From 67546762978f523749eac157903e0b01c18e083a Mon Sep 17 00:00:00 2001
From: Yijing Wang <wangyijing@huawei.com>
Date: Fri, 17 Jul 2015 17:16:31 +0800
Subject: PCI: Protect pci_bus->slots with pci_slot_mutex, not pci_bus_sem

Rajat Jain reported a deadlock when PCIe hot-add and AER recovery happen at
the same time:

thread 1:

  pciehp_enable_slot
    pciehp_configure_device
      pci_bus_add_devices
        pci_bus_add_device
          device_attach
            device_lock(dev)                       # acquire device lock
            ...
            pciehp_probe
              init_slot
                pci_hp_register
                  pci_create_slot
                    down_write(pci_bus_sem)        # deadlock here

thread 2:

  aer_isr_one_error
    aer_process_err_device
      do_recovery
        broadcast_error_message(..., report_error_detected)
          pci_walk_bus(..., cb=report_error_detected, ...)
            down_read(&pci_bus_sem)                # acquire pci_bus_sem
            report_error_detected(dev)             # cb()
              device_lock(dev)                     # deadlock here

Previously, the bus->devices and bus->slots list were protected by
pci_bus_sem.  In pci_create_slot(), we held it for writing so we could
add to the bus->slots list.

Add a new local pci_slot_mutex to protect bus->slots.  Hold pci_bus_sem for
reading while searching the bus->devices list.

[bhelgaas: changelog]
Link: http://lkml.kernel.org/r/CAA93t1qpPqbih+UB0McA_d_+2rVaNkXsinAUxYzK9+JXSS+L-g@mail.gmail.com
Reported-by: Rajat Jain <rajatja@google.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 include/linux/pci.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'include/linux/pci.h')

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8a0321a8fb59..aaee493174e2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -446,7 +446,8 @@ struct pci_bus {
 	struct list_head children;	/* list of child buses */
 	struct list_head devices;	/* list of devices on this bus */
 	struct pci_dev	*self;		/* bridge device as seen by parent */
-	struct list_head slots;		/* list of slots on this bus */
+	struct list_head slots;		/* list of slots on this bus;
+					   protected by pci_slot_mutex */
 	struct resource *resource[PCI_BRIDGE_RESOURCE_NUM];
 	struct list_head resources;	/* address space routed to this bus */
 	struct resource busn_res;	/* bus numbers routed to this bus */
-- 
cgit v1.2.3


From 017ffe64e8b8c8db0f50433a71da41c6a4e12710 Mon Sep 17 00:00:00 2001
From: Yijing Wang <wangyijing@huawei.com>
Date: Fri, 17 Jul 2015 17:16:32 +0800
Subject: PCI: Hold pci_slot_mutex while searching bus->slots list

Previously, pci_setup_device() and similar functions searched the
pci_bus->slots list without any locking.  It was possible for another
thread to update the list while we searched it.

Add pci_dev_assign_slot() to search the list while holding pci_slot_mutex.

[bhelgaas: changelog, fold in CONFIG_SYSFS fix]
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 arch/powerpc/kernel/pci_of_scan.c |  6 +-----
 arch/sparc/kernel/pci.c           |  6 +-----
 drivers/pci/probe.c               |  6 +-----
 drivers/pci/slot.c                | 11 +++++++++++
 include/linux/pci.h               |  5 +++++
 5 files changed, 19 insertions(+), 15 deletions(-)

(limited to 'include/linux/pci.h')

diff --git a/arch/powerpc/kernel/pci_of_scan.c b/arch/powerpc/kernel/pci_of_scan.c
index 42e02a2d570b..5e2debfc6ce5 100644
--- a/arch/powerpc/kernel/pci_of_scan.c
+++ b/arch/powerpc/kernel/pci_of_scan.c
@@ -126,7 +126,6 @@ struct pci_dev *of_create_pci_dev(struct device_node *node,
 {
 	struct pci_dev *dev;
 	const char *type;
-	struct pci_slot *slot;
 
 	dev = pci_alloc_dev(bus);
 	if (!dev)
@@ -145,10 +144,7 @@ struct pci_dev *of_create_pci_dev(struct device_node *node,
 	dev->needs_freset = 0;		/* pcie fundamental reset required */
 	set_pcie_port_type(dev);
 
