enabling graphics memory dma remapping

Here're three patches below:

- intel_iommu-explicit-export-current-graphics-dmar-status.patch

This exports current status of graphics dma remap engine, which depends on current platform iommu support, kernel config or runtime config. This info will be used in agp module for detect whether we should do remapping or not.

- AGP-Add-generic-support-for-graphics-dma-remapping.patch

This adds new hooks into agp bridge driver to do map/unmap when bind/unbind memory into GART table. The aim is to provide generic interfaces to let driver implement hardware specific operations.

- AGP-intel_agp-add-support-for-graphics-dma-remapping.patch

This implements graphics dma remapping support in intel_agp module, current only desktop chipset G33 series can use it.

[agp-mm] [intel_iommu] explicit export current graphics dmar status

To make it possbile to tell other modules about curent graphics dmar engine status, that could decide if graphics driver should remap physical address to dma address.

Also this one trys to make dmar_disabled really present current status of DMAR, which would be used for completely express graphics dmar engine is active or not.

Signed-off-by Zhenyu Wang <[email protected]>

---
 drivers/pci/intel-iommu.c |   18 ++++++++++++++++--
 include/linux/dmar.h      |    6 ++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

drivers/pci/intel-iommu.c +16 -2

index e079a52..81a0abc 100644
@@ -53,7 +53,7 @@
 static void domain_remove_dev_info(struct dmar_domain *domain);
 
 static int dmar_disabled;
-static int __initdata dmar_map_gfx = 1;
+static int dmar_map_gfx = 1;
 static int dmar_forcedac;
 
 #define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))

@@ -86,6 +86,16 @@ static int __init intel_iommu_setup(char *str)
 }
 __setup("intel_iommu=", intel_iommu_setup);
 
+int intel_iommu_gfx_remapping(void)
+{
+#ifndef CONFIG_DMAR_GFX_WA
+	if (!dmar_disabled && iommu_detected && dmar_map_gfx)
+		return 1;
+#endif
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_iommu_gfx_remapping);
+
 static struct kmem_cache *iommu_domain_cache;
 static struct kmem_cache *iommu_devinfo_cache;
 static struct kmem_cache *iommu_iova_cache;

@@ -2189,8 +2199,12 @@ static void __init iommu_exit_mempool(void)
 
 void __init detect_intel_iommu(void)
 {
-	if (swiotlb || no_iommu || iommu_detected || dmar_disabled)
+	if (dmar_disabled)
+		return;
+	if (swiotlb || no_iommu || iommu_detected) {
+		dmar_disabled = 1;
 		return;
+	}
 	if (early_dmar_detect()) {
 		iommu_detected = 1;
 	}

include/linux/dmar.h +6 -0

index ffb6439..8ae435e 100644
@@ -47,6 +47,8 @@ extern int intel_iommu_init(void);
 extern int dmar_table_init(void);
 extern int early_dmar_detect(void);
 
+extern int intel_iommu_gfx_remapping(void);
+
 extern struct list_head dmar_drhd_units;
 extern struct list_head dmar_rmrr_units;
 

@@ -81,6 +83,10 @@ static inline int intel_iommu_init(void)
 {
 	return -ENODEV;
 }
+static inline int intel_iommu_gfx_remapping(void)
+{
+	return 0;
+}
 
 #endif /* !CONFIG_DMAR */
 #endif /* __DMAR_H__ */

Signature · 1 line

1.5.3.4

Quoted 10 lines · Zhenyu Wang

[agp-mm] [intel_iommu] explicit export current graphics dmar status

To make it possbile to tell other modules about curent graphics dmar engine status, that could decide if graphics driver should remap physical address to dma address.

Also this one trys to make dmar_disabled really present current status of DMAR, which would be used for completely express graphics dmar engine is active or not.

Quoted 39 lines

Signed-off-by Zhenyu Wang <[email protected]>

---
 drivers/pci/intel-iommu.c |   18 ++++++++++++++++--
 include/linux/dmar.h      |    6 ++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

drivers/pci/intel-iommu.c +11 -1

index e079a52..81a0abc 100644
@@ -53,7 +53,7 @@
 static void domain_remove_dev_info(struct dmar_domain *domain);
 
 static int dmar_disabled;
-static int __initdata dmar_map_gfx = 1;
+static int dmar_map_gfx = 1;
 static int dmar_forcedac;
 
 #define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))

@@ -86,6 +86,16 @@ static int __init intel_iommu_setup(char *str)
 }
 __setup("intel_iommu=", intel_iommu_setup);
 
+int intel_iommu_gfx_remapping(void)
+{
+#ifndef CONFIG_DMAR_GFX_WA
+	if (!dmar_disabled && iommu_detected && dmar_map_gfx)
+		return 1;
+#endif
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_iommu_gfx_remapping);
+
 static struct kmem_cache *iommu_domain_cache;
 static struct kmem_cache *iommu_devinfo_cache;
 static struct kmem_cache *iommu_iova_cache;

