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Groups > linux.kernel > #1653431 > unrolled thread

[PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.

Started byAshok Raj <ashok.raj@intel.com>
First post2017-05-30 19:40 +0200
Last post2017-05-30 23:00 +0200
Articles 4 — 3 participants

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Contents

  [PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes. Ashok Raj <ashok.raj@intel.com> - 2017-05-30 19:40 +0200
    Re: [PATCH 2/2] PCI: Save properties required to handle FLR for  replay purposes. Bjorn Helgaas <helgaas@kernel.org> - 2017-05-30 22:00 +0200
      Re: [PATCH 2/2] PCI: Save properties required to handle FLR for  replay purposes. "Raj, Ashok" <ashok.raj@intel.com> - 2017-05-30 22:10 +0200
    Re: [PATCH 2/2] PCI: Save properties required to handle FLR for  replay purposes. Bjorn Helgaas <helgaas@kernel.org> - 2017-05-30 23:00 +0200

#1653431 — [PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.

FromAshok Raj <ashok.raj@intel.com>
Date2017-05-30 19:40 +0200
Subject[PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.
Message-ID<tMThD-1Qx-11@gated-at.bofh.it>
From: CQ Tang <cq.tang@intel.com>

Requires: https://patchwork.kernel.org/patch/9593891


After a FLR, pci-states need to be restored. This patch saves PASID features
and PRI reqs cached.

To: Bjorn Helgaas <bhelgaas@google.com>
To: Joerg Roedel <joro@8bytes.org>
To: linux-pci@vger.kernel.org
To: linux-kernel@vger.kernel.org
Cc: Jean-Phillipe Brucker <jean-philippe.brucker@arm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: iommu@lists.linux-foundation.org

Signed-off-by: CQ Tang <cq.tang@intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
---
 drivers/pci/ats.c       | 65 +++++++++++++++++++++++++++++++++++++------------
 drivers/pci/pci.c       |  3 +++
 include/linux/pci-ats.h | 10 ++++++++
 include/linux/pci.h     |  6 +++++
 4 files changed, 69 insertions(+), 15 deletions(-)

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 2126497..a769955 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -160,17 +160,16 @@ int pci_enable_pri(struct pci_dev *pdev, u32 reqs)
 	if (!pos)
 		return -EINVAL;
 
-	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
 	pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
-	if ((control & PCI_PRI_CTRL_ENABLE) ||
-	    !(status & PCI_PRI_STATUS_STOPPED))
+	if (!(status & PCI_PRI_STATUS_STOPPED))
 		return -EBUSY;
 
 	pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests);
 	reqs = min(max_requests, reqs);
+	pdev->pri_reqs_alloc = reqs;
 	pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
 
-	control |= PCI_PRI_CTRL_ENABLE;
+	control = PCI_PRI_CTRL_ENABLE;
 	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
 
 	pdev->pri_enabled = 1;
@@ -206,6 +205,29 @@ void pci_disable_pri(struct pci_dev *pdev)
 EXPORT_SYMBOL_GPL(pci_disable_pri);
 
 /**
+ * pci_restore_pri_state - Restore PRI
+ * @pdev: PCI device structure
+ *
+ */
+void pci_restore_pri_state(struct pci_dev *pdev)
+{
+   u16 control = PCI_PRI_CTRL_ENABLE;
+   u32 reqs = pdev->pri_reqs_alloc;
+   int pos;
+
+   pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+   if (!pos)
+       return;
+
+   if (!pdev->pri_enabled)
+       return;
+
+   pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
+   pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
+}
+EXPORT_SYMBOL_GPL(pci_restore_pri_state);
+
+/**
  * pci_reset_pri - Resets device's PRI state
  * @pdev: PCI device structure
  *
@@ -224,12 +246,7 @@ int pci_reset_pri(struct pci_dev *pdev)
 	if (!pos)
 		return -EINVAL;
 
-	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
-	if (control & PCI_PRI_CTRL_ENABLE)
-		return -EBUSY;
-
-	control |= PCI_PRI_CTRL_RESET;
-
+	control = PCI_PRI_CTRL_RESET;
 	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
 
 	return 0;
@@ -259,12 +276,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
 	if (!pos)
 		return -EINVAL;
 
-	pci_read_config_word(pdev, pos + PCI_PASID_CTRL, &control);
 	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
-
-	if (control & PCI_PASID_CTRL_ENABLE)
-		return -EINVAL;
-
 	supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
 
