[PATCH -v2] ibft: Fix finding IBFT ACPI table on UEFI

[Yinghai Lu <yinghai.lu@oracle.com>]

Found one system with UEFI/iBFT, Kernel does not detect the iBFT during
iscsi_ibft module loading.

the root cause: for x86, We have calling of find_ibft_region() much early.
in setup_arch() before ACPI is enabled.

Try to call find_ibft_region() second time in ibft_init().

At that time ACPI iBFT already get permanent mapped with ioremap.
So isa_virt_to_bus will get wrong phys from right virt address.
We could just skip that phys address printing.

For legacy one, print the found address early.

-v2: update comments and description according to Konrad.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 drivers/firmware/iscsi_ibft.c      |   14 ++++++++++++--
 drivers/firmware/iscsi_ibft_find.c |    1 +
 2 files changed, 13 insertions(+), 2 deletions(-)

Index: linux-2.6/drivers/firmware/iscsi_ibft.c
===================================================================
--- linux-2.6.orig/drivers/firmware/iscsi_ibft.c
+++ linux-2.6/drivers/firmware/iscsi_ibft.c
@@ -753,9 +753,19 @@ static int __init ibft_init(void)
 {
 	int rc = 0;
 
+	/*
+	   Retry as on UEFI systems the setup_arch()/find_ibft_region()
+	   is called before ACPI tables are parsed so we never
+	   get the data.
+	*/
+	if (!ibft_addr) {
+		unsigned long size = 0;
+
+		find_ibft_region(&size);
+	}
+
 	if (ibft_addr) {
-		printk(KERN_INFO "iBFT detected at 0x%llx.\n",
-		       (u64)isa_virt_to_bus(ibft_addr));
+		pr_info("iBFT detected.\n");
 
 		rc = ibft_check_device();
 		if (rc)
Index: linux-2.6/drivers/firmware/iscsi_ibft_find.c
===================================================================
--- linux-2.6.orig/drivers/firmware/iscsi_ibft_find.c
+++ linux-2.6/drivers/firmware/iscsi_ibft_find.c
@@ -94,6 +94,7 @@ static int __init find_ibft_in_mem(void)
 				 * 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;
 				}
 			}