Changes in / [b6636dc:23c1fae] in mainline

File:

• kernel/arch/arm32/src/mm/page_fault.c (modified) (3 diffs)

kernel/arch/arm32/src/mm/page_fault.c

@@ -77 +77 @@
 }
 
-/** Decides whether the instruction is load/store or not.
- *
- * @param instr Instruction
- *
- * @return true when instruction is load/store, false otherwise
- *
- */
-static inline bool is_load_store_instruction(instruction_t instr)
-{
-        /* load store immediate offset */
-        if (instr.type == 0x2)
-                return true;
-        
-        /* load store register offset */
-        if ((instr.type == 0x3) && (instr.bit4 == 0))
-                return true;
-        
-        /* load store multiple */
-        if (instr.type == 0x4)
-                return true;
-        
-        /* oprocessor load/store */
-        if (instr.type == 0x6)
-                return true;
-        
-        return false;
-}
-
-/** Decides whether the instruction is swap or not.
- *
- * @param instr Instruction
- *
- * @return true when instruction is swap, false otherwise
- */
-static inline bool is_swap_instruction(instruction_t instr)
-{
-        /* swap, swapb instruction */
-        if ((instr.type == 0x0) &&
-            ((instr.opcode == 0x8) || (instr.opcode == 0xa)) &&
-            (instr.access == 0x0) && (instr.bits567 == 0x4) && (instr.bit4 == 1))
-                return true;
-        
-        return false;
-}
-
 /** Decides whether read or write into memory is requested.
  *
@@ -146 +101 @@
         }
 
-        /* load store instructions */
-        if (is_load_store_instruction(instr)) {
-                if (instr.access == 1) {
-                        return PF_ACCESS_READ;
-                } else {
-                        return PF_ACCESS_WRITE;
+        /* See ARM Architecture reference manual ARMv7-A and ARMV7-R edition
+         * A5.3 (PDF p. 206) */
+        static const struct {
+                uint32_t mask;
+                uint32_t value;
+                pf_access_t access;
+        } ls_inst[] = {
+                /* Store word/byte */
+                { 0x0e100000, 0x04000000, PF_ACCESS_WRITE }, /*STR(B) imm*/
+                { 0x0e100010, 0x06000000, PF_ACCESS_WRITE }, /*STR(B) reg*/
+                /* Load word/byte */
+                { 0x0e100000, 0x04100000, PF_ACCESS_READ }, /*LDR(B) imm*/
+                { 0x0e100010, 0x06100000, PF_ACCESS_READ }, /*LDR(B) reg*/
+                /* Store half-word/dual  A5.2.8 */
+                { 0x0e1000b0, 0x000000b0, PF_ACCESS_WRITE }, /*STRH imm reg*/
+                /* Load half-word/dual A5.2.8 */
+                { 0x0e0000f0, 0x000000d0, PF_ACCESS_READ }, /*LDRH imm reg*/
+                { 0x0e1000b0, 0x001000b0, PF_ACCESS_READ }, /*LDRH imm reg*/
+                /* Block data transfer, Store */
+                { 0x0e100000, 0x08000000, PF_ACCESS_WRITE }, /* STM variants */
+                { 0x0e100000, 0x08100000, PF_ACCESS_READ },  /* LDM variants */
+                /* Swap */
+                { 0x0fb00000, 0x01000000, PF_ACCESS_WRITE },
+        };
+        uint32_t inst = *(uint32_t*)instr_addr;
+        for (unsigned i = 0; i < sizeof(ls_inst) / sizeof(ls_inst[0]); ++i) {
+                if ((inst & ls_inst[i].mask) == ls_inst[i].value) {
+                        return ls_inst[i].access;
                 }
-        }
-
-        /* swap, swpb instruction */
-        if (is_swap_instruction(instr)) {
-                return PF_ACCESS_WRITE;
         }
 
@@ -163 +135 @@
             "(instr_code: %#0" PRIx32 ", badvaddr:%p).",
             instr_union.pc, (void *) badvaddr);
-
-        return PF_ACCESS_EXEC;
 }