 	/* User wants to enable anything unsupported? */
@@ -272,6 +284,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
 		return -EINVAL;
 
 	control = PCI_PASID_CTRL_ENABLE | features;
+	pdev->pasid_features = features;
 
 	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
 
@@ -305,6 +318,28 @@ void pci_disable_pasid(struct pci_dev *pdev)
 EXPORT_SYMBOL_GPL(pci_disable_pasid);
 
 /**
+ * pci_restore_pasid_state - Restore PASID capabilities.
+ * @pdev: PCI device structure
+ *
+ */
+void pci_restore_pasid_state(struct pci_dev *pdev)
+{
+   u16 control;
+   int pos;
+
+   pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
+   if (!pos)
+       return;
+
+   if (!pdev->pasid_enabled)
+       return;
+
+   control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
+   pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
+}
+EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
+
+/**
  * pci_pasid_features - Check which PASID features are supported
  * @pdev: PCI device structure
  *
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 7904d02..c9a6510 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -28,6 +28,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/pci_hotplug.h>
 #include <linux/vmalloc.h>
+#include <linux/pci-ats.h>
 #include <asm/setup.h>
 #include <asm/dma.h>
 #include <linux/aer.h>
@@ -1171,6 +1172,8 @@ void pci_restore_state(struct pci_dev *dev)
 
 	/* PCI Express register must be restored first */
 	pci_restore_pcie_state(dev);
+	pci_restore_pasid_state(dev);
+	pci_restore_pri_state(dev);
 	pci_restore_ats_state(dev);
 	pci_restore_vc_state(dev);
 
diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
index 57e0b82..782fb8e 100644
--- a/include/linux/pci-ats.h
+++ b/include/linux/pci-ats.h
@@ -7,6 +7,7 @@
 
 int pci_enable_pri(struct pci_dev *pdev, u32 reqs);
 void pci_disable_pri(struct pci_dev *pdev);
+void pci_restore_pri_state(struct pci_dev *pdev);
 int pci_reset_pri(struct pci_dev *pdev);
 
 #else /* CONFIG_PCI_PRI */
@@ -20,6 +21,10 @@ static inline void pci_disable_pri(struct pci_dev *pdev)
 {
 }
 
+static inline void pci_restore_pri_state(struct pci_dev *pdev)
+{
+}
+
 static inline int pci_reset_pri(struct pci_dev *pdev)
 {
 	return -ENODEV;
@@ -31,6 +36,7 @@ static inline int pci_reset_pri(struct pci_dev *pdev)
 
 int pci_enable_pasid(struct pci_dev *pdev, int features);
 void pci_disable_pasid(struct pci_dev *pdev);
+void pci_restore_pasid_state(struct pci_dev *pdev);
 int pci_pasid_features(struct pci_dev *pdev);
 int pci_max_pasids(struct pci_dev *pdev);
 
@@ -45,6 +51,10 @@ static inline void pci_disable_pasid(struct pci_dev *pdev)
 {
 }
 
+static inline void pci_restore_pasid_state(struct pci_dev *pdev)
+{
+}
+
 static inline int pci_pasid_features(struct pci_dev *pdev)
 {
 	return -EINVAL;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index bee980e..1ddb8e0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -395,6 +395,12 @@ struct pci_dev {
 	u8		ats_stu;	/* ATS Smallest Translation Unit */
 	atomic_t	ats_ref_cnt;	/* number of VFs with ATS enabled */
 #endif
+#ifdef CONFIG_PCI_PRI
+	u32		pri_reqs_alloc; /* Number of PRI requests allocated */
+#endif
+#ifdef CONFIG_PCI_PASID
+	u16		pasid_features;
+#endif
 	phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */
 	size_t romlen; /* Length of ROM if it's not from the BAR */
 	char *driver_override; /* Driver name to force a match */
-- 
2.7.4

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#1653533 — Re: [PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.

FromBjorn Helgaas <helgaas@kernel.org>
Date2017-05-30 22:00 +0200
SubjectRe: [PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.
Message-ID<tMVt8-37M-13@gated-at.bofh.it>
In reply to#1653431
On Tue, May 30, 2017 at 09:25:49AM -0700, Ashok Raj wrote:
> From: CQ Tang <cq.tang@intel.com>
> 
> Requires: https://patchwork.kernel.org/patch/9593891

The above patch (9593891) is not in my tree or Linus' tree, so I can't
do anything with this yet.

