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authorRaul E Rangel <rrangel@chromium.org>2021-07-12 14:19:43 -0600
committerRaul Rangel <rrangel@chromium.org>2021-07-18 15:15:15 +0000
commit6f3c9018c6b830311db3a819706fc14954a5b0c2 (patch)
tree54f17cc33574d329a6b1c6849e1a98510bf4ae14 /src/soc/amd
parentb29f9d471bade1cf6d5e0994af7ccf722ac65ef0 (diff)
soc/amd/common/block/lpc/spi_dma: Use mutex to protect DMA registers
Once we enable COOP_MULTITASKING, we need to guarantee that we don't have multiple threads trying to access the DMA hardware. BUG=b:179699789 TEST=Boot guybrush with APOB patches. Signed-off-by: Raul E Rangel <rrangel@chromium.org> Change-Id: Ibb8e31c95d6722521425772f4210af45626c8e09 Reviewed-on: https://review.coreboot.org/c/coreboot/+/56231 Reviewed-by: Karthik Ramasubramanian <kramasub@google.com> Reviewed-by: Furquan Shaikh <furquan@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src/soc/amd')
-rw-r--r--src/soc/amd/common/block/lpc/spi_dma.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/src/soc/amd/common/block/lpc/spi_dma.c b/src/soc/amd/common/block/lpc/spi_dma.c
index b00b8ac511..fdc4f32593 100644
--- a/src/soc/amd/common/block/lpc/spi_dma.c
+++ b/src/soc/amd/common/block/lpc/spi_dma.c
@@ -13,6 +13,7 @@
#include <soc/pci_devs.h>
#include <spi_flash.h>
#include <string.h>
+#include <thread.h>
#include <types.h>
/* The ROM is memory mapped just below 4GiB. Form a pointer for the base. */
@@ -164,6 +165,8 @@ static bool continue_spi_dma_transaction(const struct region_device *rd,
return false;
}
+static struct thread_mutex spi_dma_hw_mutex;
+
static ssize_t spi_dma_readat_dma(const struct region_device *rd, void *destination,
size_t source, size_t size)
{
@@ -177,12 +180,16 @@ static ssize_t spi_dma_readat_dma(const struct region_device *rd, void *destinat
printk(BIOS_SPEW, "%s: start: dest: %p, source: %#zx, size: %zu\n", __func__,
destination, source, size);
+ thread_mutex_lock(&spi_dma_hw_mutex);
+
start_spi_dma_transaction(&transaction);
do {
udelay(2);
} while (continue_spi_dma_transaction(rd, &transaction));
+ thread_mutex_unlock(&spi_dma_hw_mutex);
+
printk(BIOS_SPEW, "%s: end: dest: %p, source: %#zx, remaining: %zu\n",
__func__, destination, source, transaction.remaining);