[PATCH v1 0/4] PCI: pci_resource_to_user() cleanups

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5 messages, 1 author, 2016-06-17 · open the first message on its own page

[PATCH v1 0/4] PCI: pci_resource_to_user() cleanups

From: Bjorn Helgaas <bhelgaas@google.com>
Date: 2016-06-17 20:11:53

The /sys/devices/pci.../.../resource and /proc/bus/pci/devices files
contain PCI BAR addresses.  On most architectures these addresses are
"resource" values, e.g., CPU physical memory addresses or Linux I/O port
numbers.  These may be offset from the raw PCI values if there are multiple
PCI host bridges.

On others (microblaze, mips, powerpc, sparc) they are raw PCI values as
they would appear on the PCI bus.  pci_resource_to_user() converts from the
struct resource to whatever the arch wants to expose.  It's a no-op on
most arches.

The PCI core provides a pcibios_resource_to_bus() function that converts
from struct resource values to raw PCI bus values.  These patches use that
when possible instead of the arch-specific hand-coded equivalent.

These shouldn't fix or break anything unless I've made a mistake.

---

Bjorn Helgaas (4):
      PCI: Unify pci_resource_to_user() declarations
      microblaze/PCI: Implement pci_resource_to_user() with pcibios_resource_to_bus()
      powerpc/pci: Implement pci_resource_to_user() with pcibios_resource_to_bus()
      sparc/PCI: Implement pci_resource_to_user() with pcibios_resource_to_bus()


 arch/microblaze/include/asm/pci.h |    3 ---
 arch/microblaze/pci/pci-common.c  |   42 ++++++++++++-------------------------
 arch/mips/include/asm/pci.h       |   10 ---------
 arch/mips/pci/pci.c               |   10 +++++++++
 arch/powerpc/include/asm/pci.h    |    3 ---
 arch/powerpc/kernel/pci-common.c  |   42 ++++++++++++-------------------------
 arch/sparc/include/asm/pci_64.h   |    3 ---
 arch/sparc/kernel/pci.c           |   20 ++++++++++--------
 include/linux/pci.h               |    6 ++++-
 9 files changed, 54 insertions(+), 85 deletions(-)

[PATCH v1 1/4] PCI: Unify pci_resource_to_user() declarations

From: Bjorn Helgaas <bhelgaas@google.com>
Date: 2016-06-17 20:12:03

Replace the pci_resource_to_user() declarations in each arch that defines
HAVE_ARCH_PCI_RESOURCE_TO_USER with a single one in linux/pci.h.

Change the MIPS static inline implementation to a non-inline version so the
static inline doesn't conflict with the new non-static linux/pci.h
declaration.

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 arch/microblaze/include/asm/pci.h |    3 ---
 arch/mips/include/asm/pci.h       |   10 ----------
 arch/mips/pci/pci.c               |   10 ++++++++++
 arch/powerpc/include/asm/pci.h    |    3 ---
 arch/sparc/include/asm/pci_64.h   |    3 ---
 include/linux/pci.h               |    6 +++++-
 6 files changed, 15 insertions(+), 20 deletions(-)
diff --git a/arch/microblaze/include/asm/pci.h b/arch/microblaze/include/asm/pci.h
index fc3ecb5..2a120bb 100644
--- a/arch/microblaze/include/asm/pci.h
+++ b/arch/microblaze/include/asm/pci.h
@@ -82,9 +82,6 @@ extern pgprot_t	pci_phys_mem_access_prot(struct file *file,
 					 pgprot_t prot);
 
 #define HAVE_ARCH_PCI_RESOURCE_TO_USER
-extern void pci_resource_to_user(const struct pci_dev *dev, int bar,
-				 const struct resource *rsrc,
-				 resource_size_t *start, resource_size_t *end);
 
 extern void pcibios_setup_bus_devices(struct pci_bus *bus);
 extern void pcibios_setup_bus_self(struct pci_bus *bus);
diff --git a/arch/mips/include/asm/pci.h b/arch/mips/include/asm/pci.h
index 86b239d..9b63cd4 100644
--- a/arch/mips/include/asm/pci.h
+++ b/arch/mips/include/asm/pci.h
@@ -80,16 +80,6 @@ extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
 
