From 178b5d072e2bd2038fc9065b9722da296e6f5e16 Mon Sep 17 00:00:00 2001 From: Andreas Fritiofson Date: Sun, 29 Dec 2013 21:59:36 +0100 Subject: [PATCH] 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 Reviewed-on: http://openocd.zylin.com/1848 Tested-by: jenkins Reviewed-by: Spencer Oliver --- src/target/cortex_m.c | 91 +++++++++++++++++++++------------------------------ 1 file changed, 37 insertions(+), 54 deletions(-) diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c index a22478852..d95c25ee7 100644 --- a/src/target/cortex_m.c +++ b/src/target/cortex_m.c @@ -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); - 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); - 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); + retval = mem_ap_write_u32(swjdp, DCB_DCRSR, regnum); if (retval != ERROR_OK) return retval; - retval = dap_run(swjdp); + retval = mem_ap_read_atomic_u32(swjdp, DCB_DCRDR, value); 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); - 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); - 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); + retval = mem_ap_write_u32(swjdp, DCB_DCRDR, value); if (retval != ERROR_OK) return retval; - retval = dap_run(swjdp); + retval = mem_ap_write_atomic_u32(swjdp, DCB_DCRSR, regnum | DCRSR_WnR); 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, ®, 20); + cortexm_dap_read_coreregister_u32(target, ®, 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; -- 2.11.4.GIT