-	list_for_each_entry(slot, &dev->bus->slots, list)
-		if (PCI_SLOT(dev->devfn) == slot->number)
-			dev->slot = slot;
-
+	pci_dev_assign_slot(dev);
 	dev->vendor = get_int_prop(node, "vendor-id", 0xffff);
 	dev->device = get_int_prop(node, "device-id", 0xffff);
 	dev->subsystem_vendor = get_int_prop(node, "subsystem-vendor-id", 0);
diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index c928bc64b4ba..3a0e1a986bfe 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -249,7 +249,6 @@ static struct pci_dev *of_create_pci_dev(struct pci_pbm_info *pbm,
 					 struct pci_bus *bus, int devfn)
 {
 	struct dev_archdata *sd;
-	struct pci_slot *slot;
 	struct platform_device *op;
 	struct pci_dev *dev;
 	const char *type;
@@ -290,10 +289,7 @@ static struct pci_dev *of_create_pci_dev(struct pci_pbm_info *pbm,
 	dev->multifunction = 0;		/* maybe a lie? */
 	set_pcie_port_type(dev);
 
-	list_for_each_entry(slot, &dev->bus->slots, list)
-		if (PCI_SLOT(dev->devfn) == slot->number)
-			dev->slot = slot;
-
+	pci_dev_assign_slot(dev);
 	dev->vendor = of_getintprop_default(node, "vendor-id", 0xffff);
 	dev->device = of_getintprop_default(node, "device-id", 0xffff);
 	dev->subsystem_vendor =
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index cefd636681b6..2a9ce16cb374 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1133,7 +1133,6 @@ int pci_setup_device(struct pci_dev *dev)
 {
 	u32 class;
 	u8 hdr_type;
-	struct pci_slot *slot;
 	int pos = 0;
 	struct pci_bus_region region;
 	struct resource *res;
@@ -1149,10 +1148,7 @@ int pci_setup_device(struct pci_dev *dev)
 	dev->error_state = pci_channel_io_normal;
 	set_pcie_port_type(dev);
 
-	list_for_each_entry(slot, &dev->bus->slots, list)
-		if (PCI_SLOT(dev->devfn) == slot->number)
-			dev->slot = slot;
-
+	pci_dev_assign_slot(dev);
 	/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
 	   set this higher, assuming the system even supports it.  */
 	dev->dma_mask = 0xffffffff;
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index 4bd3fce93fa4..429d34c348b9 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -194,6 +194,17 @@ static int rename_slot(struct pci_slot *slot, const char *name)
 	return result;
 }
 
+void pci_dev_assign_slot(struct pci_dev *dev)
+{
+	struct pci_slot *slot;
+
+	mutex_lock(&pci_slot_mutex);
+	list_for_each_entry(slot, &dev->bus->slots, list)
+		if (PCI_SLOT(dev->devfn) == slot->number)
+			dev->slot = slot;
+	mutex_unlock(&pci_slot_mutex);
+}
+
 static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
 {
 	struct pci_slot *slot;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index aaee493174e2..b3ba7fef2916 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -798,6 +798,11 @@ struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
 				 const char *name,
 				 struct hotplug_slot *hotplug);
 void pci_destroy_slot(struct pci_slot *slot);
+#ifdef CONFIG_SYSFS
+void pci_dev_assign_slot(struct pci_dev *dev);
+#else
+static inline void pci_dev_assign_slot(struct pci_dev *dev) { }
+#endif
 int pci_scan_slot(struct pci_bus *bus, int devfn);
 struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn);
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus);
-- 
cgit v1.2.3


From edc90fee916b4f0d14af9c6b5c08666747488ef8 Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Fri, 17 Jul 2015 15:05:46 -0500
Subject: PCI: Allocate ATS struct during enumeration

Previously, we allocated pci_ats structures when an IOMMU driver called
pci_enable_ats().  An SR-IOV VF shares the STU setting with its PF, so when
enabling ATS on the VF, we allocated a pci_ats struct for the PF if it
didn't already have one.  We held the sriov->lock to serialize threads
concurrently enabling ATS on several VFS so only one would allocate the PF
pci_ats.

Gregor reported a deadlock here:

  pci_enable_sriov
    sriov_enable
      virtfn_add
        mutex_lock(dev->sriov->lock)      # acquire sriov->lock
        pci_device_add
          device_add
            BUS_NOTIFY_ADD_DEVICE notifier chain
            iommu_bus_notifier
              amd_iommu_add_device        # iommu_ops.add_device
                init_iommu_group
                  iommu_group_get_for_dev
                    iommu_group_add_device
                      __iommu_attach_device
                        amd_iommu_attach_device  # iommu_ops.attach_device
                          attach_device
                            pci_enable_ats
                              mutex_lock(dev->sriov->lock) # deadlock

There's no reason to delay allocating the pci_ats struct, and if we
allocate it for each device at enumeration-time, there's no need for
locking in pci_enable_ats().

