[PATCH 00/11] PCI: pci_resource_alignment() improvement + cleanups

[PATCH 00/11] PCI: pci_resource_alignment() improvement + cleanups

[Ilpo Järvinen]

pci_resource_alignment() returns 0 when resource is already assigned
and in case of disabled bridge windows. This has caused problems to
calculations relying on pci_resource_alignment():

https://lore.kernel.org/linux-pci/LV8P221MB1472A24B9975F7C8E8D6BF929947A@LV8P221MB1472.NAMP221.PROD.OUTLOOK.COM/

This series reworks pci_resource_alignment() interface to return always
non-zero alignment if the resource exists. For assigned bridge windows,
the calculation is using heuristic based on size and start address
alignment as calculating the alignment again is costly (would require
sizing the entire sub-hierarchy).

As pci_resource_alignment() is becoming more complicated, it's also
moved to setup-res.c. While moving pci_resource_alignment()'s arguments
are converted into const to tell compiler it can rely on resource
remaining the same across the call.

This was intended to be part of a larger series that addresses some
shortcomings in pci=realloc. The pci=realloc changes will recalculate
bridge window sizes considering also assigned resources which required
making these changes to pci_resource_alignment().

As this also relates to the issue linked above, I'm sending it already
now without pci=realloc changes that are still incomplete. The first
patches originate from the large pci=realloc work but seem generally
useful even if independent of the alignment improvements so I've
included them here without reorganizing the series to contain only
alignment related changes.

Ilpo Järvinen (11):
  PCI: Log all resource claims
  PCI: Rename added to add_list
  PCI: Consolidate add_list (aka realloc_head) empty sanity checks
  PCI: Remove const removal cast
  resource: Make resource_alignment() input const resource
  powerpc/pseries: Make pseries_get_iov_fw_value() & pnv_iov_get()
    pci_dev const
  PCI: Make pci_sriov_resource_alignment() pci_dev const
  PCI: Convert pci_resource_alignment() input parameters to const
  PCI: Move pci_resource_alignment() to setup-res.c file
  PCI: Lower bound bridge windown alignment
  PCI: Return valid alignment for assigned resources

 arch/powerpc/include/asm/machdep.h         |  2 +-
 arch/powerpc/kernel/pci-common.c           |  2 +-
 arch/powerpc/platforms/powernv/pci-sriov.c |  4 +-
 arch/powerpc/platforms/powernv/pci.h       |  5 ++-
 arch/powerpc/platforms/pseries/setup.c     |  5 ++-
 drivers/pci/iov.c                          |  7 +--
 drivers/pci/pci.h                          | 24 ++++-------
 drivers/pci/setup-bus.c                    | 50 ++++++++++++----------
 drivers/pci/setup-cardbus.c                |  2 +-
 drivers/pci/setup-res.c                    | 37 ++++++++++++++++
 include/linux/ioport.h                     |  2 +-
 include/linux/pci.h                        |  8 ++--
 kernel/resource.c                          |  2 +-
 13 files changed, 94 insertions(+), 56 deletions(-)


base-commit: 254f49634ee16a731174d2ae34bc50bd5f45e731
-- 
2.39.5

[PATCH 01/11] PCI: Log all resource claims

[Ilpo Järvinen]

There are two ways to graft resource into resource tree in PCI,
pci_assign_resource() and pci_claim_resource(). Only the former logs
the action which complicated troubleshooting the cases where resources
are assigned by pci_claim_resource() which mostly assigns the addresses
inherited from the FW.

Add logging into pci_claim_resource() to make troubleshooting easier.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/setup-res.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index fbc05cda96ee..0d203325562b 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -167,6 +167,8 @@ int pci_claim_resource(struct pci_dev *dev, int resource)
 		return -EBUSY;
 	}
 
+	pci_dbg(dev, "%s %pR: claiming\n", res_name, res);
+
 	return 0;
 }
 EXPORT_SYMBOL(pci_claim_resource);
-- 
2.39.5

[PATCH 02/11] PCI: Rename added to add_list

[Ilpo Järvinen]

The resource fitting algorithm uses different names from the list
holding the optional sizes: added, add_head, add_list, and
realloc_head. 'add_list' sounds the most natural and some of the
related variables also use 'add' such as 'add_size'.

