efi/libstub: Add a helper function to split 64-bit values

In several places 64-bit values need to be split up into two 32-bit
fields, in order to be backward-compatible with the old 32-bit ABIs.

Instead of open-coding this, add a helper function to set a 64-bit value
as two 32-bit fields.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-3-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 5ff63230a1f119cab7c37bf7f4588d17e794f230..e8aa70ba08d5269126bca33932c8cd95876693a5 100644 (file)
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -87,6 +87,13 @@ extern const efi_system_table_t *efi_system_table;
                ((handle = efi_get_handle_at((array), i)) || true);     \
             i++)
 
+static inline
+void efi_set_u64_split(u64 data, u32 *lo, u32 *hi)
+{
+       *lo = lower_32_bits(data);
+       *hi = upper_32_bits(data);
+}
+
 /*
  * Allocation types for calls to boottime->allocate_pages.
  */

diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index 216327d0b03495bf47f89639a3e5ea44a77f86d8..64cee0febae09f7a681b9b729b1b6d7142049850 100644 (file)
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -422,7 +422,6 @@ static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
        efi_graphics_output_protocol_t *gop;
        efi_graphics_output_protocol_mode_t *mode;
        efi_graphics_output_mode_info_t *info;
-       efi_physical_addr_t fb_base;
 
        gop = find_gop(proto, size, handles);
 
@@ -442,9 +441,8 @@ static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
        si->lfb_width  = info->horizontal_resolution;
        si->lfb_height = info->vertical_resolution;
 
-       fb_base          = efi_table_attr(mode, frame_buffer_base);
-       si->lfb_base     = lower_32_bits(fb_base);
-       si->ext_lfb_base = upper_32_bits(fb_base);
+       efi_set_u64_split(efi_table_attr(mode, frame_buffer_base),
+                         &si->lfb_base, &si->ext_lfb_base);
        if (si->ext_lfb_base)
                si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
 

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index d4bafd7f6f9f156c77c8ce9f231c75923c1a54d2..f91d4aab0156d86dc3faa911bbe46e1b21c9fd7f 100644 (file)
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -408,9 +408,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
        if (!cmdline_ptr)
                goto fail;
 
-       hdr->cmd_line_ptr = (unsigned long)cmdline_ptr;
-       /* Fill in upper bits of command line address, NOP on 32 bit  */
-       boot_params->ext_cmd_line_ptr = (u64)(unsigned long)cmdline_ptr >> 32;
+       efi_set_u64_split((unsigned long)cmdline_ptr,
+                         &hdr->cmd_line_ptr, &boot_params->ext_cmd_line_ptr);
 
        hdr->ramdisk_image = 0;
        hdr->ramdisk_size = 0;
@@ -427,10 +426,10 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
                                                 ULONG_MAX);
                        if (status != EFI_SUCCESS)
                                goto fail2;
-                       hdr->ramdisk_image = ramdisk_addr & 0xffffffff;
-                       hdr->ramdisk_size  = ramdisk_size & 0xffffffff;
-                       boot_params->ext_ramdisk_image = (u64)ramdisk_addr >> 32;
-                       boot_params->ext_ramdisk_size  = (u64)ramdisk_size >> 32;
+                       efi_set_u64_split(ramdisk_addr, &hdr->ramdisk_image,
+                                         &boot_params->ext_ramdisk_image);
+                       efi_set_u64_split(ramdisk_size, &hdr->ramdisk_size,
+                                         &boot_params->ext_ramdisk_size);
                }
        }
 
@@ -639,17 +638,14 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
                                   : EFI32_LOADER_SIGNATURE;
        memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
 
-       p->efi->efi_systab              = (unsigned long)efi_system_table;
+       efi_set_u64_split((unsigned long)efi_system_table,
+                         &p->efi->efi_systab, &p->efi->efi_systab_hi);
        p->efi->efi_memdesc_size        = *map->desc_size;
        p->efi->efi_memdesc_version     = *map->desc_ver;
-       p->efi->efi_memmap              = (unsigned long)*map->map;
+       efi_set_u64_split((unsigned long)*map->map,
+                         &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
        p->efi->efi_memmap_size         = *map->map_size;
 
-#ifdef CONFIG_X86_64
-       p->efi->efi_systab_hi           = (unsigned long)efi_system_table >> 32;
-       p->efi->efi_memmap_hi           = (unsigned long)*map->map >> 32;
-#endif
-
        return EFI_SUCCESS;
 }
 
@@ -785,10 +781,10 @@ unsigned long efi_main(efi_handle_t handle,
 
                status = efi_load_initrd_dev_path(&addr, &size, ULONG_MAX);
                if (status == EFI_SUCCESS) {
-                       hdr->ramdisk_image              = (u32)addr;
-                       hdr->ramdisk_size               = (u32)size;
-                       boot_params->ext_ramdisk_image  = (u64)addr >> 32;
-                       boot_params->ext_ramdisk_size   = (u64)size >> 32;
+                       efi_set_u64_split(addr, &hdr->ramdisk_image,
+                                         &boot_params->ext_ramdisk_image);
+                       efi_set_u64_split(size, &hdr->ramdisk_size,
+                                         &boot_params->ext_ramdisk_size);
                } else if (status != EFI_NOT_FOUND) {
                        efi_printk("efi_load_initrd_dev_path() failed!\n");
                        goto fail;