 #define HAVE_ARCH_PCI_RESOURCE_TO_USER
 
-static inline void pci_resource_to_user(const struct pci_dev *dev, int bar,
-		const struct resource *rsrc, resource_size_t *start,
-		resource_size_t *end)
-{
-	phys_addr_t size = resource_size(rsrc);
-
-	*start = fixup_bigphys_addr(rsrc->start, size);
-	*end = rsrc->start + size;
-}
-
 /*
  * Dynamic DMA mapping stuff.
  * MIPS has everything mapped statically.
diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c
index f1b11f0..5717384 100644
--- a/arch/mips/pci/pci.c
+++ b/arch/mips/pci/pci.c
@@ -319,6 +319,16 @@ void pcibios_fixup_bus(struct pci_bus *bus)
 EXPORT_SYMBOL(PCIBIOS_MIN_IO);
 EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
 
+void pci_resource_to_user(const struct pci_dev *dev, int bar,
+			  const struct resource *rsrc, resource_size_t *start,
+			  resource_size_t *end)
+{
+	phys_addr_t size = resource_size(rsrc);
+
+	*start = fixup_bigphys_addr(rsrc->start, size);
+	*end = rsrc->start + size;
+}
+
 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
 			enum pci_mmap_state mmap_state, int write_combine)
 {
diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index a6f3ac0..e9bd6cf 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -136,9 +136,6 @@ extern pgprot_t	pci_phys_mem_access_prot(struct file *file,
 					 pgprot_t prot);
 
 #define HAVE_ARCH_PCI_RESOURCE_TO_USER
-extern void pci_resource_to_user(const struct pci_dev *dev, int bar,
-				 const struct resource *rsrc,
-				 resource_size_t *start, resource_size_t *end);
 
 extern resource_size_t pcibios_io_space_offset(struct pci_controller *hose);
 extern void pcibios_setup_bus_devices(struct pci_bus *bus);
diff --git a/arch/sparc/include/asm/pci_64.h b/arch/sparc/include/asm/pci_64.h
index 022d160..2303635 100644
--- a/arch/sparc/include/asm/pci_64.h
+++ b/arch/sparc/include/asm/pci_64.h
@@ -55,9 +55,6 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
 }
 
 #define HAVE_ARCH_PCI_RESOURCE_TO_USER
-void pci_resource_to_user(const struct pci_dev *dev, int bar,
-			  const struct resource *rsrc,
-			  resource_size_t *start, resource_size_t *end);
 #endif /* __KERNEL__ */
 
 #endif /* __SPARC64_PCI_H */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b67e4df..9c201d4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1554,7 +1554,11 @@ static inline const char *pci_name(const struct pci_dev *pdev)
 /* Some archs don't want to expose struct resource to userland as-is
  * in sysfs and /proc
  */
-#ifndef HAVE_ARCH_PCI_RESOURCE_TO_USER
+#ifdef HAVE_ARCH_PCI_RESOURCE_TO_USER
+void pci_resource_to_user(const struct pci_dev *dev, int bar,
+			  const struct resource *rsrc,
+			  resource_size_t *start, resource_size_t *end);
+#else
 static inline void pci_resource_to_user(const struct pci_dev *dev, int bar,
 		const struct resource *rsrc, resource_size_t *start,
 		resource_size_t *end)

[PATCH v1 2/4] microblaze/PCI: Implement pci_resource_to_user() with pcibios_resource_to_bus()

From: Bjorn Helgaas <bhelgaas@google.com>
Date: 2016-06-17 20:12:09

"User" addresses are shown in /sys/devices/pci.../.../resource and
/proc/bus/pci/devices and used as mmap offsets for /proc/bus/pci/BB/DD.F
files.  For I/O port resources on microblaze, these are PCI bus addresses,
i.e., raw BAR values.

Previously pci_resource_to_user() computed the user address by subtracting
"hose->io_base_virt - _IO_BASE" from the resource start:

  pci_resource_to_user()
    if (IO)
      offset = (unsigned long)hose->io_base_virt - _IO_BASE;
    *start = rsrc->start - offset;

We've already told the PCI core about that "hose->io_base_virt - _IO_BASE"
offset:

  pcibios_setup_phb_resources()
    res = &hose->io_resource;
    pci_add_resource_offset(resources, res, hose->io_base_virt - _IO_BASE);

so pcibios_resource_to_bus() knows how to do that translation.

