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spi: stm32-qspi: Optimize FIFO accesses using u16 or u32

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FIFO accesses uses u8 only for read/write.
In order to optimize throughput, add u16 or u32 read/write
accesses when possible.

Running mtd_speedtest on a 4MB sNOR partition using a
stm32mp257f-ev1 board gives the following results:

           before        after   gain
Read :  5773 KiB/s  22170 KiB/s   384%
Write:   796 KiB/s    890 KiB/s    12%

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://patch.msgid.link/20251208-upstream_qspi_ospi_updates-v2-6-62526c9467dc@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Patrice Chotard 2025-12-08 08:29:13 +01:00 committed by Mark Brown
parent 4ef80c71c6
commit 1ca9128164
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 40 additions and 11 deletions
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51
drivers/spi/spi-stm32-qspi.c
View File

@ -153,34 +153,53 @@ static irqreturn_t stm32_qspi_irq(int irq, void *dev_id)
return IRQ_HANDLED;
}
static void stm32_qspi_read_fifo(u8 *val, void __iomem *addr)
static void stm32_qspi_read_fifo(void *val, void __iomem *addr, u8 len)
{
*val = readb_relaxed(addr);
switch (len) {
case sizeof(u32):
*((u32 *)val) = readl_relaxed(addr);
break;
case sizeof(u16):
*((u16 *)val) = readw_relaxed(addr);
break;
case sizeof(u8):
*((u8 *)val) = readb_relaxed(addr);
};
}
static void stm32_qspi_write_fifo(u8 *val, void __iomem *addr)
static void stm32_qspi_write_fifo(void *val, void __iomem *addr, u8 len)
{
writeb_relaxed(*val, addr);
switch (len) {
case sizeof(u32):
writel_relaxed(*((u32 *)val), addr);
break;
case sizeof(u16):
writew_relaxed(*((u16 *)val), addr);
break;
case sizeof(u8):
writeb_relaxed(*((u8 *)val), addr);
};
}
static int stm32_qspi_tx_poll(struct stm32_qspi *qspi,
const struct spi_mem_op *op)
{
void (*tx_fifo)(u8 *val, void __iomem *addr);
void (*fifo)(void *val, void __iomem *addr, u8 len);
u32 len = op->data.nbytes, sr;
u8 *buf;
void *buf;
int ret;
u8 step;
if (op->data.dir == SPI_MEM_DATA_IN) {
tx_fifo = stm32_qspi_read_fifo;
fifo = stm32_qspi_read_fifo;
buf = op->data.buf.in;
} else {
tx_fifo = stm32_qspi_write_fifo;
buf = (u8 *)op->data.buf.out;
fifo = stm32_qspi_write_fifo;
buf = (void *)op->data.buf.out;
}
while (len--) {
while (len) {
ret = readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_SR,
sr, (sr & SR_FTF), 1,
STM32_FIFO_TIMEOUT_US);
@ -189,7 +208,17 @@ static int stm32_qspi_tx_poll(struct stm32_qspi *qspi,
len, sr);
return ret;
}
tx_fifo(buf++, qspi->io_base + QSPI_DR);
if (len >= sizeof(u32))
step = sizeof(u32);
else if (len >= sizeof(u16))
step = sizeof(u16);
else
step = sizeof(u8);
fifo(buf, qspi->io_base + QSPI_DR, step);
len -= step;
buf += step;
}
return 0;