MIPS: SEAD3: Parse memsize in DT shim
Parse the memsize argument provided by the bootloader in the DT shim
code, allowing the user to override it on the command line. This places
all of the DT manipulation code into sead3-dtshim.c.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14058/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mti-sead3/sead3-dtshim.c b/arch/mips/mti-sead3/sead3-dtshim.c
index 6e32ceb..d6b0708 100644
--- a/arch/mips/mti-sead3/sead3-dtshim.c
+++ b/arch/mips/mti-sead3/sead3-dtshim.c
@@ -22,6 +22,73 @@
static unsigned char fdt_buf[16 << 10] __initdata;
+static int append_memory(void *fdt)
+{
+ unsigned long phys_memsize, memsize;
+ __be32 mem_array[2];
+ int err, mem_off;
+ char *var;
+
+ /* find memory size from the bootloader environment */
+ var = fw_getenv("memsize");
+ if (var) {
+ err = kstrtoul(var, 0, &phys_memsize);
+ if (err) {
+ pr_err("Failed to read memsize env variable '%s'\n",
+ var);
+ return -EINVAL;
+ }
+ } else {
+ pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
+ phys_memsize = 32 << 20;
+ }
+
+ /* default to using all available RAM */
+ memsize = phys_memsize;
+
+ /* allow the user to override the usable memory */
+ var = strstr(arcs_cmdline, "memsize=");
+ if (var)
+ memsize = memparse(var + strlen("memsize="), NULL);
+
+ /* if the user says there's more RAM than we thought, believe them */
+ phys_memsize = max_t(unsigned long, phys_memsize, memsize);
+
+ /* find or add a memory node */
+ mem_off = fdt_path_offset(fdt, "/memory");
+ if (mem_off == -FDT_ERR_NOTFOUND)
+ mem_off = fdt_add_subnode(fdt, 0, "memory");
+ if (mem_off < 0) {
+ pr_err("Unable to find or add memory DT node: %d\n", mem_off);
+ return mem_off;
+ }
+
+ err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
+ if (err) {
+ pr_err("Unable to set memory node device_type: %d\n", err);
+ return err;
+ }
+
+ mem_array[0] = 0;
+ mem_array[1] = cpu_to_be32(phys_memsize);
+ err = fdt_setprop(fdt, mem_off, "reg", mem_array, sizeof(mem_array));
+ if (err) {
+ pr_err("Unable to set memory regs property: %d\n", err);
+ return err;
+ }
+
+ mem_array[0] = 0;
+ mem_array[1] = cpu_to_be32(memsize);
+ err = fdt_setprop(fdt, mem_off, "linux,usable-memory",
+ mem_array, sizeof(mem_array));
+ if (err) {
+ pr_err("Unable to set linux,usable-memory property: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
static int remove_gic(void *fdt)
{
const unsigned int cpu_ehci_int = 2;
@@ -205,6 +272,10 @@
if (err)
panic("Unable to open FDT: %d", err);
+ err = append_memory(fdt_buf);
+ if (err)
+ panic("Unable to patch FDT: %d", err);
+
err = remove_gic(fdt_buf);
if (err)
panic("Unable to patch FDT: %d", err);