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
---
 arch/microblaze/pci/pci-common.c |   42 +++++++++++++-------------------------
 1 file changed, 14 insertions(+), 28 deletions(-)
diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
index 1974567..81556b8 100644
--- a/arch/microblaze/pci/pci-common.c
+++ b/arch/microblaze/pci/pci-common.c
@@ -444,39 +444,25 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar,
 			  const struct resource *rsrc,
 			  resource_size_t *start, resource_size_t *end)
 {
-	struct pci_controller *hose = pci_bus_to_host(dev->bus);
-	resource_size_t offset = 0;
+	struct pci_bus_region region;
 
-	if (hose == NULL)
+	if (rsrc->flags & IORESOURCE_IO) {
+		pcibios_resource_to_bus(dev->bus, &region,
+					(struct resource *) rsrc);
+		*start = region.start;
+		*end = region.end;
 		return;
+	}
 
-	if (rsrc->flags & IORESOURCE_IO)
-		offset = (unsigned long)hose->io_base_virt - _IO_BASE;
-
-	/* We pass a fully fixed up address to userland for MMIO instead of
-	 * a BAR value because X is lame and expects to be able to use that
-	 * to pass to /dev/mem !
+	/* We pass a CPU physical address to userland for MMIO instead of a
+	 * BAR value because X is lame and expects to be able to use that
+	 * to pass to /dev/mem!
 	 *
-	 * That means that we'll have potentially 64 bits values where some
-	 * userland apps only expect 32 (like X itself since it thinks only
-	 * Sparc has 64 bits MMIO) but if we don't do that, we break it on
-	 * 32 bits CHRPs :-(
-	 *
-	 * Hopefully, the sysfs insterface is immune to that gunk. Once X
-	 * has been fixed (and the fix spread enough), we can re-enable the
-	 * 2 lines below and pass down a BAR value to userland. In that case
-	 * we'll also have to re-enable the matching code in
-	 * __pci_mmap_make_offset().
-	 *
-	 * BenH.
+	 * That means we may have 64-bit values where some apps only expect
+	 * 32 (like X itself since it thinks only Sparc has 64-bit MMIO).
 	 */
-#if 0
-	else if (rsrc->flags & IORESOURCE_MEM)
-		offset = hose->pci_mem_offset;
-#endif
-
-	*start = rsrc->start - offset;
-	*end = rsrc->end - offset;
+	*start = rsrc->start;
+	*end = rsrc->end;
 }
 
 /**

[PATCH v1 3/4] powerpc/pci: Implement pci_resource_to_user() with pcibios_resource_to_bus()

From: Bjorn Helgaas <bhelgaas@google.com>
Date: 2016-06-17 20:12:17

"User" addresses are shown in /sys/devices/pci.../.../resource and
/proc/bus/pci/devices and used as mmap offsets for /proc/bus/pci/BB/DD.F
files.  For I/O port resources on powerpc, these are PCI bus addresses,
i.e., raw BAR values.

Previously pci_resource_to_user() computed the user address by subtracting
"hose->io_base_virt - _IO_BASE" from the resource start:

  pci_resource_to_user()
    if (IO)
      offset = (unsigned long)hose->io_base_virt - _IO_BASE;
    *start = rsrc->start - offset;

We've already told the PCI core about that "hose->io_base_virt - _IO_BASE"
offset:

  pcibios_setup_phb_resources()
    res = &hose->io_resource;
    offset = pcibios_io_space_offset();
    /* i.e., "offset = hose->io_base_virt - _IO_BASE" */
    pci_add_resource_offset(resources, res, offset);

so pcibios_resource_to_bus() knows how to do that translation.

