efi/arm: libstub: move ARM specific code out of generic routines

Move some code that is only reachable when IS_ENABLED(CONFIG_ARM) into
the ARM EFI arch code.

Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

3 files changed, 82 insertions, 2 deletions

diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h
index 3088ef72704e..4bdd930167c0 100644
--- a/arch/arm/include/asm/efi.h
+++ b/arch/arm/include/asm/efi.h
@@ -17,6 +17,7 @@
 
 #ifdef CONFIG_EFI
 void efi_init(void);
+void arm_efi_init(void);
 
 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
 int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
@@ -37,7 +38,7 @@ void efi_virtmap_load(void);
 void efi_virtmap_unload(void);
 
 #else
-#define efi_init()
+#define arm_efi_init()
 #endif /* CONFIG_EFI */
 
 /* arch specific definitions used by the stub code */
diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c
index e57dbcc89123..e50ad7eefc02 100644
--- a/arch/arm/kernel/efi.c
+++ b/arch/arm/kernel/efi.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/efi.h>
+#include <linux/memblock.h>
 #include <asm/efi.h>
 #include <asm/mach/map.h>
 #include <asm/mmu_context.h>
@@ -73,3 +74,81 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
 		return efi_set_mapping_permissions(mm, md);
 	return 0;
 }
+
+static unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR;
+static unsigned long __initdata cpu_state_table = EFI_INVALID_TABLE_ADDR;
+
+const efi_config_table_type_t efi_arch_tables[] __initconst = {
+	{LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, &screen_info_table},
+	{LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table},
+	{}
+};
+
+static void __init load_screen_info_table(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;
+
+		if (memblock_is_map_memory(screen_info.lfb_base))
+			memblock_mark_nomap(screen_info.lfb_base,
+					    screen_info.lfb_size);
+	}
+}
+
+static void __init load_cpu_state_table(void)
+{
+	if (cpu_state_table != EFI_INVALID_TABLE_ADDR) {
+		struct efi_arm_entry_state *state;
+		bool dump_state = true;
+
+		state = early_memremap_ro(cpu_state_table,
+					  sizeof(struct efi_arm_entry_state));
+		if (state == NULL) {
+			pr_warn("Unable to map CPU entry state table.\n");
+			return;
+		}
+
+		if ((state->sctlr_before_ebs & 1) == 0)
+			pr_warn(FW_BUG "EFI stub was entered with MMU and Dcache disabled, please fix your firmware!\n");
+		else if ((state->sctlr_after_ebs & 1) == 0)
+			pr_warn(FW_BUG "ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware!\n");
+		else
+			dump_state = false;
+
+		if (dump_state || efi_enabled(EFI_DBG)) {
+			pr_info("CPSR at EFI stub entry        : 0x%08x\n",
+				state->cpsr_before_ebs);
+			pr_info("SCTLR at EFI stub entry       : 0x%08x\n",
+				state->sctlr_before_ebs);
+			pr_info("CPSR after ExitBootServices() : 0x%08x\n",
+				state->cpsr_after_ebs);
+			pr_info("SCTLR after ExitBootServices(): 0x%08x\n",
+				state->sctlr_after_ebs);
+		}
+		early_memunmap(state, sizeof(struct efi_arm_entry_state));
+	}
+}
+
+void __init arm_efi_init(void)
+{
+	efi_init();
+
+	load_screen_info_table();
+
+	/* ARM does not permit early mappings to persist across paging_init() */
+	efi_memmap_unmap();
+
+	load_cpu_state_table();
+}
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 1e8a50a97edf..cb88c6e69377 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1141,7 +1141,7 @@ void __init setup_arch(char **cmdline_p)
 #endif
 	setup_dma_zone(mdesc);
 	xen_early_init();
-	efi_init();
+	arm_efi_init();
 	/*
 	 * Make sure the calculation for lowmem/highmem is set appropriately
 	 * before reserving/allocating any memory