[PATCH v8 05/08] iommu/ipmmu-vmsa: Add new IOMMU_DOMAIN_DMA ops

From: Magnus Damm
Date: Wed May 17 2017 - 06:11:47 EST


From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>

Introduce an alternative set of iommu_ops suitable for 64-bit ARM
as well as 32-bit ARM when CONFIG_IOMMU_DMA=y. Also adjust the
Kconfig to depend on ARM or IOMMU_DMA. Initialize the device
from ->xlate() when CONFIG_IOMMU_DMA=y.

Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
---

Changes since V7:
- None

drivers/iommu/Kconfig | 1
drivers/iommu/ipmmu-vmsa.c | 164 +++++++++++++++++++++++++++++++++++++++++---
2 files changed, 156 insertions(+), 9 deletions(-)

--- 0001/drivers/iommu/Kconfig
+++ work/drivers/iommu/Kconfig 2017-05-17 16:41:43.030607110 +0900
@@ -274,6 +274,7 @@ config EXYNOS_IOMMU_DEBUG

config IPMMU_VMSA
bool "Renesas VMSA-compatible IPMMU"
+ depends on ARM || IOMMU_DMA
depends on ARM_LPAE
depends on ARCH_RENESAS || COMPILE_TEST
select IOMMU_API
--- 0009/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c 2017-05-17 16:42:02.730607110 +0900
@@ -10,6 +10,7 @@

#include <linux/bitmap.h>
#include <linux/delay.h>
+#include <linux/dma-iommu.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/export.h>
@@ -22,8 +23,10 @@
#include <linux/sizes.h>
#include <linux/slab.h>

+#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
#include <asm/dma-iommu.h>
#include <asm/pgalloc.h>
+#endif

#include "io-pgtable.h"

@@ -57,6 +60,8 @@ struct ipmmu_vmsa_archdata {
struct ipmmu_vmsa_device *mmu;
unsigned int *utlbs;
unsigned int num_utlbs;
+ struct device *dev;
+ struct list_head list;
};

static DEFINE_SPINLOCK(ipmmu_devices_lock);
@@ -522,14 +527,6 @@ static struct iommu_domain *__ipmmu_doma
return &domain->io_domain;
}

-static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
-{
- if (type != IOMMU_DOMAIN_UNMANAGED)
- return NULL;
-
- return __ipmmu_domain_alloc(type);
-}
-
static void ipmmu_domain_free(struct iommu_domain *io_domain)
{
struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
@@ -572,7 +569,8 @@ static int ipmmu_attach_device(struct io
dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
dev_name(mmu->dev), dev_name(domain->mmu->dev));
ret = -EINVAL;
- }
+ } else
+ dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);

spin_unlock_irqrestore(&domain->lock, flags);

@@ -708,6 +706,7 @@ static int ipmmu_init_platform_device(st
archdata->mmu = mmu;
archdata->utlbs = utlbs;
archdata->num_utlbs = num_utlbs;
+ archdata->dev = dev;
dev->archdata.iommu = archdata;
return 0;

@@ -716,6 +715,16 @@ error:
return ret;
}

+#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
+
+static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
+{
+ if (type != IOMMU_DOMAIN_UNMANAGED)
+ return NULL;
+
+ return __ipmmu_domain_alloc(type);
+}
+
static int ipmmu_add_device(struct device *dev)
{
struct ipmmu_vmsa_archdata *archdata;
@@ -825,6 +834,141 @@ static const struct iommu_ops ipmmu_ops
.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
};

