From 6f3c9018c6b830311db3a819706fc14954a5b0c2 Mon Sep 17 00:00:00 2001 From: Raul E Rangel Date: Mon, 12 Jul 2021 14:19:43 -0600 Subject: 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 Change-Id: Ibb8e31c95d6722521425772f4210af45626c8e09 Reviewed-on: https://review.coreboot.org/c/coreboot/+/56231 Reviewed-by: Karthik Ramasubramanian Reviewed-by: Furquan Shaikh Tested-by: build bot (Jenkins) --- src/soc/amd/common/block/lpc/spi_dma.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'src/soc/amd/common') 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 #include #include +#include #include /* 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); -- cgit v1.2.3