ibft: Fix finding IBFT ACPI table on UEFI

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

Root cause: on x86 (UEFI), we are calling of find_ibft_region() much earlier
- specifically in setup_arch() before ACPI is enabled.

Try to split acpi checking code out and call that later

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.
-v3: fix problem about module use case that is found by Konrad.
-v4: use acpi_get_table() instead of acpi_table_parse() to handle module use case that is found by Konrad again..
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>

1 files changed, 2 insertions, 24 deletions

diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c
index bfe723266fd8..4da4eb9ae926 100644
--- a/drivers/firmware/iscsi_ibft_find.c
+++ b/drivers/firmware/iscsi_ibft_find.c
@@ -45,13 +45,6 @@ EXPORT_SYMBOL_GPL(ibft_addr);
 static const struct {
 	char *sign;
 } ibft_signs[] = {
-#ifdef CONFIG_ACPI
-	/*
-	 * One spec says "IBFT", the other says "iBFT". We have to check
-	 * for both.
-	 */
-	{ ACPI_SIG_IBFT },
-#endif
 	{ "iBFT" },
 	{ "BIFT" },	/* Broadcom iSCSI Offload */
 };
@@ -62,14 +55,6 @@ static const struct {
 #define VGA_MEM 0xA0000 /* VGA buffer */
 #define VGA_SIZE 0x20000 /* 128kB */
 
-#ifdef CONFIG_ACPI
-static int __init acpi_find_ibft(struct acpi_table_header *header)
-{
-	ibft_addr = (struct acpi_table_ibft *)header;
-	return 0;
-}
-#endif /* CONFIG_ACPI */
-
 static int __init find_ibft_in_mem(void)
 {
 	unsigned long pos;
@@ -94,6 +79,7 @@ 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;
 				}
 			}
@@ -108,20 +94,12 @@ done:
  */
 unsigned long __init find_ibft_region(unsigned long *sizep)
 {
-#ifdef CONFIG_ACPI
-	int i;
-#endif
 	ibft_addr = NULL;
 
-#ifdef CONFIG_ACPI
-	for (i = 0; i < ARRAY_SIZE(ibft_signs) && !ibft_addr; i++)
-		acpi_table_parse(ibft_signs[i].sign, 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)
+	if (!efi_enabled)
 		find_ibft_in_mem();
 
 	if (ibft_addr) {