]> git.ipfire.org Git - thirdparty/linux.git/commitdiff
EDAC/bluefield: Use Arm SMC for EMI access on BlueField-2
authorDavid Thompson <davthompson@nvidia.com>
Mon, 21 Oct 2024 23:30:13 +0000 (19:30 -0400)
committerBorislav Petkov (AMD) <bp@alien8.de>
Tue, 22 Oct 2024 16:36:13 +0000 (18:36 +0200)
The BlueField EDAC driver supports the first generation BlueField-1 SoC, but
not the second generation BlueField-2 SoC. The BlueField-2 SoC is different in
that only secure accesses are allowed to the External Memory Interface (EMI)
register block. On BlueField-2, all read/write accesses from Linux to EMI
registers are routed via the Arm Secure Monitor Call (SMC) through Arm Trusted
Firmware (ATF), which runs at EL3 privileged state.

On BlueField-1, EMI registers are mapped and accessed directly. In order to
support BlueField-2, the driver's read and write access methods must be
extended with additional logic to include secure access to the EMI registers
via SMCs.

  [ bp: Move struct member comments above them, simplify. ]

Signed-off-by: David Thompson <davthompson@nvidia.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shravan Kumar Ramani <shravankr@nvidia.com>
Link: https://lore.kernel.org/r/20241021233013.18405-1-davthompson@nvidia.com
drivers/edac/bluefield_edac.c

index 0e539c1073510a4c9bb205e03e738426bf2ee650..739132e5ed8af089bf54f8abe36118a4060db2bf 100644 (file)
 #define MLXBF_EDAC_MAX_DIMM_PER_MC     2
 #define MLXBF_EDAC_ERROR_GRAIN         8
 
+#define MLXBF_WRITE_REG_32             (0x82000009)
+#define MLXBF_READ_REG_32              (0x8200000A)
+#define MLXBF_SIP_SVC_VERSION          (0x8200ff03)
+
+#define MLXBF_SMCCC_ACCESS_VIOLATION   (-4)
+
+#define MLXBF_SVC_REQ_MAJOR            0
+#define MLXBF_SVC_REQ_MINOR            3
+
 /*
- * Request MLNX_SIP_GET_DIMM_INFO
+ * Request MLXBF_SIP_GET_DIMM_INFO
  *
  * Retrieve information about DIMM on a certain slot.
  *
  * Call register usage:
- * a0: MLNX_SIP_GET_DIMM_INFO
+ * a0: MLXBF_SIP_GET_DIMM_INFO
  * a1: (Memory controller index) << 16 | (Dimm index in memory controller)
  * a2-7: not used.
  *
@@ -61,7 +70,7 @@
  * a0: MLXBF_DIMM_INFO defined below describing the DIMM.
  * a1-3: not used.
  */
-#define MLNX_SIP_GET_DIMM_INFO         0x82000008
+#define MLXBF_SIP_GET_DIMM_INFO                0x82000008
 
 /* Format for the SMC response about the memory information */
 #define MLXBF_DIMM_INFO__SIZE_GB GENMASK_ULL(15, 0)
 #define MLXBF_DIMM_INFO__PACKAGE_X GENMASK_ULL(31, 24)
 
 struct bluefield_edac_priv {
+       /* pointer to device structure */
+       struct device *dev;
        int dimm_ranks[MLXBF_EDAC_MAX_DIMM_PER_MC];
        void __iomem *emi_base;
        int dimm_per_mc;
+       /* access to secure regs supported */
+       bool svc_sreg_support;
+       /* SMC table# for secure regs access */
+       u32 sreg_tbl;
 };
 
 static u64 smc_call1(u64 smc_op, u64 smc_arg)
@@ -86,6 +101,71 @@ static u64 smc_call1(u64 smc_op, u64 smc_arg)
        return res.a0;
 }
 