Allocate pci_ats struct during enumeration, when we initialize other
capabilities.

Note that this implementation requires ATS to be enabled on the PF first,
before on any of the VFs because the PF controls the STU for all the VFs.

Link: http://permalink.gmane.org/gmane.linux.kernel.iommu/9433
Reported-by: Gregor Dick <gdick@solarflare.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/pci/ats.c       | 98 +++++++++++++++++++++----------------------------
 drivers/pci/probe.c     |  3 ++
 drivers/pci/remove.c    |  1 +
 include/linux/pci-ats.h |  2 +-
 include/linux/pci.h     |  9 +++++
 5 files changed, 56 insertions(+), 57 deletions(-)

(limited to 'include/linux/pci.h')

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index a8099d4d0c9d..2026f5388796 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -17,7 +17,7 @@
 
 #include "pci.h"
 
-static int ats_alloc_one(struct pci_dev *dev, int ps)
+static void ats_alloc_one(struct pci_dev *dev)
 {
 	int pos;
 	u16 cap;
@@ -25,20 +25,19 @@ static int ats_alloc_one(struct pci_dev *dev, int ps)
 
 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
 	if (!pos)
-		return -ENODEV;
+		return;
 
 	ats = kzalloc(sizeof(*ats), GFP_KERNEL);
-	if (!ats)
-		return -ENOMEM;
+	if (!ats) {
+		dev_warn(&dev->dev, "can't allocate space for ATS state\n");
+		return;
+	}
 
 	ats->pos = pos;
-	ats->stu = ps;
 	pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
 	ats->qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
 					    PCI_ATS_MAX_QDEP;
 	dev->ats = ats;
-
-	return 0;
 }
 
 static void ats_free_one(struct pci_dev *dev)
@@ -47,6 +46,16 @@ static void ats_free_one(struct pci_dev *dev)
 	dev->ats = NULL;
 }
 
+void pci_ats_init(struct pci_dev *dev)
+{
+	ats_alloc_one(dev);
+}
+
+void pci_ats_free(struct pci_dev *dev)
+{
+	ats_free_one(dev);
+}
+
 /**
  * pci_enable_ats - enable the ATS capability
  * @dev: the PCI device
@@ -56,43 +65,35 @@ static void ats_free_one(struct pci_dev *dev)
  */
 int pci_enable_ats(struct pci_dev *dev, int ps)
 {
-	int rc;
 	u16 ctrl;
 
 	BUG_ON(dev->ats && dev->ats->is_enabled);
 
+	if (!dev->ats)
+		return -EINVAL;
+
 	if (ps < PCI_ATS_MIN_STU)
 		return -EINVAL;
 
-	if (dev->is_physfn || dev->is_virtfn) {
-		struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
+	/*
+	 * Note that enabling ATS on a VF fails unless it's already enabled
+	 * with the same STU on the PF.
+	 */
+	ctrl = PCI_ATS_CTRL_ENABLE;
+	if (dev->is_virtfn) {
+		struct pci_dev *pdev = dev->physfn;
 
-		mutex_lock(&pdev->sriov->lock);
-		if (pdev->ats)
-			rc = pdev->ats->stu == ps ? 0 : -EINVAL;
-		else
-			rc = ats_alloc_one(pdev, ps);
+		if (pdev->ats->stu != ps)
+			return -EINVAL;
 
-		if (!rc)
-			pdev->ats->ref_cnt++;
-		mutex_unlock(&pdev->sriov->lock);
-		if (rc)
-			return rc;
-	}
-
-	if (!dev->is_physfn) {
-		rc = ats_alloc_one(dev, ps);
-		if (rc)
-			return rc;
+		atomic_inc(&pdev->ats->ref_cnt);  /* count enabled VFs */
+	} else {
+		dev->ats->stu = ps;
+		ctrl |= PCI_ATS_CTRL_STU(dev->ats->stu - PCI_ATS_MIN_STU);
 	}
-
-	ctrl = PCI_ATS_CTRL_ENABLE;
-	if (!dev->is_virtfn)
-		ctrl |= PCI_ATS_CTRL_STU(ps - PCI_ATS_MIN_STU);
 	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
 
 	dev->ats->is_enabled = 1;
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pci_enable_ats);
@@ -107,24 +108,20 @@ void pci_disable_ats(struct pci_dev *dev)
 
