[MIPS] Avoid indexed cacheops.
authorRalf Baechle <ralf@linux-mips.org>
Thu, 27 Sep 2007 17:26:43 +0000 (18:26 +0100)
committerRalf Baechle <ralf@linux-mips.org>
Thu, 11 Oct 2007 22:46:12 +0000 (23:46 +0100)
On MP configurations it's highly dubious what this code will actually
affect since blasting away cachelines may or may not do the right
thing wrt. cache coherency.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
arch/mips/mm/c-r4k.c

index 738b89803a44f57a7acabb68f24d1cd848db9a47..cf48371e569085000ddf8a101aaea7b93f83ff0e 100644 (file)
@@ -8,6 +8,7 @@
  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  */
 #include <linux/init.h>
+#include <linux/highmem.h>
 #include <linux/kernel.h>
 #include <linux/linkage.h>
 #include <linux/sched.h>
@@ -318,23 +319,6 @@ static void __init r4k_blast_scache_setup(void)
                r4k_blast_scache = blast_scache128;
 }
 
-/*
- * This is former mm's flush_cache_all() which really should be
- * flush_cache_vunmap these days ...
- */
-static inline void local_r4k_flush_cache_all(void * args)
-{
-       r4k_blast_dcache();
-}
-
-static void r4k_flush_cache_all(void)
-{
-       if (!cpu_has_dc_aliases)
-               return;
-
-       r4k_on_each_cpu(local_r4k_flush_cache_all, NULL, 1, 1);
-}
-
 static inline void local_r4k___flush_cache_all(void * args)
 {
 #if defined(CONFIG_CPU_LOONGSON2)
@@ -423,13 +407,14 @@ static inline void local_r4k_flush_cache_page(void *args)
        struct flush_cache_page_args *fcp_args = args;
        struct vm_area_struct *vma = fcp_args->vma;
        unsigned long addr = fcp_args->addr;
-       unsigned long paddr = fcp_args->pfn << PAGE_SHIFT;
+       struct page *page = pfn_to_page(fcp_args->pfn);
        int exec = vma->vm_flags & VM_EXEC;
        struct mm_struct *mm = vma->vm_mm;
        pgd_t *pgdp;
        pud_t *pudp;
        pmd_t *pmdp;
        pte_t *ptep;
+       void *vaddr;
 
        /*
         * If ownes no valid ASID yet, cannot possibly have gotten
@@ -451,43 +436,40 @@ static inline void local_r4k_flush_cache_page(void *args)
        if (!(pte_val(*ptep) & _PAGE_PRESENT))
                return;
 
-       /*
-        * Doing flushes for another ASID than the current one is
-        * too difficult since stupid R4k caches do a TLB translation
-        * for every cache flush operation.  So we do indexed flushes
-        * in that case, which doesn't overly flush the cache too much.
-        */
-       if ((mm == current->active_mm) && (pte_val(*ptep) & _PAGE_VALID)) {
-               if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc)) {
-                       r4k_blast_dcache_page(addr);
-                       if (exec && !cpu_icache_snoops_remote_store)
-                               r4k_blast_scache_page(addr);
-               }
-               if (exec)
-                       r4k_blast_icache_page(addr);
-
-               return;
+       if ((mm == current->active_mm) && (pte_val(*ptep) & _PAGE_VALID))
+               vaddr = NULL;
+       else {
+               /*
+                * Use kmap_coherent or kmap_atomic to do flushes for
+                * another ASID than the current one.
+                */
+               if (cpu_has_dc_aliases)
+                       vaddr = kmap_coherent(page, addr);
+               else
+                       vaddr = kmap_atomic(page, KM_USER0);
+               addr = (unsigned long)vaddr;
        }
 
-       /*
-        * Do indexed flush, too much work to get the (possible) TLB refills
-        * to work correctly.
-        */
        if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc)) {
-               r4k_blast_dcache_page_indexed(cpu_has_pindexed_dcache ?
-                                             paddr : addr);
-               if (exec && !cpu_icache_snoops_remote_store) {
-                       r4k_blast_scache_page_indexed(paddr);
-               }
+               r4k_blast_dcache_page(addr);
+               if (exec && !cpu_icache_snoops_remote_store)
+                       r4k_blast_scache_page(addr);
        }
        if (exec) {
-               if (cpu_has_vtag_icache && mm == current->active_mm) {
+               if (vaddr && cpu_has_vtag_icache && mm == current->active_mm) {
                        int cpu = smp_processor_id();
 
                        if (cpu_context(cpu, mm) != 0)
                                drop_mmu_context(mm, cpu);
                } else
-                       r4k_blast_icache_page_indexed(addr);
+                       r4k_blast_icache_page(addr);
+       }
+
+       if (vaddr) {
+               if (cpu_has_dc_aliases)
+                       kunmap_coherent();
+               else
+                       kunmap_atomic(vaddr, KM_USER0);
        }
 }
 
@@ -1279,7 +1261,7 @@ void __init r4k_cache_init(void)
                                        PAGE_SIZE - 1);
        else
                shm_align_mask = PAGE_SIZE-1;
-       flush_cache_all         = r4k_flush_cache_all;
+       flush_cache_all         = cache_noop;
        __flush_cache_all       = r4k___flush_cache_all;
        flush_cache_mm          = r4k_flush_cache_mm;
        flush_cache_page        = r4k_flush_cache_page;