target/cortex_a: Extract code to read/write from/to register to/from DCC

In preparation for supporting the ARM MCRR and MRRC commands which will
require using two 32-bit registers to read/write a 64-bit internal
register, extract the common logic to read/write from/to a register
to/from DCC and make that parameterized such that we can do this through
not just r0.

Change-Id: Iadb73f5cde8cf5961b5a18ddd198bf39d791e610
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-on: http://openocd.zylin.com/5227
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

diff --git a/src/target/cortex_a.c b/src/target/cortex_a.c
index 3ed2481ba957c01ff0541fb02d27cc6757165bba..8773ea1607a1019a6c778bc5e14088e2e4008259 100644 (file)
--- a/src/target/cortex_a.c
+++ b/src/target/cortex_a.c
@@ -425,22 +425,35 @@ static int cortex_a_instr_write_data_dcc(struct arm_dpm *dpm,
                        &dscr);
 }
 
-static int cortex_a_instr_write_data_r0(struct arm_dpm *dpm,
-       uint32_t opcode, uint32_t data)
+static int cortex_a_instr_write_data_rt_dcc(struct arm_dpm *dpm,
+       uint8_t rt, uint32_t data)
 {
        struct cortex_a_common *a = dpm_to_a(dpm);
        uint32_t dscr = DSCR_INSTR_COMP;
        int retval;
 
+       if (rt > 15)
+               return ERROR_TARGET_INVALID;
+
        retval = cortex_a_write_dcc(a, data);
        if (retval != ERROR_OK)
                return retval;
 
-       /* DCCRX to R0, "MCR p14, 0, R0, c0, c5, 0", 0xEE000E15 */
-       retval = cortex_a_exec_opcode(
+       /* DCCRX to Rt, "MCR p14, 0, R0, c0, c5, 0", 0xEE000E15 */
+       return cortex_a_exec_opcode(
                        a->armv7a_common.arm.target,
-                       ARMV4_5_MRC(14, 0, 0, 0, 5, 0),
+                       ARMV4_5_MRC(14, 0, rt, 0, 5, 0),
                        &dscr);
+}
+
+static int cortex_a_instr_write_data_r0(struct arm_dpm *dpm,
+       uint32_t opcode, uint32_t data)
+{
+       struct cortex_a_common *a = dpm_to_a(dpm);
+       uint32_t dscr = DSCR_INSTR_COMP;
+       int retval;
+
+       retval = cortex_a_instr_write_data_rt_dcc(dpm, 0, data);
        if (retval != ERROR_OK)
                return retval;
 
@@ -482,31 +495,43 @@ static int cortex_a_instr_read_data_dcc(struct arm_dpm *dpm,
        return cortex_a_read_dcc(a, data, &dscr);
 }
 
-
-static int cortex_a_instr_read_data_r0(struct arm_dpm *dpm,
-       uint32_t opcode, uint32_t *data)
+static int cortex_a_instr_read_data_rt_dcc(struct arm_dpm *dpm,
+       uint8_t rt, uint32_t *data)
 {
        struct cortex_a_common *a = dpm_to_a(dpm);
        uint32_t dscr = DSCR_INSTR_COMP;
        int retval;
 
-       /* the opcode, writing data to R0 */
+       if (rt > 15)
+               return ERROR_TARGET_INVALID;
+
        retval = cortex_a_exec_opcode(
                        a->armv7a_common.arm.target,
-                       opcode,
+                       ARMV4_5_MCR(14, 0, rt, 0, 5, 0),
                        &dscr);
        if (retval != ERROR_OK)
                return retval;
 
-       /* write R0 to DCC */
+       return cortex_a_read_dcc(a, data, &dscr);
+}
+
+static int cortex_a_instr_read_data_r0(struct arm_dpm *dpm,
+       uint32_t opcode, uint32_t *data)
+{
+       struct cortex_a_common *a = dpm_to_a(dpm);
+       uint32_t dscr = DSCR_INSTR_COMP;
+       int retval;
+
+       /* the opcode, writing data to R0 */
        retval = cortex_a_exec_opcode(
                        a->armv7a_common.arm.target,
-                       ARMV4_5_MCR(14, 0, 0, 0, 5, 0),
+                       opcode,
                        &dscr);
        if (retval != ERROR_OK)
                return retval;
 
-       return cortex_a_read_dcc(a, data, &dscr);
+       /* write R0 to DCC */
+       return cortex_a_instr_read_data_rt_dcc(dpm, 0, data);
 }
 
 static int cortex_a_bpwp_enable(struct arm_dpm *dpm, unsigned index_t,