From: Thierry Reding treding@nvidia.com
If early firmware initialized the display hardware and the display controllers are scanning out a framebuffer (e.g. a splash screen), make sure to pass information about the memory location of that framebuffer to the kernel before booting to avoid the kernel from using that memory for the buddy allocator.
This same mechanism can also be used in the kernel to set up early SMMU mappings and avoid SMMU faults caused by the display controller reading from memory for which it has no mapping.
Signed-off-by: Thierry Reding treding@nvidia.com --- board/nvidia/p2371-2180/p2371-2180.c | 47 ++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+)
diff --git a/board/nvidia/p2371-2180/p2371-2180.c b/board/nvidia/p2371-2180/p2371-2180.c index a444d692d7ea..4985302d6bc2 100644 --- a/board/nvidia/p2371-2180/p2371-2180.c +++ b/board/nvidia/p2371-2180/p2371-2180.c @@ -6,6 +6,7 @@
#include <common.h> #include <environment.h> +#include <fdtdec.h> #include <i2c.h> #include <linux/libfdt.h> #include <asm/arch/gpio.h> @@ -138,9 +139,55 @@ static void ft_mac_address_setup(void *fdt) } }
+static int ft_copy_carveout(void *dst, const void *src, const char *node) +{ + struct fdt_memory fb; + int err; + + err = fdtdec_get_carveout(src, node, "memory-region", 0, &fb); + if (err < 0) { + if (err != -FDT_ERR_NOTFOUND) + printf("failed to get carveout for %s: %d\n", node, + err); + + return err; + } + + err = fdtdec_set_carveout(dst, node, "memory-region", 0, "framebuffer", + &fb); + if (err < 0) { + printf("failed to set carveout for %s: %d\n", node, err); + return err; + } + + return 0; +} + +static void ft_carveout_setup(void *fdt) +{ + const void *cboot_fdt = (const void *)cboot_boot_x0; + static const char * const nodes[] = { + "/host1x@50000000/dc@54200000", + "/host1x@50000000/dc@54240000", + }; + unsigned int i; + int err; + + for (i = 0; i < ARRAY_SIZE(nodes); i++) { + err = ft_copy_carveout(fdt, cboot_fdt, nodes[i]); + if (err < 0) { + if (err != -FDT_ERR_NOTFOUND) + printf("failed to copy carveout for %s: %d\n", + nodes[i], err); + continue; + } + } +} + int ft_board_setup(void *fdt, bd_t *bd) { ft_mac_address_setup(fdt); + ft_carveout_setup(fdt);
return 0; }