* [PATCH 2/3] pci: Add arch_can_pci_mmap_wc() macro
[not found] <0e5266c6c883baa0e4a98dce796f8ab2ee18e71f.1489598108.git.dwmw2@infradead.org>
@ 2017-03-15 17:17 ` David Woodhouse
2017-03-15 17:17 ` David Woodhouse
2017-03-15 17:18 ` [PATCH 3/3] pci: Move multiple declarations of pci_mmap_page_range() to <linux/pci.h> David Woodhouse
1 sibling, 1 reply; 3+ messages in thread
From: David Woodhouse @ 2017-03-15 17:17 UTC (permalink / raw)
To: linux-arch, linux-kernel, linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 6908 bytes --]
From: David Woodhouse <dwmw@amazon.co.uk>
Most of the almost-identical versions of pci_mmap_page_range() silently
ignore the 'write_combine' argument and give uncached mappings.
Yet we allow the PCIIOC_WRITE_COMBINE ioctl in /proc/bus/pci, expose the
'resourceX_wc' file in sysfs, and allow an attempted mapping to apparently
succeed.
To fix this, introduce a macro arch_can_pci_mmap_wc() which indicates
whether the platform can do a write-combining mapping. On x86 this ends
up being pat_enabled(), while the few other platforms that support it
can just set it to a literal '1'.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
Documentation/filesystems/sysfs-pci.txt | 4 ++++
arch/arm64/include/asm/pci.h | 1 +
arch/ia64/include/asm/pci.h | 2 ++
arch/powerpc/include/asm/pci.h | 5 +++--
arch/x86/include/asm/pci.h | 2 ++
arch/xtensa/include/asm/pci.h | 6 +++++-
arch/xtensa/kernel/pci.c | 2 +-
drivers/pci/pci-sysfs.c | 6 ++++--
drivers/pci/proc.c | 17 ++++++++++-------
9 files changed, 32 insertions(+), 13 deletions(-)
diff --git a/Documentation/filesystems/sysfs-pci.txt b/Documentation/filesystems/sysfs-pci.txt
index 6ea1ced..25b7f1c 100644
--- a/Documentation/filesystems/sysfs-pci.txt
+++ b/Documentation/filesystems/sysfs-pci.txt
@@ -117,6 +117,10 @@ code must define HAVE_PCI_MMAP and provide a pci_mmap_page_range function.
Platforms are free to only support subsets of the mmap functionality, but
useful return codes should be provided.
+Platforms which support write-combining maps of PCI resources must define
+arch_can_pci_mmap_wc() which shall evaluate to non-zero at runtime when
+write-combining is permitted.
+
Legacy resources are protected by the HAVE_PCI_LEGACY define. Platforms
wishing to support legacy functionality should define it and provide
pci_legacy_read, pci_legacy_write and pci_mmap_legacy_page_range functions.
diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h
index f73734f..53b1541 100644
--- a/arch/arm64/include/asm/pci.h
+++ b/arch/arm64/include/asm/pci.h
@@ -38,6 +38,7 @@ static inline int pci_proc_domain(struct pci_bus *bus)
#endif /* CONFIG_PCI */
#define HAVE_PCI_MMAP
+#define arch_can_pci_mmap_wc() 1
extern 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/ia64/include/asm/pci.h b/arch/ia64/include/asm/pci.h
index c0835b0..6283758 100644
--- a/arch/ia64/include/asm/pci.h
+++ b/arch/ia64/include/asm/pci.h
@@ -51,6 +51,8 @@ extern unsigned long ia64_max_iommu_merge_mask;
#define PCI_DMA_BUS_IS_PHYS (ia64_max_iommu_merge_mask == ~0UL)
#define HAVE_PCI_MMAP
+#define arch_can_pci_mmap_wc() 1
+
extern int pci_mmap_page_range (struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine);
#define HAVE_PCI_LEGACY
diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index 93eded8..b5b68c6 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -81,8 +81,9 @@ struct vm_area_struct;
int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine);
-/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() */
-#define HAVE_PCI_MMAP 1
+/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() and it does WC */
+#define HAVE_PCI_MMAP 1
+#define arch_can_pci_mmap_wc() 1
extern int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val,
size_t count);
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index 1411dbe..f6e22c2 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -7,6 +7,7 @@
#include <linux/string.h>
#include <linux/scatterlist.h>
#include <asm/io.h>
+#include <asm/pat.h>
#include <asm/x86_init.h>
#ifdef __KERNEL__
@@ -102,6 +103,7 @@ int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq);
#define HAVE_PCI_MMAP
+#define arch_can_pci_mmap_wc() pat_enabled()
extern 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/xtensa/include/asm/pci.h b/arch/xtensa/include/asm/pci.h
index 5d6bd93..f106879 100644
--- a/arch/xtensa/include/asm/pci.h
+++ b/arch/xtensa/include/asm/pci.h
@@ -51,7 +51,11 @@ int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine);
/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() */
-#define HAVE_PCI_MMAP 1
+#define HAVE_PCI_MMAP 1
+
+/* This was wrapped in #if 0 since the first merge of xtensa support...