@@ -2189,8 +2199,12 @@ static void __init iommu_exit_mempool(void)
 

drivers/pci/intel-iommu.c static void __init iommu_exit_mempool(void) · line 2206

Quoted 8 lines

drivers/pci/intel-iommu.c +4 -1

 void __init detect_intel_iommu(void)
 {
-	if (swiotlb || no_iommu || iommu_detected || dmar_disabled)
+	if (dmar_disabled)
+		return;
+	if (swiotlb || no_iommu || iommu_detected) {
+		dmar_disabled = 1;
 		return;

Quoted 17 lines

drivers/pci/intel-iommu.c +1 -0

+	}
 	if (early_dmar_detect()) {
 		iommu_detected = 1;
 	}

include/linux/dmar.h +2 -0

index ffb6439..8ae435e 100644
@@ -47,6 +47,8 @@ extern int intel_iommu_init(void);
 extern int dmar_table_init(void);
 extern int early_dmar_detect(void);
 
+extern int intel_iommu_gfx_remapping(void);
+
 extern struct list_head dmar_drhd_units;
 extern struct list_head dmar_rmrr_units;
 

include/linux/dmar.h static inline int intel_iommu_init(void) · line 89

Quoted 8 lines

include/linux/dmar.h +4 -0

@@ -81,6 +83,10 @@ static inline int intel_iommu_init(void)
 {
 	return -ENODEV;
 }
+static inline int intel_iommu_gfx_remapping(void)
+{
+	return 0;
+}

Quoted 6 lines

include/linux/dmar.h +0 -0

 #endif /* !CONFIG_DMAR */
 #endif /* __DMAR_H__ */

Signature · 1 line

1.5.3.4

Any comments to this one? Is it ok to push this iommu patch with agp dma remapping patches to next -mm?

Quoted 7 lines

Quoted 7 lines

[agp-mm] [intel_iommu] explicit export current graphics dmar status

To make it possbile to tell other modules about curent graphics dmar engine status, that could decide if graphics driver should remap physical address to dma address.

Quoted 3 lines

Quoted 3 lines

Also this one trys to make dmar_disabled really present current status of DMAR, which would be used for completely express graphics dmar engine is active or not.

do you think this exporting will be needed?
If so why and when would someone use it?

Quoted 40 lines

Quoted 40 lines

Signed-off-by Zhenyu Wang <[email protected]>

---
 drivers/pci/intel-iommu.c |   18 ++++++++++++++++--
 include/linux/dmar.h      |    6 ++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

drivers/pci/intel-iommu.c +11 -1

index e079a52..81a0abc 100644
@@ -53,7 +53,7 @@
 static void domain_remove_dev_info(struct dmar_domain *domain);
 
 static int dmar_disabled;
-static int __initdata dmar_map_gfx = 1;
+static int dmar_map_gfx = 1;
 static int dmar_forcedac;
 
 #define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))

@@ -86,6 +86,16 @@ static int __init intel_iommu_setup(char *str)
 }
 __setup("intel_iommu=", intel_iommu_setup);
 
+int intel_iommu_gfx_remapping(void)
+{
+#ifndef CONFIG_DMAR_GFX_WA
+	if (!dmar_disabled && iommu_detected && dmar_map_gfx)
+		return 1;
+#endif
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_iommu_gfx_remapping);
+
 static struct kmem_cache *iommu_domain_cache;
 static struct kmem_cache *iommu_devinfo_cache;
 static struct kmem_cache *iommu_iova_cache;

@@ -2189,8 +2199,12 @@ static void __init iommu_exit_mempool(void)
 

Quoted 8 lines

drivers/pci/intel-iommu.c static void __init iommu_exit_mempool(void) · line 2206

Quoted 8 lines

drivers/pci/intel-iommu.c +4 -1

 void __init detect_intel_iommu(void)
 {
-	if (swiotlb || no_iommu || iommu_detected || dmar_disabled)
+	if (dmar_disabled)
+		return;
+	if (swiotlb || no_iommu || iommu_detected) {
+		dmar_disabled = 1;
 		return;

Why the bloat? This block of 7 lines looks like it does the same as the 2 you replaced.

Quoted 18 lines

Quoted 18 lines

drivers/pci/intel-iommu.c +1 -0

+	}
 	if (early_dmar_detect()) {
 		iommu_detected = 1;
 	}

include/linux/dmar.h +2 -0

index ffb6439..8ae435e 100644
@@ -47,6 +47,8 @@ extern int intel_iommu_init(void);
 extern int dmar_table_init(void);
 extern int early_dmar_detect(void);
 
+extern int intel_iommu_gfx_remapping(void);
+
 extern struct list_head dmar_drhd_units;
 extern struct list_head dmar_rmrr_units;
 

Quoted 8 lines

include/linux/dmar.h static inline int intel_iommu_init(void) · line 89

Quoted 8 lines

include/linux/dmar.h +4 -0

@@ -81,6 +83,10 @@ static inline int intel_iommu_init(void)
 {
 	return -ENODEV;
 }
+static inline int intel_iommu_gfx_remapping(void)
+{
+	return 0;
+}

Um this function is silly lets not post it.

