From fd909a5e3dc6d7434bd68bea5c89ffed0f18b586 Mon Sep 17 00:00:00 2001 From: Andreas Fritiofson Date: Sun, 16 Feb 2014 09:29:01 +0100 Subject: [PATCH] adi_v5_swd: Read RDBUFF once after a sequence of AP reads Increases performance by a factor of two for long reads. Change-Id: I81a7a83835058560c6a53a43c3cc991100f01766 Signed-off-by: Andreas Fritiofson Reviewed-on: http://openocd.zylin.com/1954 Tested-by: jenkins Reviewed-by: Paul Fertser --- src/target/adi_v5_swd.c | 30 +++++++++++++++++++++++++++--- src/target/arm_adi_v5.c | 1 + src/target/arm_adi_v5.h | 6 ++++++ 3 files changed, 34 insertions(+), 3 deletions(-) diff --git a/src/target/adi_v5_swd.c b/src/target/adi_v5_swd.c index c9c3ae5865..c78aef27ae 100644 --- a/src/target/adi_v5_swd.c +++ b/src/target/adi_v5_swd.c @@ -58,6 +58,17 @@ /* YUK! - but this is currently a global.... */ extern struct jtag_interface *jtag_interface; +static int swd_finish_read(struct adiv5_dap *dap) +{ + const struct swd_driver *swd = jtag_interface->swd; + int retval = ERROR_OK; + if (dap->last_read != NULL) { + retval = swd->read_reg(swd_cmd(true, false, DP_RDBUFF), dap->last_read); + dap->last_read = NULL; + } + return retval; +} + static int (swd_queue_dp_write)(struct adiv5_dap *dap, unsigned reg, uint32_t data); @@ -129,6 +140,10 @@ static int (swd_queue_dp_write)(struct adiv5_dap *dap, unsigned reg, const struct swd_driver *swd = jtag_interface->swd; assert(swd); + retval = swd_finish_read(dap); + if (retval != ERROR_OK) + return retval; + retval = swd_queue_dp_bankselect(dap, reg); if (retval != ERROR_OK) return retval; @@ -169,12 +184,14 @@ static int (swd_queue_ap_read)(struct adiv5_dap *dap, unsigned reg, if (retval != ERROR_OK) return retval; - retval = swd->read_reg(swd_cmd(true, true, reg), data); + retval = swd->read_reg(swd_cmd(true, true, reg), dap->last_read); + dap->last_read = data; if (retval != ERROR_OK) { /* fault response */ uint8_t ack = retval & 0xff; swd_queue_ap_abort(dap, &ack); + return retval; } return retval; @@ -186,8 +203,13 @@ static int (swd_queue_ap_write)(struct adiv5_dap *dap, unsigned reg, /* REVISIT status return ... */ const struct swd_driver *swd = jtag_interface->swd; assert(swd); + int retval; - int retval = swd_queue_ap_bankselect(dap, reg); + retval = swd_finish_read(dap); + if (retval != ERROR_OK) + return retval; + + retval = swd_queue_ap_bankselect(dap, reg); if (retval != ERROR_OK) return retval; @@ -207,10 +229,12 @@ static int swd_run(struct adiv5_dap *dap) { /* for now the SWD interface hard-wires a zero-size queue. */ + int retval = swd_finish_read(dap); + /* FIXME but we still need to check and scrub * any hardware errors ... */ - return ERROR_OK; + return retval; } const struct dap_ops swd_dap_ops = { diff --git a/src/target/arm_adi_v5.c b/src/target/arm_adi_v5.c index 2e56396ced..a18101daff 100644 --- a/src/target/arm_adi_v5.c +++ b/src/target/arm_adi_v5.c @@ -661,6 +661,7 @@ int ahbap_debugport_init(struct adiv5_dap *dap) */ dap->ap_current = !0; dap_ap_select(dap, 0); + dap->last_read = NULL; /* DP initialization */ diff --git a/src/target/arm_adi_v5.h b/src/target/arm_adi_v5.h index d132c57cb6..c51e8f81b7 100644 --- a/src/target/arm_adi_v5.h +++ b/src/target/arm_adi_v5.h @@ -187,6 +187,12 @@ struct adiv5_dap { /* information about current pending SWjDP-AHBAP transaction */ uint8_t ack; + /** + * Holds the pointer to the destination word for the last queued read, + * for use with posted AP read sequence optimization. + */ + uint32_t *last_read; + /** * Configures how many extra tck clocks are added after starting a * MEM-AP access before we try to read its status (and/or result). -- 2.30.2