[PATCH] x86, tboot: iomem fixes

[PATCH] x86, tboot: iomem fixes

[Qiaowei Ren]

Fixes for iomem annotations in arch/x86/kernel/tboot.c

Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
---
 arch/x86/kernel/tboot.c |   43 +++++++++++--------------------------------
 1 file changed, 11 insertions(+), 32 deletions(-)

diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 3ff42d2..d06574c 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -442,33 +442,12 @@ late_initcall(tboot_late_init);
 #define TXTCR_HEAP_BASE             0x0300
 #define TXTCR_HEAP_SIZE             0x0308
 
-#define SHA1_SIZE      20
-
-struct sha1_hash {
-	u8 hash[SHA1_SIZE];
-};
-
-struct sinit_mle_data {
-	u32               version;             /* currently 6 */
-	struct sha1_hash  bios_acm_id;
-	u32               edx_senter_flags;
-	u64               mseg_valid;
-	struct sha1_hash  sinit_hash;
-	struct sha1_hash  mle_hash;
-	struct sha1_hash  stm_hash;
-	struct sha1_hash  lcp_policy_hash;
-	u32               lcp_policy_control;
-	u32               rlp_wakeup_addr;
-	u32               reserved;
-	u32               num_mdrs;
-	u32               mdrs_off;
-	u32               num_vtd_dmars;
-	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 +464,25 @@ 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

[PATCH] x86, tboot: iomem fixes

[Qiaowei Ren]

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 |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 3ff42d2..c902237 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_off = readl(heap_ptr + SINIT_MLE_DATA_VTD_DMAR_OFF);
 	dmar_tbl = (struct acpi_table_header *)(heap_ptr +
-		   ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
-		   sizeof(u64));
+			dmar_tbl_off - sizeof(u64));
 
 	/* don't unmap heap because dmar.c needs access to this */
 
-- 
1.7.9.5

Re: [PATCH] x86, tboot: iomem fixes

[Ingo Molnar]

* Qiaowei Ren <qiaowei.ren@intel.com> wrote:

> +#define SINIT_MLE_DATA_VTD_DMAR_OFF	140

>  	/* get addr of DMAR table */
> +	dmar_tbl_off = readl(heap_ptr + SINIT_MLE_DATA_VTD_DMAR_OFF);
>  	dmar_tbl = (struct acpi_table_header *)(heap_ptr +
> -		   ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
> -		   sizeof(u64));
> +			dmar_tbl_off - sizeof(u64));

So the offset of ->vtd_dmars_off within struct sinit_mle_data is 140?

The new code is less readable: what's wrong with getting the offset 
automatically via C, instead of hardcoding it manually? You can use 
offsetof() primitive for increased readability.

Thanks,

	Ingo

RE: [PATCH] x86, tboot: iomem fixes

[Ren, Qiaowei]

On 2013-07-20, Ingo Molnar wrote:
> 
> * Qiaowei Ren <qiaowei.ren@intel.com> wrote:
> 
>> +#define SINIT_MLE_DATA_VTD_DMAR_OFF	140
> 
>>  	/* get addr of DMAR table */ +	dmar_tbl_off = readl(heap_ptr +
>>  SINIT_MLE_DATA_VTD_DMAR_OFF); 	dmar_tbl = (struct acpi_table_header
>>  *)(heap_ptr +
>> -		   ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
>> -		   sizeof(u64));
>> +			dmar_tbl_off - sizeof(u64));
> 
> So the offset of ->vtd_dmars_off within struct sinit_mle_data is 140?
> 
> The new code is less readable: what's wrong with getting the offset
> automatically via C, instead of hardcoding it manually? You can use
> offsetof() primitive for increased readability.
> 
Ok. Thanks for your suggestion. I will try to use offsetof() to increase readability.

Thanks,
Qiaowei