From eaa50fc59e5841910987e90b0438b2643041f508 Mon Sep 17 00:00:00 2001 From: Tomer Tayar Date: Mon, 20 Aug 2018 00:01:44 +0300 Subject: [PATCH] qed: Prevent a possible deadlock during driver load and unload 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 Signed-off-by: Ariel Elior Signed-off-by: David S. Miller --- drivers/net/ethernet/qlogic/qed/qed_mcp.c | 43 ++++++++++++++++------- drivers/net/ethernet/qlogic/qed/qed_mcp.h | 21 ++++++----- 2 files changed, 44 insertions(+), 20 deletions(-) diff --git a/drivers/net/ethernet/qlogic/qed/qed_mcp.c b/drivers/net/ethernet/qlogic/qed/qed_mcp.c index 5f3dbdc7ff1d..b7279e625db3 100644 --- a/drivers/net/ethernet/qlogic/qed/qed_mcp.c +++ b/drivers/net/ethernet/qlogic/qed/qed_mcp.c @@ -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) diff --git a/drivers/net/ethernet/qlogic/qed/qed_mcp.h b/drivers/net/ethernet/qlogic/qed/qed_mcp.h index 047976d5c6e9..b9d3ecf7aad6 100644 --- a/drivers/net/ethernet/qlogic/qed/qed_mcp.h +++ b/drivers/net/ethernet/qlogic/qed/qed_mcp.h @@ -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 { -- 2.30.2