To reduce variation, rename 'added' and 'add_head' to 'add_list'.
Also rename some 'realloc_head' cases selectively to 'add_list'.

While it would be nice to rename every 'realloc_head' to 'add_list' for
consistency, it might create a backport headache with all to work going
into this algorithm that may need to be eventually backported. Thus,
it's better to leave 'realloc_head' as is for now.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/pci.h       |  2 +-
 drivers/pci/setup-bus.c | 26 +++++++++++++-------------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 4a14f88e543a..4fcf5a25ad9e 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -515,7 +515,7 @@ int pci_dev_res_add_to_list(struct list_head *head, struct pci_dev *dev,
 void __pci_bus_size_bridges(struct pci_bus *bus,
 			struct list_head *realloc_head);
 void __pci_bus_assign_resources(const struct pci_bus *bus,
-				struct list_head *realloc_head,
+				struct list_head *add_list,
 				struct list_head *fail_head);
 bool pci_bus_clip_resource(struct pci_dev *dev, int idx);
 void pci_walk_bus_locked(struct pci_bus *top,
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 4cf120ebe5ad..3765693e95f0 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -756,13 +756,13 @@ static void __assign_resources_sorted(struct list_head *head,
 }
 
 static void pdev_assign_resources_sorted(struct pci_dev *dev,
-					 struct list_head *add_head,
+					 struct list_head *add_list,
 					 struct list_head *fail_head)
 {
 	LIST_HEAD(head);
 
 	pdev_sort_resources(dev, &head);
-	__assign_resources_sorted(&head, add_head, fail_head);
+	__assign_resources_sorted(&head, add_list, fail_head);
 
 }
 
@@ -1502,13 +1502,13 @@ static void pdev_assign_fixed_resources(struct pci_dev *dev)
 }
 
 void __pci_bus_assign_resources(const struct pci_bus *bus,
-				struct list_head *realloc_head,
+				struct list_head *add_list,
 				struct list_head *fail_head)
 {
 	struct pci_bus *b;
 	struct pci_dev *dev;
 
-	pbus_assign_resources_sorted(bus, realloc_head, fail_head);
+	pbus_assign_resources_sorted(bus, add_list, fail_head);
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		pdev_assign_fixed_resources(dev);
@@ -1517,7 +1517,7 @@ void __pci_bus_assign_resources(const struct pci_bus *bus,
 		if (!b)
 			continue;
 
-		__pci_bus_assign_resources(b, realloc_head, fail_head);
+		__pci_bus_assign_resources(b, add_list, fail_head);
 
 		switch (dev->hdr_type) {
 		case PCI_HEADER_TYPE_BRIDGE:
@@ -1613,19 +1613,19 @@ void pci_bus_claim_resources(struct pci_bus *b)
 EXPORT_SYMBOL(pci_bus_claim_resources);
 
 static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
-					  struct list_head *add_head,
+					  struct list_head *add_list,
 					  struct list_head *fail_head)
 {
 	struct pci_bus *b;
 
 	pdev_assign_resources_sorted((struct pci_dev *)bridge,
-					 add_head, fail_head);
+				     add_list, fail_head);
 
 	b = bridge->subordinate;
 	if (!b)
 		return;
 
-	__pci_bus_assign_resources(b, add_head, fail_head);
+	__pci_bus_assign_resources(b, add_list, fail_head);
 
 	switch (bridge->class >> 8) {
 	case PCI_CLASS_BRIDGE_PCI:
@@ -2303,7 +2303,7 @@ static int pbus_reassign_bridge_resources(struct pci_bus *bus, struct resource *
 	unsigned long type = res->flags;
 	struct pci_dev_resource *dev_res;
 	struct pci_dev *bridge = NULL;
-	LIST_HEAD(added);
+	LIST_HEAD(add_list);
 	LIST_HEAD(failed);
 	unsigned int i;
 	int ret = 0;
@@ -2337,10 +2337,10 @@ static int pbus_reassign_bridge_resources(struct pci_bus *bus, struct resource *
 	if (!bridge)
 		return -ENOENT;
 