> After a FLR, pci-states need to be restored. This patch saves PASID features
> and PRI reqs cached.
> 
> To: Bjorn Helgaas <bhelgaas@google.com>
> To: Joerg Roedel <joro@8bytes.org>
> To: linux-pci@vger.kernel.org
> To: linux-kernel@vger.kernel.org
> Cc: Jean-Phillipe Brucker <jean-philippe.brucker@arm.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: iommu@lists.linux-foundation.org
> 
> Signed-off-by: CQ Tang <cq.tang@intel.com>
> Signed-off-by: Ashok Raj <ashok.raj@intel.com>
> ---
>  drivers/pci/ats.c       | 65 +++++++++++++++++++++++++++++++++++++------------
>  drivers/pci/pci.c       |  3 +++
>  include/linux/pci-ats.h | 10 ++++++++
>  include/linux/pci.h     |  6 +++++
>  4 files changed, 69 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
> index 2126497..a769955 100644
> --- a/drivers/pci/ats.c
> +++ b/drivers/pci/ats.c
> @@ -160,17 +160,16 @@ int pci_enable_pri(struct pci_dev *pdev, u32 reqs)
>  	if (!pos)
>  		return -EINVAL;
>  
> -	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
>  	pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
> -	if ((control & PCI_PRI_CTRL_ENABLE) ||
> -	    !(status & PCI_PRI_STATUS_STOPPED))
> +	if (!(status & PCI_PRI_STATUS_STOPPED))
>  		return -EBUSY;
>  
>  	pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests);
>  	reqs = min(max_requests, reqs);
> +	pdev->pri_reqs_alloc = reqs;
>  	pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
>  
> -	control |= PCI_PRI_CTRL_ENABLE;
> +	control = PCI_PRI_CTRL_ENABLE;
>  	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
>  
>  	pdev->pri_enabled = 1;
> @@ -206,6 +205,29 @@ void pci_disable_pri(struct pci_dev *pdev)
>  EXPORT_SYMBOL_GPL(pci_disable_pri);
>  
>  /**
> + * pci_restore_pri_state - Restore PRI
> + * @pdev: PCI device structure
> + *
> + */
> +void pci_restore_pri_state(struct pci_dev *pdev)
> +{
> +   u16 control = PCI_PRI_CTRL_ENABLE;
> +   u32 reqs = pdev->pri_reqs_alloc;
> +   int pos;
> +
> +   pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
> +   if (!pos)
> +       return;
> +
> +   if (!pdev->pri_enabled)
> +       return;
> +
> +   pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
> +   pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
> +}
> +EXPORT_SYMBOL_GPL(pci_restore_pri_state);
> +
> +/**
>   * pci_reset_pri - Resets device's PRI state
>   * @pdev: PCI device structure
>   *
> @@ -224,12 +246,7 @@ int pci_reset_pri(struct pci_dev *pdev)
>  	if (!pos)
>  		return -EINVAL;
>  
> -	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
> -	if (control & PCI_PRI_CTRL_ENABLE)
> -		return -EBUSY;
> -
> -	control |= PCI_PRI_CTRL_RESET;
> -
> +	control = PCI_PRI_CTRL_RESET;
>  	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
>  
>  	return 0;
> @@ -259,12 +276,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
>  	if (!pos)
>  		return -EINVAL;
>  
> -	pci_read_config_word(pdev, pos + PCI_PASID_CTRL, &control);
>  	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
> -
> -	if (control & PCI_PASID_CTRL_ENABLE)
> -		return -EINVAL;
> -
>  	supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
>  
>  	/* User wants to enable anything unsupported? */
> @@ -272,6 +284,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
>  		return -EINVAL;
>  
>  	control = PCI_PASID_CTRL_ENABLE | features;
> +	pdev->pasid_features = features;
>  
