From e258b9a2d52bb31d99405cad4b44047022dc4007 Mon Sep 17 00:00:00 2001 From: Kyösti Mälkki Date: Fri, 18 Nov 2016 19:59:23 +0200 Subject: intel sandy/ivy: Improve DIMM replacement detection MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When MRC cache is available, first read only the SPD unique identifier bytes required to detect possible DIMM replacement. As this is 11 vs 256 bytes with slow SMBus operations, we save about 70ms for every installed DIMM on normal boot path. In the DIMM replacement case this adds some 10ms per installed DIMM as some SPD gets read twice, but we are on slow RAM training boot path anyways. Change-Id: I294a56e7b7562c3dea322c644b21a15abb033870 Signed-off-by: Kyösti Mälkki Reviewed-on: https://review.coreboot.org/17491 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel Reviewed-by: Aaron Durbin Reviewed-by: Patrick Rudolph --- src/northbridge/intel/sandybridge/raminit.c | 23 +++++++++++++--------- src/northbridge/intel/sandybridge/raminit_native.h | 4 ++-- 2 files changed, 16 insertions(+), 11 deletions(-) (limited to 'src/northbridge/intel') diff --git a/src/northbridge/intel/sandybridge/raminit.c b/src/northbridge/intel/sandybridge/raminit.c index 63e951f00a..f3a1ba5f41 100644 --- a/src/northbridge/intel/sandybridge/raminit.c +++ b/src/northbridge/intel/sandybridge/raminit.c @@ -361,11 +361,16 @@ static int verify_crc16_spds_ddr3(spd_raw_data *spd, ramctr_timing *ctrl) return match; } -void read_spd(spd_raw_data * spd, u8 addr) +void read_spd(spd_raw_data * spd, u8 addr, bool id_only) { int j; - for (j = 0; j < 256; j++) - (*spd)[j] = do_smbus_read_byte(SMBUS_IO_BASE, addr, j); + if (id_only) { + for (j = 117; j < 128; j++) + (*spd)[j] = do_smbus_read_byte(SMBUS_IO_BASE, addr, j); + } else { + for (j = 0; j < 256; j++) + (*spd)[j] = do_smbus_read_byte(SMBUS_IO_BASE, addr, j); + } } static void dram_find_spds_ddr3(spd_raw_data *spd, ramctr_timing *ctrl) @@ -4235,14 +4240,12 @@ static void init_dram_ddr3(int mobile, int min_tck, int s3resume) ctrl_cached = (ramctr_timing *)mrc_cache->mrc_data; } - - if (!s3resume) { - memset(spds, 0, sizeof(spds)); - mainboard_get_spd(spds); - } - /* verify MRC cache for fast boot */ if (!s3resume && ctrl_cached) { + /* Load SPD unique information data. */ + memset(spds, 0, sizeof(spds)); + mainboard_get_spd(spds, 1); + /* check SPD CRC16 to make sure the DIMMs haven't been replaced */ fast_boot = verify_crc16_spds_ddr3(spds, ctrl_cached); if (!fast_boot) @@ -4273,6 +4276,8 @@ static void init_dram_ddr3(int mobile, int min_tck, int s3resume) ctrl.tCK = min_tck; /* Get DDR3 SPD data */ + memset(spds, 0, sizeof(spds)); + mainboard_get_spd(spds, 0); dram_find_spds_ddr3(spds, &ctrl); err = try_init_dram_ddr3(&ctrl, fast_boot, s3resume, me_uma_size); diff --git a/src/northbridge/intel/sandybridge/raminit_native.h b/src/northbridge/intel/sandybridge/raminit_native.h index 0b26bd9b30..2a91772152 100644 --- a/src/northbridge/intel/sandybridge/raminit_native.h +++ b/src/northbridge/intel/sandybridge/raminit_native.h @@ -20,7 +20,7 @@ #include /* The order is ch0dimmA, ch0dimmB, ch1dimmA, ch1dimmB. */ -void read_spd(spd_raw_data *spd, u8 addr); -void mainboard_get_spd(spd_raw_data *spd); +void read_spd(spd_raw_data *spd, u8 addr, bool id_only); +void mainboard_get_spd(spd_raw_data *spd, bool id_only); #endif /* RAMINIT_H */ -- cgit v1.2.3