-	__pci_bus_size_bridges(bridge->subordinate, &added);
-	__pci_bridge_assign_resources(bridge, &added, &failed);
-	if (WARN_ON_ONCE(!list_empty(&added)))
-		pci_dev_res_free_list(&added);
+	__pci_bus_size_bridges(bridge->subordinate, &add_list);
+	__pci_bridge_assign_resources(bridge, &add_list, &failed);
+	if (WARN_ON_ONCE(!list_empty(&add_list)))
+		pci_dev_res_free_list(&add_list);
 
 	if (!list_empty(&failed)) {
 		if (pci_required_resource_failed(&failed, type))
-- 
2.39.5

[PATCH 03/11] PCI: Consolidate add_list (aka realloc_head) empty sanity checks

[Ilpo Järvinen]

Callers of __pci_bridge_assign_resources() and
__pci_bus_assign_resources() perform
WARN_ON_ONCE(list_empty(add_list))) checks to sanity check that all
optional sizes were processed (and removed) from the list. The empty
list sanity check is duplicated code so the more appropriate place for
it would be inside the called function.

Placing the empty list check into __pci_bus_assign_resources() also
ensures all callsites do perform the sanity check which currently is
not the case when being called from enable_slot(). This inconsistency
was noted by Sashiko though only inside its in depth log but not
flagged as a real problem, possibly because this is only a sanity check
that should never fire. Nonetheless, this sanity check has been very
useful to catch problems early in the past so it's good to do it
consistenty everywhere.

As __pci_bus_assign_resources() is recursive function, it needs to be
renamed to __pci_bus_assign_resources_one() to only perform the empty
list check at the end of processing the entire hierarchy in
__pci_bus_assign_resources().

Suggested-by: sashiko.dev # Sanity check missing from enable_slot()
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/setup-bus.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 3765693e95f0..1e0e28efe8b8 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1501,9 +1501,9 @@ static void pdev_assign_fixed_resources(struct pci_dev *dev)
 	}
 }
 
-void __pci_bus_assign_resources(const struct pci_bus *bus,
-				struct list_head *add_list,
-				struct list_head *fail_head)
+static void __pci_bus_assign_resources_one(const struct pci_bus *bus,
+					   struct list_head *add_list,
+					   struct list_head *fail_head)
 {
 	struct pci_bus *b;
 	struct pci_dev *dev;
@@ -1517,7 +1517,7 @@ void __pci_bus_assign_resources(const struct pci_bus *bus,
 		if (!b)
 			continue;
 
-		__pci_bus_assign_resources(b, add_list, fail_head);
+		__pci_bus_assign_resources_one(b, add_list, fail_head);
 
 		switch (dev->hdr_type) {
 		case PCI_HEADER_TYPE_BRIDGE:
@@ -1537,6 +1537,16 @@ void __pci_bus_assign_resources(const struct pci_bus *bus,
 	}
 }
 
+void __pci_bus_assign_resources(const struct pci_bus *bus,
+				struct list_head *add_list,
+				struct list_head *fail_head)
+{
+	__pci_bus_assign_resources_one(bus, add_list, fail_head);
+
+	if (WARN_ON_ONCE(add_list && !list_empty(add_list)))
+		pci_dev_res_free_list(add_list);
+}
+
 void pci_bus_assign_resources(const struct pci_bus *bus)
 {
 	__pci_bus_assign_resources(bus, NULL, NULL);
@@ -1641,6 +1651,9 @@ static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
 			 pci_domain_nr(b), b->number);
 		break;
 	}
+
+	if (WARN_ON_ONCE(add_list && !list_empty(add_list)))
+		pci_dev_res_free_list(add_list);
 }
 
 static void pci_bridge_release_resources(struct pci_bus *bus,
@@ -2205,8 +2218,6 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
 
 		/* Depth last, allocate resources and update the hardware. */
 		__pci_bus_assign_resources(bus, add_list, &fail_head);
-		if (WARN_ON_ONCE(add_list && !list_empty(add_list)))
-			pci_dev_res_free_list(add_list);
 		tried_times++;
 