+static int secure_readl(void __iomem *addr, u32 *result, u32 sreg_tbl)
+{
+       struct arm_smccc_res res;
+       int status;
+
+       arm_smccc_smc(MLXBF_READ_REG_32, sreg_tbl, (uintptr_t)addr,
+                     0, 0, 0, 0, 0, &res);
+
+       status = res.a0;
+
+       if (status == SMCCC_RET_NOT_SUPPORTED ||
+           status == MLXBF_SMCCC_ACCESS_VIOLATION)
+               return -1;
+
+       *result = (u32)res.a1;
+       return 0;
+}
+
+static int secure_writel(void __iomem *addr, u32 data, u32 sreg_tbl)
+{
+       struct arm_smccc_res res;
+       int status;
+
+       arm_smccc_smc(MLXBF_WRITE_REG_32, sreg_tbl, data, (uintptr_t)addr,
+                     0, 0, 0, 0, &res);
+
+       status = res.a0;
+
+       if (status == SMCCC_RET_NOT_SUPPORTED ||
+           status == MLXBF_SMCCC_ACCESS_VIOLATION)
+               return -1;
+       else
+               return 0;
+}
+
+static int bluefield_edac_readl(struct bluefield_edac_priv *priv, u32 offset, u32 *result)
+{
+       void __iomem *addr;
+       int err = 0;
+
+       addr = priv->emi_base + offset;
+
+       if (priv->svc_sreg_support)
+               err = secure_readl(addr, result, priv->sreg_tbl);
+       else
+               *result = readl(addr);
+
+       return err;
+}
+
+static int bluefield_edac_writel(struct bluefield_edac_priv *priv, u32 offset, u32 data)
+{
+       void __iomem *addr;
+       int err = 0;
+
+       addr = priv->emi_base + offset;
+
+       if (priv->svc_sreg_support)
+               err = secure_writel(addr, data, priv->sreg_tbl);
+       else
+               writel(data, addr);
+
+       return err;
+}
+
 /*
  * Gather the ECC information from the External Memory Interface registers
  * and report it to the edac handler.
@@ -99,7 +179,7 @@ static void bluefield_gather_report_ecc(struct mem_ctl_info *mci,
        u32 ecc_latch_select, dram_syndrom, serr, derr, syndrom;
        enum hw_event_mc_err_type ecc_type;
        u64 ecc_dimm_addr;
-       int ecc_dimm;
+       int ecc_dimm, err;
 
        ecc_type = is_single_ecc ? HW_EVENT_ERR_CORRECTED :
                                   HW_EVENT_ERR_UNCORRECTED;
@@ -109,14 +189,19 @@ static void bluefield_gather_report_ecc(struct mem_ctl_info *mci,
         * registers with information about the last ECC error occurrence.
         */
        ecc_latch_select = MLXBF_ECC_LATCH_SEL__START;
-       writel(ecc_latch_select, priv->emi_base + MLXBF_ECC_LATCH_SEL);
+       err = bluefield_edac_writel(priv, MLXBF_ECC_LATCH_SEL, ecc_latch_select);
+       if (err)
+               dev_err(priv->dev, "ECC latch select write failed.\n");
 
        /*
         * Verify that the ECC reported info in the registers is of the
         * same type as the one asked to report. If not, just report the
         * error without the detailed information.
         */
-       dram_syndrom = readl(priv->emi_base + MLXBF_SYNDROM);
+       err = bluefield_edac_readl(priv, MLXBF_SYNDROM, &dram_syndrom);
+       if (err)
+               dev_err(priv->dev, "DRAM syndrom read failed.\n");
+
        serr = FIELD_GET(MLXBF_SYNDROM__SERR, dram_syndrom);
        derr = FIELD_GET(MLXBF_SYNDROM__DERR, dram_syndrom);
        syndrom = FIELD_GET(MLXBF_SYNDROM__SYN, dram_syndrom);
@@ -127,13 +212,21 @@ static void bluefield_gather_report_ecc(struct mem_ctl_info *mci,
                return;
        }
 
-       dram_additional_info = readl(priv->emi_base + MLXBF_ADD_INFO);
+       err = bluefield_edac_readl(priv, MLXBF_ADD_INFO, &dram_additional_info);
+       if (err)
+               dev_err(priv->dev, "DRAM additional info read failed.\n");
+
        err_prank = FIELD_GET(MLXBF_ADD_INFO__ERR_PRANK, dram_additional_info);
 
        ecc_dimm = (err_prank >= 2 && priv->dimm_ranks[0] <= 2) ? 1 : 0;
 
-       edea0 = readl(priv->emi_base + MLXBF_ERR_ADDR_0);
-       edea1 = readl(priv->emi_base + MLXBF_ERR_ADDR_1);
+       err = bluefield_edac_readl(priv, MLXBF_ERR_ADDR_0, &edea0);
+       if (err)
+               dev_err(priv->dev, "Error addr 0 read failed.\n");
+
+       err = bluefield_edac_readl(priv, MLXBF_ERR_ADDR_1, &edea1);
+       if (err)
+               dev_err(priv->dev, "Error addr 1 read failed.\n");
 
        ecc_dimm_addr = ((u64)edea1 << 32) | edea0;
 
@@ -147,6 +240,7 @@ static void bluefield_edac_check(struct mem_ctl_info *mci)
 {
        struct bluefield_edac_priv *priv = mci->pvt_info;
        u32 ecc_count, single_error_count, double_error_count, ecc_error = 0;
+       int err;
 
