diff options
| -rw-r--r-- | drivers/soc/qcom/rpmh-internal.h | 13 | ||||
| -rw-r--r-- | drivers/soc/qcom/rpmh-rsc.c | 55 |
2 files changed, 28 insertions, 40 deletions
diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h index dba8510c0669..1f2857b3f38e 100644 --- a/drivers/soc/qcom/rpmh-internal.h +++ b/drivers/soc/qcom/rpmh-internal.h @@ -28,7 +28,6 @@ struct rsc_drv; * @offset: Start of the TCS group relative to the TCSes in the RSC. * @num_tcs: Number of TCSes in this type. * @ncpt: Number of commands in each TCS. - * @lock: Lock for synchronizing this TCS writes. * @req: Requests that are sent from the TCS; only used for ACTIVE_ONLY * transfers (could be on a wake/sleep TCS if we are borrowing for * an ACTIVE_ONLY transfer). @@ -48,7 +47,6 @@ struct tcs_group { u32 offset; int num_tcs; int ncpt; - spinlock_t lock; const struct tcs_request *req[MAX_TCS_PER_TYPE]; DECLARE_BITMAP(slots, MAX_TCS_SLOTS); }; @@ -103,14 +101,9 @@ struct rpmh_ctrlr { * @tcs_in_use: S/W state of the TCS; only set for ACTIVE_ONLY * transfers, but might show a sleep/wake TCS in use if * it was borrowed for an active_only transfer. You - * must hold both the lock in this struct and the - * tcs_lock for the TCS in order to mark a TCS as - * in-use, but you only need the lock in this structure - * (aka the drv->lock) to mark one freed. - * @lock: Synchronize state of the controller. If you will be - * grabbing this lock and a tcs_lock at the same time, - * grab the tcs_lock first so we always have a - * consistent lock ordering. + * must hold the lock in this struct (AKA drv->lock) in + * order to update this. + * @lock: Synchronize state of the controller. * @pm_lock: Synchronize during PM notifications. * Used when solver mode is not present. * @client: Handle to the DRV's client. diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c index a5659a7306e4..fb142dfbb237 100644 --- a/drivers/soc/qcom/rpmh-rsc.c +++ b/drivers/soc/qcom/rpmh-rsc.c @@ -192,11 +192,7 @@ static void write_tcs_reg_sync(const struct rsc_drv *drv, int reg, int tcs_id, * * Returns true if nobody has claimed this TCS (by setting tcs_in_use). * - * Context: Must be called with the drv->lock held or the tcs_lock for the TCS - * being tested. If only the tcs_lock is held then it is possible that - * this function will return that a tcs is still busy when it has been - * recently been freed but it will never return free when a TCS is - * actually in use. + * Context: Must be called with the drv->lock held. * * Return: true if the given TCS is free. */ @@ -255,8 +251,6 @@ void rpmh_rsc_invalidate(struct rsc_drv *drv) * This is normally pretty straightforward except if we are trying to send * an ACTIVE_ONLY message but don't have any active_only TCSes. * - * Called without drv->lock held and with no tcs_lock locks held. - * * Return: A pointer to a tcs_group or an ERR_PTR. */ static struct tcs_group *get_tcs_for_msg(struct rsc_drv *drv, @@ -594,24 +588,19 @@ static int tcs_write(struct rsc_drv *drv, const struct tcs_request *msg) if (IS_ERR(tcs)) return PTR_ERR(tcs); - spin_lock_irqsave(&tcs->lock, flags); - spin_lock(&drv->lock); + spin_lock_irqsave(&drv->lock, flags); /* * The h/w does not like if we send a request to the same address, * when one is already in-flight or being processed. */ ret = check_for_req_inflight(drv, tcs, msg); - if (ret) { - spin_unlock(&drv->lock); - goto done_write; - } + if (ret) + goto unlock; - tcs_id = find_free_tcs(tcs); - if (tcs_id < 0) { - ret = tcs_id; - spin_unlock(&drv->lock); - goto done_write; - } + ret = find_free_tcs(tcs); + if (ret < 0) + goto unlock; + tcs_id = ret; tcs->req[tcs_id - tcs->offset] = msg; set_bit(tcs_id, drv->tcs_in_use); @@ -625,13 +614,22 @@ static int tcs_write(struct rsc_drv *drv, const struct tcs_request *msg) write_tcs_reg_sync(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id, 0); enable_tcs_irq(drv, tcs_id, true); } - spin_unlock(&drv->lock); + spin_unlock_irqrestore(&drv->lock, flags); + /* + * These two can be done after the lock is released because: + * - We marked "tcs_in_use" under lock. + * - Once "tcs_in_use" has been marked nobody else could be writing + * to these registers until the interrupt goes off. + * - The interrupt can't go off until we trigger w/ the last line + * of __tcs_set_trigger() below. + */ __tcs_buffer_write(drv, tcs_id, 0, msg); __tcs_set_trigger(drv, tcs_id, true); -done_write: - spin_unlock_irqrestore(&tcs->lock, flags); + return 0; +unlock: + spin_unlock_irqrestore(&drv->lock, flags); return ret; } @@ -686,8 +684,6 @@ int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request *msg) * Only for use on sleep/wake TCSes since those are the only ones we maintain * tcs->slots for. * - * Must be called with the tcs_lock for the group held. - * * Return: -ENOMEM if there was no room, else 0. */ static int find_slots(struct tcs_group *tcs, const struct tcs_request *msg, @@ -722,25 +718,25 @@ static int find_slots(struct tcs_group *tcs, const struct tcs_request *msg, * This should only be called for for sleep/wake state, never active-only * state. * + * The caller must ensure that no other RPMH actions are happening and the + * controller is idle when this function is called since it runs lockless. + * * Return: 0 if no error; else -error. */ int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv, const struct tcs_request *msg) { struct tcs_group *tcs; int tcs_id = 0, cmd_id = 0; - unsigned long flags; int ret; tcs = get_tcs_for_msg(drv, msg); if (IS_ERR(tcs)) return PTR_ERR(tcs); - spin_lock_irqsave(&tcs->lock, flags); /* find the TCS id and the command in the TCS to write to */ ret = find_slots(tcs, msg, &tcs_id, &cmd_id); if (!ret) __tcs_buffer_write(drv, tcs_id, cmd_id, msg); - spin_unlock_irqrestore(&tcs->lock, flags); return ret; } @@ -769,8 +765,8 @@ static bool rpmh_rsc_ctrlr_is_busy(struct rsc_drv *drv) * should be checked for not busy, because we used wake TCSes for * active requests in this case. * - * Since this is called from the last cpu, need not take drv or tcs - * lock before checking tcs_is_free(). + * Since this is called from the last cpu, need not take drv->lock + * before checking tcs_is_free(). */ if (!tcs->num_tcs) tcs = &drv->tcs[WAKE_TCS]; @@ -899,7 +895,6 @@ static int rpmh_probe_tcs_config(struct platform_device *pdev, tcs->type = tcs_cfg[i].type; tcs->num_tcs = tcs_cfg[i].n; tcs->ncpt = ncpt; - spin_lock_init(&tcs->lock); if (!tcs->num_tcs || tcs->type == CONTROL_TCS) continue; |