Quoted 10 lines

Quoted 6 lines

include/linux/dmar.h +0 -0

 #endif /* !CONFIG_DMAR */
 #endif /* __DMAR_H__ */

Signature · 1 line

1.5.3.4

Any comments to this one? Is it ok to push this iommu patch with agp dma remapping patches to next -mm?

Its not ready for posting.

--mgross

Mark, sorry for missing this for long time...

Quoted 11 lines · mark gross

Quoted 10 lines

Quoted 10 lines

[agp-mm] [intel_iommu] explicit export current graphics dmar status

To make it possbile to tell other modules about curent graphics dmar engine status, that could decide if graphics driver should remap physical address to dma address.

Also this one trys to make dmar_disabled really present current status of DMAR, which would be used for completely express graphics dmar engine is active or not.

Quoted 2 lines

do you think this exporting will be needed?
If so why and when would someone use it?

This is used for our graphics driver module to know if we have to do dma remapping in iommu case, both in kernel config and kernel boot time param config.

The simplest case is that DMAR_GFX_WA is on, which no dma mapping will act in intel_agp.

If no DMAR_GFX_WA, we still have boot param to turn off whole intel iommu (intel_iommu=off), just turn off graphics remap engine (intel_iommu=igfx_off). So this exported interface is used to know that in runtime.

Quoted 40 lines

Quoted 40 lines

Quoted 40 lines

Signed-off-by Zhenyu Wang <[email protected]>

---
 drivers/pci/intel-iommu.c |   18 ++++++++++++++++--
 include/linux/dmar.h      |    6 ++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

drivers/pci/intel-iommu.c +11 -1

index e079a52..81a0abc 100644
@@ -53,7 +53,7 @@
 static void domain_remove_dev_info(struct dmar_domain *domain);
 
 static int dmar_disabled;
-static int __initdata dmar_map_gfx = 1;
+static int dmar_map_gfx = 1;
 static int dmar_forcedac;
 
 #define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))

@@ -86,6 +86,16 @@ static int __init intel_iommu_setup(char *str)
 }
 __setup("intel_iommu=", intel_iommu_setup);
 
+int intel_iommu_gfx_remapping(void)
+{
+#ifndef CONFIG_DMAR_GFX_WA
+	if (!dmar_disabled && iommu_detected && dmar_map_gfx)
+		return 1;
+#endif
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_iommu_gfx_remapping);
+
 static struct kmem_cache *iommu_domain_cache;
 static struct kmem_cache *iommu_devinfo_cache;
 static struct kmem_cache *iommu_iova_cache;

@@ -2189,8 +2199,12 @@ static void __init iommu_exit_mempool(void)
 

Quoted 11 lines

Quoted 8 lines

drivers/pci/intel-iommu.c static void __init iommu_exit_mempool(void) · line 2206

Quoted 8 lines

drivers/pci/intel-iommu.c +4 -1

 void __init detect_intel_iommu(void)
 {
-	if (swiotlb || no_iommu || iommu_detected || dmar_disabled)
+	if (dmar_disabled)
+		return;
+	if (swiotlb || no_iommu || iommu_detected) {
+		dmar_disabled = 1;
 		return;

Why the bloat? This block of 7 lines looks like it does the same as the 2 you replaced.

No, dmar_disabled is not set in origin, which can't tell if it's turned off with (intel_iommu=off) later.

Quoted 36 lines

Quoted 18 lines

Quoted 18 lines

drivers/pci/intel-iommu.c +1 -0

+	}
 	if (early_dmar_detect()) {
 		iommu_detected = 1;
 	}

include/linux/dmar.h +2 -0

index ffb6439..8ae435e 100644
@@ -47,6 +47,8 @@ extern int intel_iommu_init(void);
 extern int dmar_table_init(void);
 extern int early_dmar_detect(void);
 
+extern int intel_iommu_gfx_remapping(void);
+
 extern struct list_head dmar_drhd_units;
 extern struct list_head dmar_rmrr_units;
 

Quoted 8 lines

include/linux/dmar.h static inline int intel_iommu_init(void) · line 89

Quoted 8 lines

include/linux/dmar.h +4 -0

@@ -81,6 +83,10 @@ static inline int intel_iommu_init(void)
 {
 	return -ENODEV;
 }
+static inline int intel_iommu_gfx_remapping(void)
+{
+	return 0;
+}

Um this function is silly lets not post it.

Quoted 7 lines

Quoted 6 lines

include/linux/dmar.h +0 -0

 #endif /* !CONFIG_DMAR */
 #endif /* __DMAR_H__ */

Signature · 1 line

1.5.3.4

Quoted 5 lines

Quoted 3 lines

Any comments to this one? Is it ok to push this iommu patch with agp dma remapping patches to next -mm?

Its not ready for posting.

Quoted 3 lines

This is used for our graphics driver module to know if we have to do dma remapping in iommu case, both in kernel config and kernel boot time param config.

ok. How soon do you need this export?

send me your current patch and eta for the graphics module patches so I can better coordinate with you.