ARMv7-A: stop using CP15 ops

The ARMv7-A code uses read_cp15() to access fault registers.
Instead, use DPM operations directly, passing in the relevant
MRC instructions.

This eliminates per-operation overhead (though it'll be hard
to observe, this is uncommon) and helps eliminate read_cp15().

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

diff --git a/src/target/armv7a.c b/src/target/armv7a.c
index 3d94329fd29558f7110a156dcbc6e2452fbfd1f1..e23208f191c9b2fc3ae90cb715797859b39018f4 100644 (file)
--- a/src/target/armv7a.c
+++ b/src/target/armv7a.c
@@ -38,17 +38,48 @@ static void armv7a_show_fault_registers(struct target *target)
 {
        uint32_t dfsr, ifsr, dfar, ifar;
        struct armv7a_common *armv7a = target_to_armv7a(target);
-
-       armv7a->read_cp15(target, 0, 0, 5, 0, &dfsr);
-       armv7a->read_cp15(target, 0, 1, 5, 0, &ifsr);
-       armv7a->read_cp15(target, 0, 0, 6, 0, &dfar);
-       armv7a->read_cp15(target, 0, 2, 6, 0, &ifar);
+       struct arm_dpm *dpm = armv7a->armv4_5_common.dpm;
+       int retval;
+
+       retval = dpm->prepare(dpm);
+       if (retval != ERROR_OK)
+               return;
+
+       /* ARMV4_5_MRC(cpnum, op1, r0, CRn, CRm, op2) */
+
+       /* c5/c0 - {data, instruction} fault status registers */
+       retval = dpm->instr_read_data_r0(dpm,
+                       ARMV4_5_MRC(15, 0, 0, 5, 0, 0),
+                       &dfsr);
+       if (retval != ERROR_OK)
+               goto done;
+
+       retval = dpm->instr_read_data_r0(dpm,
+                       ARMV4_5_MRC(15, 0, 0, 5, 0, 1),
+                       &ifsr);
+       if (retval != ERROR_OK)
+               goto done;
+
+       /* c6/c0 - {data, instruction} fault address registers */
+       retval = dpm->instr_read_data_r0(dpm,
+                       ARMV4_5_MRC(15, 0, 0, 6, 0, 0),
+                       &dfar);
+       if (retval != ERROR_OK)
+               goto done;
+
+       retval = dpm->instr_read_data_r0(dpm,
+                       ARMV4_5_MRC(15, 0, 0, 6, 0, 2),
+                       &ifar);
+       if (retval != ERROR_OK)
+               goto done;
 
        LOG_USER("Data fault registers        DFSR: %8.8" PRIx32
                        ", DFAR: %8.8" PRIx32, dfsr, dfar);
        LOG_USER("Instruction fault registers IFSR: %8.8" PRIx32
                        ", IFAR: %8.8" PRIx32, ifsr, ifar);
 
+done:
+       /* (void) */ dpm->finish(dpm);
 }
 
 int armv7a_arch_state(struct target *target)