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Commit 4ebeb1ec authored by CQ Tang's avatar CQ Tang Committed by Bjorn Helgaas
Browse files

PCI: Restore PRI and PASID state after Function-Level Reset 



After a Function-Level Reset, PCI states need to be restored.  Save PASID
features and PRI reqs cached.

[bhelgaas: search for capability only if PRI/PASID were enabled]
Signed-off-by: default avatarCQ Tang <cq.tang@intel.com>
Signed-off-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jean-Phillipe Brucker <jean-philippe.brucker@arm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
parent a4f4fa68

drivers/pci/ats.c

+48 −16
Original line number Diff line number Diff line
@@ -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;
@@ -205,6 +204,28 @@ 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;



	if (!pdev->pri_enabled)

		return;



	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);

	if (!pos)

		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 +245,7 @@ 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 +275,7 @@ 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 +283,7 @@ 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);
@@ -284,7 +296,6 @@ EXPORT_SYMBOL_GPL(pci_enable_pasid); 
/**

 * pci_disable_pasid - Disable the PASID capability

 * @pdev: PCI device structure

 *

 */

void pci_disable_pasid(struct pci_dev *pdev)

{
@@ -304,6 +315,27 @@ 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;



	if (!pdev->pasid_enabled)

		return;



	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);

	if (!pos)

		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

drivers/pci/pci.c

+3 −0
Original line number Diff line number Diff line
@@ -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>
@@ -1173,6 +1174,8 @@ 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);

include/linux/pci-ats.h

+10 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/pci.h

+6 −0
Original line number Diff line number Diff line
@@ -400,6 +400,12 @@ struct pci_dev { 
	u16		ats_cap;	/* ATS Capability offset */

	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 */