diff options
| -rw-r--r-- | drivers/spi/spi-axi-spi-engine.c | 40 | ||||
| -rw-r--r-- | drivers/spi/spi-stm32.c | 28 | ||||
| -rw-r--r-- | drivers/spi/spi.c | 259 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 20 |
4 files changed, 267 insertions, 80 deletions
diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c index ca66d202f0e2..6177c1a8d56e 100644 --- a/drivers/spi/spi-axi-spi-engine.c +++ b/drivers/spi/spi-axi-spi-engine.c @@ -109,6 +109,7 @@ struct spi_engine { spinlock_t lock; void __iomem *base; + struct spi_engine_message_state msg_state; struct completion msg_complete; unsigned int int_enable; }; @@ -499,17 +500,11 @@ static irqreturn_t spi_engine_irq(int irq, void *devid) return IRQ_HANDLED; } -static int spi_engine_prepare_message(struct spi_controller *host, - struct spi_message *msg) +static int spi_engine_optimize_message(struct spi_message *msg) { struct spi_engine_program p_dry, *p; - struct spi_engine_message_state *st; size_t size; - st = kzalloc(sizeof(*st), GFP_KERNEL); - if (!st) - return -ENOMEM; - spi_engine_precompile_message(msg); p_dry.length = 0; @@ -517,31 +512,22 @@ static int spi_engine_prepare_message(struct spi_controller *host, size = sizeof(*p->instructions) * (p_dry.length + 1); p = kzalloc(sizeof(*p) + size, GFP_KERNEL); - if (!p) { - kfree(st); + if (!p) return -ENOMEM; - } spi_engine_compile_message(msg, false, p); spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC( AXI_SPI_ENGINE_CUR_MSG_SYNC_ID)); - st->p = p; - st->cmd_buf = p->instructions; - st->cmd_length = p->length; - msg->state = st; + msg->opt_state = p; return 0; } -static int spi_engine_unprepare_message(struct spi_controller *host, - struct spi_message *msg) +static int spi_engine_unoptimize_message(struct spi_message *msg) { - struct spi_engine_message_state *st = msg->state; - - kfree(st->p); - kfree(st); + kfree(msg->opt_state); return 0; } @@ -550,10 +536,18 @@ static int spi_engine_transfer_one_message(struct spi_controller *host, struct spi_message *msg) { struct spi_engine *spi_engine = spi_controller_get_devdata(host); - struct spi_engine_message_state *st = msg->state; + struct spi_engine_message_state *st = &spi_engine->msg_state; + struct spi_engine_program *p = msg->opt_state; unsigned int int_enable = 0; unsigned long flags; + /* reinitialize message state for this transfer */ + memset(st, 0, sizeof(*st)); + st->p = p; + st->cmd_buf = p->instructions; + st->cmd_length = p->length; + msg->state = st; + reinit_completion(&spi_engine->msg_complete); spin_lock_irqsave(&spi_engine->lock, flags); @@ -658,8 +652,8 @@ static int spi_engine_probe(struct platform_device *pdev) host->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); host->max_speed_hz = clk_get_rate(spi_engine->ref_clk) / 2; host->transfer_one_message = spi_engine_transfer_one_message; - host->prepare_message = spi_engine_prepare_message; - host->unprepare_message = spi_engine_unprepare_message; + host->optimize_message = spi_engine_optimize_message; + host->unoptimize_message = spi_engine_unoptimize_message; host->num_chipselect = 8; if (host->max_speed_hz == 0) diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index c32e57bb38bd..e4e7ddb7524a 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -1118,6 +1118,21 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id) return IRQ_HANDLED; } +static int stm32_spi_optimize_message(struct spi_message *msg) +{ + struct spi_controller *ctrl = msg->spi->controller; + struct stm32_spi *spi = spi_controller_get_devdata(ctrl); + + /* On STM32H7, messages should not exceed a maximum size set + * later via the set_number_of_data function. In order to + * ensure that, split large messages into several messages + */ + if (spi->cfg->set_number_of_data) + return spi_split_transfers_maxwords(ctrl, msg, spi->t_size_max); + + return 0; +} + /** * stm32_spi_prepare_msg - set up the controller to transfer a single message * @ctrl: controller interface @@ -1163,18 +1178,6 @@ static int stm32_spi_prepare_msg(struct spi_controller *ctrl, !!(spi_dev->mode & SPI_LSB_FIRST), !!