Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/xfs-vipt
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/xfs-vipt:
xfs: fix xfs to work with Virtually Indexed architectures
sh: add mm API for DMA to vmalloc/vmap areas
arm: add mm API for DMA to vmalloc/vmap areas
parisc: add mm API for DMA to vmalloc/vmap areas
mm: add coherence API for DMA to vmalloc/vmap areas
diff --git a/Documentation/cachetlb.txt b/Documentation/cachetlb.txt
index da42ab4..b231414 100644
--- a/Documentation/cachetlb.txt
+++ b/Documentation/cachetlb.txt
@@ -377,3 +377,27 @@
All the functionality of flush_icache_page can be implemented in
flush_dcache_page and update_mmu_cache. In 2.7 the hope is to
remove this interface completely.
+
+The final category of APIs is for I/O to deliberately aliased address
+ranges inside the kernel. Such aliases are set up by use of the
+vmap/vmalloc API. Since kernel I/O goes via physical pages, the I/O
+subsystem assumes that the user mapping and kernel offset mapping are
+the only aliases. This isn't true for vmap aliases, so anything in
+the kernel trying to do I/O to vmap areas must manually manage
+coherency. It must do this by flushing the vmap range before doing
+I/O and invalidating it after the I/O returns.
+
+ void flush_kernel_vmap_range(void *vaddr, int size)
+ flushes the kernel cache for a given virtual address range in
+ the vmap area. This is to make sure that any data the kernel
+ modified in the vmap range is made visible to the physical
+ page. The design is to make this area safe to perform I/O on.
+ Note that this API does *not* also flush the offset map alias
+ of the area.
+
+ void invalidate_kernel_vmap_range(void *vaddr, int size) invalidates
+ the cache for a given virtual address range in the vmap area
+ which prevents the processor from making the cache stale by
+ speculatively reading data while the I/O was occurring to the
+ physical pages. This is only necessary for data reads into the
+ vmap area.
diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index 8113bb5..5fe4a2a 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -447,6 +447,16 @@
: "r" (0));
#endif
}
+static inline void flush_kernel_vmap_range(void *addr, int size)
+{
+ if ((cache_is_vivt() || cache_is_vipt_aliasing()))
+ __cpuc_flush_dcache_area(addr, (size_t)size);
+}
+static inline void invalidate_kernel_vmap_range(void *addr, int size)
+{
+ if ((cache_is_vivt() || cache_is_vipt_aliasing()))
+ __cpuc_flush_dcache_area(addr, (size_t)size);
+}
#define ARCH_HAS_FLUSH_ANON_PAGE
static inline void flush_anon_page(struct vm_area_struct *vma,
diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index 7a73b61..4772777 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -38,6 +38,18 @@
#define flush_kernel_dcache_range(start,size) \
flush_kernel_dcache_range_asm((start), (start)+(size));
+/* vmap range flushes and invalidates. Architecturally, we don't need
+ * the invalidate, because the CPU should refuse to speculate once an
+ * area has been flushed, so invalidate is left empty */
+static inline void flush_kernel_vmap_range(void *vaddr, int size)
+{
+ unsigned long start = (unsigned long)vaddr;
+
+ flush_kernel_dcache_range_asm(start, start + size);
+}
+static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
+{
+}
#define flush_cache_vmap(start, end) flush_cache_all()
#define flush_cache_vunmap(start, end) flush_cache_all()
diff --git a/arch/sh/include/asm/cacheflush.h b/arch/sh/include/asm/cacheflush.h
index dda96eb..da3ebec 100644
--- a/arch/sh/include/asm/cacheflush.h
+++ b/arch/sh/include/asm/cacheflush.h
@@ -63,6 +63,14 @@
if (boot_cpu_data.dcache.n_aliases && PageAnon(page))
__flush_anon_page(page, vmaddr);
}
+static inline void flush_kernel_vmap_range(void *addr, int size)
+{
+ __flush_wback_region(addr, size);
+}
+static inline void invalidate_kernel_vmap_range(void *addr, int size)
+{
+ __flush_invalidate_region(addr, size);
+}
#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
static inline void flush_kernel_dcache_page(struct page *page)
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 77b8be8..6f3ebb6 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -76,6 +76,27 @@
#define xfs_buf_deallocate(bp) \
kmem_zone_free(xfs_buf_zone, (bp));
+static inline int
+xfs_buf_is_vmapped(
+ struct xfs_buf *bp)
+{
+ /*
+ * Return true if the buffer is vmapped.
+ *
+ * The XBF_MAPPED flag is set if the buffer should be mapped, but the
+ * code is clever enough to know it doesn't have to map a single page,
+ * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1.
+ */
+ return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1;
+}
+
+static inline int
+xfs_buf_vmap_len(
+ struct xfs_buf *bp)
+{
+ return (bp->b_page_count * PAGE_SIZE) - bp->b_offset;
+}
+
/*
* Page Region interfaces.
*
@@ -314,7 +335,7 @@
if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) {
uint i;
- if ((bp->b_flags & XBF_MAPPED) && (bp->b_page_count > 1))
+ if (xfs_buf_is_vmapped(bp))
free_address(bp->b_addr - bp->b_offset);
for (i = 0; i < bp->b_page_count; i++) {
@@ -1107,6 +1128,9 @@
xfs_buf_ioerror(bp, -error);
+ if (!error && xfs_buf_is_vmapped(bp) && (bp->b_flags & XBF_READ))
+ invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp));
+
do {
struct page *page = bvec->bv_page;
@@ -1216,6 +1240,10 @@
submit_io:
if (likely(bio->bi_size)) {
+ if (xfs_buf_is_vmapped(bp)) {
+ flush_kernel_vmap_range(bp->b_addr,
+ xfs_buf_vmap_len(bp));
+ }
submit_bio(rw, bio);
if (size)
goto next_chunk;
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index ab2cc20..74152c0 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -17,6 +17,12 @@
static inline void flush_kernel_dcache_page(struct page *page)
{
}
+static inline void flush_kernel_vmap_range(void *vaddr, int size)
+{
+}
+static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
+{
+}
#endif
#include <asm/kmap_types.h>