 	BUG_ON(!dev->ats || !dev->ats->is_enabled);
 
+	if (atomic_read(&dev->ats->ref_cnt))
+		return;		/* VFs still enabled */
+
+	if (dev->is_virtfn) {
+		struct pci_dev *pdev = dev->physfn;
+
+		atomic_dec(&pdev->ats->ref_cnt);
+	}
+
 	pci_read_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, &ctrl);
 	ctrl &= ~PCI_ATS_CTRL_ENABLE;
 	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
 
 	dev->ats->is_enabled = 0;
-
-	if (dev->is_physfn || dev->is_virtfn) {
-		struct pci_dev *pdev = dev->is_physfn ? dev : dev->physfn;
-
-		mutex_lock(&pdev->sriov->lock);
-		pdev->ats->ref_cnt--;
-		if (!pdev->ats->ref_cnt)
-			ats_free_one(pdev);
-		mutex_unlock(&pdev->sriov->lock);
-	}
-
-	if (!dev->is_physfn)
-		ats_free_one(dev);
 }
 EXPORT_SYMBOL_GPL(pci_disable_ats);
 
@@ -140,7 +137,6 @@ void pci_restore_ats_state(struct pci_dev *dev)
 	ctrl = PCI_ATS_CTRL_ENABLE;
 	if (!dev->is_virtfn)
 		ctrl |= PCI_ATS_CTRL_STU(dev->ats->stu - PCI_ATS_MIN_STU);
-
 	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
 }
 EXPORT_SYMBOL_GPL(pci_restore_ats_state);
@@ -159,23 +155,13 @@ EXPORT_SYMBOL_GPL(pci_restore_ats_state);
  */
 int pci_ats_queue_depth(struct pci_dev *dev)
 {
-	int pos;
-	u16 cap;
-
 	if (dev->is_virtfn)
 		return 0;
 
 	if (dev->ats)
 		return dev->ats->qdep;
 
-	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
-	if (!pos)
-		return -ENODEV;
-
-	pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
-
-	return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
-				       PCI_ATS_MAX_QDEP;
+	return -ENODEV;
 }
 EXPORT_SYMBOL_GPL(pci_ats_queue_depth);
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index cefd636681b6..c206398ca67e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1540,6 +1540,9 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	/* Single Root I/O Virtualization */
 	pci_iov_init(dev);
 
+	/* Address Translation Services */
+	pci_ats_init(dev);
+
 	/* Enable ACS P2P upstream forwarding */
 	pci_enable_acs(dev);
 }
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 8a280e9c2ad1..27617b862ca8 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -26,6 +26,7 @@ static void pci_stop_dev(struct pci_dev *dev)
 		dev->is_added = 0;
 	}
 
+	pci_ats_free(dev);
 	if (dev->bus->self)
 		pcie_aspm_exit_link_state(dev);
 }
diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
index 72031785fe1d..e2dcc2ff3d0e 100644
--- a/include/linux/pci-ats.h
+++ b/include/linux/pci-ats.h
@@ -8,7 +8,7 @@ struct pci_ats {
 	int pos;        /* capability position */
 	int stu;        /* Smallest Translation Unit */
 	int qdep;       /* Invalidate Queue Depth */
-	int ref_cnt;    /* Physical Function reference count */
+	atomic_t ref_cnt; /* number of VFs with ATS enabled */
 	unsigned int is_enabled:1;      /* Enable bit is set */
 };
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8a0321a8fb59..1817819ba57b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1294,6 +1294,15 @@ int  ht_create_irq(struct pci_dev *dev, int idx);
 void ht_destroy_irq(unsigned int irq);
 #endif /* CONFIG_HT_IRQ */
 
+#ifdef CONFIG_PCI_ATS
+/* Address Translation Service */
+void pci_ats_init(struct pci_dev *dev);
+void pci_ats_free(struct pci_dev *dev);
+#else
+static inline void pci_ats_init(struct pci_dev *dev) { }
+static inline void pci_ats_free(struct pci_dev *dev) { }
+#endif
+
 void pci_cfg_access_lock(struct pci_dev *dev);
 bool pci_cfg_access_trylock(struct pci_dev *dev);
 void pci_cfg_access_unlock(struct pci_dev *dev);
-- 
cgit v1.2.3


From d544d75ac96aa1b0a8a378826626a0fbd8ce4380 Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Fri, 17 Jul 2015 15:15:19 -0500
Subject: PCI: Embed ATS info directly into struct pci_dev

The pci_ats struct is small and will get smaller, so I don't think it's
worth allocating it separately from the pci_dev struct.

