Patchwork [RFC,v2,part,2,16/18] PCI, iommu: use hotplug-safe iterators to walk PCI buses

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Submitter Jiang Liu
Date May 14, 2013, 4:52 p.m.
Message ID <1368550322-1045-16-git-send-email-jiang.liu@huawei.com>
Download mbox | patch
Permalink /patch/243778/
State Superseded
Headers show

Comments

Jiang Liu - May 14, 2013, 4:52 p.m.
Enhance iommu drviers to use hotplug-safe iterators to walk
PCI buses.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Donald Dutile <ddutile@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: "Li, Zhen-Hua" <zhen-hual@hp.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/iommu/amd_iommu.c | 4 +++-
 drivers/iommu/dmar.c      | 6 ++++--
 2 files changed, 7 insertions(+), 3 deletions(-)
Don Dutile - May 14, 2013, 10:13 p.m.
On 05/14/2013 12:52 PM, Jiang Liu wrote:
> Enhance iommu drviers to use hotplug-safe iterators to walk
> PCI buses.
>
> Signed-off-by: Jiang Liu<jiang.liu@huawei.com>
> Cc: Joerg Roedel<joro@8bytes.org>
> Cc: Ingo Molnar<mingo@kernel.org>
> Cc: Donald Dutile<ddutile@redhat.com>
> Cc: Hannes Reinecke<hare@suse.de>
> Cc: "Li, Zhen-Hua"<zhen-hual@hp.com>
> Cc: iommu@lists.linux-foundation.org
> Cc: linux-kernel@vger.kernel.org
> ---
>   drivers/iommu/amd_iommu.c | 4 +++-
>   drivers/iommu/dmar.c      | 6 ++++--
>   2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index e046d7a..d6fdf94 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -357,6 +357,7 @@ static int init_iommu_group(struct device *dev)
>   	struct iommu_dev_data *dev_data;
>   	struct iommu_group *group;
>   	struct pci_dev *dma_pdev;
> +	struct pci_bus *b = NULL;
>   	int ret;
>
>   	group = iommu_group_get(dev);
> @@ -393,7 +394,7 @@ static int init_iommu_group(struct device *dev)
>   		 * the alias.  Be careful to also test the parent device if
>   		 * we think the alias is the root of the group.
>   		 */
> -		bus = pci_find_bus(0, alias>>  8);
> +		b = bus = pci_find_bus(0, alias>>  8);
>   		if (!bus)
>   			goto use_group;
>
> @@ -413,6 +414,7 @@ static int init_iommu_group(struct device *dev)
>   	dma_pdev = get_isolation_root(pci_dev_get(to_pci_dev(dev)));
>   use_pdev:
>   	ret = use_pdev_iommu_group(dma_pdev, dev);
> +	pci_bus_put(b);
pci_find_bus() does a pci_bus_put() after the pci_get_bus();
is this needed, or did you mean to make the above patch pci_get_bus() ?

>   	pci_dev_put(dma_pdev);
>   	return ret;
>   use_group:
> diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
> index e5cdaf8..5bb3cdc 100644
> --- a/drivers/iommu/dmar.c
> +++ b/drivers/iommu/dmar.c
> @@ -67,12 +67,12 @@ static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
>   static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
>   					   struct pci_dev **dev, u16 segment)
>   {
> -	struct pci_bus *bus;
> +	struct pci_bus *b, *bus;
>   	struct pci_dev *pdev = NULL;
>   	struct acpi_dmar_pci_path *path;
>   	int count;
>
> -	bus = pci_find_bus(segment, scope->bus);
> +	b = bus = pci_find_bus(segment, scope->bus);
>   	path = (struct acpi_dmar_pci_path *)(scope + 1);
>   	count = (scope->length - sizeof(struct acpi_dmar_device_scope))
>   		/ sizeof(struct acpi_dmar_pci_path);
> @@ -97,6 +97,8 @@ static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
>   		count --;
>   		bus = pdev->subordinate;
>   	}
> +	pci_bus_put(b);
ditto.

> +
>   	if (!pdev) {
>   		pr_warn("Device scope device [%04x:%02x:%02x.%02x] not found\n",
>   			segment, scope->bus, path->dev, path->fn);