>  	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
>  
> @@ -305,6 +318,28 @@ void pci_disable_pasid(struct pci_dev *pdev)
>  EXPORT_SYMBOL_GPL(pci_disable_pasid);
>  
>  /**
> + * pci_restore_pasid_state - Restore PASID capabilities.
> + * @pdev: PCI device structure
> + *
> + */
> +void pci_restore_pasid_state(struct pci_dev *pdev)
> +{
> +   u16 control;
> +   int pos;
> +
> +   pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
> +   if (!pos)
> +       return;
> +
> +   if (!pdev->pasid_enabled)
> +       return;
> +
> +   control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
> +   pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
> +}
> +EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
> +
> +/**
>   * pci_pasid_features - Check which PASID features are supported
>   * @pdev: PCI device structure
>   *
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 7904d02..c9a6510 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -28,6 +28,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/pci_hotplug.h>
>  #include <linux/vmalloc.h>
> +#include <linux/pci-ats.h>
>  #include <asm/setup.h>
>  #include <asm/dma.h>
>  #include <linux/aer.h>
> @@ -1171,6 +1172,8 @@ void pci_restore_state(struct pci_dev *dev)
>  
>  	/* PCI Express register must be restored first */
>  	pci_restore_pcie_state(dev);
> +	pci_restore_pasid_state(dev);
> +	pci_restore_pri_state(dev);
>  	pci_restore_ats_state(dev);
>  	pci_restore_vc_state(dev);
>  
> diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
> index 57e0b82..782fb8e 100644
> --- a/include/linux/pci-ats.h
> +++ b/include/linux/pci-ats.h
> @@ -7,6 +7,7 @@
>  
>  int pci_enable_pri(struct pci_dev *pdev, u32 reqs);
>  void pci_disable_pri(struct pci_dev *pdev);
> +void pci_restore_pri_state(struct pci_dev *pdev);
>  int pci_reset_pri(struct pci_dev *pdev);
>  
>  #else /* CONFIG_PCI_PRI */
> @@ -20,6 +21,10 @@ static inline void pci_disable_pri(struct pci_dev *pdev)
>  {
>  }
>  
> +static inline void pci_restore_pri_state(struct pci_dev *pdev)
> +{
> +}
> +
>  static inline int pci_reset_pri(struct pci_dev *pdev)
>  {
>  	return -ENODEV;
> @@ -31,6 +36,7 @@ static inline int pci_reset_pri(struct pci_dev *pdev)
>  
>  int pci_enable_pasid(struct pci_dev *pdev, int features);
>  void pci_disable_pasid(struct pci_dev *pdev);
> +void pci_restore_pasid_state(struct pci_dev *pdev);
>  int pci_pasid_features(struct pci_dev *pdev);
>  int pci_max_pasids(struct pci_dev *pdev);
>  
> @@ -45,6 +51,10 @@ static inline void pci_disable_pasid(struct pci_dev *pdev)
>  {
>  }
>  
> +static inline void pci_restore_pasid_state(struct pci_dev *pdev)
> +{
> +}
> +
>  static inline int pci_pasid_features(struct pci_dev *pdev)
>  {
>  	return -EINVAL;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index bee980e..1ddb8e0 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -395,6 +395,12 @@ struct pci_dev {
>  	u8		ats_stu;	/* ATS Smallest Translation Unit */
>  	atomic_t	ats_ref_cnt;	/* number of VFs with ATS enabled */
>  #endif
> +#ifdef CONFIG_PCI_PRI
> +	u32		pri_reqs_alloc; /* Number of PRI requests allocated */
> +#endif
> +#ifdef CONFIG_PCI_PASID
> +	u16		pasid_features;
> +#endif
>  	phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */
>  	size_t romlen; /* Length of ROM if it's not from the BAR */
>  	char *driver_override; /* Driver name to force a match */
> -- 
> 2.7.4
>

