From: David Woodhouse Date: Fri, 7 Apr 2017 10:01:00 +0000 (+0200) Subject: ia64: Remove redundant checks for WC in pci_mmap_page_range() X-Git-Tag: v4.12-rc1~65^2~2^2~1 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=fcdb10d6b179fde41ca94d032afda8f4ed796b8e;p=linux.git ia64: Remove redundant checks for WC in pci_mmap_page_range() 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 Tested-by: Tony Luck --- diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c index 27020f30caa6..7438e8c84cdd 100644 --- a/arch/ia64/pci/pci.c +++ b/arch/ia64/pci/pci.c @@ -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))