 		/* Any device complain? */
@@ -2268,8 +2279,6 @@ void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
 		pci_bridge_distribute_available_resources(bridge, &add_list);
 
 		__pci_bridge_assign_resources(bridge, &add_list, &fail_head);
-		if (WARN_ON_ONCE(!list_empty(&add_list)))
-			pci_dev_res_free_list(&add_list);
 		tried_times++;
 
 		if (list_empty(&fail_head))
@@ -2339,8 +2348,6 @@ static int pbus_reassign_bridge_resources(struct pci_bus *bus, struct resource *
 
 	__pci_bus_size_bridges(bridge->subordinate, &add_list);
 	__pci_bridge_assign_resources(bridge, &add_list, &failed);
-	if (WARN_ON_ONCE(!list_empty(&add_list)))
-		pci_dev_res_free_list(&add_list);
 
 	if (!list_empty(&failed)) {
 		if (pci_required_resource_failed(&failed, type))
@@ -2473,7 +2480,5 @@ void pci_assign_unassigned_bus_resources(struct pci_bus *bus)
 			__pci_bus_size_bridges(dev->subordinate, &add_list);
 	up_read(&pci_bus_sem);
 	__pci_bus_assign_resources(bus, &add_list, NULL);
-	if (WARN_ON_ONCE(!list_empty(&add_list)))
-		pci_dev_res_free_list(&add_list);
 }
 EXPORT_SYMBOL_GPL(pci_assign_unassigned_bus_resources);
-- 
2.39.5

[PATCH 04/11] PCI: Remove const removal cast

[Ilpo Järvinen]

__pci_bridge_assign_resources() inputs const pci_dev *bridge, but then
immediately casts const away to pass the bridge to
pdev_assign_resources_sorted().

As pdev_assign_resources_sorted() performs assignment of resources, it
is not possible to make its input parameter to const. Neither of the
__pci_bridge_assign_resources() callers requires the bridge parameter
to be const.

Thus, simply remove the out of place cast and convert the input
parameter to non-const.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/setup-bus.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 1e0e28efe8b8..c0a949f2c995 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1622,14 +1622,13 @@ void pci_bus_claim_resources(struct pci_bus *b)
 }
 EXPORT_SYMBOL(pci_bus_claim_resources);
 
-static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
+static void __pci_bridge_assign_resources(struct pci_dev *bridge,
 					  struct list_head *add_list,
 					  struct list_head *fail_head)
 {
 	struct pci_bus *b;
 
-	pdev_assign_resources_sorted((struct pci_dev *)bridge,
-				     add_list, fail_head);
+	pdev_assign_resources_sorted(bridge, add_list, fail_head);
 
 	b = bridge->subordinate;
 	if (!b)
-- 
2.39.5

[PATCH 05/11] resource: Make resource_alignment() input const resource

[Ilpo Järvinen]

resource_alignment() does not need to change resource so it can be
made const.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 include/linux/ioport.h | 2 +-
 kernel/resource.c      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 3c73c9c0d4f7..f7930b3dfd0a 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -261,7 +261,7 @@ extern int allocate_resource(struct resource *root, struct resource *new,
 struct resource *lookup_resource(struct resource *root, resource_size_t start);
 int adjust_resource(struct resource *res, resource_size_t start,
 		    resource_size_t size);
-resource_size_t resource_alignment(struct resource *res);
+resource_size_t resource_alignment(const struct resource *res);
 
 /**
  * resource_set_size - Calculate resource end address from size and start
diff --git a/kernel/resource.c b/kernel/resource.c
index d02a53fb95d8..3d17e3196a3e 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1238,7 +1238,7 @@ reserve_region_with_split(struct resource *root, resource_size_t start,
  *
  * Returns alignment on success, 0 (invalid alignment) on failure.
  */
-resource_size_t resource_alignment(struct resource *res)
+resource_size_t resource_alignment(const struct resource *res)
 {
 	switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) {
 	case IORESOURCE_SIZEALIGN:
-- 
2.39.5

[PATCH 06/11] powerpc/pseries: Make pseries_get_iov_fw_value() & pnv_iov_get() pci_dev const

