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ia64: Remove redundant checks for WC in pci_mmap_page_range()

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For a PCI MMIO BAR, phys_mem_access_prot() should always return UC or WC.
And while a mixture of cached and uncached mappings is forbidden, we were
already mixing WC and UC, which is OK. Just do as we're asked.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Tested-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
David Woodhouse 2017-04-07 12:01:00 +02:00 committed by Bjorn Helgaas
parent 61eee41ae1
commit fcdb10d6b1
1 changed files with 2 additions and 16 deletions
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18
arch/ia64/pci/pci.c
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@ -423,9 +423,6 @@ pci_mmap_page_range (struct pci_dev *dev, int bar,
struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine)
{
unsigned long size = vma->vm_end - vma->vm_start;
pgprot_t prot;
/*
* I/O space cannot be accessed via normal processor loads and
* stores on this platform.
@ -439,21 +436,10 @@ pci_mmap_page_range (struct pci_dev *dev, int bar,
*/
return -EINVAL;
prot = phys_mem_access_prot(NULL, vma->vm_pgoff, size,
vma->vm_page_prot);
/*
* If the user requested WC, the kernel uses UC or WC for this region,
* and the chipset supports WC, we can use WC. Otherwise, we have to
* use the same attribute the kernel uses.
*/
if (write_combine &&
((pgprot_val(prot) & _PAGE_MA_MASK) == _PAGE_MA_UC ||
(pgprot_val(prot) & _PAGE_MA_MASK) == _PAGE_MA_WC) &&
efi_range_is_wc(vma->vm_start, vma->vm_end - vma->vm_start))
if (write_combine)
vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
else
vma->vm_page_prot = prot;
vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start, vma->vm_page_prot))