efi/ia64: Use existing helpers to locate ESI table

Instead of iterating over the EFI config table array manually,
declare it as an arch table so it gets picked up by the existing
config table handling code.

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

arch/ia64/kernel/efi.c

@@ -45,13 +45,19 @@
 
 #define EFI_DEBUG	0
 
+#define ESI_TABLE_GUID					\
+    EFI_GUID(0x43EA58DC, 0xCF28, 0x4b06, 0xB3,		\
+	     0x91, 0xB7, 0x50, 0x59, 0x34, 0x2B, 0xD4)
+
 static unsigned long mps_phys = EFI_INVALID_TABLE_ADDR;
 static __initdata unsigned long palo_phys;
 
+unsigned long __initdata esi_phys = EFI_INVALID_TABLE_ADDR;
 unsigned long hcdp_phys = EFI_INVALID_TABLE_ADDR;
 unsigned long sal_systab_phys = EFI_INVALID_TABLE_ADDR;
 
 static __initdata efi_config_table_type_t arch_tables[] = {
+	{ESI_TABLE_GUID, "ESI", &esi_phys},
 	{HCDP_TABLE_GUID, "HCDP", &hcdp_phys},
 	{MPS_TABLE_GUID, "MPS", &mps_phys},
 	{PROCESSOR_ABSTRACTION_LAYER_OVERWRITE_GUID, "PALO", &palo_phys},

arch/ia64/kernel/esi.c

@@ -19,10 +19,6 @@ MODULE_LICENSE("GPL");
 
 #define MODULE_NAME	"esi"
 
-#define ESI_TABLE_GUID					\
-    EFI_GUID(0x43EA58DC, 0xCF28, 0x4b06, 0xB3,		\
-	     0x91, 0xB7, 0x50, 0x59, 0x34, 0x2B, 0xD4)
-
 enum esi_systab_entry_type {
 	ESI_DESC_ENTRY_POINT = 0
 };
@@ -48,27 +44,18 @@ struct pdesc {
 
 static struct ia64_sal_systab *esi_systab;
 
+extern unsigned long esi_phys;
+
 static int __init esi_init (void)
 {
-	efi_config_table_t *config_tables;
 	struct ia64_sal_systab *systab;
-	unsigned long esi = 0;
 	char *p;
 	int i;
 
-	config_tables = __va(efi.systab->tables);
-
-	for (i = 0; i < (int) efi.systab->nr_tables; ++i) {
-		if (efi_guidcmp(config_tables[i].guid, ESI_TABLE_GUID) == 0) {
-			esi = config_tables[i].table;
-			break;
-		}
-	}
-
-	if (!esi)
+	if (esi_phys == EFI_INVALID_TABLE_ADDR)
 		return -ENODEV;
 
-	systab = __va(esi);
+	systab = __va(esi_phys);
 
 	if (strncmp(systab->signature, "ESIT", 4) != 0) {
 		printk(KERN_ERR "bad signature in ESI system table!");