MIPS: Add support for uncached accelerated mappings.

[safe/jmp/linux-2.6] / arch / mips / loongson / common / mem.c

diff --git a/arch/mips/loongson/common/mem.c b/arch/mips/loongson/common/mem.c
index 981e919..ceacd09 100644 (file)
--- a/arch/mips/loongson/common/mem.c
+++ b/arch/mips/loongson/common/mem.c
@@ -58,3 +58,61 @@ int __uncached_access(struct file *file, unsigned long addr)
                ((addr >= LOONGSON_MMIO_MEM_START) &&
                 (addr < LOONGSON_MMIO_MEM_END));
 }
+
+#ifdef CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED
+
+#include <linux/pci.h>
+#include <linux/sched.h>
+#include <asm/current.h>
+
+static unsigned long uca_start, uca_end;
+
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+                             unsigned long size, pgprot_t vma_prot)
+{
+       unsigned long offset = pfn << PAGE_SHIFT;
+       unsigned long end = offset + size;
+
+       if (__uncached_access(file, offset)) {
+               if (((uca_start && offset) >= uca_start) &&
+                   (end <= uca_end))
+                       return __pgprot((pgprot_val(vma_prot) &
+                                        ~_CACHE_MASK) |
+                                       _CACHE_UNCACHED_ACCELERATED);
+               else
+                       return pgprot_noncached(vma_prot);
+       }
+       return vma_prot;
+}
+
+static int __init find_vga_mem_init(void)
+{
+       struct pci_dev *dev = 0;
+       struct resource *r;
+       int idx;
+
+       if (uca_start)
+               return 0;
+
+       for_each_pci_dev(dev) {
+               if ((dev->class >> 8) == PCI_CLASS_DISPLAY_VGA) {
+                       for (idx = 0; idx < PCI_NUM_RESOURCES; idx++) {
+                               r = &dev->resource[idx];
+                               if (!r->start && r->end)
+                                       continue;
+                               if (r->flags & IORESOURCE_IO)
+                                       continue;
+                               if (r->flags & IORESOURCE_MEM) {
+                                       uca_start = r->start;
+                                       uca_end = r->end;
+                                       return 0;
+                               }
+                       }
+               }
+       }
+
+       return 0;
+}
+
+late_initcall(find_vga_mem_init);
+#endif /* !CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED */