efi: Merge EFI system table revision and vendor checks

We have three different versions of the code that checks the EFI system
table revision and copies the firmware vendor string, and they are
mostly equivalent, with the exception of the use of early_memremap_ro
vs. __va() and the lowest major revision to warn about. Let's move this
into common code and factor out the commonalities.

Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

2 files changed, 13 insertions, 56 deletions

diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index 312308967a9d..292fe354158d 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -479,10 +479,8 @@ void __init
 efi_init (void)
 {
 	void *efi_map_start, *efi_map_end;
-	efi_char16_t *c16;
 	u64 efi_desc_size;
-	char *cp, vendor[100] = "unknown";
-	int i;
+	char *cp;
 
 	set_bit(EFI_BOOT, &efi.flags);
 	set_bit(EFI_64BIT, &efi.flags);
@@ -519,25 +517,10 @@ efi_init (void)
 	 */
 	if (efi.systab == NULL)
 		panic("Whoa! Can't find EFI system table.\n");
-	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
+	if (efi_systab_check_header(&efi.systab->hdr, 1))
 		panic("Whoa! EFI system table signature incorrect\n");
-	if ((efi.systab->hdr.revision >> 16) == 0)
-		printk(KERN_WARNING "Warning: EFI system table version "
-		       "%d.%02d, expected 1.00 or greater\n",
-		       efi.systab->hdr.revision >> 16,
-		       efi.systab->hdr.revision & 0xffff);
-
-	/* Show what we know for posterity */
-	c16 = __va(efi.systab->fw_vendor);
-	if (c16) {
-		for (i = 0;i < (int) sizeof(vendor) - 1 && *c16; ++i)
-			vendor[i] = *c16++;
-		vendor[i] = '\0';
-	}
 
-	printk(KERN_INFO "EFI v%u.%.02u by %s:",
-	       efi.systab->hdr.revision >> 16,
-	       efi.systab->hdr.revision & 0xffff, vendor);
+	efi_systab_report_header(&efi.systab->hdr, efi.systab->fw_vendor);
 
 	palo_phys      = EFI_INVALID_TABLE_ADDR;
 
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 22dc3678cdba..5bb53da48a4b 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -336,15 +336,23 @@ static int __init efi_systab_init(u64 phys)
 {
 	int size = efi_enabled(EFI_64BIT) ? sizeof(efi_system_table_64_t)
 					  : sizeof(efi_system_table_32_t);
+	const efi_table_hdr_t *hdr;
 	bool over4g = false;
 	void *p;
+	int ret;
 
-	p = early_memremap_ro(phys, size);
+	hdr = p = early_memremap_ro(phys, size);
 	if (p == NULL) {
 		pr_err("Couldn't map the system table!\n");
 		return -ENOMEM;
 	}
 
+	ret = efi_systab_check_header(hdr, 1);
+	if (ret) {
+		early_memunmap(p, size);
+		return ret;
+	}
+
 	if (efi_enabled(EFI_64BIT)) {
 		const efi_system_table_64_t *systab64 = p;
 
@@ -411,6 +419,7 @@ static int __init efi_systab_init(u64 phys)
 		efi_systab.tables		= systab32->tables;
 	}
 
+	efi_systab_report_header(hdr, efi_systab.fw_vendor);
 	early_memunmap(p, size);
 
 	if (IS_ENABLED(CONFIG_X86_32) && over4g) {
@@ -419,28 +428,11 @@ static int __init efi_systab_init(u64 phys)
 	}
 
 	efi.systab = &efi_systab;
-
-	/*
-	 * Verify the EFI Table
-	 */
-	if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
-		pr_err("System table signature incorrect!\n");
-		return -EINVAL;
-	}
-	if ((efi.systab->hdr.revision >> 16) == 0)
-		pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
-		       efi.systab->hdr.revision >> 16,
-		       efi.systab->hdr.revision & 0xffff);
-
 	return 0;
 }
 
 void __init efi_init(void)
 {
-	efi_char16_t *c16;
-	char vendor[100] = "unknown";
-	int i = 0;
-
 	if (IS_ENABLED(CONFIG_X86_32) &&
 	    (boot_params.efi_info.efi_systab_hi ||
 	     boot_params.efi_info.efi_memmap_hi)) {
@@ -458,24 +450,6 @@ void __init efi_init(void)
 	efi.fw_vendor	 = (unsigned long)efi.systab->fw_vendor;
 	efi.runtime	 = (unsigned long)efi.systab->runtime;
 
-	/*
-	 * Show what we know for posterity
-	 */
-	c16 = early_memremap_ro(efi.systab->fw_vendor,
-				sizeof(vendor) * sizeof(efi_char16_t));
-	if (c16) {
-		for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
-			vendor[i] = c16[i];
-		vendor[i] = '\0';
-		early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
-	} else {
-		pr_err("Could not map the firmware vendor!\n");
-	}
-
-	pr_info("EFI v%u.%.02u by %s\n",
-		efi.systab->hdr.revision >> 16,
-		efi.systab->hdr.revision & 0xffff, vendor);
-
 	if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
 		return;