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authorvenkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com>2008-03-18 17:00:19 -0700
committerIngo Molnar <mingo@elte.hu>2008-04-17 17:41:19 +0200
commit03d72aa18f15df9987fe5837284e15b9ccf6e3f8 (patch)
tree4acfdd5a8a652cf19906a26a183f5d18f3777a83 /arch/x86/pci
parent1219333dfdd488e85f08cf07881b8bc63cf92f21 (diff)
x86: PAT use reserve free memtype in pci_mmap_page_range
Add reserve_memtype and free_memtype wrapper for pci_mmap_page_range. Free is called on unmap, but identity map continues to be mapped as per pci_mmap_page_range request, until next request for the same region calls ioremap_change_attr(), which will go through without conflict. This way of mapping is identical to one used in ioremap/iounmap. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/pci')
-rw-r--r--arch/x86/pci/i386.c68
1 files changed, 60 insertions, 8 deletions
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index 103b9dff121..4ebf52f6b1f 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -30,6 +30,9 @@
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/errno.h>
+#include <linux/bootmem.h>
+
+#include <asm/pat.h>
#include "pci.h"
@@ -297,10 +300,34 @@ 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,
+};
+
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;
/* I/O space cannot be accessed via normal processor loads and
* stores on this platform.
@@ -308,21 +335,46 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
if (mmap_state == pci_mmap_io)
return -EINVAL;
- /* Leave vm_pgoff as-is, the PCI space address is the physical
- * address on this platform.
- */
prot = pgprot_val(vma->vm_page_prot);
- if (boot_cpu_data.x86 > 3)
- prot |= _PAGE_PCD | _PAGE_PWT;
+ if (pat_wc_enabled && write_combine)
+ prot |= _PAGE_CACHE_WC;
+ else if (boot_cpu_data.x86 > 3)
+ prot |= _PAGE_CACHE_UC;
+
vma->vm_page_prot = __pgprot(prot);
- /* Write-combine setting is ignored, it is changed via the mtrr
- * interfaces on this platform.
- */
+ flags = pgprot_val(vma->vm_page_prot) & _PAGE_CACHE_MASK;
+ if (reserve_memtype(addr, addr + len, flags, &new_flags)) {
+ /*
+ * Do not fallback to certain memory types with certain
+ * requested type:
+ * - request is uncached, return cannot be write-back
+ * - request is uncached, return cannot be write-combine
+ * - request is write-combine, return cannot be write-back
+ */
+ if ((flags == _PAGE_CACHE_UC &&
+ (new_flags == _PAGE_CACHE_WB ||
+ new_flags == _PAGE_CACHE_WC)) ||
+ (flags == _PAGE_CACHE_WC &&
+ new_flags == _PAGE_CACHE_WB)) {
+ free_memtype(addr, addr+len);
+ return -EINVAL;
+ }
+ flags = new_flags;
+ }
+
+ if (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))
return -EAGAIN;
+ vma->vm_ops = &pci_mmap_ops;
+
return 0;
}