Embed the ATS fields directly into struct pci_dev.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/pci/ats.c       | 61 +++++++++++++++++--------------------------------
 drivers/pci/remove.c    |  1 -
 include/linux/pci-ats.h | 10 +-------
 include/linux/pci.h     |  8 ++++---
 4 files changed, 27 insertions(+), 53 deletions(-)

(limited to 'include/linux/pci.h')

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 2026f5388796..690ae6e6786c 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -21,29 +21,15 @@ static void ats_alloc_one(struct pci_dev *dev)
 {
 	int pos;
 	u16 cap;
-	struct pci_ats *ats;
 
 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
 	if (!pos)
 		return;
 
-	ats = kzalloc(sizeof(*ats), GFP_KERNEL);
-	if (!ats) {
-		dev_warn(&dev->dev, "can't allocate space for ATS state\n");
-		return;
-	}
-
-	ats->pos = pos;
-	pci_read_config_word(dev, pos + PCI_ATS_CAP, &cap);
-	ats->qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
+	dev->ats_cap = pos;
+	pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap);
+	dev->ats_qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
 					    PCI_ATS_MAX_QDEP;
-	dev->ats = ats;
-}
-
-static void ats_free_one(struct pci_dev *dev)
-{
-	kfree(dev->ats);
-	dev->ats = NULL;
 }
 
 void pci_ats_init(struct pci_dev *dev)
@@ -51,11 +37,6 @@ void pci_ats_init(struct pci_dev *dev)
 	ats_alloc_one(dev);
 }
 
-void pci_ats_free(struct pci_dev *dev)
-{
-	ats_free_one(dev);
-}
-
 /**
  * pci_enable_ats - enable the ATS capability
  * @dev: the PCI device
@@ -67,9 +48,9 @@ int pci_enable_ats(struct pci_dev *dev, int ps)
 {
 	u16 ctrl;
 
-	BUG_ON(dev->ats && dev->ats->is_enabled);
+	BUG_ON(dev->ats_cap && dev->ats_enabled);
 
-	if (!dev->ats)
+	if (!dev->ats_cap)
 		return -EINVAL;
 
 	if (ps < PCI_ATS_MIN_STU)
@@ -83,17 +64,17 @@ int pci_enable_ats(struct pci_dev *dev, int ps)
 	if (dev->is_virtfn) {
 		struct pci_dev *pdev = dev->physfn;
 
-		if (pdev->ats->stu != ps)
+		if (pdev->ats_stu != ps)
 			return -EINVAL;
 
-		atomic_inc(&pdev->ats->ref_cnt);  /* count enabled VFs */
+		atomic_inc(&pdev->ats_ref_cnt);  /* count enabled VFs */
 	} else {
-		dev->ats->stu = ps;
-		ctrl |= PCI_ATS_CTRL_STU(dev->ats->stu - PCI_ATS_MIN_STU);
+		dev->ats_stu = ps;
+		ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
 	}
-	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
+	pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
 
-	dev->ats->is_enabled = 1;
+	dev->ats_enabled = 1;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pci_enable_ats);
@@ -106,22 +87,22 @@ void pci_disable_ats(struct pci_dev *dev)
 {
 	u16 ctrl;
 
-	BUG_ON(!dev->ats || !dev->ats->is_enabled);
+	BUG_ON(!dev->ats_cap || !dev->ats_enabled);
 
-	if (atomic_read(&dev->ats->ref_cnt))
+	if (atomic_read(&dev->ats_ref_cnt))
 		return;		/* VFs still enabled */
 
 	if (dev->is_virtfn) {
 		struct pci_dev *pdev = dev->physfn;
 
-		atomic_dec(&pdev->ats->ref_cnt);
+		atomic_dec(&pdev->ats_ref_cnt);
 	}
 
-	pci_read_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, &ctrl);
+	pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, &ctrl);
 	ctrl &= ~PCI_ATS_CTRL_ENABLE;
-	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
+	pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
 
-	dev->ats->is_enabled = 0;
+	dev->ats_enabled = 0;
 }
 EXPORT_SYMBOL_GPL(pci_disable_ats);
 
