diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/prom_init.c | 103 |
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", |