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>

Author: ardbiesheuvel

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 */

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();
+}

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

drivers/firmware/efi/efi-init.c

@@ -51,34 +51,10 @@ static phys_addr_t __init efi_to_phys(unsigned long addr)
 	return addr;
 }
 
-static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
-static __initdata unsigned long cpu_state_table = EFI_INVALID_TABLE_ADDR;
-
-static const efi_config_table_type_t arch_tables[] __initconst = {
-	{LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, &screen_info_table},
-	{LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table},
-	{}
-};
+extern __weak const efi_config_table_type_t efi_arch_tables[];
 
 static void __init init_screen_info(void)
 {
-	struct screen_info *si;
-
-	if (IS_ENABLED(CONFIG_ARM) &&
-	    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 (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
 	    memblock_is_map_memory(screen_info.lfb_base))
 		memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
@@ -119,8 +95,7 @@ static int __init uefi_init(u64 efi_system_table)
 		goto out;
 	}
 	retval = efi_config_parse_tables(config_tables, systab->nr_tables,
-					 IS_ENABLED(CONFIG_ARM) ? arch_tables
-								: NULL);
+					 efi_arch_tables);
 
 	early_memunmap(config_tables, table_size);
 out:
@@ -248,36 +223,4 @@ void __init efi_init(void)
 			 PAGE_ALIGN(data.size + (data.phys_map & ~PAGE_MASK)));
 
 	init_screen_info();
-
-#ifdef CONFIG_ARM
-	/* ARM does not permit early mappings to persist across paging_init() */
-	efi_memmap_unmap();
-
-	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));
-	}
-#endif
 }