microblaze: Fix consistent code

This patch fix consistent code which had problems with consistent_free
function.
I am not sure if we need to call flush_tlb_all after it but it keeps
tlbs synced.
I added noMMU and MMU version together.

Uncached shadow feature is not tested.

Signed-off-by: Michal Simek <monstr@monstr.eu>

3 files changed, 100 insertions, 92 deletions

diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h
index 16a117ed260..ca2d9287154 100644
--- a/arch/microblaze/include/asm/pgtable.h
+++ b/arch/microblaze/include/asm/pgtable.h
@@ -568,7 +568,7 @@ void __init *early_get_page(void);
 extern unsigned long ioremap_bot, ioremap_base;
 
 void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle);
-void consistent_free(void *vaddr);
+void consistent_free(size_t size, void *vaddr);
 void consistent_sync(void *vaddr, size_t size, int direction);
 void consistent_sync_page(struct page *page, unsigned long offset,
         size_t size, int direction);
diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
index ce72dd4967c..9dcd90b5df5 100644
--- a/arch/microblaze/kernel/dma.c
+++ b/arch/microblaze/kernel/dma.c
@@ -74,7 +74,7 @@ static void dma_direct_free_coherent(struct device *dev, size_t size,
                               void *vaddr, dma_addr_t dma_handle)
 {
 #ifdef NOT_COHERENT_CACHE
-        consistent_free(vaddr);
+        consistent_free(size, vaddr);
 #else
         free_pages((unsigned long)vaddr, get_order(size));
 #endif
diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c
index f956e24fe49..713431caf59 100644
--- a/arch/microblaze/mm/consistent.c
+++ b/arch/microblaze/mm/consistent.c
@@ -42,11 +42,12 @@
 #include <linux/uaccess.h>
 #include <asm/pgtable.h>
 #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)
+# define UNCACHED_SHADOW_MASK (cpuinfo.dcache_high - cpuinfo.dcache_base + 1)
+#endif
 
 /*
  * Consistent memory allocators. Used for DMA devices that want to
@@ -60,71 +61,16 @@
  */
 void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
 {
-        struct page *page, *end, *free;
-        unsigned long order;
-        void *ret, *virt;
-
-        if (in_interrupt())
-                BUG();
-
-        size = PAGE_ALIGN(size);
-        order = get_order(size);
-
-        page = alloc_pages(gfp, order);
-        if (!page)
-                goto no_page;
-
-        /* We could do with a page_to_phys and page_to_bus here. */
-        virt = page_address(page);
-        ret = ioremap(virt_to_phys(virt), size);
-        if (!ret)
-                goto no_remap;
-
-        /*
-         * 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
-        /* dma_handle is same as physical (shadowed) address */
-        *dma_handle = (dma_addr_t)ret;
-
-        /*
-         * free wasted pages.  We skip the first page since we know
-         * that it will have count = 1 and won't require freeing.
-         * We also mark the pages in use as reserved so that
-         * remap_page_range works.
-         */
-        page = virt_to_page(virt);
-        free = page + (size >> PAGE_SHIFT);
-        end  = page + (1 << order);
-
-        for (; page < end; page++) {
-                init_page_count(page);
-                if (page >= free)
-                        __free_page(page);
-                else
-                        SetPageReserved(page);
-        }
-
-        return ret;
-no_remap:
-        __free_pages(page, order);
-no_page:
-        return NULL;
-}
-
-#else
+        unsigned long order, vaddr;
+        void *ret;
+        unsigned int i, err = 0;
+        struct page *page, *end;
 
-void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
-{
-        int order, err, i;
-        unsigned long page, va, flags;
+#ifdef CONFIG_MMU
         phys_addr_t pa;
         struct vm_struct *area;
-        void     *ret;
+        unsigned long va;
+#endif
 
         if (in_interrupt())
                 BUG();
@@ -133,71 +79,133 @@ void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
         size = PAGE_ALIGN(size);
         order = get_order(size);
 