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
---
 arch/powerpc/kernel/pci-common.c |   42 +++++++++++++-------------------------
 1 file changed, 14 insertions(+), 28 deletions(-)
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 8c6beb0..6de6e0e 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -581,39 +581,25 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar,
 			  const struct resource *rsrc,
 			  resource_size_t *start, resource_size_t *end)
 {
-	struct pci_controller *hose = pci_bus_to_host(dev->bus);
-	resource_size_t offset = 0;
+	struct pci_bus_region region;
 
-	if (hose == NULL)
+	if (rsrc->flags & IORESOURCE_IO) {
+		pcibios_resource_to_bus(dev->bus, &region,
+					(struct resource *) rsrc);
+		*start = region.start;
+		*end = region.end;
 		return;
+	}
 
-	if (rsrc->flags & IORESOURCE_IO)
-		offset = (unsigned long)hose->io_base_virt - _IO_BASE;
-
-	/* We pass a fully fixed up address to userland for MMIO instead of
-	 * a BAR value because X is lame and expects to be able to use that
-	 * to pass to /dev/mem !
-	 *
-	 * That means that we'll have potentially 64 bits values where some
-	 * userland apps only expect 32 (like X itself since it thinks only
-	 * Sparc has 64 bits MMIO) but if we don't do that, we break it on
-	 * 32 bits CHRPs :-(
-	 *
-	 * Hopefully, the sysfs insterface is immune to that gunk. Once X
-	 * has been fixed (and the fix spread enough), we can re-enable the
-	 * 2 lines below and pass down a BAR value to userland. In that case
-	 * we'll also have to re-enable the matching code in
-	 * __pci_mmap_make_offset().
+	/* We pass a CPU physical address to userland for MMIO instead of a
+	 * BAR value because X is lame and expects to be able to use that
+	 * to pass to /dev/mem!
 	 *
-	 * BenH.
+	 * That means we may have 64-bit values where some apps only expect
+	 * 32 (like X itself since it thinks only Sparc has 64-bit MMIO).
 	 */
-#if 0
-	else if (rsrc->flags & IORESOURCE_MEM)
-		offset = hose->pci_mem_offset;
-#endif
-
-	*start = rsrc->start - offset;
-	*end = rsrc->end - offset;
+	*start = rsrc->start;
+	*end = rsrc->end;
 }
 
 /**

[PATCH v1 4/4] sparc/PCI: Implement pci_resource_to_user() with pcibios_resource_to_bus()

From: Bjorn Helgaas <bhelgaas@google.com>
Date: 2016-06-17 20:12:26

"User" addresses are shown in /sys/devices/pci.../.../resource and
/proc/bus/pci/devices and used as mmap offsets for /proc/bus/pci/BB/DD.F
files.  On sparc, these are PCI bus addresses, i.e., raw BAR values.

Previously pci_resource_to_user() computed the user address by
subtracting either pbm->io_space.start or pbm->mem_space.start from the
resource start.

We've already told the PCI core about those offsets here:

  pci_scan_one_pbm()
    pci_add_resource_offset(&resources, &pbm->io_space, pbm->io_space.start);
    pci_add_resource_offset(&resources, &pbm->mem_space, pbm->mem_space.start);
    pci_add_resource_offset(&resources, &pbm->mem64_space, pbm->mem_space.start);

so pcibios_resource_to_bus() knows how to do that translation.

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
---
 arch/sparc/kernel/pci.c |   20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index c2b202d..9c1878f 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -986,16 +986,18 @@ void pci_resource_to_user(const struct pci_dev *pdev, int bar,
 			  const struct resource *rp, resource_size_t *start,
 			  resource_size_t *end)
 {
-	struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
-	unsigned long offset;
-
-	if (rp->flags & IORESOURCE_IO)
-		offset = pbm->io_space.start;
-	else
-		offset = pbm->mem_space.start;
+	struct pci_bus_region region;
 
-	*start = rp->start - offset;
-	*end = rp->end - offset;
+	/*
+	 * "User" addresses are shown in /sys/devices/pci.../.../resource
+	 * and /proc/bus/pci/devices and used as mmap offsets for
+	 * /proc/bus/pci/BB/DD.F files (see proc_bus_pci_mmap()).
+	 *
+	 * On sparc, these are PCI bus addresses, i.e., raw BAR values.
+	 */
+	pcibios_resource_to_bus(pdev->bus, &region, (struct resource *) rp);
+	*start = region.start;
+	*end = region.end;
 }
 
 void pcibios_set_master(struct pci_dev *dev)
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