These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / arch / mips / mti-malta / malta-dtshim.c

diff --git a/kernel/arch/mips/mti-malta/malta-dtshim.c b/kernel/arch/mips/mti-malta/malta-dtshim.c
new file mode 100644 (file)
index 0000000..f7133ef
--- /dev/null
+++ b/kernel/arch/mips/mti-malta/malta-dtshim.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/bug.h>
+#include <linux/kernel.h>
+#include <linux/libfdt.h>
+#include <linux/of_fdt.h>
+#include <linux/sizes.h>
+#include <asm/bootinfo.h>
+#include <asm/fw/fw.h>
+#include <asm/page.h>
+
+static unsigned char fdt_buf[16 << 10] __initdata;
+
+/* determined physical memory size, not overridden by command line args         */
+extern unsigned long physical_memsize;
+
+#define MAX_MEM_ARRAY_ENTRIES 1
+
+static unsigned __init gen_fdt_mem_array(__be32 *mem_array, unsigned long size)
+{
+       unsigned long size_preio;
+       unsigned entries;
+
+       entries = 1;
+       mem_array[0] = cpu_to_be32(PHYS_OFFSET);
+       if (config_enabled(CONFIG_EVA)) {
+               /*
+                * The current Malta EVA configuration is "special" in that it
+                * always makes use of addresses in the upper half of the 32 bit
+                * physical address map, which gives it a contiguous region of
+                * DDR but limits it to 2GB.
+                */
+               mem_array[1] = cpu_to_be32(size);
+       } else {
+               size_preio = min_t(unsigned long, size, SZ_256M);
+               mem_array[1] = cpu_to_be32(size_preio);
+       }
+
+       BUG_ON(entries > MAX_MEM_ARRAY_ENTRIES);
+       return entries;
+}
+
+static void __init append_memory(void *fdt, int root_off)
+{
+       __be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
+       unsigned long memsize;
+       unsigned mem_entries;
+       int i, err, mem_off;
+       char *var, param_name[10], *var_names[] = {
+               "ememsize", "memsize",
+       };
+
+       /* if a memory node already exists, leave it alone */
+       mem_off = fdt_path_offset(fdt, "/memory");
+       if (mem_off >= 0)
+               return;
+
+       /* find memory size from the bootloader environment */
+       for (i = 0; i < ARRAY_SIZE(var_names); i++) {
+               var = fw_getenv(var_names[i]);
+               if (!var)
+                       continue;
+
+               err = kstrtoul(var, 0, &physical_memsize);
+               if (!err)
+                       break;
+
+               pr_warn("Failed to read the '%s' env variable '%s'\n",
+                       var_names[i], var);
+       }
+
+       if (!physical_memsize) {
+               pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
+               physical_memsize = 32 << 20;
+       }
+
+       if (config_enabled(CONFIG_CPU_BIG_ENDIAN)) {
+               /*
+                * SOC-it swaps, or perhaps doesn't swap, when DMA'ing
+                * the last word of physical memory.
+                */
+               physical_memsize -= PAGE_SIZE;
+       }
+
+       /* default to using all available RAM */
+       memsize = physical_memsize;
+
+       /* allow the user to override the usable memory */
+       for (i = 0; i < ARRAY_SIZE(var_names); i++) {
+               snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
+               var = strstr(arcs_cmdline, param_name);
+               if (!var)
+                       continue;
+
+               memsize = memparse(var + strlen(param_name), NULL);
+       }
+
+       /* if the user says there's more RAM than we thought, believe them */
+       physical_memsize = max_t(unsigned long, physical_memsize, memsize);
+
+       /* append memory to the DT */
+       mem_off = fdt_add_subnode(fdt, root_off, "memory");
+       if (mem_off < 0)
+               panic("Unable to add memory node to DT: %d", mem_off);
+
+       err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
+       if (err)
+               panic("Unable to set memory node device_type: %d", err);
+
+       mem_entries = gen_fdt_mem_array(mem_array, physical_memsize);
+       err = fdt_setprop(fdt, mem_off, "reg", mem_array,
+                         mem_entries * 2 * sizeof(mem_array[0]));
+       if (err)
+               panic("Unable to set memory regs property: %d", err);
+
+       mem_entries = gen_fdt_mem_array(mem_array, memsize);
+       err = fdt_setprop(fdt, mem_off, "linux,usable-memory", mem_array,
+                         mem_entries * 2 * sizeof(mem_array[0]));
+       if (err)
+               panic("Unable to set linux,usable-memory property: %d", err);
+}
+
+void __init *malta_dt_shim(void *fdt)
+{
+       int root_off, len, err;
+       const char *compat;
+
+       if (fdt_check_header(fdt))
+               panic("Corrupt DT");
+
+       err = fdt_open_into(fdt, fdt_buf, sizeof(fdt_buf));
+       if (err)
+               panic("Unable to open FDT: %d", err);
+
+       root_off = fdt_path_offset(fdt_buf, "/");
+       if (root_off < 0)
+               panic("No / node in DT");
+
+       compat = fdt_getprop(fdt_buf, root_off, "compatible", &len);
+       if (!compat)
+               panic("No root compatible property in DT: %d", len);
+
+       /* if this isn't Malta, leave the DT alone */
+       if (strncmp(compat, "mti,malta", len))
+               return fdt;
+
+       append_memory(fdt_buf, root_off);
+
+       err = fdt_pack(fdt_buf);
+       if (err)
+               panic("Unable to pack FDT: %d\n", err);
+
+       return fdt_buf;
+}