1 files changed, 104 insertions, 0 deletions
diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c
new file mode 100644
index 000000000..64bb94523
--- /dev/null
+++ b/drivers/firmware/iscsi_ibft_find.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Copyright 2007-2010 Red Hat, Inc.
+ *  by Peter Jones <pjones@redhat.com>
+ *  Copyright 2007 IBM, Inc.
+ *  by Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
+ *  Copyright 2008
+ *  by Konrad Rzeszutek <ketuzsezr@darnok.org>
+ *
+ * This code finds the iSCSI Boot Format Table.
+ */
+
+#include <linux/memblock.h>
+#include <linux/blkdev.h>
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/efi.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/acpi.h>
+#include <linux/iscsi_ibft.h>
+
+#include <asm/mmzone.h>
+
+/*
+ * Physical location of iSCSI Boot Format Table.
+ */
+struct acpi_table_ibft *ibft_addr;
+EXPORT_SYMBOL_GPL(ibft_addr);
+
+static const struct {
+	char *sign;
+} ibft_signs[] = {
+	{ "iBFT" },
+	{ "BIFT" },	/* Broadcom iSCSI Offload */
+};
+
+#define IBFT_SIGN_LEN 4
+#define IBFT_START 0x80000 /* 512kB */
+#define IBFT_END 0x100000 /* 1MB */
+#define VGA_MEM 0xA0000 /* VGA buffer */
+#define VGA_SIZE 0x20000 /* 128kB */
+
+static int __init find_ibft_in_mem(void)
+{
+	unsigned long pos;
+	unsigned int len = 0;
+	void *virt;
+	int i;
+
+	for (pos = IBFT_START; pos < IBFT_END; pos += 16) {
+		/* The table can't be inside the VGA BIOS reserved space,
+		 * so skip that area */
+		if (pos == VGA_MEM)
+			pos += VGA_SIZE;
+		virt = isa_bus_to_virt(pos);
+
+		for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) {
+			if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) ==
+			    0) {
+				unsigned long *addr =
+				    (unsigned long *)isa_bus_to_virt(pos + 4);
+				len = *addr;
+				/* if the length of the table extends past 1M,
+				 * the table cannot be valid. */
+				if (pos + len <= (IBFT_END-1)) {
+					ibft_addr = (struct acpi_table_ibft *)virt;
+					pr_info("iBFT found at 0x%lx.\n", pos);
+					goto done;
+				}
+			}
+		}
+	}
+done:
+	return len;
+}
+/*
+ * Routine used to find the iSCSI Boot Format Table. The logical
+ * kernel address is set in the ibft_addr global variable.
+ */
+unsigned long __init find_ibft_region(unsigned long *sizep)
+{
+	ibft_addr = NULL;
+
+	/* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
+	 * only use ACPI for this */
+
+	if (!efi_enabled(EFI_BOOT))
+		find_ibft_in_mem();
+
+	if (ibft_addr) {
+		*sizep = PAGE_ALIGN(ibft_addr->header.length);
+		return (u64)virt_to_phys(ibft_addr);
+	}
+
+	*sizep = 0;
+	return 0;
+}