drivers: spi: stm32: cache coherency management modifs
Expand cache coherency management code to all STM32 targets with DCACHE.
Signed-off-by: Abderrahmane Jarmouni <abderrahmane.jarmouni-ext@st.com>
diff --git a/drivers/spi/spi_ll_stm32.c b/drivers/spi/spi_ll_stm32.c
index 80ec408..39ee5c2 100644
--- a/drivers/spi/spi_ll_stm32.c
+++ b/drivers/spi/spi_ll_stm32.c
@@ -29,9 +29,9 @@
#include <zephyr/irq.h>
#include <zephyr/mem_mgmt/mem_attr.h>
-#ifdef CONFIG_SOC_SERIES_STM32H7X
+#ifdef CONFIG_DCACHE
#include <zephyr/dt-bindings/memory-attr/memory-attr-arm.h>
-#endif
+#endif /* CONFIG_DCACHE */
#ifdef CONFIG_NOCACHE_MEMORY
#include <zephyr/linker/linker-defs.h>
@@ -41,17 +41,13 @@
#include "spi_ll_stm32.h"
-/*
- * Check defined(CONFIG_DCACHE) because some platforms disable it in the tests
- * e.g. nucleo_f746zg
- */
-#if defined(CONFIG_CPU_HAS_DCACHE) && \
- defined(CONFIG_DCACHE) && \
+#if defined(CONFIG_DCACHE) && \
!defined(CONFIG_NOCACHE_MEMORY)
+/* currently, manual cache coherency management is only done on dummy_rx_tx_buffer */
#define SPI_STM32_MANUAL_CACHE_COHERENCY_REQUIRED 1
#else
#define SPI_STM32_MANUAL_CACHE_COHERENCY_REQUIRED 0
-#endif /* defined(CONFIG_CPU_HAS_DCACHE) && !defined(CONFIG_NOCACHE_MEMORY) */
+#endif /* defined(CONFIG_DCACHE) && !defined(CONFIG_NOCACHE_MEMORY) */
#define WAIT_1US 1U
@@ -111,25 +107,16 @@
return bits / 8;
}
-/* dummy value used for transferring NOP when tx buf is null
- * and use as dummy sink for when rx buf is null.
+/* dummy buffer is used for transferring NOP when tx buf is null
+ * and used as a dummy sink for when rx buf is null.
*/
-#ifdef CONFIG_NOCACHE_MEMORY
/*
- * If a nocache area is available, place it there to avoid potential DMA
- * cache-coherency problems.
- */
-static __aligned(32) uint32_t dummy_rx_tx_buffer
- __attribute__((__section__(".nocache")));
-
-#else /* CONFIG_NOCACHE_MEMORY */
-
-/*
- * If nocache areas are not available, cache coherency might need to be kept
+ * If Nocache Memory is supported, buffer will be placed in nocache region by
+ * the linker to avoid potential DMA cache-coherency problems.
+ * If Nocache Memory is not supported, cache coherency might need to be kept
* manually. See SPI_STM32_MANUAL_CACHE_COHERENCY_REQUIRED.
*/
-static __aligned(32) uint32_t dummy_rx_tx_buffer;
-#endif /* CONFIG_NOCACHE_MEMORY */
+static __aligned(32) uint32_t dummy_rx_tx_buffer __nocache;
/* This function is executed in the interrupt context */
static void dma_callback(const struct device *dev, void *arg,
@@ -182,7 +169,7 @@
dummy_rx_tx_buffer = 0;
#if SPI_STM32_MANUAL_CACHE_COHERENCY_REQUIRED
arch_dcache_flush_range((void *)&dummy_rx_tx_buffer, sizeof(uint32_t));
-#endif /* CONFIG_CPU_HAS_DCACHE && !defined(CONFIG_NOCACHE_MEMORY) */
+#endif /* SPI_STM32_MANUAL_CACHE_COHERENCY_REQUIRED */
blk_cfg->source_address = (uint32_t)&dummy_rx_tx_buffer;
blk_cfg->source_addr_adj = DMA_ADDR_ADJ_NO_CHANGE;
} else {
@@ -937,12 +924,13 @@
return res;
}
-#ifdef CONFIG_SOC_SERIES_STM32H7X
+#ifdef CONFIG_DCACHE
static bool buf_in_nocache(uintptr_t buf, size_t len_bytes)
{
bool buf_within_nocache = false;
#ifdef CONFIG_NOCACHE_MEMORY
+ /* Check if buffer is in nocache region defined by the linker */
buf_within_nocache = (buf >= ((uintptr_t)_nocache_ram_start)) &&
((buf + len_bytes - 1) <= ((uintptr_t)_nocache_ram_end));
if (buf_within_nocache) {
@@ -950,6 +938,7 @@
}
#endif /* CONFIG_NOCACHE_MEMORY */
+ /* Check if buffer is in nocache memory region defined in DT */
buf_within_nocache = mem_attr_check_buf(
(void *)buf, len_bytes, DT_MEM_ARM(ATTR_MPU_RAM_NOCACHE)) == 0;
@@ -973,7 +962,7 @@
}
return true;
}
-#endif /* CONFIG_SOC_SERIES_STM32H7X */
+#endif /* CONFIG_DCACHE */
static int transceive_dma(const struct device *dev,
const struct spi_config *config,
@@ -996,12 +985,12 @@
return -ENOTSUP;
}
-#ifdef CONFIG_SOC_SERIES_STM32H7X
+#ifdef CONFIG_DCACHE
if ((tx_bufs != NULL && !spi_buf_set_in_nocache(tx_bufs)) ||
(rx_bufs != NULL && !spi_buf_set_in_nocache(rx_bufs))) {
return -EFAULT;
}
-#endif /* CONFIG_SOC_SERIES_STM32H7X */
+#endif /* CONFIG_DCACHE */
spi_context_lock(&data->ctx, asynchronous, cb, userdata, config);
