Gitweb: http://git.kernel.org/linus/5a3ae276057840f0e60664c12fc3ef80aa59d1d4
Commit: 5a3ae276057840f0e60664c12fc3ef80aa59d1d4
Parent: 78609a812e9afa87202631d128018361f68c44a9
Author: Suresh Siddha <suresh.b.siddha@intel.com>
AuthorDate: Fri Apr 3 14:21:52 2009 -0700
Committer: Linus Torvalds <torvalds@linux-foundation.org>
CommitDate: Fri Apr 3 14:43:29 2009 -0700
x86, PAT: Remove duplicate memtype reserve in pci mmap
pci mmap code was doing memtype reserve for a while now. Recently we
added memtype tracking in remap_pfn_range, and pci code indirectly calls
remap_pfn_range. So, we don't need seperate tracking in pci code
anymore. Which means a patch that removes ~50 lines of code :-).
Also, recently we found out that the pci tracking is not working as we expect
it to work in some cases. Specifically, userlevel X mmap of pci, with some
recent version of X, is having a problem with vm_page_prot getting reset.
The pci tracking uses vm_page_prot to pass on the protection type from parent
to child during fork.
a) Parent does a pci mmap
b) We look at PAT and get either UC_MINUS or WC mapping for parent
c) Store that mapping type in vma vm_page_prot for future use
d) This thread does a fork
e) Fork results in mmap_ops ->open for the child process
f) We get the vm_page_prot from vma and reserve that type for the child process
But, between c) and e) above, the vma vm_page_prot is getting reset to zero.
This results in PAT reserve failing at the time of fork as in here.
http://marc.info/?l=linux-kernel&m=123858163103240&w=2
This cleanup makes the above problem go away as we do not depend on
vm_page_prot in our PAT code anymore.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/x86/pci/i386.c | 46 ----------------------------------------------
1 files changed, 0 insertions(+), 46 deletions(-)
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index f234a37..f1817f7 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -258,24 +258,7 @@ void pcibios_set_master(struct pci_dev *dev)
pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
}
-static void pci_unmap_page_range(struct vm_area_struct *vma)
-{
- u64 addr = (u64)vma->vm_pgoff << PAGE_SHIFT;
- free_memtype(addr, addr + vma->vm_end - vma->vm_start);
-}
-
-static void pci_track_mmap_page_range(struct vm_area_struct *vma)
-{
- u64 addr = (u64)vma->vm_pgoff << PAGE_SHIFT;
- unsigned long flags = pgprot_val(vma->vm_page_prot)
- & _PAGE_CACHE_MASK;
-
- reserve_memtype(addr, addr + vma->vm_end - vma->vm_start, flags, NULL);
-}
-
static struct vm_operations_struct pci_mmap_ops = {
- .open = pci_track_mmap_page_range,
- .close = pci_unmap_page_range,
.access = generic_access_phys,
};
@@ -283,11 +266,6 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine)
{
unsigned long prot;
- u64 addr = vma->vm_pgoff << PAGE_SHIFT;
- unsigned long len = vma->vm_end - vma->vm_start;
- unsigned long flags;
- unsigned long new_flags;
- int retval;
/* I/O space cannot be accessed via normal processor loads and
* stores on this platform.
@@ -308,30 +286,6 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
vma->vm_page_prot = __pgprot(prot);
- flags = pgprot_val(vma->vm_page_prot) & _PAGE_CACHE_MASK;
- retval = reserve_memtype(addr, addr + len, flags, &new_flags);
- if (retval)
- return retval;
-
- if (flags != new_flags) {
- if (!is_new_memtype_allowed(flags, new_flags)) {
- free_memtype(addr, addr+len);
- return -EINVAL;
- }
- flags = new_flags;
- vma->vm_page_prot = __pgprot(
- (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK) |
- flags);
- }
-
- if (((vma->vm_pgoff < max_low_pfn_mapped) ||
- (vma->vm_pgoff >= (1UL<<(32 - PAGE_SHIFT)) &&
- vma->vm_pgoff < max_pfn_mapped)) &&
- ioremap_change_attr((unsigned long)__va(addr), len, flags)) {
- free_memtype(addr, addr + len);
- return -EINVAL;
- }
-
if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start,
vma->vm_page_prot))
--
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