Angel Pons has submitted this change. ( https://review.coreboot.org/c/coreboot/+/47604 )
Change subject: nb/intel/sandybridge: Rework timA minmax code ......................................................................
nb/intel/sandybridge: Rework timA minmax code
There's no need to use `struct timA_minmax`, since most cases only care about the difference between logic delay deltas. The final step does use the minimum logic delay across all lanes, but it's a special case.
Tested on Asus P8H61-M PRO, still boots.
Change-Id: I1da95520ac915ab003e1a839685cbf5f1970eb6a Signed-off-by: Angel Pons th3fanbus@gmail.com Reviewed-on: https://review.coreboot.org/c/coreboot/+/47604 Tested-by: build bot (Jenkins) no-reply@coreboot.org Reviewed-by: Arthur Heymans arthur@aheymans.xyz --- M src/northbridge/intel/sandybridge/raminit_common.c 1 file changed, 60 insertions(+), 45 deletions(-)
Approvals: build bot (Jenkins): Verified Arthur Heymans: Looks good to me, approved
diff --git a/src/northbridge/intel/sandybridge/raminit_common.c b/src/northbridge/intel/sandybridge/raminit_common.c index 49168a9..f2f92c3 100644 --- a/src/northbridge/intel/sandybridge/raminit_common.c +++ b/src/northbridge/intel/sandybridge/raminit_common.c @@ -1,5 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0-only */
+#include <assert.h> #include <commonlib/helpers.h> #include <console/console.h> #include <string.h> @@ -1225,53 +1226,74 @@ return 0; }
-struct timA_minmax { - int timA_min_high, timA_max_high; -}; - -static void pre_timA_change(ramctr_timing *ctrl, int channel, int slotrank, - struct timA_minmax *mnmx) +static int get_logic_delay_delta(ramctr_timing *ctrl, int channel, int slotrank) { int lane; - mnmx->timA_min_high = 7; - mnmx->timA_max_high = 0; + u16 logic_delay_min = 7; + u16 logic_delay_max = 0;
FOR_ALL_LANES { - if (mnmx->timA_min_high > - (ctrl->timings[channel][slotrank].lanes[lane].timA >> 6)) - mnmx->timA_min_high = - (ctrl->timings[channel][slotrank].lanes[lane].timA >> 6); - if (mnmx->timA_max_high < - (ctrl->timings[channel][slotrank].lanes[lane].timA >> 6)) - mnmx->timA_max_high = - (ctrl->timings[channel][slotrank].lanes[lane].timA >> 6); + const u16 logic_delay = ctrl->timings[channel][slotrank].lanes[lane].timA >> 6; + + logic_delay_min = MIN(logic_delay_min, logic_delay); + logic_delay_max = MAX(logic_delay_max, logic_delay); } + + if (logic_delay_max < logic_delay_min) { + printk(BIOS_EMERG, "Logic delay max < min (%u < %u): %d, %d\n", + logic_delay_max, logic_delay_min, channel, slotrank); + } + + assert(logic_delay_max >= logic_delay_min); + + return logic_delay_max - logic_delay_min; }
-static void post_timA_change(ramctr_timing *ctrl, int channel, int slotrank, - struct timA_minmax *mnmx) +static int align_rt_io_latency(ramctr_timing *ctrl, int channel, int slotrank, int prev) { - struct timA_minmax post; - int shift_402x = 0; + int latency_offset = 0;
/* Get changed maxima */ - pre_timA_change(ctrl, channel, slotrank, &post); + const int post = get_logic_delay_delta(ctrl, channel, slotrank);
- if (mnmx->timA_max_high - mnmx->timA_min_high < - post.timA_max_high - post.timA_min_high) - shift_402x = +1; + if (prev < post) + latency_offset = +1;
- else if (mnmx->timA_max_high - mnmx->timA_min_high > - post.timA_max_high - post.timA_min_high) - shift_402x = -1; + else if (prev > post) + latency_offset = -1;
else - shift_402x = 0; + latency_offset = 0;
- ctrl->timings[channel][slotrank].io_latency += shift_402x; - ctrl->timings[channel][slotrank].roundtrip_latency += shift_402x; - printram("4024 += %d;\n", shift_402x); - printram("4028 += %d;\n", shift_402x); + ctrl->timings[channel][slotrank].io_latency += latency_offset; + ctrl->timings[channel][slotrank].roundtrip_latency += latency_offset; + printram("4024 += %d;\n", latency_offset); + printram("4028 += %d;\n", latency_offset); + + return post; +} + +static void compute_final_logic_delay(ramctr_timing *ctrl, int channel, int slotrank) +{ + u16 logic_delay_min = 7; + int lane; + + FOR_ALL_LANES { + const u16 logic_delay = ctrl->timings[channel][slotrank].lanes[lane].timA >> 6; + + logic_delay_min = MIN(logic_delay_min, logic_delay); + } + + if (logic_delay_min >= 2) { + printk(BIOS_WARNING, "Logic delay %u greater than 1: %d %d\n", + logic_delay_min, channel, slotrank); + } + + FOR_ALL_LANES { + ctrl->timings[channel][slotrank].lanes[lane].timA -= logic_delay_min << 6; + } + ctrl->timings[channel][slotrank].io_latency -= logic_delay_min; + printram("4028 -= %d;\n", logic_delay_min); }
/* @@ -1300,7 +1322,7 @@ FOR_ALL_CHANNELS FOR_ALL_POPULATED_RANKS { int all_high, some_high; int upperA[NUM_LANES]; - struct timA_minmax mnmx; + int prev;
wait_for_iosav(channel);
@@ -1343,28 +1365,21 @@
program_timings(ctrl, channel);
- pre_timA_change(ctrl, channel, slotrank, &mnmx); + prev = get_logic_delay_delta(ctrl, channel, slotrank);
err = discover_402x(ctrl, channel, slotrank, upperA); if (err) return err;
- post_timA_change(ctrl, channel, slotrank, &mnmx); - pre_timA_change(ctrl, channel, slotrank, &mnmx); + prev = align_rt_io_latency(ctrl, channel, slotrank, prev);
discover_timA_fine(ctrl, channel, slotrank, upperA);
- post_timA_change(ctrl, channel, slotrank, &mnmx); - pre_timA_change(ctrl, channel, slotrank, &mnmx); + prev = align_rt_io_latency(ctrl, channel, slotrank, prev);
- FOR_ALL_LANES { - ctrl->timings[channel][slotrank].lanes[lane].timA -= - mnmx.timA_min_high * 0x40; - } - ctrl->timings[channel][slotrank].io_latency -= mnmx.timA_min_high; - printram("4028 -= %d;\n", mnmx.timA_min_high); + compute_final_logic_delay(ctrl, channel, slotrank);
- post_timA_change(ctrl, channel, slotrank, &mnmx); + align_rt_io_latency(ctrl, channel, slotrank, prev);
printram("4/8: %d, %d, %x, %x\n", channel, slotrank, ctrl->timings[channel][slotrank].roundtrip_latency,