Commit 4ed1eea8 authored by Tomer Tayar's avatar Tomer Tayar Committed by David S. Miller

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: default avatarTomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: default avatarYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4deece6c
......@@ -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 @@ int qed_mcp_cmd_init(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
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 */
......@@ -281,118 +313,225 @@ 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;
/* Get actual driver mailbox sequence */
actual_mb_seq = DRV_MB_RD(p_hwfn, p_ptt, drv_mb_header) &
DRV_MSG_SEQ_NUMBER_MASK;
struct qed_mcp_cmd_elem *p_cmd_elem;
/* 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;
}
/* Set drv command along with the updated sequence */
DRV_MB_WR(p_hwfn, p_ptt, drv_mb_header, (cmd | seq));
/* 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;
DP_VERBOSE(p_hwfn, QED_MSG_SP,
"wrote command (%x) to MFW MB param 0x%08x\n",
(cmd | seq), param);
mcp_resp = DRV_MB_RD(p_hwfn, p_ptt, fw_mb_header);
seq_num = (u16)(mcp_resp & FW_MSG_SEQ_NUMBER_MASK);
do {
/* Wait for MFW response */
udelay(delay);
*o_mcp_resp = DRV_MB_RD(p_hwfn, p_ptt, fw_mb_header);
/* Return if no new non-handled response has been received */
if (seq_num != p_hwfn->mcp_info->drv_mb_seq)
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));
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;
}
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;
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));
}
return rc;
p_cmd_elem->b_is_completed = true;
return 0;
}
static int qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
/* 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)
struct qed_mcp_mb_params *p_mb_params,
u16 seq_num)
{
union drv_union_data union_data;
u32 union_data_addr;
int rc;
/* 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));
/* MCP not initialized */
if (!qed_mcp_is_init(p_hwfn)) {
DP_NOTICE(p_hwfn, "MFW is not initialized!\n");
return -EBUSY;
/* 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,
"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 {
/* 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);
} 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;
}
union_data_addr = p_hwfn->mcp_info->drv_mb_addr +
offsetof(struct public_drv_mb, union_data);
/* 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;
/* Ensure that only a single thread is accessing the mailbox at a
* certain time.
__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.
*/
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));
udelay(delay);
spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);
if (p_cmd_elem->b_is_completed)
break;
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);
rc = qed_mcp_update_pending_cmd(p_hwfn, p_ptt);
if (!rc)
break;
else if (rc != -EAGAIN)
goto err;
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));
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);
qed_mcp_mb_unlock(p_hwfn, p_mb_params->cmd);
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;
}
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 = QED_DRV_MB_MAX_RETRIES;
u32 delay = CHIP_MCP_RESP_ITER_US;
/* MCP not initialized */
if (!qed_mcp_is_init(p_hwfn)) {
DP_NOTICE(p_hwfn, "MFW is not initialized!\n");
return -EBUSY;
}
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,
struct qed_ptt *p_ptt,
u32 cmd,
......
......@@ -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 {
......
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