v4.19.13 snapshot.
diff --git a/arch/ia64/kernel/esi.c b/arch/ia64/kernel/esi.c
new file mode 100644
index 0000000..b091111
--- /dev/null
+++ b/arch/ia64/kernel/esi.c
@@ -0,0 +1,205 @@
+/*
+ * Extensible SAL Interface (ESI) support routines.
+ *
+ * Copyright (C) 2006 Hewlett-Packard Co
+ * 	Alex Williamson <alex.williamson@hp.com>
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include <asm/esi.h>
+#include <asm/sal.h>
+
+MODULE_AUTHOR("Alex Williamson <alex.williamson@hp.com>");
+MODULE_DESCRIPTION("Extensible SAL Interface (ESI) support");
+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
+};
+
+/*
+ * Entry type:	Size:
+ *	0	48
+ */
+#define ESI_DESC_SIZE(type)	"\060"[(unsigned) (type)]
+
+typedef struct ia64_esi_desc_entry_point {
+	u8 type;
+	u8 reserved1[15];
+	u64 esi_proc;
+	u64 gp;
+	efi_guid_t guid;
+} ia64_esi_desc_entry_point_t;
+
+struct pdesc {
+	void *addr;
+	void *gp;
+};
+
+static struct ia64_sal_systab *esi_systab;
+
+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)
+		return -ENODEV;
+
+	systab = __va(esi);
+
+	if (strncmp(systab->signature, "ESIT", 4) != 0) {
+		printk(KERN_ERR "bad signature in ESI system table!");
+		return -ENODEV;
+	}
+
+	p = (char *) (systab + 1);
+	for (i = 0; i < systab->entry_count; i++) {
+		/*
+		 * The first byte of each entry type contains the type
+		 * descriptor.
+		 */
+		switch (*p) {
+		      case ESI_DESC_ENTRY_POINT:
+			break;
+		      default:
+			printk(KERN_WARNING "Unknown table type %d found in "
+			       "ESI table, ignoring rest of table\n", *p);
+			return -ENODEV;
+		}
+
+		p += ESI_DESC_SIZE(*p);
+	}
+
+	esi_systab = systab;
+	return 0;
+}
+
+
+int ia64_esi_call (efi_guid_t guid, struct ia64_sal_retval *isrvp,
+		   enum esi_proc_type proc_type, u64 func,
+		   u64 arg1, u64 arg2, u64 arg3, u64 arg4, u64 arg5, u64 arg6,
+		   u64 arg7)
+{
+	struct ia64_fpreg fr[6];
+	unsigned long flags = 0;
+	int i;
+	char *p;
+
+	if (!esi_systab)
+		return -1;
+
+	p = (char *) (esi_systab + 1);
+	for (i = 0; i < esi_systab->entry_count; i++) {
+		if (*p == ESI_DESC_ENTRY_POINT) {
+			ia64_esi_desc_entry_point_t *esi = (void *)p;
+			if (!efi_guidcmp(guid, esi->guid)) {
+				ia64_sal_handler esi_proc;
+				struct pdesc pdesc;
+
+				pdesc.addr = __va(esi->esi_proc);
+				pdesc.gp = __va(esi->gp);
+
+				esi_proc = (ia64_sal_handler) &pdesc;
+
+				ia64_save_scratch_fpregs(fr);
+				if (proc_type == ESI_PROC_SERIALIZED)
+					spin_lock_irqsave(&sal_lock, flags);
+				else if (proc_type == ESI_PROC_MP_SAFE)
+					local_irq_save(flags);
+				else
+					preempt_disable();
+				*isrvp = (*esi_proc)(func, arg1, arg2, arg3,
+						     arg4, arg5, arg6, arg7);
+				if (proc_type == ESI_PROC_SERIALIZED)
+					spin_unlock_irqrestore(&sal_lock,
+							       flags);
+				else if (proc_type == ESI_PROC_MP_SAFE)
+					local_irq_restore(flags);
+				else
+					preempt_enable();
+				ia64_load_scratch_fpregs(fr);
+				return 0;
+			}
+		}
+		p += ESI_DESC_SIZE(*p);
+	}
+	return -1;
+}
+EXPORT_SYMBOL_GPL(ia64_esi_call);
+
+int ia64_esi_call_phys (efi_guid_t guid, struct ia64_sal_retval *isrvp,
+			u64 func, u64 arg1, u64 arg2, u64 arg3, u64 arg4,
+			u64 arg5, u64 arg6, u64 arg7)
+{
+	struct ia64_fpreg fr[6];
+	unsigned long flags;
+	u64 esi_params[8];
+	char *p;
+	int i;
+
+	if (!esi_systab)
+		return -1;
+
+	p = (char *) (esi_systab + 1);
+	for (i = 0; i < esi_systab->entry_count; i++) {
+		if (*p == ESI_DESC_ENTRY_POINT) {
+			ia64_esi_desc_entry_point_t *esi = (void *)p;
+			if (!efi_guidcmp(guid, esi->guid)) {
+				ia64_sal_handler esi_proc;
+				struct pdesc pdesc;
+
+				pdesc.addr = (void *)esi->esi_proc;
+				pdesc.gp = (void *)esi->gp;
+
+				esi_proc = (ia64_sal_handler) &pdesc;
+
+				esi_params[0] = func;
+				esi_params[1] = arg1;
+				esi_params[2] = arg2;
+				esi_params[3] = arg3;
+				esi_params[4] = arg4;
+				esi_params[5] = arg5;
+				esi_params[6] = arg6;
+				esi_params[7] = arg7;
+				ia64_save_scratch_fpregs(fr);
+				spin_lock_irqsave(&sal_lock, flags);
+				*isrvp = esi_call_phys(esi_proc, esi_params);
+				spin_unlock_irqrestore(&sal_lock, flags);
+				ia64_load_scratch_fpregs(fr);
+				return 0;
+			}
+		}
+		p += ESI_DESC_SIZE(*p);
+	}
+	return -1;
+}
+EXPORT_SYMBOL_GPL(ia64_esi_call_phys);
+
+static void __exit esi_exit (void)
+{
+}
+
+module_init(esi_init);
+module_exit(esi_exit);	/* makes module removable... */