diff options
| -rw-r--r-- | arch/x86/kernel/e820_32.c | 27 | ||||
| -rw-r--r-- | arch/x86/kernel/setup_32.c | 64 |
2 files changed, 58 insertions, 33 deletions
diff --git a/arch/x86/kernel/e820_32.c b/arch/x86/kernel/e820_32.c index 80444c5c9b1..0240cd77836 100644 --- a/arch/x86/kernel/e820_32.c +++ b/arch/x86/kernel/e820_32.c @@ -450,38 +450,25 @@ int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map) * thinkpad 560x, for example, does not cooperate with the memory * detection code.) */ -int __init copy_e820_map(struct e820entry * biosmap, int nr_map) +int __init copy_e820_map(struct e820entry *biosmap, int nr_map) { /* Only one memory region (or negative)? Ignore it */ if (nr_map < 2) return -1; do { - unsigned long long start = biosmap->addr; - unsigned long long size = biosmap->size; - unsigned long long end = start + size; - unsigned long type = biosmap->type; + u64 start = biosmap->addr; + u64 size = biosmap->size; + u64 end = start + size; + u32 type = biosmap->type; /* Overflow in 64 bits? Ignore the memory map. */ if (start > end) return -1; - /* - * Some BIOSes claim RAM in the 640k - 1M region. - * Not right. Fix it up. - */ - if (type == E820_RAM) { - if (start < 0x100000ULL && end > 0xA0000ULL) { - if (start < 0xA0000ULL) - add_memory_region(start, 0xA0000ULL-start, type); - if (end <= 0x100000ULL) - continue; - start = 0x100000ULL; - size = end - start; - } - } add_memory_region(start, size, type); - } while (biosmap++,--nr_map); + } while (biosmap++, --nr_map); + return 0; } diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c index 2b3e5d45176..14e293edd23 100644 --- a/arch/x86/kernel/setup_32.c +++ b/arch/x86/kernel/setup_32.c @@ -385,15 +385,60 @@ unsigned long __init find_max_low_pfn(void) return max_low_pfn; } +#define BIOS_EBDA_SEGMENT 0x40E +#define BIOS_LOWMEM_KILOBYTES 0x413 + /* - * workaround for Dell systems that neglect to reserve EBDA + * The BIOS places the EBDA/XBDA at the top of conventional + * memory, and usually decreases the reported amount of + * conventional memory (int 0x12) too. This also contains a + * workaround for Dell systems that neglect to reserve EBDA. + * The same workaround also avoids a problem with the AMD768MPX + * chipset: reserve a page before VGA to prevent PCI prefetch + * into it (errata #56). Usually the page is reserved anyways, + * unless you have no PS/2 mouse plugged in. */ static void __init reserve_ebda_region(void) { - unsigned int addr; - addr = get_bios_ebda(); - if (addr) - reserve_bootmem(addr, PAGE_SIZE, BOOTMEM_DEFAULT); + unsigned int lowmem, ebda_addr; + + /* To determine the position of the EBDA and the */ + /* end of conventional memory, we need to look at */ + /* the BIOS data area. In a paravirtual environment */ + /* that area is absent. We'll just have to assume */ + /* that the paravirt case can handle memory setup */ + /* correctly, without our help. */ +#ifdef CONFIG_PARAVIRT + if ((boot_params.hdr.version >= 0x207) && + (boot_params.hdr.hardware_subarch != 0)) { + return; + } +#endif + + /* end of low (conventional) memory */ + lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES); + lowmem <<= 10; + + /* start of EBDA area */ + ebda_addr = *(unsigned short *)__va(BIOS_EBDA_SEGMENT); + ebda_addr <<= 4; + + /* Fixup: bios puts an EBDA in the top 64K segment */ + /* of conventional memory, but does not adjust lowmem. */ + if ((lowmem - ebda_addr) <= 0x10000) + lowmem = ebda_addr; + + /* Fixup: bios does not report an EBDA at all. */ + /* Some old Dells seem to need 4k anyhow (bugzilla 2990) */ + if ((ebda_addr == 0) && (lowmem >= 0x9f000)) + lowmem = 0x9f000; + + /* Paranoia: should never happen, but... */ + if ((lowmem == 0) || (lowmem >= 0x100000)) + lowmem = 0x9f000; + + /* reserve all memory between lowmem and the 1MB mark */ + reserve_bootmem(lowmem, 0x100000 - lowmem, BOOTMEM_DEFAULT); } #ifndef CONFIG_NEED_MULTIPLE_NODES @@ -617,16 +662,9 @@ void __init setup_bootmem_allocator(void) */ reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT); - /* reserve EBDA region, it's a 4K region */ + /* reserve EBDA region */ reserve_ebda_region(); - /* could be an AMD 768MPX chipset. Reserve a page before VGA to prevent - PCI prefetch into it (errata #56). Usually the page is reserved anyways, - unless you have no PS/2 mouse plugged in. */ - if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && - boot_cpu_data.x86 == 6) - reserve_bootmem(0xa0000 - 4096, 4096, BOOTMEM_DEFAULT); - #ifdef CONFIG_SMP /* * But first pinch a few for the stack/trampoline stuff |