From: Tomer Tayar Date: Thu, 23 Mar 2017 13:50:15 +0000 (+0200) Subject: qed: Revise MFW command locking X-Git-Tag: v4.14-rc1~960^3~366^2~5 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4ed1eea82a21ba460e53468cc1c73cfdf83d0e00;p=platform%2Fkernel%2Flinux-rpi.git qed: Revise MFW command locking Interaction of driver -> management firmware is based on a one-pending mailbox [per interface], and various mailbox commands need to be synchronized. Current scheme is messy, and there's a difficulty extending it as it deals differently with various commands as well as making assumption on the required behavior for load/unload requests. Drop the current scheme into a completion-list-based approach; Each flow would try sending the command when possible, allowing one flow to complete another flow's completion and relieve the mailbox before sending its own command. Signed-off-by: Tomer Tayar Signed-off-by: Yuval Mintz Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/qlogic/qed/qed_mcp.c b/drivers/net/ethernet/qlogic/qed/qed_mcp.c index 87fde20..0d157de 100644 --- a/drivers/net/ethernet/qlogic/qed/qed_mcp.c +++ b/drivers/net/ethernet/qlogic/qed/qed_mcp.c @@ -111,12 +111,71 @@ void qed_mcp_read_mb(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) } } +struct qed_mcp_cmd_elem { + struct list_head list; + struct qed_mcp_mb_params *p_mb_params; + u16 expected_seq_num; + bool b_is_completed; +}; + +/* Must be called while cmd_lock is acquired */ +static struct qed_mcp_cmd_elem * +qed_mcp_cmd_add_elem(struct qed_hwfn *p_hwfn, + struct qed_mcp_mb_params *p_mb_params, + u16 expected_seq_num) +{ + struct qed_mcp_cmd_elem *p_cmd_elem = NULL; + + p_cmd_elem = kzalloc(sizeof(*p_cmd_elem), GFP_ATOMIC); + if (!p_cmd_elem) + goto out; + + p_cmd_elem->p_mb_params = p_mb_params; + p_cmd_elem->expected_seq_num = expected_seq_num; + list_add(&p_cmd_elem->list, &p_hwfn->mcp_info->cmd_list); +out: + return p_cmd_elem; +} + +/* Must be called while cmd_lock is acquired */ +static void qed_mcp_cmd_del_elem(struct qed_hwfn *p_hwfn, + struct qed_mcp_cmd_elem *p_cmd_elem) +{ + list_del(&p_cmd_elem->list); + kfree(p_cmd_elem); +} + +/* Must be called while cmd_lock is acquired */ +static struct qed_mcp_cmd_elem *qed_mcp_cmd_get_elem(struct qed_hwfn *p_hwfn, + u16 seq_num) +{ + struct qed_mcp_cmd_elem *p_cmd_elem = NULL; + + list_for_each_entry(p_cmd_elem, &p_hwfn->mcp_info->cmd_list, list) { + if (p_cmd_elem->expected_seq_num == seq_num) + return p_cmd_elem; + } + + return NULL; +} + int qed_mcp_free(struct qed_hwfn *p_hwfn) { if (p_hwfn->mcp_info) { + struct qed_mcp_cmd_elem *p_cmd_elem, *p_tmp; + kfree(p_hwfn->mcp_info->mfw_mb_cur); kfree(p_hwfn->mcp_info->mfw_mb_shadow); + + spin_lock_bh(&p_hwfn->mcp_info->cmd_lock); + list_for_each_entry_safe(p_cmd_elem, + p_tmp, + &p_hwfn->mcp_info->cmd_list, list) { + qed_mcp_cmd_del_elem(p_hwfn, p_cmd_elem); + } + spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock); } + kfree(p_hwfn->mcp_info); return 0; @@ -160,7 +219,7 @@ static int qed_load_mcp_offsets(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) p_info->drv_pulse_seq = DRV_MB_RD(p_hwfn, p_ptt, drv_pulse_mb) & DRV_PULSE_SEQ_MASK; - p_info->mcp_hist = (u16)qed_rd(p_hwfn, p_ptt, MISCS_REG_GENERIC_POR_0); + p_info->mcp_hist = qed_rd(p_hwfn, p_ptt, MISCS_REG_GENERIC_POR_0); return 0; } @@ -176,6 +235,12 @@ int qed_mcp_cmd_init(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) goto err; p_info = p_hwfn->mcp_info; + /* Initialize the MFW spinlock */ + spin_lock_init(&p_info->cmd_lock); + spin_lock_init(&p_info->link_lock); + + INIT_LIST_HEAD(&p_info->cmd_list); + if (qed_load_mcp_offsets(p_hwfn, p_ptt) != 0) { DP_NOTICE(p_hwfn, "MCP is not initialized\n"); /* Do not free mcp_info here, since public_base indicate that @@ -190,10 +255,6 @@ int qed_mcp_cmd_init(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) if (!p_info->mfw_mb_shadow || !p_info->mfw_mb_addr) goto err; - /* Initialize the MFW spinlock */ - spin_lock_init(&p_info->lock); - spin_lock_init(&p_info->link_lock); - return 0; err: @@ -201,68 +262,39 @@ err: return -ENOMEM; } -/* Locks the MFW mailbox of a PF to ensure a single access. - * The lock is achieved in most cases by holding a spinlock, causing other - * threads to wait till a previous access is done. - * In some cases (currently when a [UN]LOAD_REQ commands are sent), the single - * access is achieved by setting a blocking flag, which will fail other - * competing contexts to send their mailboxes. - */ -static int qed_mcp_mb_lock(struct qed_hwfn *p_hwfn, u32 cmd) +static void qed_mcp_reread_offsets(struct qed_hwfn *p_hwfn, + struct qed_ptt *p_ptt) { - spin_lock_bh(&p_hwfn->mcp_info->lock); - - /* The spinlock shouldn't be acquired when the mailbox command is - * [UN]LOAD_REQ, since the engine is locked by the MFW, and a parallel - * pending [UN]LOAD_REQ command of another PF together with a spinlock - * (i.e. interrupts are disabled) - can lead to a deadlock. - * It is assumed that for a single PF, no other mailbox commands can be - * sent from another context while sending LOAD_REQ, and that any - * parallel commands to UNLOAD_REQ can be cancelled. - */ - if (cmd == DRV_MSG_CODE_LOAD_DONE || cmd == DRV_MSG_CODE_UNLOAD_DONE) - p_hwfn->mcp_info->block_mb_sending = false; + u32 generic_por_0 = qed_rd(p_hwfn, p_ptt, MISCS_REG_GENERIC_POR_0); - if (p_hwfn->mcp_info->block_mb_sending) { - DP_NOTICE(p_hwfn, - "Trying to send a MFW mailbox command [0x%x] in parallel to [UN]LOAD_REQ. Aborting.\n", - cmd); - spin_unlock_bh(&p_hwfn->mcp_info->lock); - return -EBUSY; - } + /* Use MCP history register to check if MCP reset occurred between init + * time and now. + */ + if (p_hwfn->mcp_info->mcp_hist != generic_por_0) { + DP_VERBOSE(p_hwfn, + QED_MSG_SP, + "Rereading MCP offsets [mcp_hist 0x%08x, generic_por_0 0x%08x]\n", + p_hwfn->mcp_info->mcp_hist, generic_por_0); - if (cmd == DRV_MSG_CODE_LOAD_REQ || cmd == DRV_MSG_CODE_UNLOAD_REQ) { - p_hwfn->mcp_info->block_mb_sending = true; - spin_unlock_bh(&p_hwfn->mcp_info->lock); + qed_load_mcp_offsets(p_hwfn, p_ptt); + qed_mcp_cmd_port_init(p_hwfn, p_ptt); } - - return 0; -} - -static void qed_mcp_mb_unlock(struct qed_hwfn *p_hwfn, u32 cmd) -{ - if (cmd != DRV_MSG_CODE_LOAD_REQ && cmd != DRV_MSG_CODE_UNLOAD_REQ) - spin_unlock_bh(&p_hwfn->mcp_info->lock); } int qed_mcp_reset(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) { - u32 seq = ++p_hwfn->mcp_info->drv_mb_seq; - u8 delay = CHIP_MCP_RESP_ITER_US; - u32 org_mcp_reset_seq, cnt = 0; + u32 org_mcp_reset_seq, seq, delay = CHIP_MCP_RESP_ITER_US, cnt = 0; int rc = 0; - /* Ensure that only a single thread is accessing the mailbox at a - * certain time. - */ - rc = qed_mcp_mb_lock(p_hwfn, DRV_MSG_CODE_MCP_RESET); - if (rc != 0) - return rc; + /* Ensure that only a single thread is accessing the mailbox */ + spin_lock_bh(&p_hwfn->mcp_info->cmd_lock); - /* Set drv command along with the updated sequence */ org_mcp_reset_seq = qed_rd(p_hwfn, p_ptt, MISCS_REG_GENERIC_POR_0); - DRV_MB_WR(p_hwfn, p_ptt, drv_mb_header, - (DRV_MSG_CODE_MCP_RESET | seq)); + + /* Set drv command along with the updated sequence */ + qed_mcp_reread_offsets(p_hwfn, p_ptt); + seq = ++p_hwfn->mcp_info->drv_mb_seq; + DRV_MB_WR(p_hwfn, p_ptt, drv_mb_header, (DRV_MSG_CODE_MCP_RESET | seq)); do { /* Wait for MFW response */ @@ -281,72 +313,205 @@ int qed_mcp_reset(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) rc = -EAGAIN; } - qed_mcp_mb_unlock(p_hwfn, DRV_MSG_CODE_MCP_RESET); + spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock); return rc; } -static int qed_do_mcp_cmd(struct qed_hwfn *p_hwfn, - struct qed_ptt *p_ptt, - u32 cmd, - u32 param, - u32 *o_mcp_resp, - u32 *o_mcp_param) +/* Must be called while cmd_lock is acquired */ +static bool qed_mcp_has_pending_cmd(struct qed_hwfn *p_hwfn) { - u8 delay = CHIP_MCP_RESP_ITER_US; - u32 seq, cnt = 1, actual_mb_seq; - int rc = 0; + struct qed_mcp_cmd_elem *p_cmd_elem; - /* Get actual driver mailbox sequence */ - actual_mb_seq = DRV_MB_RD(p_hwfn, p_ptt, drv_mb_header) & - DRV_MSG_SEQ_NUMBER_MASK; - - /* Use MCP history register to check if MCP reset occurred between - * init time and now. + /* There is at most one pending command at a certain time, and if it + * exists - it is placed at the HEAD of the list. */ - if (p_hwfn->mcp_info->mcp_hist != - qed_rd(p_hwfn, p_ptt, MISCS_REG_GENERIC_POR_0)) { - DP_VERBOSE(p_hwfn, QED_MSG_SP, "Rereading MCP offsets\n"); - qed_load_mcp_offsets(p_hwfn, p_ptt); - qed_mcp_cmd_port_init(p_hwfn, p_ptt); + if (!list_empty(&p_hwfn->mcp_info->cmd_list)) { + p_cmd_elem = list_first_entry(&p_hwfn->mcp_info->cmd_list, + struct qed_mcp_cmd_elem, list); + return !p_cmd_elem->b_is_completed; } - seq = ++p_hwfn->mcp_info->drv_mb_seq; - /* Set drv param */ - DRV_MB_WR(p_hwfn, p_ptt, drv_mb_param, param); + return false; +} + +/* Must be called while cmd_lock is acquired */ +static int +qed_mcp_update_pending_cmd(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) +{ + struct qed_mcp_mb_params *p_mb_params; + struct qed_mcp_cmd_elem *p_cmd_elem; + u32 mcp_resp; + u16 seq_num; - /* Set drv command along with the updated sequence */ - DRV_MB_WR(p_hwfn, p_ptt, drv_mb_header, (cmd | seq)); + mcp_resp = DRV_MB_RD(p_hwfn, p_ptt, fw_mb_header); + seq_num = (u16)(mcp_resp & FW_MSG_SEQ_NUMBER_MASK); + + /* Return if no new non-handled response has been received */ + if (seq_num != p_hwfn->mcp_info->drv_mb_seq) + return -EAGAIN; + + p_cmd_elem = qed_mcp_cmd_get_elem(p_hwfn, seq_num); + if (!p_cmd_elem) { + DP_ERR(p_hwfn, + "Failed to find a pending mailbox cmd that expects sequence number %d\n", + seq_num); + return -EINVAL; + } + + p_mb_params = p_cmd_elem->p_mb_params; + + /* Get the MFW response along with the sequence number */ + p_mb_params->mcp_resp = mcp_resp; + + /* Get the MFW param */ + p_mb_params->mcp_param = DRV_MB_RD(p_hwfn, p_ptt, fw_mb_param); + + /* Get the union data */ + if (p_mb_params->p_data_dst != NULL) { + u32 union_data_addr = p_hwfn->mcp_info->drv_mb_addr + + offsetof(struct