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author | David Lechner <dlechner@baylibre.com> | 2024-02-07 17:51:24 +0300 |
---|---|---|
committer | Mark Brown <broonie@kernel.org> | 2024-02-07 18:17:42 +0300 |
commit | 531860e12da76a444e0ecfd37a9d786e7986957a (patch) | |
tree | e95ab3d6a0f9e4d7513fcc6b2a8ba9574407f98c /drivers | |
parent | c0c0293cf7a0f21ef461956d44e4add718574f3f (diff) | |
download | linux-531860e12da76a444e0ecfd37a9d786e7986957a.tar.xz |
spi: axi-spi-engine: remove use of ida for sync id
Profiling has shown that ida_alloc_range() accounts for about 10% of the
time spent in spi_sync() when using the AXI SPI Engine controller. This
call is used to create a unique id for each SPI message to match to an
IRQ when the message is complete.
Since the core SPI code serializes messages in a message queue, we can
only have one message in flight at a time, namely host->cur_msg. This
means that we can use a fixed value instead of a unique id for each
message since there can never be more than one message pending at a
time.
This patch removes the use of ida for the sync id and replaces it with a
constant value. This simplifies the driver and improves performance.
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20240207-axi-spi-engine-round-2-1-v2-1-40c0b4e85352@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/spi/spi-axi-spi-engine.c | 28 |
1 files changed, 6 insertions, 22 deletions
diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c index 6b0c72bf3395..606389566129 100644 --- a/drivers/spi/spi-axi-spi-engine.c +++ b/drivers/spi/spi-axi-spi-engine.c @@ -7,7 +7,6 @@ #include <linux/clk.h> #include <linux/fpga/adi-axi-common.h> -#include <linux/idr.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/of.h> @@ -57,6 +56,9 @@ #define SPI_ENGINE_TRANSFER_WRITE 0x1 #define SPI_ENGINE_TRANSFER_READ 0x2 +/* Arbitrary sync ID for use by host->cur_msg */ +#define AXI_SPI_ENGINE_CUR_MSG_SYNC_ID 0x1 + #define SPI_ENGINE_CMD(inst, arg1, arg2) \ (((inst) << 12) | ((arg1) << 8) | (arg2)) @@ -98,8 +100,6 @@ struct spi_engine_message_state { unsigned int rx_length; /** @rx_buf: Bytes not yet written to the RX FIFO. */ uint8_t *rx_buf; - /** @sync_id: ID to correlate SYNC interrupts with this message. */ - u8 sync_id; }; struct spi_engine { @@ -109,7 +109,6 @@ struct spi_engine { spinlock_t lock; void __iomem *base; - struct ida sync_ida; struct timer_list watchdog_timer; struct spi_controller *controller; @@ -483,9 +482,7 @@ static irqreturn_t spi_engine_irq(int irq, void *devid) } if (pending & SPI_ENGINE_INT_SYNC && msg) { - struct spi_engine_message_state *st = msg->state; - - if (completed_id == st->sync_id) { + if (completed_id == AXI_SPI_ENGINE_CUR_MSG_SYNC_ID) { if (timer_delete_sync(&spi_engine->watchdog_timer)) { msg->status = 0; msg->actual_length = msg->frame_length; @@ -510,10 +507,8 @@ static int spi_engine_prepare_message(struct spi_controller *host, struct spi_message *msg) { struct spi_engine_program p_dry, *p; - struct spi_engine *spi_engine = spi_controller_get_devdata(host); struct spi_engine_message_state *st; size_t size; - int ret; st = kzalloc(sizeof(*st), GFP_KERNEL); if (!st) @@ -531,18 +526,10 @@ static int spi_engine_prepare_message(struct spi_controller *host, return -ENOMEM; } - ret = ida_alloc_range(&spi_engine->sync_ida, 0, U8_MAX, GFP_KERNEL); - if (ret < 0) { - kfree(p); - kfree(st); - return ret; - } - - st->sync_id = ret; - spi_engine_compile_message(msg, false, p); - spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC(st->sync_id)); + 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; @@ -555,10 +542,8 @@ static int spi_engine_prepare_message(struct spi_controller *host, static int spi_engine_unprepare_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; - ida_free(&spi_engine->sync_ida, st->sync_id); kfree(st->p); kfree(st); @@ -640,7 +625,6 @@ static int spi_engine_probe(struct platform_device *pdev) spi_engine = spi_controller_get_devdata(host); spin_lock_init(&spi_engine->lock); - ida_init(&spi_engine->sync_ida); timer_setup(&spi_engine->watchdog_timer, spi_engine_timeout, TIMER_IRQSAFE); spi_engine->controller = host; |