loongson: define Loongson2F arch specific phys prot access

From 6eba97d7176eace554caddcc40c7e9719354fc62 Mon Sep 17 00:00:00 2001
From: Wu Zhangjin <[email protected]>
Date: Sat, 16 May 2009 04:34:23 +0800
Subject: [PATCH 21/30] loongson: define Loongson2F arch specific phys prot access

The main purpose is to uncache accelerate for video memory access

---
 arch/mips/include/asm/pgtable.h |   13 +++++++++
 arch/mips/loongson/Kconfig      |   12 ++++++++
 arch/mips/loongson/common/mem.c |   56
+++++++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+), 0 deletions(-)

b/arch/mips/include/asm/pgtable.h
index 6a0edf7..3954da0 100644

@@ -370,6 +370,19 @@ static inline int io_remap_pfn_range(struct

vm_area_struct *vma,
#include <asm-generic/pgtable.h>

/*
+ * uncache accelerate for video memory access
+ */
+#ifdef CONFIG_LOONGSON2F
+#define __HAVE_PHYS_MEM_ACCESS_PROT
+
+struct file;
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot);
+int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t *vma_prot);
+#endif
+
+/*
* We provide our own get_unmapped area to cope with the virtual
aliasing
* constraints placed on us by the cache architecture.
*/

index 2622017..49cb375 100644
@@ -99,3 +99,15 @@ config CS5536
 
 config SYS_HAS_MACH_PROM_INIT_CMDLINE
 	bool
+
+config UCA_SIZE
+ 	hex "Uncache Accelerated Region size"
+ 	depends on LOONGSON2F 
+ 	default 0x400000 if LEMOTE_YEELOONG2F
+ 	default 0x2000000 if LEMOTE_FULOONG2F
+ 	help
+ 	  Uncached Acceleration(UCA) can greatly improve video performance.
+ 	  Normally the Video memory can be accessed in Uncached Accelerated

mode,
+ other peripheral spaces not.
+
+ Specify a zeroed size to disable this feature.

b/arch/mips/loongson/common/mem.c
index 059d43f..4e1bf29 100644

@@ -53,3 +53,59 @@ int __uncached_access(struct file *file, unsigned

long addr)
return addr >= __pa(high_memory) ||
((addr >= LOONGSON_MMIO_MEM_START) && (addr <
LOONGSON_MMIO_MEM_END));
}
+
+#if defined(CONFIG_CPU_LOONGSON2F)
+
+#include <linux/pci.h>
+#include <linux/sched.h>
+#include <asm/current.h>
+
+static unsigned long uca_start;
+static unsigned long uca_size = CONFIG_UCA_SIZE;
+
+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_start + uca_size))
+ 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;
+ printk("find the frame buffer:start=%lx\n", uca_start);
+ return 0;
+ }
+ }
+
+ }
+ }
+ return 0;
+}
+
+late_initcall(find_vga_mem_init);
+#endif /* !CONFIG_CPU_LOONGSON2F */

1.6.2.1