Hi Magnus,
On 15/03/16 04:22, Magnus Damm wrote:
From: Magnus Damm <damm+rene...@opensource.se>
Make the driver compile on more than just 32-bit ARM
by breaking out and wrapping ARM specific functions
in #ifdefs. Not pretty, but needed to be able to use
the driver on other architectures like ARM64.
Signed-off-by: Magnus Damm <damm+rene...@opensource.se>
---
Changes since V1:
- Rebased to work without patch 2 and 3 from V1 series
drivers/iommu/ipmmu-vmsa.c | 94 +++++++++++++++++++++++++++++---------------
1 file changed, 62 insertions(+), 32 deletions(-)
--- 0004/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c 2016-03-15 12:25:45.040513000 +0900
@@ -22,8 +22,10 @@
#include <linux/sizes.h>
#include <linux/slab.h>
+#ifdef CONFIG_ARM
#include <asm/dma-iommu.h>
#include <asm/pgalloc.h>
+#endif
#include "io-pgtable.h"
@@ -38,7 +40,9 @@ struct ipmmu_vmsa_device {
DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
+#ifdef CONFIG_ARM
struct dma_iommu_mapping *mapping;
+#endif
};
struct ipmmu_vmsa_domain {
@@ -615,6 +619,60 @@ static int ipmmu_find_utlbs(struct ipmmu
return 0;
}
+#ifdef CONFIG_ARM
+static int ipmmu_map_attach(struct device *dev, struct ipmmu_vmsa_device *mmu)
+{
+ int ret;
+
+ /*
+ * Create the ARM mapping, used by the ARM DMA mapping core to allocate
+ * VAs. This will allocate a corresponding IOMMU domain.
+ *
+ * TODO:
+ * - Create one mapping per context (TLB).
+ * - Make the mapping size configurable ? We currently use a 2GB mapping
+ * at a 1GB offset to ensure that NULL VAs will fault.
+ */
+ if (!mmu->mapping) {
+ struct dma_iommu_mapping *mapping;
+
+ mapping = arm_iommu_create_mapping(&platform_bus_type,
+ SZ_1G, SZ_2G);
+ if (IS_ERR(mapping)) {
+ dev_err(mmu->dev, "failed to create ARM IOMMU
mapping\n");
+ return PTR_ERR(mapping);
+ }
+
+ mmu->mapping = mapping;
+ }
+
+ /* Attach the ARM VA mapping to the device. */
+ ret = arm_iommu_attach_device(dev, mmu->mapping);
+ if (ret < 0) {
+ dev_err(dev, "Failed to attach device to VA mapping\n");
+ arm_iommu_release_mapping(mmu->mapping);
+ }
+
+ return ret;
+}
This looks an awful lot like what the IOMMU core code now does
automatically via the (relatively new) default domain mechanism. I
suspect things might end up a fair bit simpler if you create the ARM
mapping in domain_alloc when asked for an IOMMU_DOMAIN_DMA domain. While
you're still using a single context, sticking all the client devices in
the same group will then keep everything together automatically (see
mtk_iommu.c in -next for an example) to retain the existing behaviour.
Since those mechanisms are all architecture-independent, that should
help minimise the mess when accommodating arm64 later.
Robin.
+static inline void ipmmu_detach(struct device *dev)
+{
+ arm_iommu_detach_device(dev);
+}
+static inline void ipmmu_release_mapping(struct ipmmu_vmsa_device *mmu)
+{
+ arm_iommu_release_mapping(mmu->mapping);
+}
+#else
+static inline int ipmmu_map_attach(struct device *dev,
+ struct ipmmu_vmsa_device *mmu)
+{
+ return 0;
+}
+static inline void ipmmu_detach(struct device *dev) {}
+static inline void ipmmu_release_mapping(struct ipmmu_vmsa_device *mmu) {}
+#endif
+
static int ipmmu_add_device(struct device *dev)
{
struct ipmmu_vmsa_archdata *archdata;
@@ -695,41 +753,13 @@ static int ipmmu_add_device(struct devic
archdata->num_utlbs = num_utlbs;
dev->archdata.iommu = archdata;
- /*
- * Create the ARM mapping, used by the ARM DMA mapping core to allocate
- * VAs. This will allocate a corresponding IOMMU domain.
- *
- * TODO:
- * - Create one mapping per context (TLB).
- * - Make the mapping size configurable ? We currently use a 2GB mapping
- * at a 1GB offset to ensure that NULL VAs will fault.
- */
- if (!mmu->mapping) {
- struct dma_iommu_mapping *mapping;
-
- mapping = arm_iommu_create_mapping(&platform_bus_type,
- SZ_1G, SZ_2G);
- if (IS_ERR(mapping)) {
- dev_err(mmu->dev, "failed to create ARM IOMMU
mapping\n");
- ret = PTR_ERR(mapping);
- goto error;
- }
-
- mmu->mapping = mapping;
- }
-
- /* Attach the ARM VA mapping to the device. */
- ret = arm_iommu_attach_device(dev, mmu->mapping);
- if (ret < 0) {
- dev_err(dev, "Failed to attach device to VA mapping\n");
+ ret = ipmmu_map_attach(dev, mmu);
+ if (ret < 0)
goto error;
- }
return 0;
error:
- arm_iommu_release_mapping(mmu->mapping);
-
kfree(dev->archdata.iommu);
kfree(utlbs);
@@ -745,7 +775,7 @@ static void ipmmu_remove_device(struct d
{
struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
- arm_iommu_detach_device(dev);
+ ipmmu_detach(dev);
iommu_group_remove_device(dev);
kfree(archdata->utlbs);
@@ -856,7 +886,7 @@ static int ipmmu_remove(struct platform_
list_del(&mmu->list);
spin_unlock(&ipmmu_devices_lock);
- arm_iommu_release_mapping(mmu->mapping);
+ ipmmu_release_mapping(mmu);
ipmmu_device_reset(mmu);
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