diff options
Diffstat (limited to 'arch/arm/mach-shmobile/setup-rcar-gen2.c')
| -rw-r--r-- | arch/arm/mach-shmobile/setup-rcar-gen2.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c b/arch/arm/mach-shmobile/setup-rcar-gen2.c index fdc714ebc4cd..42d5b4308923 100644 --- a/arch/arm/mach-shmobile/setup-rcar-gen2.c +++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c @@ -20,8 +20,11 @@ #include <linux/clk/shmobile.h> #include <linux/clocksource.h> +#include <linux/device.h> +#include <linux/dma-contiguous.h> #include <linux/io.h> #include <linux/kernel.h> +#include <linux/of_fdt.h> #include <asm/mach/arch.h> #include "common.h" #include "rcar-gen2.h" @@ -110,3 +113,72 @@ void __init rcar_gen2_timer_init(void) #endif clocksource_of_init(); } + +struct memory_reserve_config { + u64 reserved; + u64 base, size; +}; + +static int __init rcar_gen2_scan_mem(unsigned long node, const char *uname, + int depth, void *data) +{ + const char *type = of_get_flat_dt_prop(node, "device_type", NULL); + const __be32 *reg, *endp; + int l; + struct memory_reserve_config *mrc = data; + u64 lpae_start = 1ULL << 32; + + /* We are scanning "memory" nodes only */ + if (type == NULL || strcmp(type, "memory")) + return 0; + + reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l); + if (reg == NULL) + reg = of_get_flat_dt_prop(node, "reg", &l); + if (reg == NULL) + return 0; + + endp = reg + (l / sizeof(__be32)); + while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { + u64 base, size; + + base = dt_mem_next_cell(dt_root_addr_cells, ®); + size = dt_mem_next_cell(dt_root_size_cells, ®); + + if (base >= lpae_start) + continue; + + if ((base + size) >= lpae_start) + size = lpae_start - base; + + if (size < mrc->reserved) + continue; + + if (base < mrc->base) + continue; + + /* keep the area at top near the 32-bit legacy limit */ + mrc->base = base + size - mrc->reserved; + mrc->size = mrc->reserved; + } + + return 0; +} + +struct cma *rcar_gen2_dma_contiguous; + +void __init rcar_gen2_reserve(void) +{ + struct memory_reserve_config mrc; + + /* reserve 256 MiB at the top of the physical legacy 32-bit space */ + memset(&mrc, 0, sizeof(mrc)); + mrc.reserved = SZ_256M; + + of_scan_flat_dt(rcar_gen2_scan_mem, &mrc); +#ifdef CONFIG_DMA_CMA + if (mrc.size) + dma_contiguous_reserve_area(mrc.size, mrc.base, 0, + &rcar_gen2_dma_contiguous, true); +#endif +} |