+#define arch_can_pci_mmap_wc() 1
+*/
#endif /* __KERNEL__ */
diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c
index b848cc3..c5944d3 100644
--- a/arch/xtensa/kernel/pci.c
+++ b/arch/xtensa/kernel/pci.c
@@ -345,7 +345,7 @@ __pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma,
/* Set to write-through */
prot = (prot & _PAGE_CA_MASK) | _PAGE_CA_WT;
-#if 0
+#ifdef arch_can_pci_mmap_wc
if (!write_combine)
prot |= _PAGE_WRITETHRU;
#endif
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 25d010d..e0474f3 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1206,10 +1206,12 @@ static int pci_create_resource_files(struct pci_dev *pdev)
continue;
retval = pci_create_attr(pdev, i, 0);
+#ifdef arch_can_pci_mmap_wc
/* for prefetchable resources, create a WC mappable file */
- if (!retval && pdev->resource[i].flags & IORESOURCE_PREFETCH)
+ if (!retval && arch_can_pci_mmap_wc() &&
+ pdev->resource[i].flags & IORESOURCE_PREFETCH)
retval = pci_create_attr(pdev, i, 1);
-
+#endif
if (retval) {
pci_remove_resource_files(pdev);
return retval;
diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index f82710a..5cd960c 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -209,15 +209,18 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
fpriv->mmap_state = pci_mmap_mem;
break;
+#ifdef arch_can_pci_mmap_wc
case PCIIOC_WRITE_COMBINE:
- if (arg)
- fpriv->write_combine = 1;
- else
- fpriv->write_combine = 0;
- break;
-
+ if (arch_can_pci_mmap_wc()) {
+ if (arg)
+ fpriv->write_combine = 1;
+ else
+ fpriv->write_combine = 0;
+ break;
+ }
+ /* If arch decided it can't, fall through... */
+#endif /* arch_can_pci_mmap_wc */
#endif /* HAVE_PCI_MMAP */
-
default:
ret = -EINVAL;
break;
--
dwmw2
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^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 3/3] pci: Move multiple declarations of pci_mmap_page_range() to <linux/pci.h>
[not found] <0e5266c6c883baa0e4a98dce796f8ab2ee18e71f.1489598108.git.dwmw2@infradead.org>
2017-03-15 17:17 ` [PATCH 2/3] pci: Add arch_can_pci_mmap_wc() macro David Woodhouse
@ 2017-03-15 17:18 ` David Woodhouse
1 sibling, 0 replies; 3+ messages in thread
From: David Woodhouse @ 2017-03-15 17:18 UTC (permalink / raw)
To: linux-arch, linux-kernel, linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 9346 bytes --]
From: David Woodhouse <dwmw@amazon.co.uk>
We can declare it <linux/pci.h> even on platforms where it isn't going
to be defined. There's no need to have it littered through the various
<asm/pci.h> files.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
arch/arm/include/asm/pci.h | 2 --
arch/arm64/include/asm/pci.h | 2 --
arch/cris/include/asm/pci.h | 3 ---
arch/ia64/include/asm/pci.h | 2 --
arch/microblaze/include/asm/pci.h | 3 ---
arch/mips/include/asm/pci.h | 3 ---
arch/mn10300/include/asm/pci.h | 3 ---
arch/parisc/include/asm/pci.h | 3 ---
arch/powerpc/include/asm/pci.h | 3 ---
arch/sh/include/asm/pci.h | 3 +--
arch/sparc/include/asm/pci_64.h | 4 ----
arch/unicore32/include/asm/pci.h | 2 --
arch/x86/include/asm/pci.h | 4 ----
arch/xtensa/include/asm/pci.h | 4 ----
include/linux/pci.h | 7 +++++++
15 files changed, 8 insertions(+), 40 deletions(-)
diff --git a/arch/arm/include/asm/pci.h b/arch/arm/include/asm/pci.h
index 057d381..51118a0 100644
--- a/arch/arm/include/asm/pci.h
+++ b/arch/arm/include/asm/pci.h
@@ -29,8 +29,6 @@ static inline int pci_proc_domain(struct pci_bus *bus)
#define PCI_DMA_BUS_IS_PHYS (1)
#define HAVE_PCI_MMAP
-extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
{
diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h
index 53b1541..10fd0c2 100644
--- a/arch/arm64/include/asm/pci.h
+++ b/arch/arm64/include/asm/pci.h
@@ -39,8 +39,6 @@ static inline int pci_proc_domain(struct pci_bus *bus)
#define HAVE_PCI_MMAP
#define arch_can_pci_mmap_wc() 1
-extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
#endif /* __KERNEL__ */
#endif /* __ASM_PCI_H */
diff --git a/arch/cris/include/asm/pci.h b/arch/cris/include/asm/pci.h
index b1b289d..65198cb 100644
--- a/arch/cris/include/asm/pci.h
+++ b/arch/cris/include/asm/pci.h
@@ -42,9 +42,6 @@ struct pci_dev;
#define PCI_DMA_BUS_IS_PHYS (1)
#define HAVE_PCI_MMAP
-extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
-
#endif /* __KERNEL__ */
diff --git a/arch/ia64/include/asm/pci.h b/arch/ia64/include/asm/pci.h
index 6283758..fc60b3d 100644
--- a/arch/ia64/include/asm/pci.h
+++ b/arch/ia64/include/asm/pci.h
@@ -53,8 +53,6 @@ extern unsigned long ia64_max_iommu_merge_mask;
#define HAVE_PCI_MMAP
#define arch_can_pci_mmap_wc() 1
-extern int pci_mmap_page_range (struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
#define HAVE_PCI_LEGACY
extern int pci_mmap_legacy_page_range(struct pci_bus *bus,
struct vm_area_struct *vma,
diff --git a/arch/microblaze/include/asm/pci.h b/arch/microblaze/include/asm/pci.h
index 2a120bb..ab381d2 100644
--- a/arch/microblaze/include/asm/pci.h
+++ b/arch/microblaze/include/asm/pci.h
@@ -46,9 +46,6 @@ extern int pci_domain_nr(struct pci_bus *bus);
extern int pci_proc_domain(struct pci_bus *bus);
struct vm_area_struct;
-/* Map a range of PCI memory or I/O space for a device into user space */
-int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() */
#define HAVE_PCI_MMAP 1
diff --git a/arch/mips/include/asm/pci.h b/arch/mips/include/asm/pci.h
index 30d1129..3141e2a 100644
--- a/arch/mips/include/asm/pci.h
+++ b/arch/mips/include/asm/pci.h
@@ -111,9 +111,6 @@ extern void pcibios_set_master(struct pci_dev *dev);
#define HAVE_PCI_MMAP
-extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
-
#define HAVE_ARCH_PCI_RESOURCE_TO_USER
/*
diff --git a/arch/mn10300/include/asm/pci.h b/arch/mn10300/include/asm/pci.h
index 51159ff..082b6de 100644
--- a/arch/mn10300/include/asm/pci.h
+++ b/arch/mn10300/include/asm/pci.h
@@ -74,9 +74,6 @@ static inline int pci_controller_num(struct pci_dev *dev)
}
#define HAVE_PCI_MMAP
-extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state,
- int write_combine);
#endif /* __KERNEL__ */
diff --git a/arch/parisc/include/asm/pci.h b/arch/parisc/include/asm/pci.h
index defebd9..bb9ea90 100644
--- a/arch/parisc/include/asm/pci.h
+++ b/arch/parisc/include/asm/pci.h
@@ -201,7 +201,4 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
#define HAVE_PCI_MMAP
-extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
-
#endif /* __ASM_PARISC_PCI_H */
diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index b5b68c6..55887d1 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -77,9 +77,6 @@ extern int pci_domain_nr(struct pci_bus *bus);
extern int pci_proc_domain(struct pci_bus *bus);
