[PATCH v3] x86, tboot: iomem fixes

[Qiaowei Ren <qiaowei.ren@intel.com>]

Current code doesn't use specific interface to access I/O space.
So some potential bugs can be caused. We can fix this by using
specific API.

Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
---
 arch/x86/kernel/tboot.c |   21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 3ff42d2..afe8cf8 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -466,9 +466,12 @@ struct sinit_mle_data {
 	u32               vtd_dmars_off;
 } __packed;
 
+#define SINIT_MLE_DATA_VTD_DMAR_OFF	140
+
 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
 {
-	void *heap_base, *heap_ptr, *config;
+	void __iomem *heap_base, *heap_ptr, *config;
+	u32 dmar_tbl_off;
 
 	if (!tboot_enabled())
 		return dmar_tbl;
@@ -485,25 +488,25 @@ struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tb
 		return NULL;
 
 	/* now map TXT heap */
-	heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
-			    *(u64 *)(config + TXTCR_HEAP_SIZE));
+	heap_base = ioremap(readl(config + TXTCR_HEAP_BASE),
+			    readl(config + TXTCR_HEAP_SIZE));
 	iounmap(config);
 	if (!heap_base)
 		return NULL;
 
 	/* walk heap to SinitMleData */
 	/* skip BiosData */
-	heap_ptr = heap_base + *(u64 *)heap_base;
+	heap_ptr = heap_base + readq(heap_base);
 	/* skip OsMleData */
-	heap_ptr += *(u64 *)heap_ptr;
+	heap_ptr += readq(heap_ptr);
 	/* skip OsSinitData */
-	heap_ptr += *(u64 *)heap_ptr;
+	heap_ptr += readq(heap_ptr);
 	/* now points to SinitMleDataSize; set to SinitMleData */
 	heap_ptr += sizeof(u64);
 	/* get addr of DMAR table */
-	dmar_tbl = (struct acpi_table_header *)(heap_ptr +
-		   ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
-		   sizeof(u64));
+	dmar_tbl_off = readl(heap_ptr + SINIT_MLE_DATA_VTD_DMAR_OFF);
+	memcpy_fromio(dmar_tbl, heap_ptr + dmar_tbl_off - sizeof(u64),
+			sizeof(struct acpi_table_header));
 
 	/* don't unmap heap because dmar.c needs access to this */
 
-- 
1.7.9.5