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qed: Prevent a possible deadlock during driver load and unload

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The MFW manages an internal lock to prevent concurrent hardware
(de)initialization of different PFs.
This, together with the busy-waiting for the MFW's responses for commands,
might lead to a deadlock during concurrent load or unload of PFs.
This patch adds the option to sleep within the busy-waiting, and uses it
for the (un)load requests (which are not sent from an interrupt context) to
prevent the possible deadlock.

Signed-off-by: Tomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: Ariel Elior <Ariel.Elior@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tomer Tayar 2018-08-20 00:01:44 +03:00 committed by David S. Miller
parent 76271809f4
commit eaa50fc59e
2 changed files with 44 additions and 20 deletions
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43
drivers/net/ethernet/qlogic/qed/qed_mcp.c
View File

@ -48,7 +48,7 @@
#include "qed_reg_addr.h"
#include "qed_sriov.h"
#define CHIP_MCP_RESP_ITER_US 10
#define QED_MCP_RESP_ITER_US 10
#define QED_DRV_MB_MAX_RETRIES (500 * 1000) /* Account for 5 sec */
#define QED_MCP_RESET_RETRIES (50 * 1000) /* Account for 500 msec */
@ -317,7 +317,7 @@ static void qed_mcp_reread_offsets(struct qed_hwfn *p_hwfn,
int qed_mcp_reset(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
{
u32 org_mcp_reset_seq, seq, delay = CHIP_MCP_RESP_ITER_US, cnt = 0;
u32 org_mcp_reset_seq, seq, delay = QED_MCP_RESP_ITER_US, cnt = 0;
int rc = 0;
/* Ensure that only a single thread is accessing the mailbox */
@ -449,10 +449,10 @@ static int
_qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
struct qed_ptt *p_ptt,
struct qed_mcp_mb_params *p_mb_params,
u32 max_retries, u32 delay)
u32 max_retries, u32 usecs)
{
u32 cnt = 0, msecs = DIV_ROUND_UP(usecs, 1000);
struct qed_mcp_cmd_elem *p_cmd_elem;
u32 cnt = 0;
u16 seq_num;
int rc = 0;
@ -475,7 +475,11 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
goto err;
spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);
udelay(delay);
if (QED_MB_FLAGS_IS_SET(p_mb_params, CAN_SLEEP))
msleep(msecs);
else
udelay(usecs);
} while (++cnt < max_retries);
if (cnt >= max_retries) {
@ -504,7 +508,11 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
* The spinlock stays locked until the list element is removed.
*/
udelay(delay);
if (QED_MB_FLAGS_IS_SET(p_mb_params, CAN_SLEEP))
msleep(msecs);
else
udelay(usecs);
spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);
if (p_cmd_elem->b_is_completed)
@ -539,7 +547,7 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
"MFW mailbox: response 0x%08x param 0x%08x [after %d.%03d ms]\n",
p_mb_params->mcp_resp,
p_mb_params->mcp_param,
(cnt * delay) / 1000, (cnt * delay) % 1000);
(cnt * usecs) / 1000, (cnt * usecs) % 1000);
/* Clear the sequence number from the MFW response */
p_mb_params->mcp_resp &= FW_MSG_CODE_MASK;
@ -557,7 +565,7 @@ static int qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
{
size_t union_data_size = sizeof(union drv_union_data);
u32 max_retries = QED_DRV_MB_MAX_RETRIES;
u32 delay = CHIP_MCP_RESP_ITER_US;
u32 usecs = QED_MCP_RESP_ITER_US;
/* MCP not initialized */
if (!qed_mcp_is_init(p_hwfn)) {
@ -574,8 +582,13 @@ static int qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
return -EINVAL;
}
if (QED_MB_FLAGS_IS_SET(p_mb_params, CAN_SLEEP)) {
max_retries = DIV_ROUND_UP(max_retries, 1000);
usecs *= 1000;
}
return _qed_mcp_cmd_and_union(p_hwfn, p_ptt, p_mb_params, max_retries,
delay);
usecs);
}
int qed_mcp_cmd(struct qed_hwfn *p_hwfn,
@ -793,6 +806,7 @@ __qed_mcp_load_req(struct qed_hwfn *p_hwfn,
mb_params.data_src_size = sizeof(load_req);
mb_params.p_data_dst = &load_rsp;
mb_params.data_dst_size = sizeof(load_rsp);
mb_params.flags = QED_MB_FLAG_CAN_SLEEP;
DP_VERBOSE(p_hwfn, QED_MSG_SP,
"Load Request: param 0x%08x [init_hw %d, drv_type %d, hsi_ver %d, pda 0x%04x]\n",
@ -1014,7 +1028,8 @@ int qed_mcp_load_req(struct qed_hwfn *p_hwfn,
int qed_mcp_unload_req(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
{
u32 wol_param, mcp_resp, mcp_param;
struct qed_mcp_mb_params mb_params;
u32 wol_param;
switch (p_hwfn->cdev->wol_config) {
case QED_OV_WOL_DISABLED:
@ -1032,8 +1047,12 @@ int qed_mcp_unload_req(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
wol_param = DRV_MB_PARAM_UNLOAD_WOL_MCP;
}
return qed_mcp_cmd(p_hwfn, p_ptt, DRV_MSG_CODE_UNLOAD_REQ, wol_param,
&mcp_resp, &mcp_param);
memset(&mb_params, 0, sizeof(mb_params));
mb_params.cmd = DRV_MSG_CODE_UNLOAD_REQ;
mb_params.param = wol_param;
mb_params.flags = QED_MB_FLAG_CAN_SLEEP;
return qed_mcp_cmd_and_union(p_hwfn, p_ptt, &mb_params);
}
int qed_mcp_unload_done(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)

21
drivers/net/ethernet/qlogic/qed/qed_mcp.h
View File

@ -660,14 +660,19 @@ struct qed_mcp_info {
};
struct qed_mcp_mb_params {
u32 cmd;
u32 param;
void *p_data_src;
u8 data_src_size;
void *p_data_dst;
u8 data_dst_size;
u32 mcp_resp;
u32 mcp_param;
u32 cmd;
u32 param;
void *p_data_src;
void *p_data_dst;
u8 data_src_size;
u8 data_dst_size;
u32 mcp_resp;
u32 mcp_param;
u32 flags;
#define QED_MB_FLAG_CAN_SLEEP (0x1 << 0)
#define QED_MB_FLAGS_IS_SET(params, flag) \
({ typeof(params) __params = (params); \
(__params && (__params->flags & QED_MB_FLAG_ ## flag)); })
};
struct qed_drv_tlv_hdr {