From patchwork Wed Feb 19 18:43:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Nazzareno Trimarchi X-Patchwork-Id: 236594 List-Id: U-Boot discussion From: michael at amarulasolutions.com (Michael Trimarchi) Date: Wed, 19 Feb 2020 19:43:41 +0100 Subject: [RFC PATCH 1/2] common: fdt: Add a function for reserving memory without kernel linear mapping In-Reply-To: <20200219184342.15974-1-michael@amarulasolutions.com> References: <20200219184342.15974-1-michael@amarulasolutions.com> Message-ID: <20200219184342.15974-2-michael@amarulasolutions.com> We need to reserve memory and not put in kernel linear mapping. This avoid problem during memory remapping from the simple frame buffer in linux kernel Signed-off-by: Michael Trimarchi Reviewed-by: Simon Glass --- common/fdt_support.c | 40 ++++++++++++++++++++++++++++++++++++++++ include/fdt_support.h | 11 +++++++++++ 2 files changed, 51 insertions(+) diff --git a/common/fdt_support.c b/common/fdt_support.c index 02cf5c6241..a3662f4358 100644 --- a/common/fdt_support.c +++ b/common/fdt_support.c @@ -410,6 +410,46 @@ static int fdt_pack_reg(const void *fdt, void *buf, u64 *address, u64 *size, return p - (char *)buf; } +int fdt_fixup_reserved_memory(void *blob, const char *area, u64 start[], u64 size[]) +{ + int offs, len; + const char *subpath; + const char *path = "/reserved-memory"; + fdt32_t address_cells = cpu_to_fdt32(fdt_address_cells(blob, 0)); + fdt32_t size_cells = cpu_to_fdt32(fdt_size_cells(blob, 0)); + u8 temp[16]; /* Up to 64-bit address + 64-bit size */ + + offs = fdt_path_offset(blob, path); + if (offs < 0) { + debug("Node %s not found\n", path); + path = "/"; + subpath = "reserved-memory"; + offs = fdt_path_offset(blob, path); + offs = fdt_add_subnode(blob, offs, subpath); + if (offs < 0) { + printf("Could not create %s%s node.\n", path, subpath); + return -1; + } + path = "/reserved-memory"; + offs = fdt_path_offset(blob, path); + + fdt_setprop(blob, offs, "#address-cells", &address_cells, sizeof(address_cells)); + fdt_setprop(blob, offs, "#size-cells", &size_cells, sizeof(size_cells)); + fdt_setprop(blob, offs, "ranges", NULL, 0); + } + + offs = fdt_add_subnode(blob, offs, area ? : "private"); + if (offs < 0) { + printf("Could not create %s%s node.\n", path, subpath); + return -1; + } + + fdt_setprop(blob, offs, "no-map", NULL, 0); + len = fdt_pack_reg(blob, temp, start, size, 1); + fdt_setprop(blob, offs, "reg", temp, len); + return 0; +} + #if CONFIG_NR_DRAM_BANKS > 4 #define MEMORY_BANKS_MAX CONFIG_NR_DRAM_BANKS #else diff --git a/include/fdt_support.h b/include/fdt_support.h index ba14acd7f6..7c8a280f53 100644 --- a/include/fdt_support.h +++ b/include/fdt_support.h @@ -93,6 +93,17 @@ void do_fixup_by_compat_u32(void *fdt, const char *compat, */ int fdt_fixup_memory(void *blob, u64 start, u64 size); +/** + * Setup the memory reserved node in the DT. Creates one if none was existing before. + * + * @param blob FDT blob to update + * @param area Reserved area name + * @param start Begin of DRAM mapping in physical memory + * @param size Size of the single memory bank + * @return 0 if ok, or -1 or -FDT_ERR_... on error + */ +int fdt_fixup_reserved_memory(void *blob, const char *area, u64 start[], u64 size[]); + /** * Fill the DT memory node with multiple memory banks. * Creates the node if none was existing before.