public_drv_mb, + union_data); + qed_memcpy_from(p_hwfn, p_ptt, p_mb_params->p_data_dst, + union_data_addr, sizeof(union drv_union_data)); + } + + p_cmd_elem->b_is_completed = true; + + return 0; +} + +/* Must be called while cmd_lock is acquired */ +static void __qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, + struct qed_ptt *p_ptt, + struct qed_mcp_mb_params *p_mb_params, + u16 seq_num) +{ + union drv_union_data union_data; + u32 union_data_addr; + + /* Set the union data */ + union_data_addr = p_hwfn->mcp_info->drv_mb_addr + + offsetof(struct public_drv_mb, union_data); + memset(&union_data, 0, sizeof(union_data)); + if (p_mb_params->p_data_src != NULL) + memcpy(&union_data, p_mb_params->p_data_src, + sizeof(union_data)); + qed_memcpy_to(p_hwfn, p_ptt, union_data_addr, &union_data, + sizeof(union_data)); + + /* Set the drv param */ + DRV_MB_WR(p_hwfn, p_ptt, drv_mb_param, p_mb_params->param); + + /* Set the drv command along with the sequence number */ + DRV_MB_WR(p_hwfn, p_ptt, drv_mb_header, (p_mb_params->cmd | seq_num)); DP_VERBOSE(p_hwfn, QED_MSG_SP, - "wrote command (%x) to MFW MB param 0x%08x\n", - (cmd | seq), param); + "MFW mailbox: command 0x%08x param 0x%08x\n", + (p_mb_params->cmd | seq_num), p_mb_params->param); +} +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) +{ + struct qed_mcp_cmd_elem *p_cmd_elem; + u32 cnt = 0; + u16 seq_num; + int rc = 0; + + /* Wait until the mailbox is non-occupied */ do { - /* Wait for MFW response */ + /* Exit the loop if there is no pending command, or if the + * pending command is completed during this iteration. + * The spinlock stays locked until the command is sent. + */ + + spin_lock_bh(&p_hwfn->mcp_info->cmd_lock); + + if (!qed_mcp_has_pending_cmd(p_hwfn)) + break; + + rc = qed_mcp_update_pending_cmd(p_hwfn, p_ptt); + if (!rc) + break; + else if (rc != -EAGAIN) + goto err; + + spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock); udelay(delay); - *o_mcp_resp = DRV_MB_RD(p_hwfn, p_ptt, fw_mb_header); + } while (++cnt < max_retries); + + if (cnt >= max_retries) { + DP_NOTICE(p_hwfn, + "The MFW mailbox is occupied by an uncompleted command. Failed to send command 0x%08x [param 0x%08x].\n", + p_mb_params->cmd, p_mb_params->param); + return -EAGAIN; + } - /* Give the FW up to 5 second (500*10ms) */ - } while ((seq != (*o_mcp_resp & FW_MSG_SEQ_NUMBER_MASK)) && - (cnt++ < QED_DRV_MB_MAX_RETRIES)); + /* Send the mailbox command */ + qed_mcp_reread_offsets(p_hwfn, p_ptt); + seq_num = ++p_hwfn->mcp_info->drv_mb_seq; + p_cmd_elem = qed_mcp_cmd_add_elem(p_hwfn, p_mb_params, seq_num); + if (!p_cmd_elem) + goto err; - DP_VERBOSE(p_hwfn, QED_MSG_SP, - "[after %d ms] read (%x) seq is (%x) from FW MB\n", - cnt * delay, *o_mcp_resp, seq); - - /* Is this a reply to our command? */ - if (seq == (*o_mcp_resp & FW_MSG_SEQ_NUMBER_MASK)) { - *o_mcp_resp &= FW_MSG_CODE_MASK; - /* Get the MCP param */ - *o_mcp_param = DRV_MB_RD(p_hwfn, p_ptt, fw_mb_param); - } else { - /* FW BUG! */ - DP_ERR(p_hwfn, "MFW failed to respond [cmd 0x%x param 0x%x]\n", - cmd, param); - *o_mcp_resp = 0; - rc = -EAGAIN; + __qed_mcp_cmd_and_union(p_hwfn, p_ptt, p_mb_params, seq_num); + spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock); + + /* Wait for the MFW response */ + do { + /* Exit the loop if the command is already completed, or if the + * command is completed during