[Ilpo Järvinen]

Convert input pci_dev for pseries_get_iov_fw_value() and pnv_iov_get()
to const to be able to convert pcibios_iov_resource_alignment() as well
in an upcoming change.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 arch/powerpc/platforms/powernv/pci.h   | 2 +-
 arch/powerpc/platforms/pseries/setup.c | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 42075501663b..032b2081aedb 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -251,7 +251,7 @@ struct pnv_iov_data {
 	struct resource holes[PCI_SRIOV_NUM_BARS];
 };
 
-static inline struct pnv_iov_data *pnv_iov_get(struct pci_dev *pdev)
+static inline struct pnv_iov_data *pnv_iov_get(const struct pci_dev *pdev)
 {
 	return pdev->dev.archdata.iov_data;
 }
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 50b26ed8432d..b670c6fdfcea 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -658,7 +658,8 @@ enum get_iov_fw_value_index {
 	WDW_SIZE      = 3     /*  Get Window Size */
 };
 
-static resource_size_t pseries_get_iov_fw_value(struct pci_dev *dev, int resno,
+static resource_size_t pseries_get_iov_fw_value(const struct pci_dev *dev,
+						int resno,
 						enum get_iov_fw_value_index value)
 {
 	const int *indexes;
-- 
2.39.5

[PATCH 07/11] PCI: Make pci_sriov_resource_alignment() pci_dev const

[Ilpo Järvinen]

pci_sriov_resource_alignment() inputs struct pci_dev which it should not
need to alter to calculate alignment.

Make pci_dev pci_sriov_resource_alignment() inputs const. It requires
making pci_iov_resource_size() input const as well.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 arch/powerpc/include/asm/machdep.h         | 2 +-
 arch/powerpc/kernel/pci-common.c           | 2 +-
 arch/powerpc/platforms/powernv/pci-sriov.c | 4 ++--
 arch/powerpc/platforms/powernv/pci.h       | 3 ++-
 arch/powerpc/platforms/pseries/setup.c     | 2 +-
 drivers/pci/iov.c                          | 7 ++++---
 drivers/pci/pci.h                          | 5 +++--
 include/linux/pci.h                        | 8 +++++---
 8 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 3298eec123a3..256f9309bf4f 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -169,7 +169,7 @@ struct machdep_calls {
 
 #ifdef CONFIG_PCI_IOV
 	void (*pcibios_fixup_sriov)(struct pci_dev *pdev);
-	resource_size_t (*pcibios_iov_resource_alignment)(struct pci_dev *, int resno);
+	resource_size_t (*pcibios_iov_resource_alignment)(const struct pci_dev *, int resno);
 	int (*pcibios_sriov_enable)(struct pci_dev *pdev, u16 num_vfs);
 	int (*pcibios_sriov_disable)(struct pci_dev *pdev);
 #endif /* CONFIG_PCI_IOV */
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 8efe95a0c4ff..3c4ca90e2ab7 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -254,7 +254,7 @@ resource_size_t pcibios_default_alignment(void)
 }
 
 #ifdef CONFIG_PCI_IOV
-resource_size_t pcibios_iov_resource_alignment(struct pci_dev *pdev, int resno)
+resource_size_t pcibios_iov_resource_alignment(const struct pci_dev *pdev, int resno)
 {
 	if (ppc_md.pcibios_iov_resource_alignment)
 		return ppc_md.pcibios_iov_resource_alignment(pdev, resno);
diff --git a/arch/powerpc/platforms/powernv/pci-sriov.c b/arch/powerpc/platforms/powernv/pci-sriov.c
index 7105a573aec4..8652078801f2 100644
--- a/arch/powerpc/platforms/powernv/pci-sriov.c
+++ b/arch/powerpc/platforms/powernv/pci-sriov.c
@@ -244,8 +244,8 @@ void pnv_pci_ioda_fixup_iov(struct pci_dev *pdev)
 	}
 }
 
-resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev,
-						      int resno)
+resource_size_t pnv_pci_iov_resource_alignment(const struct pci_dev *pdev,
+					       int resno)
 {
 	resource_size_t align = pci_iov_resource_size(pdev, resno);
 	struct pnv_phb *phb = pci_bus_to_pnvhb(pdev->bus);
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 032b2081aedb..3ac718d471c2 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -257,7 +257,8 @@ static inline struct pnv_iov_data *pnv_iov_get(const struct pci_dev *pdev)
 }
 
 void pnv_pci_ioda_fixup_iov(struct pci_dev *pdev);
-resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev, int resno);
+resource_size_t pnv_pci_iov_resource_alignment(const struct pci_dev *pdev,
+					       int resno);
 
 int pnv_pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs);
 int pnv_pcibios_sriov_disable(struct pci_dev *pdev);
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index b670c6fdfcea..1223dc961242 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -789,7 +789,7 @@ static void pseries_pci_fixup_iov_resources(struct pci_dev *pdev)
 		pseries_disable_sriov_resources(pdev);
 }
 
-static resource_size_t pseries_pci_iov_resource_alignment(struct pci_dev *pdev,
+static resource_size_t pseries_pci_iov_resource_alignment(const struct pci_dev *pdev,
 							  int resno)
 {
 	const __be32 *reg;
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 91ac4e37ecb9..c86409835f73 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -150,7 +150,7 @@ static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
 		pci_remove_bus(virtbus);
 }
 
-resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
+resource_size_t pci_iov_resource_size(const struct pci_dev *dev, int resno)
 {
 	if (!dev->is_physfn)
 		return 0;
@@ -1084,7 +1084,7 @@ void pci_iov_update_resource(struct pci_dev *dev, int resno)
 	}
 }
 
-resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
+resource_size_t __weak pcibios_iov_resource_alignment(const struct pci_dev *dev,
 						      int resno)
 {
 	return pci_iov_resource_size(dev, resno);
@@ -1100,7 +1100,8 @@ resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
  * the VF BAR size multiplied by the number of VFs.  The alignment
  * is just the VF BAR size.
  */
-resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
+resource_size_t pci_sriov_resource_alignment(const struct pci_dev *dev,
+					     int resno)
 {
 	return pcibios_iov_resource_alignment(dev, resno);
 }
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 4fcf5a25ad9e..710803be3a79 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -947,7 +947,8 @@ int pci_iov_init(struct pci_dev *dev);
 void pci_iov_release(struct pci_dev *dev);
 void pci_iov_remove(struct pci_dev *dev);
 void pci_iov_update_resource(struct pci_dev *dev, int resno);
-resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno);
+resource_size_t pci_sriov_resource_alignment(const struct pci_dev *dev,
+					     int resno);
 void pci_restore_iov_state(struct pci_dev *dev);
 int pci_iov_bus_range(struct pci_bus *bus);
 void pci_iov_resource_set_size(struct pci_dev *dev, int resno, int size);
@@ -981,7 +982,7 @@ static inline int pci_iov_init(struct pci_dev *dev)
 static inline void pci_iov_release(struct pci_dev *dev) { }
 static inline void pci_iov_remove(struct pci_dev *dev) { }
 static inline void pci_iov_update_resource(struct pci_dev *dev, int resno) { }
-static inline resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev,
+static inline resource_size_t pci_sriov_resource_alignment(const struct pci_dev *dev,
 							   int resno)
 {
 	return 0;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 2c4454583c11..0ced3bbd08c0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2540,7 +2540,7 @@ int pci_vfs_assigned(struct pci_dev *dev);
 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
 int pci_sriov_get_totalvfs(struct pci_dev *dev);
 int pci_sriov_configure_simple(struct pci_dev *dev, int nr_virtfn);
-resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno);
+resource_size_t pci_iov_resource_size(const struct pci_dev *dev, int resno);
 int pci_iov_vf_bar_set_size(struct pci_dev *dev, int resno, int size);
 u32 pci_iov_vf_bar_get_sizes(struct pci_dev *dev, int resno, int num_vfs);
 void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool probe);
@@ -2548,7 +2548,8 @@ void pci_vf_drivers_autoprobe(struct pci_dev *dev, bool probe);
 /* Arch may override these (weak) */
 int pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs);
 int pcibios_sriov_disable(struct pci_dev *pdev);
-resource_size_t pcibios_iov_resource_alignment(struct pci_dev *dev, int resno);
+resource_size_t pcibios_iov_resource_alignment(const struct pci_dev *dev,
+					       int resno);
 #else
 static inline int pci_iov_virtfn_bus(struct pci_dev *dev, int id)
 {
@@ -2593,7 +2594,8 @@ static inline int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
 static inline int pci_sriov_get_totalvfs(struct pci_dev *dev)
 { return 0; }
 #define pci_sriov_configure_simple	NULL
-static inline resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
+static inline resource_size_t pci_iov_resource_size(const struct pci_dev *dev,
+						    int resno)
 { return 0; }
 static inline int pci_iov_vf_bar_set_size(struct pci_dev *dev, int resno, int size)
 { return -ENODEV; }
-- 
2.39.5