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#1653541 — Re: [PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.

From"Raj, Ashok" <ashok.raj@intel.com>
Date2017-05-30 22:10 +0200
SubjectRe: [PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.
Message-ID<tMVCN-3qh-11@gated-at.bofh.it>
In reply to#1653533
On Tue, May 30, 2017 at 02:50:33PM -0500, Bjorn Helgaas wrote:
> On Tue, May 30, 2017 at 09:25:49AM -0700, Ashok Raj wrote:
> > From: CQ Tang <cq.tang@intel.com>
> > 
> > Requires: https://patchwork.kernel.org/patch/9593891
> 
> The above patch (9593891) is not in my tree or Linus' tree, so I can't
> do anything with this yet.

I resent the patch as part of this series.. maybe should have massaged the 
commit message.. my bad :-(. Its the first patch in this series.

Jean mentioned it might take him a while before the SVM patches stabilize.
Since this patch is pretty much stand alone, he asked if i could resend it
along with the one i need.

Sorry for any confusion.

Cheers,
Ashok
> 
> > After a FLR, pci-states need to be restored. This patch saves PASID features
> > and PRI reqs cached.
> > 
> > To: Bjorn Helgaas <bhelgaas@google.com>
> > To: Joerg Roedel <joro@8bytes.org>
> > To: linux-pci@vger.kernel.org
> > To: linux-kernel@vger.kernel.org
> > Cc: Jean-Phillipe Brucker <jean-philippe.brucker@arm.com>
> > Cc: David Woodhouse <dwmw2@infradead.org>
> > Cc: iommu@lists.linux-foundation.org
> > 
> > Signed-off-by: CQ Tang <cq.tang@intel.com>
> > Signed-off-by: Ashok Raj <ashok.raj@intel.com>
> > ---
> >  drivers/pci/ats.c       | 65 +++++++++++++++++++++++++++++++++++++------------
> >  drivers/pci/pci.c       |  3 +++
> >  include/linux/pci-ats.h | 10 ++++++++
> >  include/linux/pci.h     |  6 +++++
> >  4 files changed, 69 insertions(+), 15 deletions(-)
> > 
> > diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
> > index 2126497..a769955 100644
> > --- a/drivers/pci/ats.c
> > +++ b/drivers/pci/ats.c
> > @@ -160,17 +160,16 @@ int pci_enable_pri(struct pci_dev *pdev, u32 reqs)
> >  	if (!pos)
> >  		return -EINVAL;
> >  
> > -	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
> >  	pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
> > -	if ((control & PCI_PRI_CTRL_ENABLE) ||
> > -	    !(status & PCI_PRI_STATUS_STOPPED))
> > +	if (!(status & PCI_PRI_STATUS_STOPPED))
> >  		return -EBUSY;
> >  
> >  	pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests);
> >  	reqs = min(max_requests, reqs);
> > +	pdev->pri_reqs_alloc = reqs;
> >  	pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
> >  
> > -	control |= PCI_PRI_CTRL_ENABLE;
> > +	control = PCI_PRI_CTRL_ENABLE;
> >  	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
> >  
> >  	pdev->pri_enabled = 1;
> > @@ -206,6 +205,29 @@ void pci_disable_pri(struct pci_dev *pdev)
> >  EXPORT_SYMBOL_GPL(pci_disable_pri);
> >  
> >  /**
> > + * pci_restore_pri_state - Restore PRI
> > + * @pdev: PCI device structure
> > + *
> > + */
> > +void pci_restore_pri_state(struct pci_dev *pdev)
> > +{
> > +   u16 control = PCI_PRI_CTRL_ENABLE;
> > +   u32 reqs = pdev->pri_reqs_alloc;
> > +   int pos;
> > +
> > +   pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
> > +   if (!pos)
> > +       return;
> > +
> > +   if (!pdev->pri_enabled)
> > +       return;
> > +
> > +   pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
> > +   pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
> > +}
> > +EXPORT_SYMBOL_GPL(pci_restore_pri_state);
> > +
> > +/**
> >   * pci_reset_pri - Resets device's PRI state
> >   * @pdev: PCI device structure
> >   *
> > @@ -224,12 +246,7 @@ int pci_reset_pri(struct pci_dev *pdev)
> >  	if (!pos)
> >  		return -EINVAL;
> >  
> > -	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
> > -	if (control & PCI_PRI_CTRL_ENABLE)
> > -		return -EBUSY;
> > -
> > -	control |= PCI_PRI_CTRL_RESET;
> > -
> > +	control = PCI_PRI_CTRL_RESET;
> >  	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
> >  
> >  	return 0;
> > @@ -259,12 +276,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
> >  	if (!pos)
> >  		return -EINVAL;
> >  
> > -	pci_read_config_word(pdev, pos + PCI_PASID_CTRL, &control);
