[PATCH 4.18 172/228] qed: Wait for ready indication before rereading the shmem

From: Greg Kroah-Hartman
Date: Tue Oct 02 2018 - 10:02:14 EST


4.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Tomer Tayar <Tomer.Tayar@xxxxxxxxxx>

[ Upstream commit f00d25f3154b676fcea4502a25b94bd7f142ca74 ]

The MFW might be reset and re-update its shared memory.
Upon the detection of such a reset the driver rereads this memory, but it
has to wait till the data is valid.
This patch adds the missing wait for a data ready indication.

Signed-off-by: Tomer Tayar <Tomer.Tayar@xxxxxxxxxx>
Signed-off-by: Ariel Elior <Ariel.Elior@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/qlogic/qed/qed_mcp.c | 50 ++++++++++++++++++++++++------
1 file changed, 41 insertions(+), 9 deletions(-)

--- a/drivers/net/ethernet/qlogic/qed/qed_mcp.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_mcp.c
@@ -183,18 +183,57 @@ int qed_mcp_free(struct qed_hwfn *p_hwfn
return 0;
}

+/* Maximum of 1 sec to wait for the SHMEM ready indication */
+#define QED_MCP_SHMEM_RDY_MAX_RETRIES 20
+#define QED_MCP_SHMEM_RDY_ITER_MS 50
+
static int qed_load_mcp_offsets(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
{
struct qed_mcp_info *p_info = p_hwfn->mcp_info;
+ u8 cnt = QED_MCP_SHMEM_RDY_MAX_RETRIES;
+ u8 msec = QED_MCP_SHMEM_RDY_ITER_MS;
u32 drv_mb_offsize, mfw_mb_offsize;
u32 mcp_pf_id = MCP_PF_ID(p_hwfn);

p_info->public_base = qed_rd(p_hwfn, p_ptt, MISC_REG_SHARED_MEM_ADDR);
- if (!p_info->public_base)
- return 0;
+ if (!p_info->public_base) {
+ DP_NOTICE(p_hwfn,
+ "The address of the MCP scratch-pad is not configured\n");
+ return -EINVAL;
+ }

p_info->public_base |= GRCBASE_MCP;

+ /* Get the MFW MB address and number of supported messages */
+ mfw_mb_offsize = qed_rd(p_hwfn, p_ptt,
+ SECTION_OFFSIZE_ADDR(p_info->public_base,
+ PUBLIC_MFW_MB));
+ p_info->mfw_mb_addr = SECTION_ADDR(mfw_mb_offsize, mcp_pf_id);
+ p_info->mfw_mb_length = (u16)qed_rd(p_hwfn, p_ptt,
+ p_info->mfw_mb_addr +
+ offsetof(struct public_mfw_mb,
+ sup_msgs));
+
+ /* The driver can notify that there was an MCP reset, and might read the
+ * SHMEM values before the MFW has completed initializing them.
+ * To avoid this, the "sup_msgs" field in the MFW mailbox is used as a
+ * data ready indication.
+ */
+ while (!p_info->mfw_mb_length && --cnt) {
+ msleep(msec);
+ p_info->mfw_mb_length =
+ (u16)qed_rd(p_hwfn, p_ptt,
+ p_info->mfw_mb_addr +
+ offsetof(struct public_mfw_mb, sup_msgs));
+ }
+
+ if (!cnt) {
+ DP_NOTICE(p_hwfn,
+ "Failed to get the SHMEM ready notification after %d msec\n",
+ QED_MCP_SHMEM_RDY_MAX_RETRIES * msec);
+ return -EBUSY;
+ }
+
/* Calculate the driver and MFW mailbox address */
drv_mb_offsize = qed_rd(p_hwfn, p_ptt,
SECTION_OFFSIZE_ADDR(p_info->public_base,
@@ -204,13 +243,6 @@ static int qed_load_mcp_offsets(struct q
"drv_mb_offsiz = 0x%x, drv_mb_addr = 0x%x mcp_pf_id = 0x%x\n",
drv_mb_offsize, p_info->drv_mb_addr, mcp_pf_id);

- /* Set the MFW MB address */
- mfw_mb_offsize = qed_rd(p_hwfn, p_ptt,
- SECTION_OFFSIZE_ADDR(p_info->public_base,
- PUBLIC_MFW_MB));
- p_info->mfw_mb_addr = SECTION_ADDR(mfw_mb_offsize, mcp_pf_id);
- p_info->mfw_mb_length = (u16)qed_rd(p_hwfn, p_ptt, p_info->mfw_mb_addr);
-
/* Get the current driver mailbox sequence before sending
* the first command
*/