(spi_dev->mode & SPI_CS_HIGH)); - /* On STM32H7, messages should not exceed a maximum size setted - * afterward via the set_number_of_data function. In order to - * ensure that, split large messages into several messages - */ - if (spi->cfg->set_number_of_data) { - int ret; - - ret = spi_split_transfers_maxwords(ctrl, msg, spi->t_size_max); - if (ret) - return ret; - } - spin_lock_irqsave(&spi->lock, flags); /* CPOL, CPHA and LSB FIRST bits have common register */ @@ -2180,6 +2183,7 @@ static int stm32_spi_probe(struct platform_device *pdev) ctrl->max_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_min; ctrl->min_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_max; ctrl->use_gpio_descriptors = true; + ctrl->optimize_message = stm32_spi_optimize_message; ctrl->prepare_message = stm32_spi_prepare_msg; ctrl->transfer_one = stm32_spi_transfer_one; ctrl->unprepare_message = stm32_spi_unprepare_msg; diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index c2b10e2c75f0..ba4d3fde2054 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1747,38 +1747,6 @@ static int __spi_pump_transfer_message(struct spi_controller *ctlr, trace_spi_message_start(msg); - /* - * If an SPI controller does not support toggling the CS line on each - * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO - * for the CS line, we can emulate the CS-per-word hardware function by - * splitting transfers into one-word transfers and ensuring that - * cs_change is set for each transfer. - */ - if ((msg->spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || - spi_is_csgpiod(msg->spi))) { - ret = spi_split_transfers_maxwords(ctlr, msg, 1); - if (ret) { - msg->status = ret; - spi_finalize_current_message(ctlr); - return ret; - } - - list_for_each_entry(xfer, &msg->transfers, transfer_list) { - /* Don't change cs_change on the last entry in the list */ - if (list_is_last(&xfer->transfer_list, &msg->transfers)) - break; - xfer->cs_change = 1; - } - } else { - ret = spi_split_transfers_maxsize(ctlr, msg, - spi_max_transfer_size(msg->spi)); - if (ret) { - msg->status = ret; - spi_finalize_current_message(ctlr); - return ret; - } - } - if (ctlr->prepare_message) { ret = ctlr->prepare_message(ctlr, msg); if (ret) { @@ -2106,6 +2074,43 @@ struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr) } EXPORT_SYMBOL_GPL(spi_get_next_queued_message); +/* + * __spi_unoptimize_message - shared implementation of spi_unoptimize_message() + * and spi_maybe_unoptimize_message() + * @msg: the message to unoptimize + * + * Peripheral drivers should use spi_unoptimize_message() and callers inside + * core should use spi_maybe_unoptimize_message() rather than calling this + * function directly. + * + * It is not valid to call this on a message that is not currently optimized. + */ +static void __spi_unoptimize_message(struct spi_message *msg) +{ + struct spi_controller *ctlr = msg->spi->controller; + + if (ctlr->unoptimize_message) + ctlr->unoptimize_message(msg); + + spi_res_release(ctlr, msg); + + msg->optimized = false; + msg->opt_state = NULL; +} + +/* + * spi_maybe_unoptimize_message - unoptimize msg not managed by a peripheral + * @msg: the message to unoptimize + * + * This function is used to unoptimize a message if and only if it was + * optimized by the core (via spi_maybe_optimize_message()). + */ +static void spi_maybe_unoptimize_message(struct spi_message *msg) +{ + if (!msg->pre_optimized && msg->optimized) + __spi_unoptimize_message(msg); +} + /** * spi_finalize_current_message() - the current message is complete * @ctlr: the controller to return the message to @@ -2134,15 +2139,6 @@ void spi_finalize_current_message(struct spi_controller *ctlr) spi_unmap_msg(ctlr, mesg); - /* - * In the prepare_messages callback the SPI bus has the opportunity - * to split a transfer to smaller chunks. - * - * Release the split transfers here since spi_map_msg() is done on - * the split transfers. - */ - spi_res_release(ctlr, mesg); - if (mesg->prepared && ctlr->unprepare_message) { ret = ctlr->unprepare_message(ctlr, mesg); if (ret) { @@ -2153,6 +2149,8 @@ void spi_finalize_current_message(struct spi_controller *ctlr) mesg->prepared = false; + spi_maybe_unoptimize_message(mesg); + WRITE_ONCE(ctlr->cur_msg_incomplete, false); smp_mb(); /* See __spi_pump_transfer_message()... */ if (READ_ONCE(ctlr->cur_msg_need_completion)) @@ -3782,6 +3780,10 @@ static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, * @msg: the @spi_message to transform * @maxsize: the maximum when to apply this * + * This function allocates resources that are automatically freed during the + * spi message unoptimize phase so this function should only be called from + * optimize_message callbacks. + * * Return: status of transformation */ int spi_split_transfers_maxsize(struct spi_controller *ctlr, @@ -3820,6 +3822,10 @@ EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); * @msg: the @spi_message to transform * @maxwords: the