diff mbox series

[v2,2/3] RAS/AMD/FMPM: Save SPA values

Message ID 20240301143748.854090-3-yazen.ghannam@amd.com
State New
Headers
Series FMPM Debug Updates |

Commit Message

Yazen Ghannam March 1, 2024, 2:37 p.m. UTC 
  The system physical address (SPA) of an error is not a stable value. It
will change depending on the location of the memory: parts can be
swapped. And it will change depending on memory topology: NUMA nodes
and/or interleaving can be adjusted.

Therefore, the SPA value is not part of the "FRU Memory Poison" record
format. And it will not be saved to persistent storage.

However, the SPA values can be helpful during debug and for system
admins during run time.

Save the SPA values in a separate structure. This is updated when
records are restored and when new errors are saved.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
---
Link:
https://lore.kernel.org/r/20240226152941.2615007-3-yazen.ghannam@amd.com

v1->v2:
* Changed variable names to remove "sys_" prefix. (Boris)
* Used "spa_" prefix to highlight that these are for SPA values. (Yazen)
* Added warning to "index out-of-bound" condition. (Boris)
* Reworked save_spa() flow to get a valid array position before saving
  SPA value (Yazen).

 drivers/ras/amd/fmpm.c | 68 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

Comments

Borislav Petkov March 1, 2024, 3:50 p.m. UTC | #1 
On Fri, Mar 01, 2024 at 08:37:47AM -0600, Yazen Ghannam wrote:
> The system physical address (SPA) of an error is not a stable value. It
> will change depending on the location of the memory: parts can be
> swapped. And it will change depending on memory topology: NUMA nodes
> and/or interleaving can be adjusted.
> 
> Therefore, the SPA value is not part of the "FRU Memory Poison" record
> format. And it will not be saved to persistent storage.
> 
> However, the SPA values can be helpful during debug and for system
> admins during run time.
> 
> Save the SPA values in a separate structure. This is updated when
> records are restored and when new errors are saved.
> 
> Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
> ---
> Link:
> https://lore.kernel.org/r/20240226152941.2615007-3-yazen.ghannam@amd.com
> 
> v1->v2:
> * Changed variable names to remove "sys_" prefix. (Boris)
> * Used "spa_" prefix to highlight that these are for SPA values. (Yazen)
> * Added warning to "index out-of-bound" condition. (Boris)
> * Reworked save_spa() flow to get a valid array position before saving
>   SPA value (Yazen).
> 
>  drivers/ras/amd/fmpm.c | 68 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)

Fixups ontop:

---

diff --git a/drivers/ras/amd/fmpm.c b/drivers/ras/amd/fmpm.c
index a7bb36eb60cb..8c3188488673 100644
--- a/drivers/ras/amd/fmpm.c
+++ b/drivers/ras/amd/fmpm.c
@@ -125,7 +125,7 @@ static u64 *spa_entries;
 		  0x12, 0x0a, 0x44, 0x58)
 
 /**
- * DOC: fru_poison_entries (byte)
+ * DOC: max_nr_entries (byte)
  * Maximum number of descriptor entries possible for each FRU.
  *
  * Values between '1' and '255' are valid.
@@ -285,10 +285,12 @@ static void save_spa(struct fru_rec *rec, unsigned int entry,
 	unsigned long spa;
 
 	if (entry >= max_nr_entries) {
-		pr_warn_once("entry out-of-bounds\n");
+		pr_warn_once("FRU descriptor entry %d out-of-bounds (max: %d)\n",
+			     entry, max_nr_entries);
 		return;
 	}
 
+	/* spa_nr_entries is always multiple of max_nr_entries */
 	for (i = 0; i < spa_nr_entries; i += max_nr_entries) {
 		fru_idx = i / max_nr_entries;
 		if (fru_records[fru_idx] == rec)
@@ -296,7 +298,7 @@ static void save_spa(struct fru_rec *rec, unsigned int entry,
 	}
 
 	if (i >= spa_nr_entries) {
-		pr_warn_once("record not found");
+		pr_warn_once("FRU record %d not found\n", i);
 		return;
 	}
diff mbox series

Patch

diff --git a/drivers/ras/amd/fmpm.c b/drivers/ras/amd/fmpm.c
index 80dd112b720a..a7bb36eb60cb 100644
--- a/drivers/ras/amd/fmpm.c
+++ b/drivers/ras/amd/fmpm.c
@@ -111,6 +111,11 @@  struct fru_rec {
  */
 static struct fru_rec **fru_records;
 
