[PATCH 4.19 221/321] sfc: suppress duplicate nvmem partition types in efx_ef10_mtd_probe

Greg Kroah-Hartman
2019-12-03T23:02:34Z

From: Edward Cree <ecree@solarflare.com>

[ Upstream commit 3366463513f544c12c6b88c13da4462ee9e7a1a1 ]

Use a bitmap to keep track of which partition types we've already seen;
for duplicates, return -EEXIST from efx_ef10_mtd_probe_partition() and
thus skip adding that partition.
Duplicate partitions occur because of the A/B backup scheme used by newer
sfc NICs. Prior to this patch they cause sysfs_warn_dup errors because
they have the same name, causing us not to expose any MTDs at all.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/sfc/ef10.c | 29 +++++++++++++++++++++--------
1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index 7eeac3d6cfe89..a497aace7e4f4 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -6042,22 +6042,25 @@ static const struct efx_ef10_nvram_type_info efx_ef10_nvram_types[] = {
{ NVRAM_PARTITION_TYPE_LICENSE, 0, 0, "sfc_license" },
{ NVRAM_PARTITION_TYPE_PHY_MIN, 0xff, 0, "sfc_phy_fw" },
};
+#define EF10_NVRAM_PARTITION_COUNT ARRAY_SIZE(efx_ef10_nvram_types)

static int efx_ef10_mtd_probe_partition(struct efx_nic *efx,
struct efx_mcdi_mtd_partition *part,
- unsigned int type)
+ unsigned int type,
+ unsigned long *found)
{
MCDI_DECLARE_BUF(inbuf, MC_CMD_NVRAM_METADATA_IN_LEN);
MCDI_DECLARE_BUF(outbuf, MC_CMD_NVRAM_METADATA_OUT_LENMAX);
const struct efx_ef10_nvram_type_info *info;
size_t size, erase_size, outlen;
+ int type_idx = 0;
bool protected;
int rc;

- for (info = efx_ef10_nvram_types; ; info++) {
- if (info ==
- efx_ef10_nvram_types + ARRAY_SIZE(efx_ef10_nvram_types))
+ for (type_idx = 0; ; type_idx++) {
+ if (type_idx == EF10_NVRAM_PARTITION_COUNT)
return -ENODEV;
+ info = efx_ef10_nvram_types + type_idx;
if ((type & ~info->type_mask) == info->type)
break;
}
@@ -6070,6 +6073,13 @@ static int efx_ef10_mtd_probe_partition(struct efx_nic *efx,
if (protected)
return -ENODEV; /* hide it */

+ /* If we've already exposed a partition of this type, hide this
+ * duplicate. All operations on MTDs are keyed by the type anyway,
+ * so we can't act on the duplicate.
+ */
+ if (__test_and_set_bit(type_idx, found))
+ return -EEXIST;
+
part->nvram_type = type;

MCDI_SET_DWORD(inbuf, NVRAM_METADATA_IN_TYPE, type);
@@ -6098,6 +6108,7 @@ static int efx_ef10_mtd_probe_partition(struct efx_nic *efx,
static int efx_ef10_mtd_probe(struct efx_nic *efx)
{
MCDI_DECLARE_BUF(outbuf, MC_CMD_NVRAM_PARTITIONS_OUT_LENMAX);
+ DECLARE_BITMAP(found, EF10_NVRAM_PARTITION_COUNT);
struct efx_mcdi_mtd_partition *parts;
size_t outlen, n_parts_total, i, n_parts;
unsigned int type;
@@ -6126,11 +6137,13 @@ static int efx_ef10_mtd_probe(struct efx_nic *efx)
for (i = 0; i < n_parts_total; i++) {
type = MCDI_ARRAY_DWORD(outbuf, NVRAM_PARTITIONS_OUT_TYPE_ID,
i);
- rc = efx_ef10_mtd_probe_partition(efx, &parts[n_parts], type);
- if (rc == 0)
- n_parts++;
- else if (rc != -ENODEV)
+ rc = efx_ef10_mtd_probe_partition(efx, &parts[n_parts], type,
+ found);
+ if (rc == -EEXIST || rc == -ENODEV)
+ continue;
+ if (rc)
goto fail;
+ n_parts++;
}

rc = efx_mtd_add(efx, &parts[0].common, n_parts, sizeof(*parts));
--
2.20.1