@@ -136,8 +117,8 @@ void pci_restore_ats_state(struct pci_dev *dev)
 
 	ctrl = PCI_ATS_CTRL_ENABLE;
 	if (!dev->is_virtfn)
-		ctrl |= PCI_ATS_CTRL_STU(dev->ats->stu - PCI_ATS_MIN_STU);
-	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl);
+		ctrl |= PCI_ATS_CTRL_STU(dev->ats_stu - PCI_ATS_MIN_STU);
+	pci_write_config_word(dev, dev->ats_cap + PCI_ATS_CTRL, ctrl);
 }
 EXPORT_SYMBOL_GPL(pci_restore_ats_state);
 
@@ -158,8 +139,8 @@ int pci_ats_queue_depth(struct pci_dev *dev)
 	if (dev->is_virtfn)
 		return 0;
 
-	if (dev->ats)
-		return dev->ats->qdep;
+	if (dev->ats_cap)
+		return dev->ats_qdep;
 
 	return -ENODEV;
 }
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 27617b862ca8..8a280e9c2ad1 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -26,7 +26,6 @@ static void pci_stop_dev(struct pci_dev *dev)
 		dev->is_added = 0;
 	}
 
-	pci_ats_free(dev);
 	if (dev->bus->self)
 		pcie_aspm_exit_link_state(dev);
 }
diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
index e2dcc2ff3d0e..5d81d47b0a95 100644
--- a/include/linux/pci-ats.h
+++ b/include/linux/pci-ats.h
@@ -4,14 +4,6 @@
 #include <linux/pci.h>
 
 /* Address Translation Service */
-struct pci_ats {
-	int pos;        /* capability position */
-	int stu;        /* Smallest Translation Unit */
-	int qdep;       /* Invalidate Queue Depth */
-	atomic_t ref_cnt; /* number of VFs with ATS enabled */
-	unsigned int is_enabled:1;      /* Enable bit is set */
-};
-
 #ifdef CONFIG_PCI_ATS
 
 int pci_enable_ats(struct pci_dev *dev, int ps);
@@ -26,7 +18,7 @@ int pci_ats_queue_depth(struct pci_dev *dev);
  */
 static inline int pci_ats_enabled(struct pci_dev *dev)
 {
-	return dev->ats && dev->ats->is_enabled;
+	return dev->ats_cap && dev->ats_enabled;
 }
 
 #else /* CONFIG_PCI_ATS */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 1817819ba57b..8bc16b5e4747 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -343,6 +343,7 @@ struct pci_dev {
 	unsigned int	msi_enabled:1;
 	unsigned int	msix_enabled:1;
 	unsigned int	ari_enabled:1;	/* ARI forwarding */
+	unsigned int	ats_enabled:1;	/* Address Translation Service */
 	unsigned int	is_managed:1;
 	unsigned int    needs_freset:1; /* Dev requires fundamental reset */
 	unsigned int	state_saved:1;
@@ -375,7 +376,10 @@ struct pci_dev {
 		struct pci_sriov *sriov;	/* SR-IOV capability related */
 		struct pci_dev *physfn;	/* the PF this VF is associated with */
 	};
-	struct pci_ats	*ats;	/* Address Translation Service */
+	int		ats_cap;	/* ATS Capability offset */
+	int		ats_stu;	/* ATS Smallest Translation Unit */
+	int		ats_qdep;	/* ATS Invalidate Queue Depth */
+	atomic_t	ats_ref_cnt;	/* number of VFs with ATS enabled */
 #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 */
@@ -1297,10 +1301,8 @@ void ht_destroy_irq(unsigned int irq);
 #ifdef CONFIG_PCI_ATS
 /* Address Translation Service */
 void pci_ats_init(struct pci_dev *dev);
-void pci_ats_free(struct pci_dev *dev);
 #else
 static inline void pci_ats_init(struct pci_dev *dev) { }
-static inline void pci_ats_free(struct pci_dev *dev) { }
 #endif
 
 void pci_cfg_access_lock(struct pci_dev *dev);
-- 
cgit v1.2.3


From 67930995d7fb8ae7d2078822b563010b289ace2e Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Fri, 17 Jul 2015 15:27:34 -0500
Subject: PCI: Reduce size of ATS structure elements

The extended capabilities list is linked with 12-bit pointers, and the ATS
Smallest Translation Unit and Invalidate Queue Depth fields are both 5
bits.

Use u16 and u8 to hold the extended capability address and the stu and qdep
values.  No functional change.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
---
 include/linux/pci.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'include/linux/pci.h')

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8bc16b5e4747..238b77e8ca41 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -376,9 +376,9 @@ struct pci_dev {
 		struct pci_sriov *sriov;	/* SR-IOV capability related */
 		struct pci_dev *physfn;	/* the PF this VF is associated with */
 	};
-	int		ats_cap;	/* ATS Capability offset */
-	int		ats_stu;	/* ATS Smallest Translation Unit */
-	int		ats_qdep;	/* ATS Invalidate Queue Depth */
+	u16		ats_cap;	/* ATS Capability offset */
+	u8		ats_stu;	/* ATS Smallest Translation Unit */
+	u8		ats_qdep;	/* ATS Invalidate Queue Depth */
 	atomic_t	ats_ref_cnt;	/* number of VFs with ATS enabled */
 #endif
 	phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */
-- 
cgit v1.2.3


From ff9bee895c4d11a519a6b2c49451376025a6af4e Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Fri, 17 Jul 2015 15:55:48 -0500
Subject: PCI: Move ATS declarations to linux/pci.h so they're all together

Move ATS declarations to linux/pci.h so they're all in one place.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
---
 include/linux/pci-ats.h | 41 -----------------------------------------
 include/linux/pci.h     | 10 +++++++++-
 2 files changed, 9 insertions(+), 42 deletions(-)

(limited to 'include/linux/pci.h')

diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
index 5d81d47b0a95..57e0b8250947 100644
--- a/include/linux/pci-ats.h
+++ b/include/linux/pci-ats.h
@@ -3,47 +3,6 @@
 
 #include <linux/pci.h>
 
-/* Address Translation Service */
-#ifdef CONFIG_PCI_ATS
-
-int pci_enable_ats(struct pci_dev *dev, int ps);
-void pci_disable_ats(struct pci_dev *dev);
-int pci_ats_queue_depth(struct pci_dev *dev);
-
-/**
- * pci_ats_enabled - query the ATS status
- * @dev: the PCI device
- *
- * Returns 1 if ATS capability is enabled, or 0 if not.
- */
-static inline int pci_ats_enabled(struct pci_dev *dev)
-{
-	return dev->ats_cap && dev->ats_enabled;
-}
-
-#else /* CONFIG_PCI_ATS */
-
-static inline int pci_enable_ats(struct pci_dev *dev, int ps)
-{
-	return -ENODEV;
-}
-
-static inline void pci_disable_ats(struct pci_dev *dev)
-{
-}
-
-static inline int pci_ats_queue_depth(struct pci_dev *dev)
-{
-	return -ENODEV;
-}
-
-static inline int pci_ats_enabled(struct pci_dev *dev)
-{
-	return 0;
-}
-
-#endif /* CONFIG_PCI_ATS */
-
 #ifdef CONFIG_PCI_PRI
 
 int pci_enable_pri(struct pci_dev *pdev, u32 reqs);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 238b77e8ca41..307f96a58e8b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1301,8 +1301,16 @@ void ht_destroy_irq(unsigned int irq);
 #ifdef CONFIG_PCI_ATS
 /* Address Translation Service */
 void pci_ats_init(struct pci_dev *dev);
+int pci_enable_ats(struct pci_dev *dev, int ps);
+void pci_disable_ats(struct pci_dev *dev);
+int pci_ats_queue_depth(struct pci_dev *dev);
+static inline int pci_ats_enabled(struct pci_dev *dev) { return dev->ats_cap && dev->ats_enabled; }
 #else
-static inline void pci_ats_init(struct pci_dev *dev) { }
+static inline void pci_ats_init(struct pci_dev *d) { }
+static inline int pci_enable_ats(struct pci_dev *d, int ps) { return -ENODEV; }
+static inline void pci_disable_ats(struct pci_dev *d) { }
+static inline int pci_ats_queue_depth(struct pci_dev *d) { return -ENODEV; }
+static inline int pci_ats_enabled(struct pci_dev *d) { return 0; }
 #endif
 
 void pci_cfg_access_lock(struct pci_dev *dev);
-- 
cgit v1.2.3


From a71f938f3a9a7bc879296cd34ecae9effe5edf3f Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Mon, 20 Jul 2015 09:24:32 -0500
Subject: PCI: Stop caching ATS Invalidate Queue Depth

Stop caching the Invalidate Queue Depth in struct pci_dev.
pci_ats_queue_depth() is typically called only once per device, and it
returns a fixed value per-device, so callers who need the value frequently
can cache it themselves.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/pci/ats.c   | 9 ++++-----
 include/linux/pci.h | 1 -
 2 files changed, 4 insertions(+), 6 deletions(-)

