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* [PATCH v2] iommu/of: Fix pci_request_acs() before enumerating PCI devices
@ 2021-05-17 13:17 Wang Xingang
  2021-05-19 19:14 ` Rob Herring
  0 siblings, 1 reply; 3+ messages in thread
From: Wang Xingang @ 2021-05-17 13:17 UTC (permalink / raw)
  To: will, joro, robh+dt, frowand.list
  Cc: helgaas, gregkh, iommu, linux-kernel, linux-pci, devicetree,
	xieyingtai, wangxingang5

From: Xingang Wang <wangxingang5@huawei.com>

When booting with devicetree, the pci_request_acs() is called after the
enumeration and initialization of PCI devices, thus the ACS is not
enabled. This patch add check for IOMMU in of_core_init(), and call
pci_request_acs() when iommu is detected, making sure that the ACS will
be enabled.

Fixes: 6bf6c24720d33 ("iommu/of: Request ACS from the PCI core when
configuring IOMMU linkage")
Signed-off-by: Xingang Wang <wangxingang5@huawei.com>
---
 drivers/iommu/of_iommu.c | 1 -
 drivers/of/base.c        | 9 ++++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

Change log:
v1->v2:
 - remove pci_request_acs() in of_iommu_configure
 - check and call pci_request_acs() in of_core_init()

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index a9d2df001149..54a14da242cc 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -205,7 +205,6 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
 			.np = master_np,
 		};
 
-		pci_request_acs();
 		err = pci_for_each_dma_alias(to_pci_dev(dev),
 					     of_pci_iommu_init, &info);
 	} else {
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 48e941f99558..95cd8f0e5435 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -24,6 +24,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_graph.h>
+#include <linux/pci.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <linux/string.h>
@@ -166,7 +167,7 @@ void __of_phandle_cache_inv_entry(phandle handle)
 void __init of_core_init(void)
 {
 	struct device_node *np;
-
+	bool of_iommu_detect = false;
 
 	/* Create the kset, and register existing nodes */
 	mutex_lock(&of_mutex);
@@ -180,6 +181,12 @@ void __init of_core_init(void)
 		__of_attach_node_sysfs(np);
 		if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
 			phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
+
+		/* Detect IOMMU and make sure ACS will be enabled */
+		if (!of_iommu_detect && of_get_property(np, "iommu-map", NULL)) {
+			of_iommu_detect = true;
+			pci_request_acs();
+		}
 	}
 	mutex_unlock(&of_mutex);
 
-- 
2.19.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH v2] iommu/of: Fix pci_request_acs() before enumerating PCI devices
  2021-05-17 13:17 [PATCH v2] iommu/of: Fix pci_request_acs() before enumerating PCI devices Wang Xingang
@ 2021-05-19 19:14 ` Rob Herring
  2021-05-20  3:29   ` Xingang Wang
  0 siblings, 1 reply; 3+ messages in thread
From: Rob Herring @ 2021-05-19 19:14 UTC (permalink / raw)
  To: Wang Xingang
  Cc: will, joro, frowand.list, helgaas, gregkh, iommu, linux-kernel,
	linux-pci, devicetree, xieyingtai

On Mon, May 17, 2021 at 01:17:05PM +0000, Wang Xingang wrote:
> From: Xingang Wang <wangxingang5@huawei.com>
> 
> When booting with devicetree, the pci_request_acs() is called after the
> enumeration and initialization of PCI devices, thus the ACS is not
> enabled. This patch add check for IOMMU in of_core_init(), and call
> pci_request_acs() when iommu is detected, making sure that the ACS will
> be enabled.
> 
> Fixes: 6bf6c24720d33 ("iommu/of: Request ACS from the PCI core when
> configuring IOMMU linkage")
> Signed-off-by: Xingang Wang <wangxingang5@huawei.com>
> ---
>  drivers/iommu/of_iommu.c | 1 -
>  drivers/of/base.c        | 9 ++++++++-
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> Change log:
> v1->v2:
>  - remove pci_request_acs() in of_iommu_configure
>  - check and call pci_request_acs() in of_core_init()
> 
> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
> index a9d2df001149..54a14da242cc 100644
> --- a/drivers/iommu/of_iommu.c
> +++ b/drivers/iommu/of_iommu.c
> @@ -205,7 +205,6 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
>  			.np = master_np,
>  		};
>  
> -		pci_request_acs();
>  		err = pci_for_each_dma_alias(to_pci_dev(dev),
>  					     of_pci_iommu_init, &info);
>  	} else {
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 48e941f99558..95cd8f0e5435 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -24,6 +24,7 @@
>  #include <linux/of.h>
>  #include <linux/of_device.h>
>  #include <linux/of_graph.h>
> +#include <linux/pci.h>
>  #include <linux/spinlock.h>
>  #include <linux/slab.h>
>  #include <linux/string.h>
> @@ -166,7 +167,7 @@ void __of_phandle_cache_inv_entry(phandle handle)
>  void __init of_core_init(void)
>  {
>  	struct device_node *np;
> -
> +	bool of_iommu_detect = false;
>  
>  	/* Create the kset, and register existing nodes */
>  	mutex_lock(&of_mutex);
> @@ -180,6 +181,12 @@ void __init of_core_init(void)
>  		__of_attach_node_sysfs(np);
>  		if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
>  			phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
> +
> +		/* Detect IOMMU and make sure ACS will be enabled */
> +		if (!of_iommu_detect && of_get_property(np, "iommu-map", NULL)) {
> +			of_iommu_detect = true;
> +			pci_request_acs();
> +		}

Private DT internal init code doesn't seem like the right place for 
this. If this needs to be ordered WRT PCI device enumeration, then 
somewhere in the PCI host bridge or bus init code seems like the right 
place to me.

