Re: [PATCH] Fix e820 end address with EFI

From: Yinghai Lu
Date: Sun Mar 01 2009 - 00:43:28 EST


On Sat, Feb 28, 2009 at 8:14 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> On Sat, Feb 28, 2009 at 8:26 AM, Brian Maly <bmaly@xxxxxxxxxx> wrote:
>>
>>   On some EFI systems (i.e. Apple) EFI runtime is mapped into higher mem
>> regions. These EFI mem regions are not always taken into consideration when
>> max_pfn is calculated in setup.c being that e820_end_of_ram_pfn() only
>> counts
>> mappings types marked as usable (E820_RAM). Currently we only count to the
>> last
>> usable e820 address range and nothing beyond. EFI can be mapped anywhere
>> within
>> e820 and is not always marked as usable e820, and so EFI runtime may be
>> missed
>> if mapped somewhere beyond last usable e820. This patch attempts to resolve
>> this problem by including all E820 mappings when EFI is enabled, so that
>> the entire e820 (and EFI runtime area) is included in computing max_pfn.
>> Tested
>> on a MacBook Pro 3.1 and resolves the issue (system now boots w/elilo+grub &
>> EFI).
>>
>
> it seems you should check and enable directly mapping when EFI runtime
> service is enabled.

it seems in efi_enter_virtual_mode already called efi_ioremap() for
the range above max_low_pfn_mapped...

so it seems you meet other problems.

YH

void __init efi_enter_virtual_mode(void)
{
efi_memory_desc_t *md;
efi_status_t status;
unsigned long size;
u64 end, systab, addr, npages;
void *p, *va;

efi.systab = NULL;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
if (!(md->attribute & EFI_MEMORY_RUNTIME))
continue;

size = md->num_pages << EFI_PAGE_SHIFT;
end = md->phys_addr + size;

if (PFN_UP(end) <= max_low_pfn_mapped)
va = __va(md->phys_addr);
else
va = efi_ioremap(md->phys_addr, size);

md->virt_addr = (u64) (unsigned long) va;

if (!va) {
printk(KERN_ERR PFX "ioremap of 0x%llX failed!\n",
(unsigned long long)md->phys_addr);
continue;
}

if (!(md->attribute & EFI_MEMORY_WB)) {
addr = md->virt_addr;
npages = md->num_pages;
memrange_efi_to_native(&addr, &npages);
set_memory_uc(addr, npages);
}

systab = (u64) (unsigned long) efi_phys.systab;
if (md->phys_addr <= systab && systab < end) {
systab += md->virt_addr - md->phys_addr;
efi.systab = (efi_system_table_t *) (unsigned
long) systab;
}
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/