-        page = __get_free_pages(gfp, order);
-        if (!page) {
-                BUG();
+        vaddr = __get_free_pages(gfp, order);
+        if (!vaddr)
                 return NULL;
-        }
 
         /*
          * we need to ensure that there are no cachelines in use,
          * or worse dirty in this area.
          */
-        flush_dcache_range(virt_to_phys(page), virt_to_phys(page) + size);
+        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)
+                printk(KERN_WARNING
+                        "ERROR: Your cache coherent area is CACHED!!!\n");
+
+        /* 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 == NULL) {
-                free_pages(page, order);
+        if (!area) {
+                free_pages(vaddr, order);
                 return NULL;
         }
         va = (unsigned long) area->addr;
         ret = (void *)va;
 
         /* This gives us the real physical address of the first page. */
-        *dma_handle = pa = virt_to_bus((void *)page);
-
-        /* MS: This is the whole magic - use cache inhibit pages */
-        flags = _PAGE_KERNEL | _PAGE_NO_CACHE;
+        *dma_handle = pa = virt_to_bus((void *)vaddr);
+#endif
 
         /*
-         * Set refcount=1 on all pages in an order>0
-         * allocation so that vfree() will actually
-         * free all pages that were allocated.
+         * free wasted pages.  We skip the first page since we know
+         * that it will have count = 1 and won't require freeing.
+         * We also mark the pages in use as reserved so that
+         * remap_page_range works.
          */
-        if (order > 0) {
-                struct page *rpage = virt_to_page(page);
-                for (i = 1; i < (1 << order); i++)
-                        init_page_count(rpage+i);
+        page = virt_to_page(vaddr);
+        end = page + (1 << order);
+
+        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++;
         }
 
-        err = 0;
-        for (i = 0; i < size && err == 0; i += PAGE_SIZE)
-                err = map_page(va+i, pa+i, flags);
+        /* Free the otherwise unused pages. */
+        while (page < end) {
+                __free_page(page);
+                page++;
+        }
 
         if (err) {
-                vfree((void *)va);
+                free_pages(vaddr, order);
                 return NULL;
         }
 
         return ret;
 }
-#endif /* CONFIG_MMU */
 EXPORT_SYMBOL(consistent_alloc);
 
 /*
  * free page(s) as defined by the above mapping.
  */
-void consistent_free(void *vaddr)
+void consistent_free(size_t size, void *vaddr)
 {
+        struct page *page;
+
         if (in_interrupt())
                 BUG();
 
+        size = PAGE_ALIGN(size);
+
+#ifndef CONFIG_MMU
         /* Clear SHADOW_MASK bit in address, and free as per usual */
-#ifdef CONFIG_XILINX_UNCACHED_SHADOW
+# ifdef CONFIG_XILINX_UNCACHED_SHADOW
         vaddr = (void *)((unsigned)vaddr & ~UNCACHED_SHADOW_MASK);
+# endif
+        page = virt_to_page(vaddr);
+
+        do {
+                ClearPageReserved(page);
+                __free_page(page);
+                page++;
+        } while (size -= PAGE_SIZE);
+#else
+        do {
+                pte_t *ptep;
+                unsigned long pfn;
+
+                ptep = pte_offset_kernel(pmd_offset(pgd_offset_k(
+                                                (unsigned int)vaddr),
+                                        (unsigned int)vaddr),
+                                (unsigned int)vaddr);
+                if (!pte_none(*ptep) && pte_present(*ptep)) {
+                        pfn = pte_pfn(*ptep);
+                        pte_clear(&init_mm, (unsigned int)vaddr, ptep);
+                        if (pfn_valid(pfn)) {
+                                page = pfn_to_page(pfn);
+
+                                ClearPageReserved(page);
+                                __free_page(page);
+                        }
+                }
+                vaddr += PAGE_SIZE;
+        } while (size -= PAGE_SIZE);
+
+        /* flush tlb */
+        flush_tlb_all();
 #endif
-        vfree(vaddr);
 }
 EXPORT_SYMBOL(consistent_free);