MIPS: Drop CPU_SUPPORTS_UNCACHED_ACCELERATED

CPU_SUPPORTS_UNCACHED_ACCELERATED was introduced when kernel can't handle
writecombine remap well. Nowadays drivers can try writecombine remap by
themselves so this function is nolonger needed.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: chenhe@lemote.com

arch/mips/Kconfig

@@ -1973,7 +1973,6 @@ config SYS_HAS_CPU_LOONGSON2F
 	bool
 	select CPU_SUPPORTS_CPUFREQ
 	select CPU_SUPPORTS_ADDRWINCFG if 64BIT
-	select CPU_SUPPORTS_UNCACHED_ACCELERATED
 
 config SYS_HAS_CPU_LOONGSON1B
 	bool
@@ -2150,8 +2149,6 @@ config CPU_SUPPORTS_ADDRWINCFG
 config CPU_SUPPORTS_HUGEPAGES
 	bool
 	depends on !(32BIT && (ARCH_PHYS_ADDR_T_64BIT || EVA))
-config CPU_SUPPORTS_UNCACHED_ACCELERATED
-	bool
 config MIPS_PGD_C0_CONTEXT
 	bool
 	default y if 64BIT && (CPU_MIPSR2 || CPU_MIPSR6) && !CPU_XLP

arch/mips/include/asm/pgtable.h

@@ -643,17 +643,6 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 
 #include <asm-generic/pgtable.h>
 
-/*
- * uncached accelerated TLB map for video memory access
- */
-#ifdef CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED
-#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);
-#endif
-
 /*
  * We provide our own get_unmapped area to cope with the virtual aliasing
  * constraints placed on us by the cache architecture.

arch/mips/loongson2ef/common/mem.c

@@ -60,61 +60,3 @@ 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 >> 16) == PCI_BASE_CLASS_DISPLAY) {
-			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 */