        /*
         * The memory controller might not be initialized by the firmware
@@ -155,7 +249,10 @@ static void bluefield_edac_check(struct mem_ctl_info *mci)
        if (mci->edac_cap == EDAC_FLAG_NONE)
                return;
 
-       ecc_count = readl(priv->emi_base + MLXBF_ECC_CNT);
+       err = bluefield_edac_readl(priv, MLXBF_ECC_CNT, &ecc_count);
+       if (err)
+               dev_err(priv->dev, "ECC count read failed.\n");
+
        single_error_count = FIELD_GET(MLXBF_ECC_CNT__SERR_CNT, ecc_count);
        double_error_count = FIELD_GET(MLXBF_ECC_CNT__DERR_CNT, ecc_count);
 
@@ -172,8 +269,11 @@ static void bluefield_edac_check(struct mem_ctl_info *mci)
        }
 
        /* Write to clear reported errors. */
-       if (ecc_count)
-               writel(ecc_error, priv->emi_base + MLXBF_ECC_ERR);
+       if (ecc_count) {
+               err = bluefield_edac_writel(priv, MLXBF_ECC_ERR, ecc_error);
+               if (err)
+                       dev_err(priv->dev, "ECC Error write failed.\n");
+       }
 }
 
 /* Initialize the DIMMs information for the given memory controller. */
@@ -189,7 +289,7 @@ static void bluefield_edac_init_dimms(struct mem_ctl_info *mci)
                dimm = mci->dimms[i];
 
                smc_arg = mem_ctrl_idx << 16 | i;
-               smc_info = smc_call1(MLNX_SIP_GET_DIMM_INFO, smc_arg);
+               smc_info = smc_call1(MLXBF_SIP_GET_DIMM_INFO, smc_arg);
 
                if (!FIELD_GET(MLXBF_DIMM_INFO__SIZE_GB, smc_info)) {
                        dimm->mtype = MEM_EMPTY;
@@ -244,6 +344,7 @@ static int bluefield_edac_mc_probe(struct platform_device *pdev)
        struct bluefield_edac_priv *priv;
        struct device *dev = &pdev->dev;
        struct edac_mc_layer layers[1];
+       struct arm_smccc_res res;
        struct mem_ctl_info *mci;
        struct resource *emi_res;
        unsigned int mc_idx, dimm_count;
@@ -279,13 +380,43 @@ static int bluefield_edac_mc_probe(struct platform_device *pdev)
                return -ENOMEM;
 
        priv = mci->pvt_info;
+       priv->dev = dev;
+
+       /*
+        * The "sec_reg_block" property in the ACPI table determines the method
+        * the driver uses to access the EMI registers:
+        * a) property is not present - directly access registers via readl/writel
+        * b) property is present - indirectly access registers via SMC calls
+        *    (assuming required Silicon Provider service version found)
+        */
+       if (device_property_read_u32(dev, "sec_reg_block", &priv->sreg_tbl)) {
+               priv->svc_sreg_support = false;
+       } else {
+               /*
+                * Check for minimum required Arm Silicon Provider (SiP) service
+                * version, ensuring support of required SMC function IDs.
+                */
+               arm_smccc_smc(MLXBF_SIP_SVC_VERSION, 0, 0, 0, 0, 0, 0, 0, &res);
+               if (res.a0 == MLXBF_SVC_REQ_MAJOR &&
+                   res.a1 >= MLXBF_SVC_REQ_MINOR) {
+                       priv->svc_sreg_support = true;
+               } else {
+                       dev_err(dev, "Required SMCs are not supported.\n");
+                       ret = -EINVAL;
+                       goto err;
+               }
+       }
 
        priv->dimm_per_mc = dimm_count;
-       priv->emi_base = devm_ioremap_resource(dev, emi_res);
-       if (IS_ERR(priv->emi_base)) {
-               dev_err(dev, "failed to map EMI IO resource\n");
-               ret = PTR_ERR(priv->emi_base);
-               goto err;
+       if (!priv->svc_sreg_support) {
+               priv->emi_base = devm_ioremap_resource(dev, emi_res);
+               if (IS_ERR(priv->emi_base)) {
+                       dev_err(dev, "failed to map EMI IO resource\n");
+                       ret = PTR_ERR(priv->emi_base);
+                       goto err;
+               }
+       } else {
+               priv->emi_base = (void __iomem *)emi_res->start;
        }
 
        mci->pdev = dev;
@@ -320,7 +451,6 @@ err:
        edac_mc_free(mci);
 
        return ret;
-
 }
 
 static void bluefield_edac_mc_remove(struct platform_device *pdev)