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Subject[PATCH 1/2] microblaze/nommu: use the generic uncached segment support
Date
Stop providing our own arch alloc/free hooks for nommu platforms and
just expose the segment offset and use the generic dma-direct
allocator.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/microblaze/Kconfig | 2 +
arch/microblaze/mm/consistent.c | 93 +++++++++++++++------------------
2 files changed, 43 insertions(+), 52 deletions(-)

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index d411de05b628..a0d749c309f3 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -5,9 +5,11 @@ config MICROBLAZE
select ARCH_NO_SWAP
select ARCH_HAS_BINFMT_FLAT if !MMU
select ARCH_HAS_DMA_COHERENT_TO_PFN if MMU
+ select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+ select ARCH_HAS_UNCACHED_SEGMENT if !MMU
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_NO_COHERENT_DMA_MMAP if !MMU
select ARCH_WANT_IPC_PARSE_VERSION
diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c
index bc7042209c57..1a859e8b58c2 100644
--- a/arch/microblaze/mm/consistent.c
+++ b/arch/microblaze/mm/consistent.c
@@ -42,21 +42,48 @@
#include <asm/cpuinfo.h>
#include <asm/tlbflush.h>

-#ifndef CONFIG_MMU
-/* I have to use dcache values because I can't relate on ram size */
-# define UNCACHED_SHADOW_MASK (cpuinfo.dcache_high - cpuinfo.dcache_base + 1)
-#endif
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
+ phys_addr_t paddr = page_to_phys(page);
+
+ flush_dcache_range(paddr, paddr + size);
+}

+#ifndef CONFIG_MMU
/*
- * Consistent memory allocators. Used for DMA devices that want to
- * share uncached memory with the processor core.
- * My crufty no-MMU approach is simple. In the HW platform we can optionally
- * mirror the DDR up above the processor cacheable region. So, memory accessed
- * in this mirror region will not be cached. It's alloced from the same
- * pool as normal memory, but the handle we return is shifted up into the
- * uncached region. This will no doubt cause big problems if memory allocated
- * here is not also freed properly. -- JW
+ * Consistent memory allocators. Used for DMA devices that want to share
+ * uncached memory with the processor core. My crufty no-MMU approach is
+ * simple. In the HW platform we can optionally mirror the DDR up above the
+ * processor cacheable region. So, memory accessed in this mirror region will
+ * not be cached. It's alloced from the same pool as normal memory, but the
+ * handle we return is shifted up into the uncached region. This will no doubt
+ * cause big problems if memory allocated here is not also freed properly. -- JW
+ *
+ * I have to use dcache values because I can't relate on ram size:
*/
+#ifdef CONFIG_XILINX_UNCACHED_SHADOW
+#define UNCACHED_SHADOW_MASK (cpuinfo.dcache_high - cpuinfo.dcache_base + 1)
+#else
+#define UNCACHED_SHADOW_MASK 0
+#endif /* CONFIG_XILINX_UNCACHED_SHADOW */
+
+void *uncached_kernel_address(void *ptr)
+{
+ unsigned long addr = (unsigned long)ptr;
+
+ addr |= UNCACHED_SHADOW_MASK;
+ if (addr > cpuinfo.dcache_base && addr < cpuinfo.dcache_high)
+ pr_warn("ERROR: Your cache coherent area is CACHED!!!\n");
+ return (void *)addr;
+}
+
+void *cached_kernel_address(void *ptr)
+{
+ unsigned long addr = (unsigned long)ptr;
+
+ return (void *)(addr & ~UNCACHED_SHADOW_MASK);
+}
+#else /* CONFIG_MMU */
void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs)
{
@@ -64,12 +91,9 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
void *ret;
unsigned int i, err = 0;
struct page *page, *end;
-
-#ifdef CONFIG_MMU
phys_addr_t pa;
struct vm_struct *area;
unsigned long va;
-#endif

if (in_interrupt())
BUG();
@@ -86,26 +110,8 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
* we need to ensure that there are no cachelines in use,
* or worse dirty in this area.
*/
- flush_dcache_range(virt_to_phys((void *)vaddr),
- virt_to_phys((void *)vaddr) + size);
-
-#ifndef CONFIG_MMU
- ret = (void *)vaddr;
- /*
- * Here's the magic! Note if the uncached shadow is not implemented,
- * it's up to the calling code to also test that condition and make
- * other arranegments, such as manually flushing the cache and so on.
- */
-# ifdef CONFIG_XILINX_UNCACHED_SHADOW
- ret = (void *)((unsigned) ret | UNCACHED_SHADOW_MASK);
-# endif
- if ((unsigned int)ret > cpuinfo.dcache_base &&
- (unsigned int)ret < cpuinfo.dcache_high)
- pr_warn("ERROR: Your cache coherent area is CACHED!!!\n");
+ arch_dma_prep_coherent(virt_to_page((unsigned long)vaddr), size);

- /* dma_handle is same as physical (shadowed) address */
- *dma_handle = (dma_addr_t)ret;
-#else
/* Allocate some common virtual space to map the new pages. */
area = get_vm_area(size, VM_ALLOC);
if (!area) {
@@ -117,7 +123,6 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,

/* This gives us the real physical address of the first page. */
*dma_handle = pa = __virt_to_phys(vaddr);
-#endif

/*
* free wasted pages. We skip the first page since we know
@@ -131,10 +136,8 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
split_page(page, order);

for (i = 0; i < size && err == 0; i += PAGE_SIZE) {
-#ifdef CONFIG_MMU
/* MS: This is the whole magic - use cache inhibit pages */
err = map_page(va + i, pa + i, _PAGE_KERNEL | _PAGE_NO_CACHE);
-#endif

SetPageReserved(page);
page++;
@@ -154,7 +157,6 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
return ret;
}

-#ifdef CONFIG_MMU
static pte_t *consistent_virt_to_pte(void *vaddr)
{
unsigned long addr = (unsigned long)vaddr;
@@ -172,7 +174,6 @@ long arch_dma_coherent_to_pfn(struct device *dev, void *vaddr,

return pte_pfn(*ptep);
}
-#endif

/*
* free page(s) as defined by the above mapping.
@@ -187,18 +188,6 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,

size = PAGE_ALIGN(size);

-#ifndef CONFIG_MMU
- /* Clear SHADOW_MASK bit in address, and free as per usual */
-# ifdef CONFIG_XILINX_UNCACHED_SHADOW
- vaddr = (void *)((unsigned)vaddr & ~UNCACHED_SHADOW_MASK);
-# endif
- page = virt_to_page(vaddr);
-
- do {
- __free_reserved_page(page);
- page++;
- } while (size -= PAGE_SIZE);
-#else
do {
pte_t *ptep = consistent_virt_to_pte(vaddr);
unsigned long pfn;
@@ -216,5 +205,5 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,

/* flush tlb */
flush_tlb_all();
-#endif
}
+#endif /* CONFIG_MMU */
--
2.20.1
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