> >  	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
> > -
> > -	if (control & PCI_PASID_CTRL_ENABLE)
> > -		return -EINVAL;
> > -
> >  	supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
> >  
> >  	/* User wants to enable anything unsupported? */
> > @@ -272,6 +284,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
> >  		return -EINVAL;
> >  
> >  	control = PCI_PASID_CTRL_ENABLE | features;
> > +	pdev->pasid_features = features;
> >  
> >  	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
> >  
> > @@ -305,6 +318,28 @@ void pci_disable_pasid(struct pci_dev *pdev)
> >  EXPORT_SYMBOL_GPL(pci_disable_pasid);
> >  
> >  /**
> > + * pci_restore_pasid_state - Restore PASID capabilities.
> > + * @pdev: PCI device structure
> > + *
> > + */
> > +void pci_restore_pasid_state(struct pci_dev *pdev)
> > +{
> > +   u16 control;
> > +   int pos;
> > +
> > +   pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
> > +   if (!pos)
> > +       return;
> > +
> > +   if (!pdev->pasid_enabled)
> > +       return;
> > +
> > +   control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
> > +   pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
> > +}
> > +EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
> > +
> > +/**
> >   * pci_pasid_features - Check which PASID features are supported
> >   * @pdev: PCI device structure
> >   *
> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > index 7904d02..c9a6510 100644
> > --- a/drivers/pci/pci.c
> > +++ b/drivers/pci/pci.c
> > @@ -28,6 +28,7 @@
> >  #include <linux/pm_runtime.h>
> >  #include <linux/pci_hotplug.h>
> >  #include <linux/vmalloc.h>
> > +#include <linux/pci-ats.h>
> >  #include <asm/setup.h>
> >  #include <asm/dma.h>
> >  #include <linux/aer.h>
> > @@ -1171,6 +1172,8 @@ void pci_restore_state(struct pci_dev *dev)
> >  
> >  	/* PCI Express register must be restored first */
> >  	pci_restore_pcie_state(dev);
> > +	pci_restore_pasid_state(dev);
> > +	pci_restore_pri_state(dev);
> >  	pci_restore_ats_state(dev);
> >  	pci_restore_vc_state(dev);
> >  
> > diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
> > index 57e0b82..782fb8e 100644
> > --- a/include/linux/pci-ats.h
> > +++ b/include/linux/pci-ats.h
> > @@ -7,6 +7,7 @@
> >  
> >  int pci_enable_pri(struct pci_dev *pdev, u32 reqs);
> >  void pci_disable_pri(struct pci_dev *pdev);
> > +void pci_restore_pri_state(struct pci_dev *pdev);
> >  int pci_reset_pri(struct pci_dev *pdev);
> >  
> >  #else /* CONFIG_PCI_PRI */
> > @@ -20,6 +21,10 @@ static inline void pci_disable_pri(struct pci_dev *pdev)
> >  {
> >  }
> >  
> > +static inline void pci_restore_pri_state(struct pci_dev *pdev)
> > +{
> > +}
> > +
> >  static inline int pci_reset_pri(struct pci_dev *pdev)
> >  {
> >  	return -ENODEV;
> > @@ -31,6 +36,7 @@ static inline int pci_reset_pri(struct pci_dev *pdev)
> >  
> >  int pci_enable_pasid(struct pci_dev *pdev, int features);
> >  void pci_disable_pasid(struct pci_dev *pdev);
> > +void pci_restore_pasid_state(struct pci_dev *pdev);
> >  int pci_pasid_features(struct pci_dev *pdev);
> >  int pci_max_pasids(struct pci_dev *pdev);
> >  
> > @@ -45,6 +51,10 @@ static inline void pci_disable_pasid(struct pci_dev *pdev)
> >  {
> >  }
> >  
> > +static inline void pci_restore_pasid_state(struct pci_dev *pdev)
> > +{
> > +}
> > +
> >  static inline int pci_pasid_features(struct pci_dev *pdev)
> >  {
> >  	return -EINVAL;
> > diff --git a/include/linux/pci.h b/include/linux/pci.h
> > index bee980e..1ddb8e0 100644
> > --- a/include/linux/pci.h
> > +++ b/include/linux/pci.h
> > @@ -395,6 +395,12 @@ struct pci_dev {
> >  	u8		ats_stu;	/* ATS Smallest Translation Unit */
> >  	atomic_t	ats_ref_cnt;	/* number of VFs with ATS enabled */
> >  #endif
> > +#ifdef CONFIG_PCI_PRI
> > +	u32		pri_reqs_alloc; /* Number of PRI requests allocated */
> > +#endif
> > +#ifdef CONFIG_PCI_PASID
> > +	u16		pasid_features;
> > +#endif
> >  	phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */
> >  	size_t romlen; /* Length of ROM if it's not from the BAR */
> >  	char *driver_override; /* Driver name to force a match */
> > -- 
> > 2.7.4
> >