this iteration. + * The spinlock stays locked until the list element is removed. + */ + + udelay(delay); + spin_lock_bh(&p_hwfn->mcp_info->cmd_lock); + + if (p_cmd_elem->b_is_completed) + break; + + rc = qed_mcp_update_pending_cmd(p_hwfn, p_ptt); + if (!rc) + break; + else if (rc != -EAGAIN) + goto err; + + spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock); + } while (++cnt < max_retries); + + if (cnt >= max_retries) { + DP_NOTICE(p_hwfn, + "The MFW failed to respond to command 0x%08x [param 0x%08x].\n", + p_mb_params->cmd, p_mb_params->param); + + spin_lock_bh(&p_hwfn->mcp_info->cmd_lock); + qed_mcp_cmd_del_elem(p_hwfn, p_cmd_elem); + spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock); + + return -EAGAIN; } + + qed_mcp_cmd_del_elem(p_hwfn, p_cmd_elem); + spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock); + + DP_VERBOSE(p_hwfn, + QED_MSG_SP, + "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); + + /* Clear the sequence number from the MFW response */ + p_mb_params->mcp_resp &= FW_MSG_CODE_MASK; + + return 0; + +err: + spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock); return rc; } @@ -354,9 +519,8 @@ 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 union_data_addr; - - int rc; + u32 max_retries = QED_DRV_MB_MAX_RETRIES; + u32 delay = CHIP_MCP_RESP_ITER_US; /* MCP not initialized */ if (!qed_mcp_is_init(p_hwfn)) { @@ -364,33 +528,8 @@ static int qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, return -EBUSY; } - union_data_addr = p_hwfn->mcp_info->drv_mb_addr + - offsetof(struct public_drv_mb, union_data); - - /* Ensure that only a single thread is accessing the mailbox at a - * certain time. - */ - rc = qed_mcp_mb_lock(p_hwfn, p_mb_params->cmd); - if (rc) - return rc; - - if (p_mb_params->p_data_src != NULL) - qed_memcpy_to(p_hwfn, p_ptt, union_data_addr, - p_mb_params->p_data_src, - sizeof(*p_mb_params->p_data_src)); - - rc = qed_do_mcp_cmd(p_hwfn, p_ptt, p_mb_params->cmd, - p_mb_params->param, &p_mb_params->mcp_resp, - &p_mb_params->mcp_param); - - if (p_mb_params->p_data_dst != NULL) - qed_memcpy_from(p_hwfn, p_ptt, p_mb_params->p_data_dst, - union_data_addr, - sizeof(*p_mb_params->p_data_dst)); - - qed_mcp_mb_unlock(p_hwfn, p_mb_params->cmd); - - return rc; + return _qed_mcp_cmd_and_union(p_hwfn, p_ptt, p_mb_params, max_retries, + delay); } int qed_mcp_cmd(struct qed_hwfn *p_hwfn, diff --git a/drivers/net/ethernet/qlogic/qed/qed_mcp.h b/drivers/net/ethernet/qlogic/qed/qed_mcp.h index bdbfd6d..0f7b268 100644 --- a/drivers/net/ethernet/qlogic/qed/qed_mcp.h +++ b/drivers/net/ethernet/qlogic/qed/qed_mcp.h @@ -484,8 +484,13 @@ int qed_mcp_bist_nvm_test_get_image_att(struct qed_hwfn *p_hwfn, qed_device_num_engines((_p_hwfn)->cdev))) struct qed_mcp_info { - /* Spinlock used for protecting the access to the MFW mailbox */ - spinlock_t lock; + /* List for mailbox commands which were sent and wait for a response */ + struct list_head cmd_list; + + /* Spinlock used for protecting the access to the mailbox commands list + * and the sending of the commands. + */ + spinlock_t cmd_lock; /* Spinlock used for syncing SW link-changes and link-changes * originating from attention context. @@ -505,7 +510,7 @@ struct qed_mcp_info { u8 *mfw_mb_cur; u8 *mfw_mb_shadow; u16 mfw_mb_length; - u16 mcp_hist; + u32 mcp_hist; }; struct qed_mcp_mb_params {