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spi: stm32-ospi: 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 :  5693 KiB/s  21139 KiB/s   371%
Write:   765 KiB/s    910 KiB/s    19%

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://patch.msgid.link/20251208-upstream_qspi_ospi_updates-v2-2-62526c9467dc@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Patrice Chotard 2025-12-08 08:29:09 +01:00 committed by Mark Brown
parent e35a7607e0
commit cfe58ffc95
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 38 additions and 9 deletions
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47
drivers/spi/spi-stm32-ospi.c
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@ -142,14 +142,32 @@ struct stm32_ospi {
struct mutex lock;
};
static void stm32_ospi_read_fifo(u8 *val, void __iomem *addr)
static void stm32_ospi_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_ospi_write_fifo(u8 *val, void __iomem *addr)
static void stm32_ospi_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_ospi_abort(struct stm32_ospi *ospi)
@ -172,19 +190,20 @@ static int stm32_ospi_abort(struct stm32_ospi *ospi)
return timeout;
}
static int stm32_ospi_poll(struct stm32_ospi *ospi, u8 *buf, u32 len, bool read)
static int stm32_ospi_poll(struct stm32_ospi *ospi, void *buf, u32 len, bool read)
{
void __iomem *regs_base = ospi->regs_base;
void (*fifo)(u8 *val, void __iomem *addr);
void (*fifo)(void *val, void __iomem *addr, u8 len);
u32 sr;
int ret;
u8 step;
if (read)
fifo = stm32_ospi_read_fifo;
else
fifo = stm32_ospi_write_fifo;
while (len--) {
while (len) {
ret = readl_relaxed_poll_timeout_atomic(regs_base + OSPI_SR,
sr, sr & SR_FTF, 1,
STM32_FIFO_TIMEOUT_US);
@ -193,7 +212,17 @@ static int stm32_ospi_poll(struct stm32_ospi *ospi, u8 *buf, u32 len, bool read)
len, sr);
return ret;
}
fifo(buf++, regs_base + OSPI_DR);
if (len >= sizeof(u32))
step = sizeof(u32);
else if (len >= sizeof(u16))
step = sizeof(u16);
else
step = sizeof(u8);
fifo(buf, regs_base + OSPI_DR, step);
len -= step;
buf += step;
}
return 0;
@ -408,7 +437,7 @@ static int stm32_ospi_xfer(struct stm32_ospi *ospi, const struct spi_mem_op *op)
if (op->data.dir == SPI_MEM_DATA_IN)
buf = op->data.buf.in;
else
buf = (u8 *)op->data.buf.out;
buf = (void *)op->data.buf.out;
return stm32_ospi_poll(ospi, buf, op->data.nbytes,
op->data.dir == SPI_MEM_DATA_IN);