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#1653550 — Re: [PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.

FromBjorn Helgaas <helgaas@kernel.org>
Date2017-05-30 23:00 +0200
SubjectRe: [PATCH 2/2] PCI: Save properties required to handle FLR for replay purposes.
Message-ID<tMWpb-3Hl-17@gated-at.bofh.it>
In reply to#1653431
On Tue, May 30, 2017 at 09:25:49AM -0700, Ashok Raj wrote:
> From: CQ Tang <cq.tang@intel.com>
> 
> Requires: https://patchwork.kernel.org/patch/9593891
> 
> 
> After a FLR, pci-states need to be restored. This patch saves PASID features
> and PRI reqs cached.
> 
> To: Bjorn Helgaas <bhelgaas@google.com>
> To: Joerg Roedel <joro@8bytes.org>
> To: linux-pci@vger.kernel.org
> To: linux-kernel@vger.kernel.org
> Cc: Jean-Phillipe Brucker <jean-philippe.brucker@arm.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: iommu@lists.linux-foundation.org
> 
> Signed-off-by: CQ Tang <cq.tang@intel.com>
> Signed-off-by: Ashok Raj <ashok.raj@intel.com>
> ---
>  drivers/pci/ats.c       | 65 +++++++++++++++++++++++++++++++++++++------------
>  drivers/pci/pci.c       |  3 +++
>  include/linux/pci-ats.h | 10 ++++++++
>  include/linux/pci.h     |  6 +++++
>  4 files changed, 69 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
> index 2126497..a769955 100644
> --- a/drivers/pci/ats.c
> +++ b/drivers/pci/ats.c
> @@ -160,17 +160,16 @@ int pci_enable_pri(struct pci_dev *pdev, u32 reqs)
>  	if (!pos)
>  		return -EINVAL;
>  
> -	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
>  	pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
> -	if ((control & PCI_PRI_CTRL_ENABLE) ||
> -	    !(status & PCI_PRI_STATUS_STOPPED))
> +	if (!(status & PCI_PRI_STATUS_STOPPED))
>  		return -EBUSY;
>  
>  	pci_read_config_dword(pdev, pos + PCI_PRI_MAX_REQ, &max_requests);
>  	reqs = min(max_requests, reqs);
> +	pdev->pri_reqs_alloc = reqs;
>  	pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
>  
> -	control |= PCI_PRI_CTRL_ENABLE;
> +	control = PCI_PRI_CTRL_ENABLE;
>  	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
>  
>  	pdev->pri_enabled = 1;
> @@ -206,6 +205,29 @@ void pci_disable_pri(struct pci_dev *pdev)
>  EXPORT_SYMBOL_GPL(pci_disable_pri);
>  
>  /**
> + * pci_restore_pri_state - Restore PRI
> + * @pdev: PCI device structure
> + *
> + */
> +void pci_restore_pri_state(struct pci_dev *pdev)
> +{
> +   u16 control = PCI_PRI_CTRL_ENABLE;
> +   u32 reqs = pdev->pri_reqs_alloc;
> +   int pos;
> +
> +   pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
> +   if (!pos)
> +       return;
> +
> +   if (!pdev->pri_enabled)
> +       return;

I propose swapping the order of these tests, so that if PRI is not
enabled, we don't have to search for the capability.  Similarly for
PASID below.

I made these changes and re-indented these functions on my branch.  No
action required unless you object to these changes.