(limited to 'include/linux/pci.h')

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 9355f754c7c2..ceda7dc556d4 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -20,16 +20,12 @@
 void pci_ats_init(struct pci_dev *dev)
 {
 	int pos;
-	u16 cap;
 
 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS);
 	if (!pos)
 		return;
 
 	dev->ats_cap = pos;
-	pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap);
-	dev->ats_qdep = PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) :
-					    PCI_ATS_MAX_QDEP;
 }
 
 /**
@@ -131,13 +127,16 @@ EXPORT_SYMBOL_GPL(pci_restore_ats_state);
  */
 int pci_ats_queue_depth(struct pci_dev *dev)
 {
+	u16 cap;
+
 	if (!dev->ats_cap)
 		return -EINVAL;
 
 	if (dev->is_virtfn)
 		return 0;
 
-	return dev->ats_qdep;
+	pci_read_config_word(dev, dev->ats_cap + PCI_ATS_CAP, &cap);
+	return PCI_ATS_CAP_QDEP(cap) ? PCI_ATS_CAP_QDEP(cap) : PCI_ATS_MAX_QDEP;
 }
 EXPORT_SYMBOL_GPL(pci_ats_queue_depth);
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 307f96a58e8b..4b484fdfd66f 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -378,7 +378,6 @@ struct pci_dev {
 	};
 	u16		ats_cap;	/* ATS Capability offset */
 	u8		ats_stu;	/* ATS Smallest Translation Unit */
-	u8		ats_qdep;	/* ATS Invalidate Queue Depth */
 	atomic_t	ats_ref_cnt;	/* number of VFs with ATS enabled */
 #endif
 	phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */
-- 
cgit v1.2.3


From f7ef1340bb501717372a39f4807d0ad519ebd432 Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Mon, 20 Jul 2015 09:23:37 -0500
Subject: PCI: Remove pci_ats_enabled()

Remove pci_ats_enabled().  There are no callers outside the ATS code
itself.  We don't need to check ats_cap, because if we don't find an ATS
capability, we'll never set ats_enabled.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/pci/ats.c   | 6 +++---
 include/linux/pci.h | 2 --
 2 files changed, 3 insertions(+), 5 deletions(-)

(limited to 'include/linux/pci.h')

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index ceda7dc556d4..eeb9fb2b47aa 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -43,7 +43,7 @@ int pci_enable_ats(struct pci_dev *dev, int ps)
 	if (!dev->ats_cap)
 		return -EINVAL;
 
-	if (WARN_ON(pci_ats_enabled(dev)))
+	if (WARN_ON(dev->ats_enabled))
 		return -EBUSY;
 
 	if (ps < PCI_ATS_MIN_STU)
@@ -80,7 +80,7 @@ void pci_disable_ats(struct pci_dev *dev)
 	struct pci_dev *pdev;
 	u16 ctrl;
 
-	if (WARN_ON(!pci_ats_enabled(dev)))
+	if (WARN_ON(!dev->ats_enabled))
 		return;
 
 	if (atomic_read(&dev->ats_ref_cnt))
@@ -103,7 +103,7 @@ void pci_restore_ats_state(struct pci_dev *dev)
 {
 	u16 ctrl;
 
-	if (!pci_ats_enabled(dev))
+	if (!dev->ats_enabled)
 		return;
 
 	ctrl = PCI_ATS_CTRL_ENABLE;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 4b484fdfd66f..806da7634f91 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1303,13 +1303,11 @@ void pci_ats_init(struct pci_dev *dev);
 int pci_enable_ats(struct pci_dev *dev, int ps);
 void pci_disable_ats(struct pci_dev *dev);
 int pci_ats_queue_depth(struct pci_dev *dev);
-static inline int pci_ats_enabled(struct pci_dev *dev) { return dev->ats_cap && dev->ats_enabled; }
 #else
 static inline void pci_ats_init(struct pci_dev *d) { }
 static inline int pci_enable_ats(struct pci_dev *d, int ps) { return -ENODEV; }
 static inline void pci_disable_ats(struct pci_dev *d) { }
 static inline int pci_ats_queue_depth(struct pci_dev *d) { return -ENODEV; }
-static inline int pci_ats_enabled(struct pci_dev *d) { return 0; }
 #endif
 
 void pci_cfg_access_lock(struct pci_dev *dev);
-- 
cgit v1.2.3