* Bibo Mao <bibo.mao@intel.com>
* Chandramouli Narayanan <mouli@linux.intel.com>
* Huang Ying <ying.huang@intel.com>
+ * Copyright (C) 2013 SuSE Labs
+ * Borislav Petkov <bp@suse.de> - runtime services VA mapping
*
* Copied from efi_32.c to eliminate the duplicated code between EFI
* 32/64 support code. --ying 2007-10-26
set_memory_uc(addr, npages);
}
+void __init old_map_region(efi_memory_desc_t *md)
+{
+ u64 start_pfn, end_pfn, end;
+ unsigned long size;
+ void *va;
+
+ start_pfn = PFN_DOWN(md->phys_addr);
+ size = md->num_pages << PAGE_SHIFT;
+ end = md->phys_addr + size;
+ end_pfn = PFN_UP(end);
+
+ if (pfn_range_is_mapped(start_pfn, end_pfn)) {
+ va = __va(md->phys_addr);
+
+ if (!(md->attribute & EFI_MEMORY_WB))
+ efi_memory_uc((u64)(unsigned long)va, size);
+ } else
+ va = efi_ioremap(md->phys_addr, size,
+ md->type, md->attribute);
+
+ md->virt_addr = (u64) (unsigned long) va;
+ if (!va)
+ pr_err("ioremap of 0x%llX failed!\n",
+ (unsigned long long)md->phys_addr);
+}
+
/*
* This function will switch the EFI runtime services to virtual mode.
- * Essentially, look through the EFI memmap and map every region that
- * has the runtime attribute bit set in its memory descriptor and update
- * that memory descriptor with the virtual address obtained from ioremap().
- * This enables the runtime services to be called without having to
+ * Essentially, we look through the EFI memmap and map every region that
+ * has the runtime attribute bit set in its memory descriptor into the
+ * ->trampoline_pgd page table using a top-down VA allocation scheme.
+ *
+ * The old method which used to update that memory descriptor with the
+ * virtual address obtained from ioremap() is still supported when the
+ * kernel is booted with efi=old_map on its command line. Same old
+ * method enabled the runtime services to be called without having to
* thunk back into physical mode for every invocation.
+ *
+ * The new method does a pagetable switch in a preemption-safe manner
+ * so that we're in a different address space when calling a runtime
+ * function. For function arguments passing we do copy the PGDs of the
+ * kernel page table into ->trampoline_pgd prior to each call.
*/
void __init efi_enter_virtual_mode(void)
{
efi_memory_desc_t *md, *prev_md = NULL;
- efi_status_t status;
+ void *p, *new_memmap = NULL;
unsigned long size;
- u64 end, systab, start_pfn, end_pfn;
- void *p, *va, *new_memmap = NULL;
+ efi_status_t status;
+ u64 end, systab;
int count = 0;
efi.systab = NULL;
* We don't do virtual mode, since we don't do runtime services, on
* non-native EFI
*/
-
if (!efi_is_native()) {
efi_unmap_memmap();
return;
continue;
}
prev_md = md;
+
}
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md->type != EFI_BOOT_SERVICES_DATA)
continue;
+ efi_map_region(md);
+
size = md->num_pages << EFI_PAGE_SHIFT;
end = md->phys_addr + size;
- start_pfn = PFN_DOWN(md->phys_addr);
- end_pfn = PFN_UP(end);
- if (pfn_range_is_mapped(start_pfn, end_pfn)) {
- va = __va(md->phys_addr);
-
- if (!(md->attribute & EFI_MEMORY_WB))
- efi_memory_uc((u64)(unsigned long)va, size);
- } else
- va = efi_ioremap(md->phys_addr, size,
- md->type, md->attribute);
-
- md->virt_addr = (u64) (unsigned long) va;
-
- if (!va) {
- pr_err("ioremap of 0x%llX failed!\n",
- (unsigned long long)md->phys_addr);
- continue;
- }
-
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;
}
+
new_memmap = krealloc(new_memmap,
(count + 1) * memmap.desc_size,
GFP_KERNEL);
BUG_ON(!efi.systab);
+ efi_setup_page_tables();
+ efi_sync_low_kernel_mappings();
+
status = phys_efi_set_virtual_address_map(
memmap.desc_size * count,
memmap.desc_size,
efi.query_variable_info = virt_efi_query_variable_info;
efi.update_capsule = virt_efi_update_capsule;
efi.query_capsule_caps = virt_efi_query_capsule_caps;
- if (__supported_pte_mask & _PAGE_NX)
+
+ if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
runtime_code_page_mkexec();
kfree(new_memmap);
return EFI_SUCCESS;
}
EXPORT_SYMBOL_GPL(efi_query_variable_store);
+
+static int __init parse_efi_cmdline(char *str)
+{
+ if (*str == '=')
+ str++;
+
+ if (!strncmp(str, "old_map", 7))
+ set_bit(EFI_OLD_MEMMAP, &x86_efi_facility);
+
+ return 0;
+}
+early_param("efi", parse_efi_cmdline);
projects / linux-2.6-block.git / blobdiff