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-rw-r--r--arch/mips/loongson/common/mem.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/mips/loongson/common/mem.c b/arch/mips/loongson/common/mem.c
index 981e919..ceacd09 100644
--- 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 */