struct vm_area_struct;
-/* Map a range of PCI memory or I/O space for a device into user space */
-int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() and it does WC */
#define HAVE_PCI_MMAP 1
diff --git a/arch/sh/include/asm/pci.h b/arch/sh/include/asm/pci.h
index 644314f..46abbc9 100644
--- a/arch/sh/include/asm/pci.h
+++ b/arch/sh/include/asm/pci.h
@@ -66,8 +66,7 @@ extern unsigned long PCIBIOS_MIN_IO, PCIBIOS_MIN_MEM;
struct pci_dev;
#define HAVE_PCI_MMAP
-extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
+
extern void pcibios_set_master(struct pci_dev *dev);
/* Dynamic DMA mapping stuff.
diff --git a/arch/sparc/include/asm/pci_64.h b/arch/sparc/include/asm/pci_64.h
index 2303635..516fda7 100644
--- a/arch/sparc/include/asm/pci_64.h
+++ b/arch/sparc/include/asm/pci_64.h
@@ -45,10 +45,6 @@ static inline int pci_proc_domain(struct pci_bus *bus)
#define HAVE_ARCH_PCI_GET_UNMAPPED_AREA
#define get_pci_unmapped_area get_fb_unmapped_area
-int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state,
- int write_combine);
-
static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
{
return PCI_IRQ_NONE;
diff --git a/arch/unicore32/include/asm/pci.h b/arch/unicore32/include/asm/pci.h
index 37e55d0..a5129086 100644
--- a/arch/unicore32/include/asm/pci.h
+++ b/arch/unicore32/include/asm/pci.h
@@ -17,8 +17,6 @@
#include <mach/hardware.h> /* for PCIBIOS_MIN_* */
#define HAVE_PCI_MMAP
-extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
#endif /* __KERNEL__ */
#endif
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index f6e22c2..734cc94 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -104,10 +104,6 @@ int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq);
#define HAVE_PCI_MMAP
#define arch_can_pci_mmap_wc() pat_enabled()
-extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state,
- int write_combine);
-
#ifdef CONFIG_PCI
extern void early_quirks(void);
diff --git a/arch/xtensa/include/asm/pci.h b/arch/xtensa/include/asm/pci.h
index f106879..e594eee 100644
--- a/arch/xtensa/include/asm/pci.h
+++ b/arch/xtensa/include/asm/pci.h
@@ -46,10 +46,6 @@ struct pci_dev;
#define PCI_DMA_BUS_IS_PHYS (1)
-/* Map a range of PCI memory or I/O space for a device into user space */
-int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma,
- enum pci_mmap_state mmap_state, int write_combine);
-
/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() */
#define HAVE_PCI_MMAP 1
diff --git a/include/linux/pci.h b/include/linux/pci.h
index eb3da1a..1882797 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -823,6 +823,13 @@ void pcibios_update_irq(struct pci_dev *, int irq);
/* Weak but can be overriden by arch */
void pci_fixup_cardbus(struct pci_bus *);
+/* Map a range of PCI memory or I/O space for a device into user space.
+ * Architectures provide this function if they set HAVE_PCI_MMAP, and
+ * it accepts the 'write_combine' argument when arch_can_pci_mmap_wc()
+ * evaluates to nonzero. */
+int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma,
+ enum pci_mmap_state mmap_state, int write_combine);
+
/* Generic PCI functions used internally */
void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
--
dwmw2
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^ permalink raw reply related [flat|nested] 3+ messages in thread