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Diffstat (limited to 'arch/powerpc/kernel/prom_init.c')
-rw-r--r--arch/powerpc/kernel/prom_init.c103
1 files changed, 101 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index d942404779c..864334b337a 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -190,6 +190,8 @@ static int __initdata of_platform;
static char __initdata prom_cmd_line[COMMAND_LINE_SIZE];
+static unsigned long __initdata prom_memory_limit;
+
static unsigned long __initdata alloc_top;
static unsigned long __initdata alloc_top_high;
static unsigned long __initdata alloc_bottom;
@@ -484,6 +486,67 @@ static int __init prom_setprop(phandle node, const char *nodename,
return call_prom("interpret", 1, 1, (u32)(unsigned long) cmd);
}
+/* We can't use the standard versions because of RELOC headaches. */
+#define isxdigit(c) (('0' <= (c) && (c) <= '9') \
+ || ('a' <= (c) && (c) <= 'f') \
+ || ('A' <= (c) && (c) <= 'F'))
+
+#define isdigit(c) ('0' <= (c) && (c) <= '9')
+#define islower(c) ('a' <= (c) && (c) <= 'z')
+#define toupper(c) (islower(c) ? ((c) - 'a' + 'A') : (c))
+
+unsigned long prom_strtoul(const char *cp, const char **endp)
+{
+ unsigned long result = 0, base = 10, value;
+
+ if (*cp == '0') {
+ base = 8;
+ cp++;
+ if (toupper(*cp) == 'X') {
+ cp++;
+ base = 16;
+ }
+ }
+
+ while (isxdigit(*cp) &&
+ (value = isdigit(*cp) ? *cp - '0' : toupper(*cp) - 'A' + 10) < base) {
+ result = result * base + value;
+ cp++;
+ }
+
+ if (endp)
+ *endp = cp;
+
+ return result;
+}
+
+unsigned long prom_memparse(const char *ptr, const char **retptr)
+{
+ unsigned long ret = prom_strtoul(ptr, retptr);
+ int shift = 0;
+
+ /*
+ * We can't use a switch here because GCC *may* generate a
+ * jump table which won't work, because we're not running at
+ * the address we're linked at.
+ */
+ if ('G' == **retptr || 'g' == **retptr)
+ shift = 30;
+
+ if ('M' == **retptr || 'm' == **retptr)
+ shift = 20;
+
+ if ('K' == **retptr || 'k' == **retptr)
+ shift = 10;
+
+ if (shift) {
+ ret <<= shift;
+ (*retptr)++;
+ }
+
+ return ret;
+}
+
/*
* Early parsing of the command line passed to the kernel, used for
* "mem=x" and the options that affect the iommu
@@ -491,9 +554,8 @@ static int __init prom_setprop(phandle node, const char *nodename,
static void __init early_cmdline_parse(void)
{
struct prom_t *_prom = &RELOC(prom);
-#ifdef CONFIG_PPC64
const char *opt;
-#endif
+
char *p;
int l = 0;
@@ -521,6 +583,15 @@ static void __init early_cmdline_parse(void)
RELOC(prom_iommu_force_on) = 1;
}
#endif
+ opt = strstr(RELOC(prom_cmd_line), RELOC("mem="));
+ if (opt) {
+ opt += 4;
+ RELOC(prom_memory_limit) = prom_memparse(opt, (const char **)&opt);
+#ifdef CONFIG_PPC64
+ /* Align to 16 MB == size of ppc64 large page */
+ RELOC(prom_memory_limit) = ALIGN(RELOC(prom_memory_limit), 0x1000000);
+#endif
+ }
}
#ifdef CONFIG_PPC_PSERIES
@@ -1027,6 +1098,29 @@ static void __init prom_init_mem(void)
}
/*
+ * If prom_memory_limit is set we reduce the upper limits *except* for
+ * alloc_top_high. This must be the real top of RAM so we can put
+ * TCE's up there.
+ */
+
+ RELOC(alloc_top_high) = RELOC(ram_top);
+
+ if (RELOC(prom_memory_limit)) {
+ if (RELOC(prom_memory_limit) <= RELOC(alloc_bottom)) {
+ prom_printf("Ignoring mem=%x <= alloc_bottom.\n",
+ RELOC(prom_memory_limit));
+ RELOC(prom_memory_limit) = 0;
+ } else if (RELOC(prom_memory_limit) >= RELOC(ram_top)) {
+ prom_printf("Ignoring mem=%x >= ram_top.\n",
+ RELOC(prom_memory_limit));
+ RELOC(prom_memory_limit) = 0;
+ } else {
+ RELOC(ram_top) = RELOC(prom_memory_limit);
+ RELOC(rmo_top) = min(RELOC(rmo_top), RELOC(prom_memory_limit));
+ }
+ }
+
+ /*
* Setup our top alloc point, that is top of RMO or top of
* segment 0 when running non-LPAR.
* Some RS64 machines have buggy firmware where claims up at
@@ -1041,6 +1135,7 @@ static void __init prom_init_mem(void)
RELOC(alloc_top_high) = RELOC(ram_top);
prom_printf("memory layout at init:\n");
+ prom_printf(" memory_limit : %x (16 MB aligned)\n", RELOC(prom_memory_limit));
prom_printf(" alloc_bottom : %x\n", RELOC(alloc_bottom));
prom_printf(" alloc_top : %x\n", RELOC(alloc_top));
prom_printf(" alloc_top_hi : %x\n", RELOC(alloc_top_high));
@@ -2395,6 +2490,10 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
/*
* Fill in some infos for use by the kernel later on
*/
+ if (RELOC(prom_memory_limit))
+ prom_setprop(_prom->chosen, "/chosen", "linux,memory-limit",
+ &RELOC(prom_memory_limit),
+ sizeof(prom_memory_limit));
#ifdef CONFIG_PPC64
if (RELOC(prom_iommu_off))
prom_setprop(_prom->chosen, "/chosen", "linux,iommu-off",