Changeset 2bf4936 in mainline for kernel/arch/sparc64/src/mm/tlb.c

Timestamp:

2009-04-14T15:50:56Z (15 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

47a6708

Parents:

577b531

Message:

On sparc64, do fast indentity mapping only for physical memory.
For addresses above physical memory, such as I/O devices,
fall through to the C miss handler and map the memory noncacheably.
Replace deprecated Bicc instructions with proper Bcc instructions.

File:

• kernel/arch/sparc64/src/mm/tlb.c (modified) (9 diffs)

kernel/arch/sparc64/src/mm/tlb.c

@@ -200 +200 @@
 void fast_instruction_access_mmu_miss(unative_t unused, istate_t *istate)
 {
-        uintptr_t va = ALIGN_DOWN(istate->tpc, PAGE_SIZE);
+        uintptr_t page_16k = ALIGN_DOWN(istate->tpc, PAGE_SIZE);
         index_t index = (istate->tpc >> MMU_PAGE_WIDTH) % MMU_PAGES_PER_PAGE;
         pte_t *t;
 
         page_table_lock(AS, true);
-        t = page_mapping_find(AS, va);
+        t = page_mapping_find(AS, page_16k);
         if (t && PTE_EXECUTABLE(t)) {
                 /*
@@ -223 +223 @@
                  */             
                 page_table_unlock(AS, true);
-                if (as_page_fault(va, PF_ACCESS_EXEC, istate) == AS_PF_FAULT) {
+                if (as_page_fault(page_16k, PF_ACCESS_EXEC, istate) ==
+                    AS_PF_FAULT) {
                         do_fast_instruction_access_mmu_miss_fault(istate,
                             __func__);
@@ -243 +244 @@
 void fast_data_access_mmu_miss(tlb_tag_access_reg_t tag, istate_t *istate)
 {
-        uintptr_t va;
+        uintptr_t page_8k;
+        uintptr_t page_16k;
         index_t index;
         pte_t *t;
 
-        va = ALIGN_DOWN((uint64_t) tag.vpn << MMU_PAGE_WIDTH, PAGE_SIZE);
+        page_8k = (uint64_t) tag.vpn << MMU_PAGE_WIDTH;
+        page_16k = ALIGN_DOWN(page_8k, PAGE_SIZE);
         index = tag.vpn % MMU_PAGES_PER_PAGE;
 
@@ -255 +258 @@
                         do_fast_data_access_mmu_miss_fault(istate, tag,
                             __func__);
+                } else if (page_8k >= end_of_identity) {
+                        /*
+                         * The kernel is accessing the I/O space.
+                         * We still do identity mapping for I/O,
+                         * but without caching.
+                         */
+                        dtlb_insert_mapping(page_8k, KA2PA(page_8k),
+                            PAGESIZE_8K, false, false);
+                        return;
                 }
                 do_fast_data_access_mmu_miss_fault(istate, tag, "Unexpected "
@@ -261 +273 @@
 
         page_table_lock(AS, true);
-        t = page_mapping_find(AS, va);
+        t = page_mapping_find(AS, page_16k);
         if (t) {
                 /*
@@ -279 +291 @@
                  */             
                 page_table_unlock(AS, true);
-                if (as_page_fault(va, PF_ACCESS_READ, istate) == AS_PF_FAULT) {
+                if (as_page_fault(page_16k, PF_ACCESS_READ, istate) ==
+                    AS_PF_FAULT) {
                         do_fast_data_access_mmu_miss_fault(istate, tag,
                             __func__);
@@ -296 +309 @@
 void fast_data_access_protection(tlb_tag_access_reg_t tag, istate_t *istate)
 {
-        uintptr_t va;
+        uintptr_t page_16k;
         index_t index;
         pte_t *t;
 
-        va = ALIGN_DOWN((uint64_t) tag.vpn << MMU_PAGE_WIDTH, PAGE_SIZE);
+        page_16k = ALIGN_DOWN((uint64_t) tag.vpn << MMU_PAGE_WIDTH, PAGE_SIZE);
         index = tag.vpn % MMU_PAGES_PER_PAGE;   /* 16K-page emulation */
 
         page_table_lock(AS, true);
-        t = page_mapping_find(AS, va);
+        t = page_mapping_find(AS, page_16k);
         if (t && PTE_WRITABLE(t)) {
                 /*
@@ -314 +327 @@
                 t->d = true;
                 dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_SECONDARY,
-                    va + index * MMU_PAGE_SIZE);
+                    page_16k + index * MMU_PAGE_SIZE);
                 dtlb_pte_copy(t, index, false);
 #ifdef CONFIG_TSB
@@ -326 +339 @@
                  */             
                 page_table_unlock(AS, true);
-                if (as_page_fault(va, PF_ACCESS_WRITE, istate) == AS_PF_FAULT) {
+                if (as_page_fault(page_16k, PF_ACCESS_WRITE, istate) ==
+                    AS_PF_FAULT) {
                         do_fast_data_access_protection_fault(istate, tag,
                             __func__);