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Commit 03a064b4 authored by David Woodhouse's avatar David Woodhouse Committed by Bjorn Helgaas
Browse files

xtensa/PCI: Do not mmap PCI BARs to userspace as write-through 



These should be uncached, not write-through.

Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent cef4d023

arch/xtensa/kernel/pci.c

+1 −20
Original line number Diff line number Diff line
@@ -333,25 +333,6 @@ __pci_mmap_make_offset(struct pci_dev *dev, struct vm_area_struct *vma, 
	return -EINVAL;

}



/*

 * Set vm_page_prot of VMA, as appropriate for this architecture, for a pci

 * device mapping.

 */

static __inline__ void

__pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma,

		      enum pci_mmap_state mmap_state, int write_combine)

{

	int prot = pgprot_val(vma->vm_page_prot);



	/* Set to write-through */

	prot = (prot & _PAGE_CA_MASK) | _PAGE_CA_WT;

#if 0

	if (!write_combine)

		prot |= _PAGE_WRITETHRU;

#endif

	vma->vm_page_prot = __pgprot(prot);

}



/*

 * Perform the actual remap of the pages for a PCI device mapping, as

 * appropriate for this architecture.  The region in the process to map
@@ -372,7 +353,7 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, 
	if (ret < 0)

		return ret;



	__pci_mmap_set_pgprot(dev, vma, mmap_state, write_combine);

	vma->vm_page_prot = pgprot_device(vma->vm_page_prot);



	ret = io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,

			         vma->vm_end - vma->vm_start,vma->vm_page_prot);