[PATCH v4 2/4] EDAC/mce_amd: Extract node id from MCA_IPID

Naveen Krishna Chatradhi
2021-10-14T18:54:58Z

On SMCA banks of the GPU nodes, the node id information is
available in register MCA_IPID[47:44](InstanceIdHi).

Convert the hardware node ID to a value used by Linux
where GPU nodes are sequencially after the CPU nodes.

Co-developed-by: Muralidhara M K <muralimk@amd.com>
Signed-off-by: Muralidhara M K <muralimk@amd.com>
Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
Link: https://lkml.kernel.org/r/20210823185437.94417-3-nchatrad@amd.com
---
Changes since v3:
1. Use APIs from amd_nb to identify the gpu_node_start_id and cpu_node_count.
Which is required to map the hardware node id to node id enumerated by Linux.

Changes since v2:
1. Modified subject and commit message
2. Added Reviewed by Yazen Ghannam

Changes since v1:
1. Modified the commit message
2. rearranged the conditions before calling decode_dram_ecc()

drivers/edac/mce_amd.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index 67dbf4c31271..af6caa76adc7 100644
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -2,6 +2,7 @@
#include <linux/module.h>
#include <linux/slab.h>

+#include <asm/amd_nb.h>
#include <asm/cpu.h>

#include "mce_amd.h"
@@ -1072,8 +1073,27 @@ static void decode_smca_error(struct mce *m)
if (xec < smca_mce_descs[bank_type].num_descs)
pr_cont(", %s.\n", smca_mce_descs[bank_type].descs[xec]);

- if (bank_type == SMCA_UMC && xec == 0 && decode_dram_ecc)
- decode_dram_ecc(topology_die_id(m->extcpu), m);
+ if (xec == 0 && decode_dram_ecc) {
+ int node_id = 0;
+
+ if (bank_type == SMCA_UMC) {
+ node_id = topology_die_id(m->extcpu);
+ } else if (bank_type == SMCA_UMC_V2) {
+ /*
+ * SMCA_UMC_V2 exists on GPU nodes, extract the node id
+ * from register MCA_IPID[47:44](InstanceIdHi).
+ * The InstanceIdHi field represents the instance ID of the GPU.
+ * Which needs to be mapped to a value used by Linux,
+ * where GPU nodes are simply numerically after the CPU nodes.
+ */
+ node_id = ((m->ipid >> 44) & 0xF) -
+ amd_gpu_node_start_id() + amd_cpu_node_count();
+ } else {
+ return;
+ }
+
+ decode_dram_ecc(node_id, m);
+ }
}

static inline void amd_decode_err_code(u16 ec)
--
2.25.1