From: Yazen Ghannam <yazen.ghannam@xxxxxxx> [ Upstream commit 5ac6293047cf5de6daca662347c19347e856c2a5 ] Check the return value of amd_smn_read() before saving a value. This ensures invalid values aren't saved. The struct umc instance is initialized to 0 during memory allocation. Therefore, a bad read will keep the value as 0 providing the expected Read-as-Zero behavior. Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx> Link: https://lore.kernel.org/r/20240606-fix-smn-bad-read-v4-2-ffde21931c3f@xxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/edac/amd64_edac.c | 51 ++++++++++++++++++++++++++++----------- 1 file changed, 37 insertions(+), 14 deletions(-) diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c index a17f3c0cdfa60..4300c4e7683c8 100644 --- a/drivers/edac/amd64_edac.c +++ b/drivers/edac/amd64_edac.c @@ -1454,6 +1454,7 @@ static void umc_read_base_mask(struct amd64_pvt *pvt) u32 *base, *base_sec; u32 *mask, *mask_sec; int cs, umc; + u32 tmp; for_each_umc(umc) { umc_base_reg = get_umc_base(umc) + UMCCH_BASE_ADDR; @@ -1466,13 +1467,17 @@ static void umc_read_base_mask(struct amd64_pvt *pvt) base_reg = umc_base_reg + (cs * 4); base_reg_sec = umc_base_reg_sec + (cs * 4); - if (!amd_smn_read(pvt->mc_node_id, base_reg, base)) + if (!amd_smn_read(pvt->mc_node_id, base_reg, &tmp)) { + *base = tmp; edac_dbg(0, " DCSB%d[%d]=0x%08x reg: 0x%x\n", umc, cs, *base, base_reg); + } - if (!amd_smn_read(pvt->mc_node_id, base_reg_sec, base_sec)) + if (!amd_smn_read(pvt->mc_node_id, base_reg_sec, &tmp)) { + *base_sec = tmp; edac_dbg(0, " DCSB_SEC%d[%d]=0x%08x reg: 0x%x\n", umc, cs, *base_sec, base_reg_sec); + } } umc_mask_reg = get_umc_base(umc) + UMCCH_ADDR_MASK; @@ -1485,13 +1490,17 @@ static void umc_read_base_mask(struct amd64_pvt *pvt) mask_reg = umc_mask_reg + (cs * 4); mask_reg_sec = umc_mask_reg_sec + (cs * 4); - if (!amd_smn_read(pvt->mc_node_id, mask_reg, mask)) + if (!amd_smn_read(pvt->mc_node_id, mask_reg, &tmp)) { + *mask = tmp; edac_dbg(0, " DCSM%d[%d]=0x%08x reg: 0x%x\n", umc, cs, *mask, mask_reg); + } - if (!amd_smn_read(pvt->mc_node_id, mask_reg_sec, mask_sec)) + if (!amd_smn_read(pvt->mc_node_id, mask_reg_sec, &tmp)) { + *mask_sec = tmp; edac_dbg(0, " DCSM_SEC%d[%d]=0x%08x reg: 0x%x\n", umc, cs, *mask_sec, mask_reg_sec); + } } } } @@ -2910,7 +2919,7 @@ static void umc_read_mc_regs(struct amd64_pvt *pvt) { u8 nid = pvt->mc_node_id; struct amd64_umc *umc; - u32 i, umc_base; + u32 i, tmp, umc_base; /* Read registers from each UMC */ for_each_umc(i) { @@ -2918,11 +2927,20 @@ static void umc_read_mc_regs(struct amd64_pvt *pvt) umc_base = get_umc_base(i); umc = &pvt->umc[i]; - amd_smn_read(nid, umc_base + get_umc_reg(pvt, UMCCH_DIMM_CFG), &umc->dimm_cfg); - amd_smn_read(nid, umc_base + UMCCH_UMC_CFG, &umc->umc_cfg); - amd_smn_read(nid, umc_base + UMCCH_SDP_CTRL, &umc->sdp_ctrl); - amd_smn_read(nid, umc_base + UMCCH_ECC_CTRL, &umc->ecc_ctrl); - amd_smn_read(nid, umc_base + UMCCH_UMC_CAP_HI, &umc->umc_cap_hi); + if (!amd_smn_read(nid, umc_base + get_umc_reg(pvt, UMCCH_DIMM_CFG), &tmp)) + umc->dimm_cfg = tmp; + + if (!amd_smn_read(nid, umc_base + UMCCH_UMC_CFG, &tmp)) + umc->umc_cfg = tmp; + + if (!amd_smn_read(nid, umc_base + UMCCH_SDP_CTRL, &tmp)) + umc->sdp_ctrl = tmp; + + if (!amd_smn_read(nid, umc_base + UMCCH_ECC_CTRL, &tmp)) + umc->ecc_ctrl = tmp; + + if (!amd_smn_read(nid, umc_base + UMCCH_UMC_CAP_HI, &tmp)) + umc->umc_cap_hi = tmp; } } @@ -3651,16 +3669,21 @@ static void gpu_read_mc_regs(struct amd64_pvt *pvt) { u8 nid = pvt->mc_node_id; struct amd64_umc *umc; - u32 i, umc_base; + u32 i, tmp, umc_base; /* Read registers from each UMC */ for_each_umc(i) { umc_base = gpu_get_umc_base(pvt, i, 0); umc = &pvt->umc[i]; - amd_smn_read(nid, umc_base + UMCCH_UMC_CFG, &umc->umc_cfg); - amd_smn_read(nid, umc_base + UMCCH_SDP_CTRL, &umc->sdp_ctrl); - amd_smn_read(nid, umc_base + UMCCH_ECC_CTRL, &umc->ecc_ctrl); + if (!amd_smn_read(nid, umc_base + UMCCH_UMC_CFG, &tmp)) + umc->umc_cfg = tmp; + + if (!amd_smn_read(nid, umc_base + UMCCH_SDP_CTRL, &tmp)) + umc->sdp_ctrl = tmp; + + if (!amd_smn_read(nid, umc_base + UMCCH_ECC_CTRL, &tmp)) + umc->ecc_ctrl = tmp; } } -- 2.43.0
