amd64_edac: Improve error injection

When injecting DRAM ECC errors over the F3xB[8,C] interface, the machine
does this by injecting the error in the next non-cached access. This
takes relatively long time on a normal system so that in order for us to
expedite it, we disable the caches around the injection.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 0e7e4388bdcccb1fb930f9927aa0b0c8fc53a02b..b52d848def592c285690c8f5a5d1f74e1d0b37cb 100644 (file)
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -60,8 +60,8 @@ struct scrubrate {
        { 0x00, 0UL},        /* scrubbing off */
 };
 
-static int __amd64_read_pci_cfg_dword(struct pci_dev *pdev, int offset,
-                                     u32 *val, const char *func)
+int __amd64_read_pci_cfg_dword(struct pci_dev *pdev, int offset,
+                              u32 *val, const char *func)
 {
        int err = 0;
 
@@ -1983,11 +1983,11 @@ static void amd64_handle_ue(struct mem_ctl_info *mci, struct mce *m)
 static inline void __amd64_decode_bus_error(struct mem_ctl_info *mci,
                                            struct mce *m)
 {
-       u16 ec = EC(m->status);
-       u8 xec = XEC(m->status, 0x1f);
        u8 ecc_type = (m->status >> 45) & 0x3;
+       u8 xec = XEC(m->status, 0x1f);
+       u16 ec = EC(m->status);
 
-       /* Bail early out if this was an 'observed' error */
+       /* Bail out early if this was an 'observed' error */
        if (PP(ec) == NBSL_PP_OBS)
                return;
 

diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index 0b184a809f879ef559f2bafeda5faec421990398..eacce615fe1c7aa720cf1d41e34ce95719a1d513 100644 (file)
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -273,9 +273,10 @@
 #define SET_NB_ARRAY_ADDR(section)     (((section) & 0x3) << 1)
 
 #define F10_NB_ARRAY_DATA              0xBC
+#define F10_NB_ARR_ECC_WR_REQ          BIT(17)
 #define SET_NB_DRAM_INJECTION_WRITE(inj)  \
                                        (BIT(((inj.word) & 0xF) + 20) | \
-                                       BIT(17) | inj.bit_map)
+                                       F10_NB_ARR_ECC_WR_REQ | inj.bit_map)
 #define SET_NB_DRAM_INJECTION_READ(inj)  \
                                        (BIT(((inj.word) & 0xF) + 20) | \
                                        BIT(16) |  inj.bit_map)
@@ -306,9 +307,9 @@ enum amd_families {
 
 /* Error injection control structure */
 struct error_injection {
-       u32     section;
-       u32     word;
-       u32     bit_map;
+       u32      section;
+       u32      word;
+       u32      bit_map;
 };
 
 /* low and high part of PCI config space regs */
@@ -460,6 +461,8 @@ struct amd64_family_type {
        struct low_ops ops;
 };
 
+int __amd64_read_pci_cfg_dword(struct pci_dev *pdev, int offset,
+                              u32 *val, const char *func);
 int __amd64_write_pci_cfg_dword(struct pci_dev *pdev, int offset,
                                u32 val, const char *func);
 
@@ -476,3 +479,15 @@ int amd64_get_dram_hole_info(struct mem_ctl_info *mci, u64 *hole_base,
                             u64 *hole_offset, u64 *hole_size);
 
 #define to_mci(k) container_of(k, struct mem_ctl_info, dev)
+
+/* Injection helpers */
+static inline void disable_caches(void *dummy)
+{
+       write_cr0(read_cr0() | X86_CR0_CD);
+       wbinvd();
+}
+
+static inline void enable_caches(void *dummy)
+{
+       write_cr0(read_cr0() & ~X86_CR0_CD);
+}

diff --git a/drivers/edac/amd64_edac_inj.c b/drivers/edac/amd64_edac_inj.c
index 8977e2fa61da837fdb4a815ba27eb332cd67ec2e..8c171fa1cb9bc65f5531e178bd45cb9a0ef0c9ad 100644 (file)
--- a/drivers/edac/amd64_edac_inj.c
+++ b/drivers/edac/amd64_edac_inj.c
@@ -153,8 +153,8 @@ static ssize_t amd64_inject_write_store(struct device *dev,
 {
        struct mem_ctl_info *mci = to_mci(dev);
        struct amd64_pvt *pvt = mci->pvt_info;
+       u32 section, word_bits, tmp;
        unsigned long value;
-       u32 section, word_bits;
        int ret;
 
        ret = strict_strtoul(data, 10, &value);
@@ -168,9 +168,25 @@ static ssize_t amd64_inject_write_store(struct device *dev,
 
        word_bits = SET_NB_DRAM_INJECTION_WRITE(pvt->injection);
 
+       pr_notice_once("Don't forget to decrease MCE polling interval in\n"
+                       "/sys/bus/machinecheck/devices/machinecheck<CPUNUM>/check_interval\n"
+                       "so that you can get the error report faster.\n");
+
+       on_each_cpu(disable_caches, NULL, 1);
+
        /* Issue 'word' and 'bit' along with the READ request */
        amd64_write_pci_cfg(pvt->F3, F10_NB_ARRAY_DATA, word_bits);
 
+ retry:
+       /* wait until injection happens */
+       amd64_read_pci_cfg(pvt->F3, F10_NB_ARRAY_DATA, &tmp);
+       if (tmp & F10_NB_ARR_ECC_WR_REQ) {
+               cpu_relax();
+               goto retry;
+       }
+
+       on_each_cpu(enable_caches, NULL, 1);
+
        edac_dbg(0, "section=0x%x word_bits=0x%x\n", section, word_bits);
 
        return count;