[PATCH 08/11] PCI: Convert pci_resource_alignment() input parameters to const

[Ilpo Järvinen]

pci_resource_alignment() calculates resource alignment and should not
alter its input structs. Make its input parameters const.

It requires making also pci_cardbus_resource_alignment() input const.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/pci.h           | 8 ++++----
 drivers/pci/setup-cardbus.c | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 710803be3a79..e0fcc33dfef6 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -419,7 +419,7 @@ static inline bool pci_is_cardbus_bridge(struct pci_dev *dev)
 	return dev->hdr_type == PCI_HEADER_TYPE_CARDBUS;
 }
 #ifdef CONFIG_CARDBUS
-unsigned long pci_cardbus_resource_alignment(struct resource *res);
+unsigned long pci_cardbus_resource_alignment(const struct resource *res);
 int pci_bus_size_cardbus_bridge(struct pci_bus *bus,
 				struct list_head *realloc_head);
 int pci_cardbus_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
@@ -428,7 +428,7 @@ int pci_cardbus_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
 int pci_setup_cardbus(char *str);
 
 #else
-static inline unsigned long pci_cardbus_resource_alignment(struct resource *res)
+static inline unsigned long pci_cardbus_resource_alignment(const struct resource *res)
 {
 	return 0;
 }
@@ -1044,8 +1044,8 @@ static inline void pci_suspend_ptm(struct pci_dev *dev) { }
 static inline void pci_resume_ptm(struct pci_dev *dev) { }
 #endif
 
-static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
-						     struct resource *res)
+static inline resource_size_t pci_resource_alignment(const struct pci_dev *dev,
+						     const struct resource *res)
 {
 	int resno = pci_resource_num(dev, res);
 
diff --git a/drivers/pci/setup-cardbus.c b/drivers/pci/setup-cardbus.c
index 1ebd13a1f730..0cba404080ad 100644
--- a/drivers/pci/setup-cardbus.c
+++ b/drivers/pci/setup-cardbus.c
@@ -22,7 +22,7 @@
 static unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
 static unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
 
-unsigned long pci_cardbus_resource_alignment(struct resource *res)
+unsigned long pci_cardbus_resource_alignment(const struct resource *res)
 {
 	if (res->flags & IORESOURCE_IO)
 		return pci_cardbus_io_size;
-- 
2.39.5

[PATCH 09/11] PCI: Move pci_resource_alignment() to setup-res.c file

[Ilpo Järvinen]

pci_resource_alignment() is a bit one the complex side to have in a
header so put it into setup-res.c.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/pci.h       | 13 ++-----------
 drivers/pci/setup-res.c | 12 ++++++++++++
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index e0fcc33dfef6..472b6c2f7c4d 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -1044,17 +1044,8 @@ static inline void pci_suspend_ptm(struct pci_dev *dev) { }
 static inline void pci_resume_ptm(struct pci_dev *dev) { }
 #endif
 
