On Wed, Jun 8, 2016 at 3:35 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> At the same time, can you kill __pci_mmap_set_pgprot() for powerpc.
Can you please put your two patches and this attached one into to pci/next?
Then I could send updated PCI: Let pci_mmap_page_range() take resource address.
Thanks
Yinghai
From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Subject: [PATCH] powerpc/PCI: Remove __pci_mmap_set_pgprot()
PCI: Ignore write-combining when mapping I/O port space
already handle the io port mmap path.
For mmio mmap path, caller should state that correctly if write_combine
is really needed.
via proc path it should look like:
mmap(fd, ...) # default is I/O, non-combining
ioctl(fd, PCIIOC_WRITE_COMBINE, 1); # request write-combining
ioctl(fd, PCIIOC_MMAP_IS_MEM); # request memory space
mmap(fd, ...)
sysfs path, it should use resource]?]_wc.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
arch/powerpc/kernel/pci-common.c | 37 ++++---------------------------------
1 file changed, 4 insertions(+), 33 deletions(-)
Index: linux-2.6/arch/powerpc/kernel/pci-common.c
===================================================================
--- linux-2.6.orig/arch/powerpc/kernel/pci-common.c
+++ linux-2.6/arch/powerpc/kernel/pci-common.c
@@ -356,36 +356,6 @@ static struct resource *__pci_mmap_make_
}
/*
- * Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
- * device mapping.
- */
-static pgprot_t __pci_mmap_set_pgprot(struct pci_dev *dev, struct resource *rp,
- pgprot_t protection,
- enum pci_mmap_state mmap_state,
- int write_combine)
-{
-
- /* Write combine is always 0 on non-memory space mappings. On
- * memory space, if the user didn't pass 1, we check for a
- * "prefetchable" resource. This is a bit hackish, but we use
- * this to workaround the inability of /sysfs to provide a write
- * combine bit
- */
- if (mmap_state != pci_mmap_mem)
- write_combine = 0;
- else if (write_combine == 0) {
- if (rp->flags & IORESOURCE_PREFETCH)
- write_combine = 1;
- }
-
- /* XXX would be nice to have a way to ask for write-through */
- if (write_combine)
- return pgprot_noncached_wc(protection);
- else
- return pgprot_noncached(protection);
-}
-
-/*
* This one is used by /dev/mem and fbdev who have no clue about the
* PCI device, it tries to find the PCI device first and calls the
* above routine
@@ -458,9 +428,10 @@ int pci_mmap_page_range(struct pci_dev *
return -EINVAL;
vma->vm_pgoff = offset >> PAGE_SHIFT;
- vma->vm_page_prot = __pci_mmap_set_pgprot(dev, rp,
- vma->vm_page_prot,
- mmap_state, write_combine);
+ if (write_combine)
+ vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot);
+ else
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
ret = remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start, vma->vm_page_prot);