number of words to limit each transfer to * + * This function allocates resources that are automatically freed during the + * spi message unoptimize phase so this function should only be called from + * optimize_message callbacks. + * * Return: status of transformation */ int spi_split_transfers_maxwords(struct spi_controller *ctlr, @@ -4194,6 +4200,167 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) return 0; } +/* + * spi_split_transfers - generic handling of transfer splitting + * @msg: the message to split + * + * Under certain conditions, a SPI controller may not support arbitrary + * transfer sizes or other features required by a peripheral. This function + * will split the transfers in the message into smaller transfers that are + * supported by the controller. + * + * Controllers with special requirements not covered here can also split + * transfers in the optimize_message() callback. + * + * Context: can sleep + * Return: zero on success, else a negative error code + */ +static int spi_split_transfers(struct spi_message *msg) +{ + struct spi_controller *ctlr = msg->spi->controller; + struct spi_transfer *xfer; + int ret; + + /* + * If an SPI controller does not support toggling the CS line on each + * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO + * for the CS line, we can emulate the CS-per-word hardware function by + * splitting transfers into one-word transfers and ensuring that + * cs_change is set for each transfer. + */ + if ((msg->spi->mode & SPI_CS_WORD) && + (!(ctlr->mode_bits & SPI_CS_WORD) || spi_is_csgpiod(msg->spi))) { + ret = spi_split_transfers_maxwords(ctlr, msg, 1); + if (ret) + return ret; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + /* Don't change cs_change on the last entry in the list */ + if (list_is_last(&xfer->transfer_list, &msg->transfers)) + break; + + xfer->cs_change = 1; + } + } else { + ret = spi_split_transfers_maxsize(ctlr, msg, + spi_max_transfer_size(msg->spi)); + if (ret) + return ret; + } + + return 0; +} + +/* + * __spi_optimize_message - shared implementation for spi_optimize_message() + * and spi_maybe_optimize_message() + * @spi: the device that will be used for the message + * @msg: the message to optimize + * + * Peripheral drivers will call spi_optimize_message() and the spi core will + * call spi_maybe_optimize_message() instead of calling this directly. + * + * It is not valid to call this on a message that has already been optimized. + * + * Return: zero on success, else a negative error code + */ +static int __spi_optimize_message(struct spi_device *spi, + struct spi_message *msg) +{ + struct spi_controller *ctlr = spi->controller; + int ret; + + ret = __spi_validate(spi, msg); + if (ret) + return ret; + + ret = spi_split_transfers(msg); + if (ret) + return ret; + + if (ctlr->optimize_message) { + ret = ctlr->optimize_message(msg); + if (ret) { + spi_res_release(ctlr, msg); + return ret; + } + } + + msg->optimized = true; + + return 0; +} + +/* + * spi_maybe_optimize_message - optimize message if it isn't already pre-optimized + * @spi: the device that will be used for the message + * @msg: the message to optimize + * Return: zero on success, else a negative error code + */ +static int spi_maybe_optimize_message(struct spi_device *spi, + struct spi_message *msg) +{ + if (msg->pre_optimized) + return 0; + + return __spi_optimize_message(spi, msg); +} + +/** + * spi_optimize_message - do any one-time validation and setup for a SPI message + * @spi: the device that will be used for the message + * @msg: the message to optimize + * + * Peripheral drivers that reuse the same message repeatedly may call this to + * perform as much message prep as possible once, rather than repeating it each + * time a message transfer is performed to improve throughput and reduce CPU + * usage. + * + * Once a message has been optimized, it cannot be modified with the exception + * of updating the contents of any xfer->tx_buf (the pointer can't be changed, + * only the data in the memory it points to). + * + * Calls to this function must be balanced with calls to spi_unoptimize_message() + * to avoid leaking resources. + * + * Context: can sleep + * Return: zero on success, else a negative error code + */ +int spi_optimize_message(struct spi_device *spi, struct spi_message *msg) +{ + int ret; + + ret = __spi_optimize_message(spi, msg); + if (ret) + return ret; + + /* + * This flag indicates that the peripheral driver called spi_optimize_message() + * and therefore we shouldn't