-static inline resource_size_t pci_resource_alignment(const struct pci_dev *dev,
-						     const struct resource *res)
-{
-	int resno = pci_resource_num(dev, res);
-
-	if (pci_resource_is_iov(resno))
-		return pci_sriov_resource_alignment(dev, resno);
-	if (dev->class >> 8 == PCI_CLASS_BRIDGE_CARDBUS)
-		return pci_cardbus_resource_alignment(res);
-	return resource_alignment(res);
-}
+resource_size_t pci_resource_alignment(const struct pci_dev *dev,
+				       const struct resource *res);
 
 resource_size_t pci_min_window_alignment(struct pci_bus *bus,
 					 unsigned long type);
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 0d203325562b..18e8775ea848 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -246,6 +246,18 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev,
 	return 0;
 }
 
+resource_size_t pci_resource_alignment(const struct pci_dev *dev,
+				       const struct resource *res)
+{
+	int resno = pci_resource_num(dev, res);
+
+	if (pci_resource_is_iov(resno))
+		return pci_sriov_resource_alignment(dev, resno);
+	if (dev->class >> 8 == PCI_CLASS_BRIDGE_CARDBUS)
+		return pci_cardbus_resource_alignment(res);
+	return resource_alignment(res);
+}
+
 /*
  * For mem bridge windows, try to relocate tail remainder space to space
  * before res->start if there's enough free space there. This enables
-- 
2.39.5

[PATCH 10/11] PCI: Lower bound bridge window alignment

[Ilpo Järvinen]

pci_resource_alignment() does not consider bridge windows special,
yet their alignment is subject to different requirements from BAR
alignment.

Add lower bound to bridge window alignment to help callers out to
always have large enough alignment.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/setup-res.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 18e8775ea848..c15bce20815d 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -19,7 +19,10 @@
 #include <linux/errno.h>
 #include <linux/ioport.h>
 #include <linux/cache.h>
+#include <linux/minmax.h>
 #include <linux/slab.h>
+#include <linux/types.h>
+
 #include "pci.h"
 
 static void pci_std_update_resource(struct pci_dev *dev, int resno)
@@ -250,12 +253,19 @@ resource_size_t pci_resource_alignment(const struct pci_dev *dev,
 				       const struct resource *res)
 {
 	int resno = pci_resource_num(dev, res);
+	resource_size_t min_align = 0;
 
 	if (pci_resource_is_iov(resno))
 		return pci_sriov_resource_alignment(dev, resno);
+
 	if (dev->class >> 8 == PCI_CLASS_BRIDGE_CARDBUS)
 		return pci_cardbus_resource_alignment(res);
-	return resource_alignment(res);
+
+	if (pci_resource_is_bridge_win(resno) &&
+	    (res->flags & (IORESOURCE_IO|IORESOURCE_MEM)))
+		min_align = pci_min_window_alignment(dev->bus, res->flags);
+
+	return max(resource_alignment(res), min_align);
 }
 
 /*
-- 
2.39.5

[PATCH 11/11] PCI: Return valid alignment for assigned resources

[Ilpo Järvinen]

When a resource is assigned, IORESOURCE_STARTALIGN flag is cleared,
resulting in pci_resource_alignment() returning 0 in some situations
(at least for bridge windows).

Add heuristic to pci_resource_alignment() which mimics start and size
alignment by taking minimum of those for an assigned resource. It may
overestimate alignment when start has large alignment but the exact
alignment information is not available and regenerating it by sizing
the bridge again is costly.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/setup-res.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index c15bce20815d..03098f159ec9 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -13,6 +13,7 @@
  *	     Resource sorting
  */
 
+#include <linux/bitops.h>
 #include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/pci.h>
@@ -265,6 +266,18 @@ resource_size_t pci_resource_alignment(const struct pci_dev *dev,
 	    (res->flags & (IORESOURCE_IO|IORESOURCE_MEM)))
 		min_align = pci_min_window_alignment(dev->bus, res->flags);
 
+	if (resource_assigned(res)) {
+		resource_size_t start_align = 1, size_align;
+
+		size_align = roundup_pow_of_two(resource_size(res));
+		if (res->start)
+			start_align <<= __ffs(res->start);
+		else
+			start_align = size_align;
+
+		return max(min(start_align, size_align), min_align);
+	}
+
 	return max(resource_alignment(res), min_align);
 }
 
-- 
2.39.5