Also, shouldn't this be conditional on 'iommu-map' being in the host 
bridge or a parent or ??? rather than just any iommu-map anywhere in the 
DT.

>  	}
>  	mutex_unlock(&of_mutex);
>  
> -- 
> 2.19.1
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH v2] iommu/of: Fix pci_request_acs() before enumerating PCI devices
  2021-05-19 19:14 ` Rob Herring
@ 2021-05-20  3:29   ` Xingang Wang
  0 siblings, 0 replies; 3+ messages in thread
From: Xingang Wang @ 2021-05-20  3:29 UTC (permalink / raw)
  To: Rob Herring
  Cc: will, joro, frowand.list, helgaas, gregkh, iommu, linux-kernel,
	linux-pci, devicetree, xieyingtai



On 2021/5/20 3:14, Rob Herring wrote:
> On Mon, May 17, 2021 at 01:17:05PM +0000, Wang Xingang wrote:
>> From: Xingang Wang <wangxingang5@huawei.com>
>>
>> When booting with devicetree, the pci_request_acs() is called after the
>> enumeration and initialization of PCI devices, thus the ACS is not
>> enabled. This patch add check for IOMMU in of_core_init(), and call
>> pci_request_acs() when iommu is detected, making sure that the ACS will
>> be enabled.
>>
>> Fixes: 6bf6c24720d33 ("iommu/of: Request ACS from the PCI core when
>> configuring IOMMU linkage")
>> Signed-off-by: Xingang Wang <wangxingang5@huawei.com>
>> ---
>>   drivers/iommu/of_iommu.c | 1 -
>>   drivers/of/base.c        | 9 ++++++++-
>>   2 files changed, 8 insertions(+), 2 deletions(-)
>>
>> Change log:
>> v1->v2:
>>   - remove pci_request_acs() in of_iommu_configure
>>   - check and call pci_request_acs() in of_core_init()
>>
>> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
>> index a9d2df001149..54a14da242cc 100644
>> --- a/drivers/iommu/of_iommu.c
>> +++ b/drivers/iommu/of_iommu.c
>> @@ -205,7 +205,6 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
>>   			.np = master_np,
>>   		};
>>   
>> -		pci_request_acs();
>>   		err = pci_for_each_dma_alias(to_pci_dev(dev),
>>   					     of_pci_iommu_init, &info);
>>   	} else {
>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>> index 48e941f99558..95cd8f0e5435 100644
>> --- a/drivers/of/base.c
>> +++ b/drivers/of/base.c
>> @@ -24,6 +24,7 @@
>>   #include <linux/of.h>
>>   #include <linux/of_device.h>
>>   #include <linux/of_graph.h>
>> +#include <linux/pci.h>
>>   #include <linux/spinlock.h>
>>   #include <linux/slab.h>
>>   #include <linux/string.h>
>> @@ -166,7 +167,7 @@ void __of_phandle_cache_inv_entry(phandle handle)
>>   void __init of_core_init(void)
>>   {
>>   	struct device_node *np;
>> -
>> +	bool of_iommu_detect = false;
>>   
>>   	/* Create the kset, and register existing nodes */
>>   	mutex_lock(&of_mutex);
>> @@ -180,6 +181,12 @@ void __init of_core_init(void)
>>   		__of_attach_node_sysfs(np);
>>   		if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
>>   			phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
>> +
>> +		/* Detect IOMMU and make sure ACS will be enabled */
>> +		if (!of_iommu_detect && of_get_property(np, "iommu-map", NULL)) {
>> +			of_iommu_detect = true;
>> +			pci_request_acs();
>> +		}
> 
> Private DT internal init code doesn't seem like the right place for
> this. If this needs to be ordered WRT PCI device enumeration, then
> somewhere in the PCI host bridge or bus init code seems like the right
> place to me.
> 
> Also, shouldn't this be conditional on 'iommu-map' being in the host
> bridge or a parent or ??? rather than just any iommu-map anywhere in the
> DT.
> 

Thanks for your suggestion, I will fix this and move the modification to 
procedure of pci_host_common_probe(), and before pci_host_probe().

>>   	}
>>   	mutex_unlock(&of_mutex);
>>   
>> -- 
>> 2.19.1
>>
> .
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-05-20  3:29 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-05-17 13:17 [PATCH v2] iommu/of: Fix pci_request_acs() before enumerating PCI devices Wang Xingang
2021-05-19 19:14 ` Rob Herring
2021-05-20  3:29   ` Xingang Wang

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