summaryrefslogtreecommitdiff
path: root/drivers/firmware/efi/libstub/arm-stub.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/firmware/efi/libstub/arm-stub.c')
-rw-r--r--drivers/firmware/efi/libstub/arm-stub.c67
1 files changed, 63 insertions, 4 deletions
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index eb48a1a1a576..dcae482a9a17 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -17,10 +17,10 @@
#include "efistub.h"
-static int __init efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
+static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
{
- static efi_guid_t const var_guid __initconst = EFI_GLOBAL_VARIABLE_GUID;
- static efi_char16_t const var_name[] __initconst = {
+ static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID;
+ static efi_char16_t const var_name[] = {
'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };
efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable;
@@ -164,7 +164,7 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
* for both archictectures, with the arch-specific code provided in the
* handle_kernel_image() function.
*/
-unsigned long __init efi_entry(void *handle, efi_system_table_t *sys_table,
+unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
unsigned long *image_addr)
{
efi_loaded_image_t *image;
@@ -295,3 +295,62 @@ fail_free_image:
fail:
return EFI_ERROR;
}
+
+/*
+ * This is the base address at which to start allocating virtual memory ranges
+ * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
+ * any allocation we choose, and eliminate the risk of a conflict after kexec.
+ * The value chosen is the largest non-zero power of 2 suitable for this purpose
+ * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
+ * be mapped efficiently.
+ */
+#define EFI_RT_VIRTUAL_BASE 0x40000000
+
+/*
+ * efi_get_virtmap() - create a virtual mapping for the EFI memory map
+ *
+ * This function populates the virt_addr fields of all memory region descriptors
+ * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
+ * are also copied to @runtime_map, and their total count is returned in @count.
+ */
+void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
+ unsigned long desc_size, efi_memory_desc_t *runtime_map,
+ int *count)
+{
+ u64 efi_virt_base = EFI_RT_VIRTUAL_BASE;
+ efi_memory_desc_t *out = runtime_map;
+ int l;
+
+ for (l = 0; l < map_size; l += desc_size) {
+ efi_memory_desc_t *in = (void *)memory_map + l;
+ u64 paddr, size;
+
+ if (!(in->attribute & EFI_MEMORY_RUNTIME))
+ continue;
+
+ /*
+ * Make the mapping compatible with 64k pages: this allows
+ * a 4k page size kernel to kexec a 64k page size kernel and
+ * vice versa.
+ */
+ paddr = round_down(in->phys_addr, SZ_64K);
+ size = round_up(in->num_pages * EFI_PAGE_SIZE +
+ in->phys_addr - paddr, SZ_64K);
+
+ /*
+ * Avoid wasting memory on PTEs by choosing a virtual base that
+ * is compatible with section mappings if this region has the
+ * appropriate size and physical alignment. (Sections are 2 MB
+ * on 4k granule kernels)
+ */
+ if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
+ efi_virt_base = round_up(efi_virt_base, SZ_2M);
+
+ in->virt_addr = efi_virt_base + in->phys_addr - paddr;
+ efi_virt_base += size;
+
+ memcpy(out, in, desc_size);
+ out = (void *)out + desc_size;
+ ++*count;
+ }
+}