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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2016-04-25 21:06:53 +0100
committerIngo Molnar <mingo@kernel.org>2016-04-28 11:33:59 +0200
commit801820bee9bccb7c156af2b95c7208f428a06ae7 (patch)
treee2d486dc835f643ffa966d7b499f2ef17d3f1d7b /drivers/firmware
parent57fdb89aeb7b0e3aab19847ab7399e5d76f11e6f (diff)
downloadlinux-801820bee9bccb7c156af2b95c7208f428a06ae7.tar.bz2
efi/arm/libstub: Make screen_info accessible to the UEFI stub
In order to hand over the framebuffer described by the GOP protocol and discovered by the UEFI stub, make struct screen_info accessible by the stub. This involves allocating a loader data buffer and passing it to the kernel proper via a UEFI Configuration Table, since the UEFI stub executes in the context of the decompressor, and cannot access the kernel's copy of struct screen_info directly. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-22-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/arm-init.c34
-rw-r--r--drivers/firmware/efi/efi.c5
-rw-r--r--drivers/firmware/efi/libstub/arm32-stub.c37
3 files changed, 73 insertions, 3 deletions
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index 909d974d35d9..ac95dd8b119f 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -11,12 +11,15 @@
*
*/
+#define pr_fmt(fmt) "efi: " fmt
+
#include <linux/efi.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/mm_types.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
+#include <linux/screen_info.h>
#include <asm/efi.h>
@@ -51,6 +54,32 @@ static phys_addr_t efi_to_phys(unsigned long addr)
return addr;
}
+static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
+
+static __initdata efi_config_table_type_t arch_tables[] = {
+ {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table},
+ {NULL_GUID, NULL, NULL}
+};
+
+static void __init init_screen_info(void)
+{
+ struct screen_info *si;
+
+ if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
+ si = early_memremap_ro(screen_info_table, sizeof(*si));
+ if (!si) {
+ pr_err("Could not map screen_info config table\n");
+ return;
+ }
+ screen_info = *si;
+ early_memunmap(si, sizeof(*si));
+
+ /* dummycon on ARM needs non-zero values for columns/lines */
+ screen_info.orig_video_cols = 80;
+ screen_info.orig_video_lines = 25;
+ }
+}
+
static int __init uefi_init(void)
{
efi_char16_t *c16;
@@ -108,7 +137,8 @@ static int __init uefi_init(void)
goto out;
}
retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
- sizeof(efi_config_table_t), NULL);
+ sizeof(efi_config_table_t),
+ arch_tables);
early_memunmap(config_tables, table_size);
out:
@@ -223,4 +253,6 @@ void __init efi_init(void)
PAGE_ALIGN(params.mmap_size +
(params.mmap & ~PAGE_MASK)));
}
+
+ init_screen_info();
}
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 583e647912a5..4991371012b4 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -353,8 +353,9 @@ static __init int match_config_table(efi_guid_t *guid,
for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
if (!efi_guidcmp(*guid, table_types[i].guid)) {
*(table_types[i].ptr) = table;
- pr_cont(" %s=0x%lx ",
- table_types[i].name, table);
+ if (table_types[i].name)
+ pr_cont(" %s=0x%lx ",
+ table_types[i].name, table);
return 1;
}
}
diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c
index 6f42be4d0084..e1f0b28e1dcb 100644
--- a/drivers/firmware/efi/libstub/arm32-stub.c
+++ b/drivers/firmware/efi/libstub/arm32-stub.c
@@ -26,6 +26,43 @@ efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
return EFI_SUCCESS;
}
+static efi_guid_t screen_info_guid = LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID;
+
+struct screen_info *alloc_screen_info(efi_system_table_t *sys_table_arg)
+{
+ struct screen_info *si;
+ efi_status_t status;
+
+ /*
+ * Unlike on arm64, where we can directly fill out the screen_info
+ * structure from the stub, we need to allocate a buffer to hold
+ * its contents while we hand over to the kernel proper from the
+ * decompressor.
+ */
+ status = efi_call_early(allocate_pool, EFI_RUNTIME_SERVICES_DATA,
+ sizeof(*si), (void **)&si);
+
+ if (status != EFI_SUCCESS)
+ return NULL;
+
+ status = efi_call_early(install_configuration_table,
+ &screen_info_guid, si);
+ if (status == EFI_SUCCESS)
+ return si;
+
+ efi_call_early(free_pool, si);
+ return NULL;
+}
+
+void free_screen_info(efi_system_table_t *sys_table_arg, struct screen_info *si)
+{
+ if (!si)
+ return;
+
+ efi_call_early(install_configuration_table, &screen_info_guid, NULL);
+ efi_call_early(free_pool, si);
+}
+
efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
unsigned long *image_addr,
unsigned long *image_size,