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cortex_m: Avoid unnecessary saving and restoring of DCRDR 

This is used for the emulated DCC channel which is only maintained as long
as target->dbg_msg_enabled is set. Skip the saving and restoring if not
enabled to save one dap_run() per core register access.

Note that we could've probably queued all core register accesses in the
same transaction if the armv7 register framework hadn't required
synchronous register accesses.

Change-Id: I4fe6d713261ee5db42422203eb63035fdcc48891
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: http://openocd.zylin.com/1848
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
This commit is contained in:
Andreas Fritiofson 2013-12-29 21:59:36 +01:00 committed by Spencer Oliver
parent bd0fbef5c8
commit 178b5d072e
1 changed files with 37 additions and 54 deletions
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91
src/target/cortex_m.c
View File

@ -62,84 +62,70 @@
static int cortex_m_store_core_reg_u32(struct target *target,
uint32_t num, uint32_t value);
static int cortexm_dap_read_coreregister_u32(struct adiv5_dap *swjdp,
static int cortexm_dap_read_coreregister_u32(struct target *target,
uint32_t *value, int regnum)
{
struct armv7m_common *armv7m = target_to_armv7m(target);
struct adiv5_dap *swjdp = armv7m->arm.dap;
int retval;
uint32_t dcrdr;
/* because the DCB_DCRDR is used for the emulated dcc channel
* we have to save/restore the DCB_DCRDR when used */
if (target->dbg_msg_enabled) {
retval = mem_ap_read_u32(swjdp, DCB_DCRDR, &dcrdr);
if (retval != ERROR_OK)
return retval;
}
retval = mem_ap_read_u32(swjdp, DCB_DCRDR, &dcrdr);
retval = mem_ap_write_u32(swjdp, DCB_DCRSR, regnum);
if (retval != ERROR_OK)
return retval;
/* mem_ap_write_u32(swjdp, DCB_DCRSR, regnum); */
retval = dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRSR & 0xFFFFFFF0);
if (retval != ERROR_OK)
return retval;
retval = dap_queue_ap_write(swjdp, AP_REG_BD0 | (DCB_DCRSR & 0xC), regnum);
retval = mem_ap_read_atomic_u32(swjdp, DCB_DCRDR, value);
if (retval != ERROR_OK)
return retval;
/* mem_ap_read_u32(swjdp, DCB_DCRDR, value); */
retval = dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRDR & 0xFFFFFFF0);
if (retval != ERROR_OK)
return retval;
retval = dap_queue_ap_read(swjdp, AP_REG_BD0 | (DCB_DCRDR & 0xC), value);
if (retval != ERROR_OK)
return retval;
retval = dap_run(swjdp);
if (retval != ERROR_OK)
return retval;
/* restore DCB_DCRDR - this needs to be in a seperate
* transaction otherwise the emulated DCC channel breaks */
if (retval == ERROR_OK)
retval = mem_ap_write_atomic_u32(swjdp, DCB_DCRDR, dcrdr);
if (target->dbg_msg_enabled) {
/* restore DCB_DCRDR - this needs to be in a separate
* transaction otherwise the emulated DCC channel breaks */
if (retval == ERROR_OK)
retval = mem_ap_write_atomic_u32(swjdp, DCB_DCRDR, dcrdr);
}
return retval;
}
static int cortexm_dap_write_coreregister_u32(struct adiv5_dap *swjdp,
static int cortexm_dap_write_coreregister_u32(struct target *target,
uint32_t value, int regnum)
{
struct armv7m_common *armv7m = target_to_armv7m(target);
struct adiv5_dap *swjdp = armv7m->arm.dap;
int retval;
uint32_t dcrdr;
/* because the DCB_DCRDR is used for the emulated dcc channel
* we have to save/restore the DCB_DCRDR when used */
if (target->dbg_msg_enabled) {
retval = mem_ap_read_u32(swjdp, DCB_DCRDR, &dcrdr);
if (retval != ERROR_OK)
return retval;
}
retval = mem_ap_read_u32(swjdp, DCB_DCRDR, &dcrdr);
