MIPS: use the generic uncached segment support in dma-direct

Stop providing the arch alloc/free hooks and just expose the segment
offset instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Burton <paul.burton@mips.com>

arch/mips/Kconfig

@@ -8,6 +8,7 @@ config MIPS
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
+	select ARCH_HAS_UNCACHED_SEGMENT
 	select ARCH_SUPPORTS_UPROBES
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF if 64BIT

arch/mips/include/asm/page.h

@@ -258,9 +258,6 @@ extern int __virt_addr_valid(const volatile void *kaddr);
 	 ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
 	 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 
-#define UNCAC_ADDR(addr)	(UNCAC_BASE + __pa(addr))
-#define CAC_ADDR(addr)		((unsigned long)__va((addr) - UNCAC_BASE))
-
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 

arch/mips/jazz/jazzdma.c

@@ -575,10 +575,6 @@ static void *jazz_dma_alloc(struct device *dev, size_t size,
 		return NULL;
 	}
 
-	if (!(attrs & DMA_ATTR_NON_CONSISTENT)) {
-		dma_cache_wback_inv((unsigned long)ret, size);
-		ret = (void *)UNCAC_ADDR(ret);
-	}
 	return ret;
 }
 
@@ -586,8 +582,6 @@ static void jazz_dma_free(struct device *dev, size_t size, void *vaddr,
 		dma_addr_t dma_handle, unsigned long attrs)
 {
 	vdma_free(dma_handle);
-	if (!(attrs & DMA_ATTR_NON_CONSISTENT))
-		vaddr = (void *)CAC_ADDR((unsigned long)vaddr);
 	dma_direct_free_pages(dev, size, vaddr, dma_handle, attrs);
 }
 

arch/mips/mm/dma-noncoherent.c

@@ -44,33 +44,25 @@ static inline bool cpu_needs_post_dma_flush(struct device *dev)
 	}
 }
 
-void *arch_dma_alloc(struct device *dev, size_t size,
-		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+void arch_dma_prep_coherent(struct page *page, size_t size)
 {
-	void *ret;
-
-	ret = dma_direct_alloc_pages(dev, size, dma_handle, gfp, attrs);
-	if (ret && !(attrs & DMA_ATTR_NON_CONSISTENT)) {
-		dma_cache_wback_inv((unsigned long) ret, size);
-		ret = (void *)UNCAC_ADDR(ret);
-	}
-
-	return ret;
+	dma_cache_wback_inv((unsigned long)page_address(page), size);
 }
 
-void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
-		dma_addr_t dma_addr, unsigned long attrs)
+void *uncached_kernel_address(void *addr)
 {
-	if (!(attrs & DMA_ATTR_NON_CONSISTENT))
-		cpu_addr = (void *)CAC_ADDR((unsigned long)cpu_addr);
-	dma_direct_free_pages(dev, size, cpu_addr, dma_addr, attrs);
+	return (void *)(__pa(addr) + UNCAC_BASE);
+}
+
+void *cached_kernel_address(void *addr)
+{
+	return __va(addr) - UNCAC_BASE;
 }
 
 long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
 		dma_addr_t dma_addr)
 {
-	unsigned long addr = CAC_ADDR((unsigned long)cpu_addr);
-	return page_to_pfn(virt_to_page((void *)addr));
+	return page_to_pfn(virt_to_page(cached_kernel_address(cpu_addr)));
 }
 
 pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,