ibft: For UEFI machines actually do scan ACPI for iBFT.

For machines with IBFT 1.03 do scan the ACPI table for 'iBFT'
or for 'IBFT'. If the machine is in UEFI mode, only do the ACPI
table scan. For all other machines (pre IBFT 1.03) do
a memory scan if not found in the ACPI tables.

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
Tested-by: Mike Christie <michaelc@cs.wisc.edu>

1 files changed, 19 insertions, 12 deletions

diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c
index dd85555d3296..82a7a1566290 100644
--- a/drivers/firmware/iscsi_ibft_find.c
+++ b/drivers/firmware/iscsi_ibft_find.c
@@ -57,23 +57,12 @@ static int __init acpi_find_ibft(struct acpi_table_header *header)
 }
 #endif /* CONFIG_ACPI */
 
-/*
- * 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)
+static int __init find_ibft_in_mem(void)
 {
         unsigned long pos;
         unsigned int len = 0;
         void *virt;
 
-        ibft_addr = NULL;
-
-        /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
-         * only use ACPI for this */
-        if (efi_enabled)
-                return 0;
-
         for (pos = IBFT_START; pos < IBFT_END; pos += 16) {
                 /* The table can't be inside the VGA BIOS reserved space,
                  * so skip that area */
@@ -92,6 +81,17 @@ unsigned long __init find_ibft_region(unsigned long *sizep)
                         }
                 }
         }
+        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;
+
 #ifdef CONFIG_ACPI
         /*
          * One spec says "IBFT", the other says "iBFT". We have to check
@@ -102,6 +102,13 @@ unsigned long __init find_ibft_region(unsigned long *sizep)
         if (!ibft_addr)
                 acpi_table_parse("iBFT", acpi_find_ibft);
 #endif /* CONFIG_ACPI */
+
+        /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
+         * only use ACPI for this */
+
+        if (!ibft_addr && !efi_enabled)
+                find_ibft_in_mem();
+
         if (ibft_addr) {
                 *sizep = PAGE_ALIGN(ibft_addr->header.length);
                 return (u64)isa_virt_to_bus(ibft_addr);