+/* system physical addresses array */
+static u64 *spa_entries;
+
+#define INVALID_SPA	~0ULL
+
 #define CPER_CREATOR_FMP						\
 	GUID_INIT(0xcd5c2993, 0xf4b2, 0x41b2, 0xb5, 0xd4, 0xf9, 0xc3,	\
 		  0xa0, 0x33, 0x08, 0x75)
@@ -140,6 +145,9 @@  static unsigned int max_nr_fru;
 /* Total length of record including headers and list of descriptor entries. */
 static size_t max_rec_len;
 
+/* Total number of SPA entries across all FRUs. */
+static unsigned int spa_nr_entries;
+
 /*
  * Protect the local records cache in fru_records and prevent concurrent
  * writes to storage. This is only needed after init once notifier block
@@ -269,6 +277,52 @@  static bool rec_has_fpd(struct fru_rec *rec, struct cper_fru_poison_desc *fpd)
 	return false;
 }
 
+static void save_spa(struct fru_rec *rec, unsigned int entry,
+		     u64 addr, u64 id, unsigned int cpu)
+{
+	unsigned int i, fru_idx, spa_entry;
+	struct atl_err a_err;
+	unsigned long spa;
+
+	if (entry >= max_nr_entries) {
+		pr_warn_once("entry out-of-bounds\n");
+		return;
+	}
+
+	for (i = 0; i < spa_nr_entries; i += max_nr_entries) {
+		fru_idx = i / max_nr_entries;
+		if (fru_records[fru_idx] == rec)
+			break;
+	}
+
+	if (i >= spa_nr_entries) {
+		pr_warn_once("record not found");
+		return;
+	}
+
+	spa_entry = i + entry;
+	if (spa_entry >= spa_nr_entries) {
+		pr_warn_once("spa_entries[] index out-of-bounds\n");
+		return;
+	}
+
+	memset(&a_err, 0, sizeof(struct atl_err));
+
+	a_err.addr = addr;
+	a_err.ipid = id;
+	a_err.cpu  = cpu;
+
+	spa = amd_convert_umc_mca_addr_to_sys_addr(&a_err);
+	if (IS_ERR_VALUE(spa)) {
+		pr_debug("Failed to get system address\n");
+		return;
+	}
+
+	spa_entries[spa_entry] = spa;
+	pr_debug("fru_idx: %u, entry: %u, spa_entry: %u, spa: 0x%016llx\n",
+		 fru_idx, entry, spa_entry, spa_entries[spa_entry]);
+}
+
 static void update_fru_record(struct fru_rec *rec, struct mce *m)
 {
 	struct cper_sec_fru_mem_poison *fmp = &rec->fmp;
@@ -301,6 +355,7 @@  static void update_fru_record(struct fru_rec *rec, struct mce *m)
 	entry  = fmp->nr_entries;
 
 save_fpd:
+	save_spa(rec, entry, m->addr, m->ipid, m->extcpu);
 	fpd_dest  = &rec->entries[entry];
 	memcpy(fpd_dest, &fpd, sizeof(struct cper_fru_poison_desc));
 
@@ -385,6 +440,7 @@  static void retire_mem_fmp(struct fru_rec *rec)
 			continue;
 
 		retire_dram_row(fpd->addr, fpd->hw_id, err_cpu);
+		save_spa(rec, i, fpd->addr, fpd->hw_id, err_cpu);
 	}
 }
 
@@ -696,6 +752,8 @@  static int get_system_info(void)
 	if (!max_nr_entries)
 		max_nr_entries = FMPM_DEFAULT_MAX_NR_ENTRIES;
 
+	spa_nr_entries = max_nr_fru * max_nr_entries;
+
 	max_rec_len  = sizeof(struct fru_rec);
 	max_rec_len += sizeof(struct cper_fru_poison_desc) * max_nr_entries;
 
@@ -714,6 +772,7 @@  static void free_records(void)
 		kfree(rec);
 
 	kfree(fru_records);
+	kfree(spa_entries);
 }
 
 static int allocate_records(void)
@@ -734,6 +793,15 @@  static int allocate_records(void)
 		}
 	}
 
+	spa_entries = kcalloc(spa_nr_entries, sizeof(u64), GFP_KERNEL);
+	if (!spa_entries) {
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	for (i = 0; i < spa_nr_entries; i++)
+		spa_entries[i] = INVALID_SPA;
+
 	return ret;
 
 out_free: