[PATCH AUTOSEL 6.10 070/121] EDAC/amd64: Check return value of amd_smn_read()

Sasha Levin
2024-08-01T00:15:17Z

From: Yazen Ghannam <yazen.ghannam@amd.com>

[ 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@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20240606-fix-smn-bad-read-v4-2-ffde21931c3f@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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