retval = mem_ap_write_u32(swjdp, DCB_DCRDR, value);
if (retval != ERROR_OK)
return retval;
/* mem_ap_write_u32(swjdp, DCB_DCRDR, core_regs[i]); */
retval = dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRDR & 0xFFFFFFF0);
if (retval != ERROR_OK)
return retval;
retval = dap_queue_ap_write(swjdp, AP_REG_BD0 | (DCB_DCRDR & 0xC), value);
retval = mem_ap_write_atomic_u32(swjdp, DCB_DCRSR, regnum | DCRSR_WnR);
if (retval != ERROR_OK)
return retval;
/* mem_ap_write_u32(swjdp, DCB_DCRSR, i | DCRSR_WnR); */
retval = dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRSR & 0xFFFFFFF0);
if (retval != ERROR_OK)
return retval;
retval = dap_queue_ap_write(swjdp, AP_REG_BD0 | (DCB_DCRSR & 0xC), regnum | DCRSR_WnR);
if (retval != ERROR_OK)
return retval;
retval = dap_run(swjdp);
if (retval != ERROR_OK)
return retval;
/* restore DCB_DCRDR - this needs to be in a seperate
* transaction otherwise the emulated DCC channel breaks */
if (retval == ERROR_OK)
retval = mem_ap_write_atomic_u32(swjdp, DCB_DCRDR, dcrdr);
if (target->dbg_msg_enabled) {
/* restore DCB_DCRDR - this needs to be in a seperate
* transaction otherwise the emulated DCC channel breaks */
if (retval == ERROR_OK)
retval = mem_ap_write_atomic_u32(swjdp, DCB_DCRDR, dcrdr);
}
return retval;
}
@ -1480,8 +1466,6 @@ static int cortex_m_load_core_reg_u32(struct target *target,
uint32_t num, uint32_t *value)
{
int retval;
struct armv7m_common *armv7m = target_to_armv7m(target);
struct adiv5_dap *swjdp = armv7m->arm.dap;
/* NOTE: we "know" here that the register identifiers used
* in the v7m header match the Cortex-M3 Debug Core Register
@ -1490,7 +1474,7 @@ static int cortex_m_load_core_reg_u32(struct target *target,
switch (num) {
case 0 ... 18:
/* read a normal core register */
retval = cortexm_dap_read_coreregister_u32(swjdp, value, num);
retval = cortexm_dap_read_coreregister_u32(target, value, num);
if (retval != ERROR_OK) {
LOG_ERROR("JTAG failure %i", retval);
@ -1507,7 +1491,7 @@ static int cortex_m_load_core_reg_u32(struct target *target,
* in one Debug Core register. So say r0 and r2 docs;
* it was removed from r1 docs, but still works.
*/
cortexm_dap_read_coreregister_u32(swjdp, value, 20);
cortexm_dap_read_coreregister_u32(target, value, 20);
switch (num) {
case ARMV7M_PRIMASK:
@ -1543,7 +1527,6 @@ static int cortex_m_store_core_reg_u32(struct target *target,
int retval;
uint32_t reg;
struct armv7m_common *armv7m = target_to_armv7m(target);
struct adiv5_dap *swjdp = armv7m->arm.dap;
/* NOTE: we "know" here that the register identifiers used
* in the v7m header match the Cortex-M3 Debug Core Register
@ -1551,7 +1534,7 @@ static int cortex_m_store_core_reg_u32(struct target *target,
*/
switch (num) {
case 0 ... 18:
retval = cortexm_dap_write_coreregister_u32(swjdp, value, num);
retval = cortexm_dap_write_coreregister_u32(target, value, num);
if (retval != ERROR_OK) {
struct reg *r;
@ -1571,7 +1554,7 @@ static int cortex_m_store_core_reg_u32(struct target *target,
* in one Debug Core register. So say r0 and r2 docs;
* it was removed from r1 docs, but still works.
*/
cortexm_dap_read_coreregister_u32(swjdp, &reg, 20);
cortexm_dap_read_coreregister_u32(target, &reg, 20);
switch (num) {
case ARMV7M_PRIMASK:
@ -1591,7 +1574,7 @@ static int cortex_m_store_core_reg_u32(struct target *target,
break;
}
cortexm_dap_write_coreregister_u32(swjdp, reg, 20);
cortexm_dap_write_coreregister_u32(target, reg, 20);
LOG_DEBUG("write special reg %i value 0x%" PRIx32 " ", (int)num, value);
break;