xtensa: use the generic uncached segment support

Switch xtensa over to use the generic uncached support, and thus the
generic implementations of dma_alloc_* and dma_alloc_*, which also
gains support for mmaping DMA memory.  The non-working nommu DMA
support has been disabled, but could be re-enabled easily if platforms
that actually have an uncached segment show up.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index a8e7beb..c95a347 100644 (file)
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -3,8 +3,10 @@ config XTENSA
        def_bool y
        select ARCH_32BIT_OFF_T
        select ARCH_HAS_BINFMT_FLAT if !MMU
-       select ARCH_HAS_SYNC_DMA_FOR_CPU
-       select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+       select ARCH_HAS_DMA_PREP_COHERENT if MMU
+       select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU
+       select ARCH_HAS_SYNC_DMA_FOR_DEVICE if MMU
+       select ARCH_HAS_UNCACHED_SEGMENT if MMU
        select ARCH_USE_QUEUED_RWLOCKS
        select ARCH_USE_QUEUED_SPINLOCKS
        select ARCH_WANT_FRAME_POINTERS

diff --git a/arch/xtensa/include/asm/platform.h b/arch/xtensa/include/asm/platform.h
index 913826d..f2c4852 100644 (file)
--- a/arch/xtensa/include/asm/platform.h
+++ b/arch/xtensa/include/asm/platform.h
@@ -65,31 +65,4 @@ extern void platform_calibrate_ccount (void);
  */
 void cpu_reset(void) __attribute__((noreturn));
 
-/*
- * Memory caching is platform-dependent in noMMU xtensa configurations.
- * The following set of functions should be implemented in platform code
- * in order to enable coherent DMA memory operations when CONFIG_MMU is not
- * enabled. Default implementations do nothing and issue a warning.
- */
-
-/*
- * Check whether p points to a cached memory.
- */
-bool platform_vaddr_cached(const void *p);
-
-/*
- * Check whether p points to an uncached memory.
- */
-bool platform_vaddr_uncached(const void *p);
-
-/*
- * Return pointer to an uncached view of the cached sddress p.
- */
-void *platform_vaddr_to_uncached(void *p);
-
-/*
- * Return pointer to a cached view of the uncached sddress p.
- */
-void *platform_vaddr_to_cached(void *p);
-
 #endif /* _XTENSA_PLATFORM_H */

diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile
index 6f62902..d4082c6 100644 (file)
--- a/arch/xtensa/kernel/Makefile
+++ b/arch/xtensa/kernel/Makefile
@@ -5,10 +5,11 @@
 
 extra-y := head.o vmlinux.lds
 
-obj-y := align.o coprocessor.o entry.o irq.o pci-dma.o platform.o process.o \
+obj-y := align.o coprocessor.o entry.o irq.o platform.o process.o \
         ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \
         vectors.o
 
+obj-$(CONFIG_MMU) += pci-dma.o
 obj-$(CONFIG_PCI) += pci.o
 obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o
 obj-$(CONFIG_FUNCTION_TRACER) += mcount.o

diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index 154979d..1c82e21 100644 (file)
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -81,122 +81,25 @@ void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
        }
 }
 
-#ifdef CONFIG_MMU
-bool platform_vaddr_cached(const void *p)
-{
-       unsigned long addr = (unsigned long)p;
-
-       return addr >= XCHAL_KSEG_CACHED_VADDR &&
-              addr - XCHAL_KSEG_CACHED_VADDR < XCHAL_KSEG_SIZE;
-}
-
-bool platform_vaddr_uncached(const void *p)
-{
-       unsigned long addr = (unsigned long)p;
-
-       return addr >= XCHAL_KSEG_BYPASS_VADDR &&
-              addr - XCHAL_KSEG_BYPASS_VADDR < XCHAL_KSEG_SIZE;
-}
-
-void *platform_vaddr_to_uncached(void *p)
-{
-       return p + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR;
-}
-
-void *platform_vaddr_to_cached(void *p)
-{
-       return p + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
-}
-#else
-bool __attribute__((weak)) platform_vaddr_cached(const void *p)
-{
-       WARN_ONCE(1, "Default %s implementation is used\n", __func__);
-       return true;
-}
-
-bool __attribute__((weak)) platform_vaddr_uncached(const void *p)
-{
-       WARN_ONCE(1, "Default %s implementation is used\n", __func__);
-       return false;
-}
-
-void __attribute__((weak)) *platform_vaddr_to_uncached(void *p)
+void arch_dma_prep_coherent(struct page *page, size_t size)
 {
-       WARN_ONCE(1, "Default %s implementation is used\n", __func__);
-       return p;
-}
-
-void __attribute__((weak)) *platform_vaddr_to_cached(void *p)
-{
-       WARN_ONCE(1, "Default %s implementation is used\n", __func__);
-       return p;
+       __invalidate_dcache_range((unsigned long)page_address(page), size);
 }
-#endif
 
 /*
- * Note: We assume that the full memory space is always mapped to 'kseg'
- *      Otherwise we have to use page attributes (not implemented).
+ * Memory caching is platform-dependent in noMMU xtensa configurations.
+ * The following two functions should be implemented in platform code
+ * in order to enable coherent DMA memory operations when CONFIG_MMU is not
+ * enabled.
  */
-
-void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
-               gfp_t flag, unsigned long attrs)
-{
-       unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-       struct page *page = NULL;
-
-       /* ignore region speicifiers */
-
-       flag &= ~(__GFP_DMA | __GFP_HIGHMEM);
-
-       if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
-               flag |= GFP_DMA;
-
-       if (gfpflags_allow_blocking(flag))
-               page = dma_alloc_from_contiguous(dev, count, get_order(size),
-                                                flag & __GFP_NOWARN);
-
-       if (!page)
-               page = alloc_pages(flag | __GFP_ZERO, get_order(size));
-
-       if (!page)
-               return NULL;
-
-       *handle = phys_to_dma(dev, page_to_phys(page));
-
 #ifdef CONFIG_MMU
-       if (PageHighMem(page)) {
-               void *p;
-
-               p = dma_common_contiguous_remap(page, size,
-                                               pgprot_noncached(PAGE_KERNEL),
-                                               __builtin_return_address(0));
-               if (!p) {
-                       if (!dma_release_from_contiguous(dev, page, count))
-                               __free_pages(page, get_order(size));
-               }
-               return p;
-       }
-#endif
-       BUG_ON(!platform_vaddr_cached(page_address(page)));
-       __invalidate_dcache_range((unsigned long)page_address(page), size);
-       return platform_vaddr_to_uncached(page_address(page));
+void *uncached_kernel_address(void *p)
+{
+       return p + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR;
 }
 
-void arch_dma_free(struct device *dev, size_t size, void *vaddr,
-               dma_addr_t dma_handle, unsigned long attrs)
+void *cached_kernel_address(void *p)
 {
-       unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-       struct page *page;
-
-       if (platform_vaddr_uncached(vaddr)) {
-               page = virt_to_page(platform_vaddr_to_cached(vaddr));
-       } else {
-#ifdef CONFIG_MMU
-               dma_common_free_remap(vaddr, size);
-#endif
-               page = pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_handle)));
-       }
-
-       if (!dma_release_from_contiguous(dev, page, count))
-               __free_pages(page, get_order(size));
+       return p + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
 }
+#endif /* CONFIG_MMU */