x86/mce/AMD, EDAC/mce_amd: Enumerate Reserved SMCA bank type

commit 68627a697c195937672ce07683094c72b1174786 upstream.

Currently, bank 4 is reserved on Fam17h, so we chose not to initialize
bank 4 in the smca_banks array. This means that when we check if a bank
is initialized, like during boot or resume, we will see that bank 4 is
not initialized and try to initialize it.

This will cause a call trace, when resuming from suspend, due to
rdmsr_*on_cpu() calls in the init path. The rdmsr_*on_cpu() calls issue
an IPI but we're running with interrupts disabled. This triggers:

  WARNING: CPU: 0 PID: 11523 at kernel/smp.c:291 smp_call_function_single+0xdc/0xe0
  ...

Reserved banks will be read-as-zero, so their MCA_IPID register will be
zero. So, like the smca_banks array, the threshold_banks array will not
have an entry for a reserved bank since all its MCA_MISC* registers will
be zero.

Enumerate a "Reserved" bank type that matches on a HWID_MCATYPE of 0,0.

Use the "Reserved" type when checking if a bank is reserved. It's
possible that other bank numbers may be reserved on future systems.

Don't try to find the block address on reserved banks.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.14.x
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180221101900.10326-7-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 96ea4b5ba6581785b4921421246ddfe096d3d208..340070415c2c3a93b0305ed7624ceaa62bd4362f 100644 (file)
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -346,6 +346,7 @@ enum smca_bank_types {
        SMCA_IF,        /* Instruction Fetch */
        SMCA_L2_CACHE,  /* L2 Cache */
        SMCA_DE,        /* Decoder Unit */
+       SMCA_RESERVED,  /* Reserved */
        SMCA_EX,        /* Execution Unit */
        SMCA_FP,        /* Floating Point */
        SMCA_L3_CACHE,  /* L3 Cache */

diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index 63747c772234b5f968c22aa40dbb052607a864db..0e78ff5a7365a35e62edc639dde7820fcbda68c0 100644 (file)
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -82,6 +82,7 @@ static struct smca_bank_name smca_names[] = {
        [SMCA_IF]       = { "insn_fetch",       "Instruction Fetch Unit" },
        [SMCA_L2_CACHE] = { "l2_cache",         "L2 Cache" },
        [SMCA_DE]       = { "decode_unit",      "Decode Unit" },
+       [SMCA_RESERVED] = { "reserved",         "Reserved" },
        [SMCA_EX]       = { "execution_unit",   "Execution Unit" },
        [SMCA_FP]       = { "floating_point",   "Floating Point Unit" },
        [SMCA_L3_CACHE] = { "l3_cache",         "L3 Cache" },
@@ -127,6 +128,9 @@ static enum smca_bank_types smca_get_bank_type(unsigned int bank)
 static struct smca_hwid smca_hwid_mcatypes[] = {
        /* { bank_type, hwid_mcatype, xec_bitmap } */
 
+       /* Reserved type */
+       { SMCA_RESERVED, HWID_MCATYPE(0x00, 0x0), 0x0 },
+
        /* ZN Core (HWID=0xB0) MCA types */
        { SMCA_LS,       HWID_MCATYPE(0xB0, 0x0), 0x1FFFEF },
        { SMCA_IF,       HWID_MCATYPE(0xB0, 0x1), 0x3FFF },
@@ -431,6 +435,9 @@ static u32 get_block_address(unsigned int cpu, u32 current_addr, u32 low, u32 hi
        u32 addr = 0, offset = 0;
 
        if (mce_flags.smca) {
+               if (smca_get_bank_type(bank) == SMCA_RESERVED)
+                       return addr;
+
                if (!block) {
                        addr = MSR_AMD64_SMCA_MCx_MISC(bank);
                } else {

diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index a11a671c7a3866cb416d20eb4f302968028d7080..2ab4d61ee47e86d41a730302632ebb0a7cd4b4be 100644 (file)
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -854,21 +854,24 @@ static void decode_mc6_mce(struct mce *m)
 static void decode_smca_error(struct mce *m)
 {
        struct smca_hwid *hwid;
-       unsigned int bank_type;
+       enum smca_bank_types bank_type;
        const char *ip_name;
        u8 xec = XEC(m->status, xec_mask);
 
        if (m->bank >= ARRAY_SIZE(smca_banks))
                return;
 
-       if (x86_family(m->cpuid) >= 0x17 && m->bank == 4)
-               pr_emerg(HW_ERR "Bank 4 is reserved on Fam17h.\n");
-
        hwid = smca_banks[m->bank].hwid;
        if (!hwid)
                return;
 
        bank_type = hwid->bank_type;
+
+       if (bank_type == SMCA_RESERVED) {
+               pr_emerg(HW_ERR "Bank %d is reserved.\n", m->bank);
+               return;
+       }
+
        ip_name = smca_get_long_name(bank_type);
 
        pr_emerg(HW_ERR "%s Extended Error Code: %d\n", ip_name, xec);