static void __init __map_region(efi_memory_desc_t *md, u64 va)
{
pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
unsigned long pf = 0;
if (!(md->attribute & EFI_MEMORY_WB))
pf |= _PAGE_PCD;
if (kernel_map_pages_in_pgd(pgd, md->phys_addr, va, md->num_pages, pf))
pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
md->phys_addr, va);
}
static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
{
unsigned long pfn;
pgd_t *pgd = efi_pgd;
int err1, err2;
/* Update the 1:1 mapping */
pfn = md->phys_addr >> PAGE_SHIFT;
err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
if (err1) {
pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
md->phys_addr, md->virt_addr);
}
err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
if (err2) {
pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
md->phys_addr, md->virt_addr);
}
return err1 || err2;
}
static void __init __map_region(efi_memory_desc_t *md, u64 va)
{
unsigned long flags = _PAGE_RW;
unsigned long pfn;
pgd_t *pgd = efi_pgd;
if (!(md->attribute & EFI_MEMORY_WB))
flags |= _PAGE_PCD;
pfn = md->phys_addr >> PAGE_SHIFT;
if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
md->phys_addr, va);
}
int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
{
unsigned long pfn, text;
struct page *page;
unsigned npages;
pgd_t *pgd;
if (efi_enabled(EFI_OLD_MEMMAP))
return 0;
efi_scratch.efi_pgt = (pgd_t *)__pa(efi_pgd);
pgd = efi_pgd;
/*
* It can happen that the physical address of new_memmap lands in memory
* which is not mapped in the EFI page table. Therefore we need to go
* and ident-map those pages containing the map before calling
* phys_efi_set_virtual_address_map().
*/
pfn = pa_memmap >> PAGE_SHIFT;
if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, _PAGE_NX | _PAGE_RW)) {
pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
return 1;
}
efi_scratch.use_pgd = true;
/*
* Certain firmware versions are way too sentimential and still believe
* they are exclusive and unquestionable owners of the first physical page,
* even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
* (but then write-access it later during SetVirtualAddressMap()).
*
* Create a 1:1 mapping for this page, to avoid triple faults during early
* boot with such firmware. We are free to hand this page to the BIOS,
* as trim_bios_range() will reserve the first page and isolate it away
* from memory allocators anyway.
*/
if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, _PAGE_RW)) {
pr_err("Failed to create 1:1 mapping for the first page!\n");
return 1;
}
/*
* When making calls to the firmware everything needs to be 1:1
* mapped and addressable with 32-bit pointers. Map the kernel
* text and allocate a new stack because we can't rely on the
* stack pointer being < 4GB.
*/
if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
return 0;
page = alloc_page(GFP_KERNEL|__GFP_DMA32);
if (!page)
panic("Unable to allocate EFI runtime stack < 4GB\n");
efi_scratch.phys_stack = virt_to_phys(page_address(page));
efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */
npages = (_etext - _text) >> PAGE_SHIFT;
text = __pa(_text);
pfn = text >> PAGE_SHIFT;
if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, _PAGE_RW)) {
pr_err("Failed to map kernel text 1:1\n");
return 1;
}
return 0;
}