diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2017-04-12 13:25:54 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-04-18 13:01:42 -0500 |
| commit | ae749c7ab475de2c9c427058db19921c91846e89 (patch) | |
| tree | 0fbb5e8de9c0827c196f5296409622beb5e9aec9 /arch/x86/include/asm/pci.h | |
| parent | 03a064b431eb5cb0a91012699ac1e4d6302b327d (diff) | |
PCI: Add arch_can_pci_mmap_wc() macro
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>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'arch/x86/include/asm/pci.h')
| -rw-r--r-- | arch/x86/include/asm/pci.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h index 1411dbed5e5e..f6e22c271efa 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); |