MIPS: cache: Provide cache flush operations for XFS

Until now flush_kernel_vmap_range() and invalidate_kernel_vmap_range() did
not exist on MIPS resulting in heavy cache corruption on XFS filesystems.

Left for the post-3.0 time: optimization and make this work with highmem,
too.  Since the combination of highmem + cache aliases atm doesn't work
this isn't a regression.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/2505/

1 files changed, 35 insertions, 0 deletions

diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index b9aabb998a32..a79fe9aa7721 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -722,6 +722,39 @@ static void r4k_flush_icache_all(void)
                 r4k_blast_icache();
 }
 
+struct flush_kernel_vmap_range_args {
+        unsigned long   vaddr;
+        int             size;
+};
+
+static inline void local_r4k_flush_kernel_vmap_range(void *args)
+{
+        struct flush_kernel_vmap_range_args *vmra = args;
+        unsigned long vaddr = vmra->vaddr;
+        int size = vmra->size;
+
+        /*
+         * Aliases only affect the primary caches so don't bother with
+         * S-caches or T-caches.
+         */
+        if (cpu_has_safe_index_cacheops && size >= dcache_size)
+                r4k_blast_dcache();
+        else {
+                R4600_HIT_CACHEOP_WAR_IMPL;
+                blast_dcache_range(vaddr, vaddr + size);
+        }
+}
+
+static void r4k_flush_kernel_vmap_range(unsigned long vaddr, int size)
+{
+        struct flush_kernel_vmap_range_args args;
+
+        args.vaddr = (unsigned long) vaddr;
+        args.size = size;
+
+        r4k_on_each_cpu(local_r4k_flush_kernel_vmap_range, &args);
+}
+
 static inline void rm7k_erratum31(void)
 {
         const unsigned long ic_lsize = 32;
@@ -1403,6 +1436,8 @@ void __cpuinit r4k_cache_init(void)
         flush_cache_page        = r4k_flush_cache_page;
         flush_cache_range       = r4k_flush_cache_range;
 
+        __flush_kernel_vmap_range = r4k_flush_kernel_vmap_range;
+
         flush_cache_sigtramp    = r4k_flush_cache_sigtramp;
         flush_icache_all        = r4k_flush_icache_all;
         local_flush_data_cache_page     = local_r4k_flush_data_cache_page;