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Jiang Liu - May 15, 2013, 3:36 p.m.
On 05/15/2013 06:13 AM, Don Dutile wrote:
> On 05/14/2013 12:52 PM, Jiang Liu wrote:
>> Enhance iommu drviers to use hotplug-safe iterators to walk
>> PCI buses.
>>
>> Signed-off-by: Jiang Liu<jiang.liu@huawei.com>
>> Cc: Joerg Roedel<joro@8bytes.org>
>> Cc: Ingo Molnar<mingo@kernel.org>
>> Cc: Donald Dutile<ddutile@redhat.com>
>> Cc: Hannes Reinecke<hare@suse.de>
>> Cc: "Li, Zhen-Hua"<zhen-hual@hp.com>
>> Cc: iommu@lists.linux-foundation.org
>> Cc: linux-kernel@vger.kernel.org
>> ---
>>   drivers/iommu/amd_iommu.c | 4 +++-
>>   drivers/iommu/dmar.c      | 6 ++++--
>>   2 files changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
>> index e046d7a..d6fdf94 100644
>> --- a/drivers/iommu/amd_iommu.c
>> +++ b/drivers/iommu/amd_iommu.c
>> @@ -357,6 +357,7 @@ static int init_iommu_group(struct device *dev)
>>       struct iommu_dev_data *dev_data;
>>       struct iommu_group *group;
>>       struct pci_dev *dma_pdev;
>> +    struct pci_bus *b = NULL;
>>       int ret;
>>
>>       group = iommu_group_get(dev);
>> @@ -393,7 +394,7 @@ static int init_iommu_group(struct device *dev)
>>            * the alias.  Be careful to also test the parent device if
>>            * we think the alias is the root of the group.
>>            */
>> -        bus = pci_find_bus(0, alias>>  8);
>> +        b = bus = pci_find_bus(0, alias>>  8);
>>           if (!bus)
>>               goto use_group;
>>
>> @@ -413,6 +414,7 @@ static int init_iommu_group(struct device *dev)
>>       dma_pdev = get_isolation_root(pci_dev_get(to_pci_dev(dev)));
>>   use_pdev:
>>       ret = use_pdev_iommu_group(dma_pdev, dev);
>> +    pci_bus_put(b);
> pci_find_bus() does a pci_bus_put() after the pci_get_bus();
> is this needed, or did you mean to make the above patch pci_get_bus() ?
Hi Don,
     Thanks for review!
     My fault, I should use pci_get_bus() instead, will fix it in next 
version.
Regards!
Gerry


>
>>       pci_dev_put(dma_pdev);
>>       return ret;
>>   use_group:
>> diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
>> index e5cdaf8..5bb3cdc 100644
>> --- a/drivers/iommu/dmar.c
>> +++ b/drivers/iommu/dmar.c
>> @@ -67,12 +67,12 @@ static void __init dmar_register_drhd_unit(struct 
>> dmar_drhd_unit *drhd)
>>   static int __init dmar_parse_one_dev_scope(struct 
>> acpi_dmar_device_scope *scope,
>>                          struct pci_dev **dev, u16 segment)
>>   {
>> -    struct pci_bus *bus;
>> +    struct pci_bus *b, *bus;
>>       struct pci_dev *pdev = NULL;
>>       struct acpi_dmar_pci_path *path;
>>       int count;
>>
>> -    bus = pci_find_bus(segment, scope->bus);
>> +    b = bus = pci_find_bus(segment, scope->bus);
>>       path = (struct acpi_dmar_pci_path *)(scope + 1);
>>       count = (scope->length - sizeof(struct acpi_dmar_device_scope))
>>           / sizeof(struct acpi_dmar_pci_path);
>> @@ -97,6 +97,8 @@ static int __init dmar_parse_one_dev_scope(struct 
>> acpi_dmar_device_scope *scope,
>>           count --;
>>           bus = pdev->subordinate;
>>       }
>> +    pci_bus_put(b);
> ditto.
>
>> +
>>       if (!pdev) {
>>           pr_warn("Device scope device [%04x:%02x:%02x.%02x] not 
>> found\n",
>>               segment, scope->bus, path->dev, path->fn);
>

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Patch

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index e046d7a..d6fdf94 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -357,6 +357,7 @@  static int init_iommu_group(struct device *dev)
 	struct iommu_dev_data *dev_data;
 	struct iommu_group *group;
 	struct pci_dev *dma_pdev;
+	struct pci_bus *b = NULL;
 	int ret;
 
 	group = iommu_group_get(dev);
@@ -393,7 +394,7 @@  static int init_iommu_group(struct device *dev)
 		 * the alias.  Be careful to also test the parent device if
 		 * we think the alias is the root of the group.
 		 */
-		bus = pci_find_bus(0, alias >> 8);
+		b = bus = pci_find_bus(0, alias >> 8);
 		if (!bus)
 			goto use_group;
 
@@ -413,6 +414,7 @@  static int init_iommu_group(struct device *dev)
 	dma_pdev = get_isolation_root(pci_dev_get(to_pci_dev(dev)));
 use_pdev:
 	ret = use_pdev_iommu_group(dma_pdev, dev);
+	pci_bus_put(b);
 	pci_dev_put(dma_pdev);
 	return ret;
 use_group:
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index e5cdaf8..5bb3cdc 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -67,12 +67,12 @@  static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
 static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
 					   struct pci_dev **dev, u16 segment)
 {
-	struct pci_bus *bus;
+	struct pci_bus *b, *bus;
 	struct pci_dev *pdev = NULL;
 	struct acpi_dmar_pci_path *path;
 	int count;
 
-	bus = pci_find_bus(segment, scope->bus);
+	b = bus = pci_find_bus(segment, scope->bus);
 	path = (struct acpi_dmar_pci_path *)(scope + 1);
 	count = (scope->length - sizeof(struct acpi_dmar_device_scope))
 		/ sizeof(struct acpi_dmar_pci_path);
@@ -97,6 +97,8 @@  static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
 		count --;
 		bus = pdev->subordinate;
 	}
+	pci_bus_put(b);
+
 	if (!pdev) {
 		pr_warn("Device scope device [%04x:%02x:%02x.%02x] not found\n",
 			segment, scope->bus, path->dev, path->fn);