unoptimize message automatically when finalizing + * the message but rather wait until spi_unoptimize_message() is called + * by the peripheral driver. + */ + msg->pre_optimized = true; + + return 0; +} +EXPORT_SYMBOL_GPL(spi_optimize_message); + +/** + * spi_unoptimize_message - releases any resources allocated by spi_optimize_message() + * @msg: the message to unoptimize + * + * Calls to this function must be balanced with calls to spi_optimize_message(). + * + * Context: can sleep + */ +void spi_unoptimize_message(struct spi_message *msg) +{ + __spi_unoptimize_message(msg); + msg->pre_optimized = false; +} +EXPORT_SYMBOL_GPL(spi_unoptimize_message); + static int __spi_async(struct spi_device *spi, struct spi_message *message) { struct spi_controller *ctlr = spi->controller; @@ -4258,8 +4425,8 @@ int spi_async(struct spi_device *spi, struct spi_message *message) int ret; unsigned long flags; - ret = __spi_validate(spi, message); - if (ret != 0) + ret = spi_maybe_optimize_message(spi, message); + if (ret) return ret; spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags); @@ -4271,6 +4438,8 @@ int spi_async(struct spi_device *spi, struct spi_message *message) spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); + spi_maybe_unoptimize_message(message); + return ret; } EXPORT_SYMBOL_GPL(spi_async); @@ -4331,8 +4500,8 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message) return -ESHUTDOWN; } - status = __spi_validate(spi, message); - if (status != 0) + status = spi_maybe_optimize_message(spi, message); + if (status) return status; SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync); diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 2b8e2746769a..ddfb66dd4caf 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -475,6 +475,8 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch * * @set_cs: set the logic level of the chip select line. May be called * from interrupt context. + * @optimize_message: optimize the message for reuse + * @unoptimize_message: release resources allocated by optimize_message * @prepare_message: set up the controller to transfer a single message, * for example doing DMA mapping. Called from threaded * context. @@ -715,6 +717,8 @@ struct spi_controller { struct completion xfer_completion; size_t max_dma_len; + int (*optimize_message)(struct spi_message *msg); + int (*unoptimize_message)(struct spi_message *msg); int (*prepare_transfer_hardware)(struct spi_controller *ctlr); int (*transfer_one_message)(struct spi_controller *ctlr, struct spi_message *mesg); @@ -1111,6 +1115,8 @@ struct spi_transfer { * @spi: SPI device to which the transaction is queued * @is_dma_mapped: if true, the caller provided both DMA and CPU virtual * addresses for each transfer buffer + * @pre_optimized: peripheral driver pre-optimized the message + * @optimized: the message is in the optimized state * @prepared: spi_prepare_message was called for the this message * @status: zero for success, else negative errno * @complete: called to report transaction completions @@ -1120,6 +1126,7 @@ struct spi_transfer { * successful segments * @queue: for use by whichever driver currently owns the message * @state: for use by whichever driver currently owns the message + * @opt_state: for use by whichever driver currently owns the message * @resources: for resource management when the SPI message is processed * * A @spi_message is used to execute an atomic sequence of data transfers, @@ -1143,6 +1150,11 @@ struct spi_message { unsigned is_dma_mapped:1; + /* spi_optimize_message() was called for this message */ + bool pre_optimized; + /* __spi_optimize_message() was called for this message */ + bool optimized; + /* spi_prepare_message() was called for this message */ bool prepared; @@ -1172,6 +1184,11 @@ struct spi_message { */ struct list_head queue; void *state; + /* + * Optional state for use by controller driver between calls to + * __spi_optimize_message() and __spi_unoptimize_message(). + */ + void *opt_state; /* List of spi_res resources when the SPI message is processed */ struct list_head resources; @@ -1255,6 +1272,9 @@ static inline void spi_message_free(struct spi_message *m) kfree(m); } +extern int spi_optimize_message(struct spi_device *spi, struct spi_message *msg); +extern void spi_unoptimize_message(struct spi_message *msg); + extern int spi_setup(struct spi_device *spi); extern int spi_async(struct spi_device *spi, struct spi_message *message); extern int spi_slave_abort(struct spi_device *spi); |