+#endif /* !CONFIG_ARM && CONFIG_IOMMU_DMA */
+
+#ifdef CONFIG_IOMMU_DMA
+
+static DEFINE_SPINLOCK(ipmmu_slave_devices_lock);
+static LIST_HEAD(ipmmu_slave_devices);
+
+static struct iommu_domain *ipmmu_domain_alloc_dma(unsigned type)
+{
+ struct iommu_domain *io_domain = NULL;
+
+ switch (type) {
+ case IOMMU_DOMAIN_UNMANAGED:
+ io_domain = __ipmmu_domain_alloc(type);
+ break;
+
+ case IOMMU_DOMAIN_DMA:
+ io_domain = __ipmmu_domain_alloc(type);
+ if (io_domain)
+ iommu_get_dma_cookie(io_domain);
+ break;
+ }
+
+ return io_domain;
+}
+
+static void ipmmu_domain_free_dma(struct iommu_domain *io_domain)
+{
+ switch (io_domain->type) {
+ case IOMMU_DOMAIN_DMA:
+ iommu_put_dma_cookie(io_domain);
+ /* fall-through */
+ default:
+ ipmmu_domain_free(io_domain);
+ break;
+ }
+}
+
+static int ipmmu_add_device_dma(struct device *dev)
+{
+ struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
+ struct iommu_group *group;
+
+ /* The device has been verified in xlate() */
+ if (!archdata)
+ return -ENODEV;
+
+ group = iommu_group_get_for_dev(dev);
+ if (IS_ERR(group))
+ return PTR_ERR(group);
+
+ spin_lock(&ipmmu_slave_devices_lock);
+ list_add(&archdata->list, &ipmmu_slave_devices);
+ spin_unlock(&ipmmu_slave_devices_lock);
+ return 0;
+}
+
+static void ipmmu_remove_device_dma(struct device *dev)
+{
+ struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
+
+ spin_lock(&ipmmu_slave_devices_lock);
+ list_del(&archdata->list);
+ spin_unlock(&ipmmu_slave_devices_lock);
+
+ iommu_group_remove_device(dev);
+}
+
+static struct device *ipmmu_find_sibling_device(struct device *dev)
+{
+ struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
+ struct ipmmu_vmsa_archdata *sibling_archdata = NULL;
+ bool found = false;
+
+ spin_lock(&ipmmu_slave_devices_lock);
+
+ list_for_each_entry(sibling_archdata, &ipmmu_slave_devices, list) {
+ if (archdata == sibling_archdata)
+ continue;
+ if (sibling_archdata->mmu == archdata->mmu) {
+ found = true;
+ break;
+ }
+ }
+
+ spin_unlock(&ipmmu_slave_devices_lock);
+
+ return found ? sibling_archdata->dev : NULL;
+}
+
+static struct iommu_group *ipmmu_find_group_dma(struct device *dev)
+{
+ struct iommu_group *group;
+ struct device *sibling;
+
+ sibling = ipmmu_find_sibling_device(dev);
+ if (sibling)
+ group = iommu_group_get(sibling);
+ if (!sibling || IS_ERR(group))
+ group = generic_device_group(dev);
+
+ return group;
+}
+
+static int ipmmu_of_xlate_dma(struct device *dev,
+ struct of_phandle_args *spec)
+{
+ /* If the IPMMU device is disabled in DT then return error
+ * to make sure the of_iommu code does not install ops
+ * even though the iommu device is disabled
+ */
+ if (!of_device_is_available(spec->np))
+ return -ENODEV;
+
+ return ipmmu_init_platform_device(dev);
+}
+
+static const struct iommu_ops ipmmu_ops = {
+ .domain_alloc = ipmmu_domain_alloc_dma,
+ .domain_free = ipmmu_domain_free_dma,
+ .attach_dev = ipmmu_attach_device,
+ .detach_dev = ipmmu_detach_device,
+ .map = ipmmu_map,
+ .unmap = ipmmu_unmap,
+ .map_sg = default_iommu_map_sg,
+ .iova_to_phys = ipmmu_iova_to_phys,
+ .add_device = ipmmu_add_device_dma,
+ .remove_device = ipmmu_remove_device_dma,
+ .device_group = ipmmu_find_group_dma,
+ .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
+ .of_xlate = ipmmu_of_xlate_dma,
+};
+
+#endif /* CONFIG_IOMMU_DMA */
+
/* -----------------------------------------------------------------------------
* Probe/remove and init
*/
@@ -914,7 +1058,9 @@ static int ipmmu_remove(struct platform_
list_del(&mmu->list);
spin_unlock(&ipmmu_devices_lock);

+#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
arm_iommu_release_mapping(mmu->mapping);
+#endif

ipmmu_device_reset(mmu);