> +
> +   pci_write_config_dword(pdev, pos + PCI_PRI_ALLOC_REQ, reqs);
> +   pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
> +}
> +EXPORT_SYMBOL_GPL(pci_restore_pri_state);
> +
> +/**
>   * pci_reset_pri - Resets device's PRI state
>   * @pdev: PCI device structure
>   *
> @@ -224,12 +246,7 @@ int pci_reset_pri(struct pci_dev *pdev)
>  	if (!pos)
>  		return -EINVAL;
>  
> -	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
> -	if (control & PCI_PRI_CTRL_ENABLE)
> -		return -EBUSY;
> -
> -	control |= PCI_PRI_CTRL_RESET;
> -
> +	control = PCI_PRI_CTRL_RESET;
>  	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);
>  
>  	return 0;
> @@ -259,12 +276,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
>  	if (!pos)
>  		return -EINVAL;
>  
> -	pci_read_config_word(pdev, pos + PCI_PASID_CTRL, &control);
>  	pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported);
> -
> -	if (control & PCI_PASID_CTRL_ENABLE)
> -		return -EINVAL;
> -
>  	supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;
>  
>  	/* User wants to enable anything unsupported? */
> @@ -272,6 +284,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
>  		return -EINVAL;
>  
>  	control = PCI_PASID_CTRL_ENABLE | features;
> +	pdev->pasid_features = features;
>  
>  	pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
>  
> @@ -305,6 +318,28 @@ void pci_disable_pasid(struct pci_dev *pdev)
>  EXPORT_SYMBOL_GPL(pci_disable_pasid);
>  
>  /**
> + * pci_restore_pasid_state - Restore PASID capabilities.
> + * @pdev: PCI device structure
> + *
> + */
> +void pci_restore_pasid_state(struct pci_dev *pdev)
> +{
> +   u16 control;
> +   int pos;
> +
> +   pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
> +   if (!pos)
> +       return;
> +
> +   if (!pdev->pasid_enabled)
> +       return;
> +
> +   control = PCI_PASID_CTRL_ENABLE | pdev->pasid_features;
> +   pci_write_config_word(pdev, pos + PCI_PASID_CTRL, control);
> +}
> +EXPORT_SYMBOL_GPL(pci_restore_pasid_state);
> +
> +/**
>   * pci_pasid_features - Check which PASID features are supported
>   * @pdev: PCI device structure
>   *
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 7904d02..c9a6510 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -28,6 +28,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/pci_hotplug.h>
>  #include <linux/vmalloc.h>
> +#include <linux/pci-ats.h>
>  #include <asm/setup.h>
>  #include <asm/dma.h>
>  #include <linux/aer.h>
> @@ -1171,6 +1172,8 @@ void pci_restore_state(struct pci_dev *dev)
>  
>  	/* PCI Express register must be restored first */
>  	pci_restore_pcie_state(dev);
> +	pci_restore_pasid_state(dev);
> +	pci_restore_pri_state(dev);
>  	pci_restore_ats_state(dev);
>  	pci_restore_vc_state(dev);
>  
> diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
> index 57e0b82..782fb8e 100644
> --- a/include/linux/pci-ats.h
> +++ b/include/linux/pci-ats.h
> @@ -7,6 +7,7 @@
>  
>  int pci_enable_pri(struct pci_dev *pdev, u32 reqs);
>  void pci_disable_pri(struct pci_dev *pdev);
> +void pci_restore_pri_state(struct pci_dev *pdev);
>  int pci_reset_pri(struct pci_dev *pdev);
>  
>  #else /* CONFIG_PCI_PRI */
> @@ -20,6 +21,10 @@ static inline void pci_disable_pri(struct pci_dev *pdev)
>  {
>  }
>  
> +static inline void pci_restore_pri_state(struct pci_dev *pdev)
> +{
> +}
> +
>  static inline int pci_reset_pri(struct pci_dev *pdev)
>  {
>  	return -ENODEV;
> @@ -31,6 +36,7 @@ static inline int pci_reset_pri(struct pci_dev *pdev)
>  
>  int pci_enable_pasid(struct pci_dev *pdev, int features);
>  void pci_disable_pasid(struct pci_dev *pdev);
> +void pci_restore_pasid_state(struct pci_dev *pdev);
>  int pci_pasid_features(struct pci_dev *pdev);
>  int pci_max_pasids(struct pci_dev *pdev);
>  
> @@ -45,6 +51,10 @@ static inline void pci_disable_pasid(struct pci_dev *pdev)
>  {
>  }
>  
> +static inline void pci_restore_pasid_state(struct pci_dev *pdev)
> +{
> +}
> +
>  static inline int pci_pasid_features(struct pci_dev *pdev)
>  {
>  	return -EINVAL;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index bee980e..1ddb8e0 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -395,6 +395,12 @@ struct pci_dev {
>  	u8		ats_stu;	/* ATS Smallest Translation Unit */
>  	atomic_t	ats_ref_cnt;	/* number of VFs with ATS enabled */
>  #endif
> +#ifdef CONFIG_PCI_PRI
> +	u32		pri_reqs_alloc; /* Number of PRI requests allocated */
> +#endif
> +#ifdef CONFIG_PCI_PASID
> +	u16		pasid_features;
> +#endif
>  	phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */
>  	size_t romlen; /* Length of ROM if it's not from the BAR */
>  	char *driver_override; /* Driver name to force a match */
> -- 
> 2.7.4
>

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