	struct pci_host_bridge *host, *h;
-	struct pci_host_bridge_window *window, *n;
 
 	down_read(&pci_host_bridge_sem);
 	list_for_each_entry(h, &pci_host_bridge_list, list) {
@@ -53,7 +51,7 @@  struct pci_host_bridge *pci_create_host_bridge(
 	if (!host)
 		return NULL;
 
-	host->sysdata = sysdata;
+	host->sysdata = info->arg;
 	host->busnum = PCI_BUSNUM(db);
 	host->domain = PCI_DOMAIN(db);
 	host->ops = ops;
@@ -63,18 +61,23 @@  struct pci_host_bridge *pci_create_host_bridge(
 
 	/* this is hack, just for build, will be removed later*/
 	b = kzalloc(sizeof(*b), GFP_KERNEL);
-	b->sysdata = sysdata;
+	b->sysdata = host->sysdata;
 	pci_bus_assign_domain_nr(b, parent);
 	host->domain = pci_domain_nr(b);
+	kfree(b);
 
-	if (!resources) {
+	if (info->res_type == PCI_HOST_RES_DEFAULT) {
 		/* Use default IO/MEM/BUS resources*/
 		pci_add_resource(&host->windows, &ioport_resource);
 		pci_add_resource(&host->windows, &iomem_resource);
 		pci_add_resource(&host->windows, &busn_resource);
 	} else {
-		list_for_each_entry_safe(window, n, resources, list)
-			list_move_tail(&window->list, &host->windows);
+		if (!info->init_res || info->init_res(host, info)) {
+			pr_err("pci host %04x:%02x init resources fail\n",
+					host->domain, host->busnum);
+			kfree(host);
+			return NULL;
+		}
 	}
 
 	dev_set_name(&host->dev, "pci%04x:%02x", host->domain, 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index d472da4..42158fd 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1863,6 +1863,21 @@  void __weak pcibios_remove_bus(struct pci_bus *bus)
 {
 }
 
+static int pci_default_init_res(struct pci_host_bridge *host,
+		struct pci_host_info *info)
+{
+	struct pci_host_bridge_window *window, *n;
+
+	if (info->res_type != PCI_HOST_RES_DEFAULT) 
+		list_for_each_entry_safe(window, n, info->resources,
+				list)
+			list_move_tail(&window->list, &host->windows);
+	else
+		info->res_type = PCI_HOST_RES_DEFAULT;
+
+	return 0;
+}
+
 struct pci_bus *__pci_create_root_bus(struct pci_host_bridge *bridge)
 {
 	int error;
@@ -1949,13 +1964,17 @@  err_out:
 	return NULL;
 }
 
-struct pci_bus *pci_create_root_bus(struct device *parent, u32 bus,
+struct pci_bus *pci_create_root_bus(struct device *parent, u32 db,
 		struct pci_ops *ops, void *sysdata, struct list_head *resources)
 {
 	struct pci_host_bridge *host;
+	struct pci_host_info info;
+	
+	info.arg= sysdata;
+	info.resources = resources;
+	info.init_res = pci_default_init_res;
 
-	host = pci_create_host_bridge(parent, bus, ops, 
-			sysdata ,resources);
+	host = pci_create_host_bridge(parent, db, ops, &info);
 	if (!host)
 		return NULL;
 
@@ -2038,8 +2057,13 @@  struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
 	bool found = false;
 	struct pci_host_bridge *host;
 	int max;
+	struct pci_host_info info;
+	
+	info.arg = sysdata;
+	info.resources = resources;
+	info.init_res = pci_default_init_res;
 
-	host = pci_create_host_bridge(parent, db, ops, sysdata, resources);
+	host = pci_create_host_bridge(parent, db, ops, &info);
 	if (!host)
 		return NULL;
 
@@ -2070,6 +2094,47 @@  struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
 }
 EXPORT_SYMBOL(pci_scan_root_bus);
 
+struct pci_host_bridge *pci_scan_host_bridge(
+		struct device *parent, u32 db, struct pci_ops *ops,
+		struct pci_host_info *info)
+{
+	struct pci_host_bridge_window *window;
+	bool found = false;
+	struct pci_host_bridge *host;
+	int max;
+
+	host = pci_create_host_bridge(parent, db, ops, info);
+	if (!host)
+		return NULL;
+
+	list_for_each_entry(window, &host->windows, list)
+		if (window->res->flags & IORESOURCE_BUS) {
+			found = true;
+			break;
+		}
+
+	host->bus = __pci_create_root_bus(host);
+	if (!host->bus) {
+		pci_free_host_bridge(host);
+		return NULL;
+	}
+
+	if (!found) {
+		dev_info(&host->bus->dev,
+		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
+			host->busnum);
+		pci_bus_insert_busn_res(host->bus, host->busnum, 255);
+	}
+
+	max = pci_scan_child_bus(host->bus);
+	if (!found)
+		pci_bus_update_busn_res_end(host->bus, max);
+
+	return host;
+
+}
+EXPORT_SYMBOL(pci_scan_host_bridge);
+
 /**
  * pci_rescan_bus_bridge_resize - scan a PCI bus for devices.
  * @bridge: PCI bridge for the bus to scan
diff --git a/include/linux/pci.h b/include/linux/pci.h
index daa7f40..a51f5f5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -412,6 +412,21 @@  struct pci_host_bridge {
 	void *release_data;
 };
 
+struct pci_host_info {
+	u8 res_type;
+	void *arg;
+	struct list_head *resources; /*just for build, will clean up later */
+	int (*init_res)(struct pci_host_bridge *host, 
+			struct pci_host_info *info);
+};
+
+static inline void init_pci_host_info(struct pci_host_info *info)
+{
+	memset(info, 0 , sizeof(*info));
+}
+
+#define PCI_HOST_RES_DEFAULT	0x2
+
 #define	to_pci_host_bridge(n) container_of(n, struct pci_host_bridge, dev)
 void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
 		     void (*release_fn)(struct pci_host_bridge *),
@@ -420,7 +435,7 @@  void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge);
 struct pci_host_bridge *pci_create_host_bridge(
 		struct device *parent, u32 db, struct pci_ops *ops, 
-		void *sys, struct list_head *resources);
+		struct pci_host_info *info);
 /*
  * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond
  * to P2P or CardBus bridge windows) go in a table.  Additional ones (for
@@ -785,6 +800,9 @@  void pci_bus_release_busn_res(struct pci_bus *b);
 struct pci_bus *pci_scan_root_bus(struct device *parent, u32 bus,
 					     struct pci_ops *ops, void *sysdata,
 					     struct list_head *resources);
+struct pci_host_bridge *pci_scan_host_bridge(struct device *parent,
+		u32 db, struct pci_ops *ops,
+		struct pci_host_info *info);
 struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
 				int busnr);
 void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);