[PATCH v5 08/17] iommu/dma: Introduce iommu_dma_prepare_msi_list()
Andrew Jones
andrew.jones at oss.qualcomm.com
Mon Aug 31 07:59:34 PDT 2026
Add iommu_dma_prepare_msi_list() to map an ordered physical address list
through the current domain backend. Validate that the requested granule
is a power of two no smaller than PAGE_SIZE and that every address is
aligned to it.
Refactor iommu_dma_prepare_msi() to obtain the backend granule and align
its single address before using the same list dispatcher. Convert the
DMA-IOMMU and iommufd backend entry points to consume address lists
directly.
Signed-off-by: Andrew Jones <andrew.jones at oss.qualcomm.com>
---
drivers/iommu/dma-iommu.c | 13 ++--
drivers/iommu/dma-iommu.h | 13 +++-
drivers/iommu/iommu-priv.h | 7 ++-
drivers/iommu/iommu.c | 109 +++++++++++++++++++++++++++------
drivers/iommu/iommufd/driver.c | 24 +++-----
include/linux/iommu.h | 8 +++
6 files changed, 126 insertions(+), 48 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 38a0c4e244d6..c9fdc792416c 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -2173,7 +2173,7 @@ static bool has_msi_cookie(const struct iommu_domain *domain)
domain->cookie_type == IOMMU_COOKIE_DMA_MSI);
}
-static size_t cookie_msi_granule(const struct iommu_domain *domain)
+size_t iommu_dma_msi_granule(const struct iommu_domain *domain)
{
switch (domain->cookie_type) {
case IOMMU_COOKIE_DMA_IOVA:
@@ -2304,23 +2304,20 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
}
int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
- phys_addr_t msi_addr)
+ const phys_addr_t *phys_addrs, unsigned int nr_addrs, size_t granule)
{
struct device *dev = msi_desc_to_dev(desc);
const struct iommu_dma_msi_page *msi_page;
- phys_addr_t phys_addr;
- size_t granule;
if (!has_msi_cookie(domain)) {
msi_desc_set_iommu_msi_iova(desc, 0, 0);
return 0;
}
-
- granule = cookie_msi_granule(domain);
- phys_addr = ALIGN_DOWN(msi_addr, granule);
+ if (granule != iommu_dma_msi_granule(domain))
+ return -EOPNOTSUPP;
iommu_group_mutex_assert(dev);
- msi_page = iommu_dma_get_msi_page(dev, &phys_addr, 1, granule, domain);
+ msi_page = iommu_dma_get_msi_page(dev, phys_addrs, nr_addrs, granule, domain);
if (!msi_page)
return -ENOMEM;
diff --git a/drivers/iommu/dma-iommu.h b/drivers/iommu/dma-iommu.h
index 040d00252563..bf9cd4102d35 100644
--- a/drivers/iommu/dma-iommu.h
+++ b/drivers/iommu/dma-iommu.h
@@ -19,8 +19,9 @@ int iommu_dma_init_fq(struct iommu_domain *domain);
void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
+size_t iommu_dma_msi_granule(const struct iommu_domain *domain);
int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
- phys_addr_t msi_addr);
+ const phys_addr_t *phys_addrs, unsigned int nr_addrs, size_t granule);
extern bool iommu_dma_forcedac;
@@ -53,8 +54,14 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he
{
}
-static inline int iommu_dma_sw_msi(struct iommu_domain *domain,
- struct msi_desc *desc, phys_addr_t msi_addr)
+static inline size_t iommu_dma_msi_granule(const struct iommu_domain *domain)
+{
+ return 0;
+}
+
+static inline int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+ const phys_addr_t *phys_addrs, unsigned int nr_addrs,
+ size_t granule)
{
return -ENODEV;
}
diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h
index aaffad5854fc..1122c99566d5 100644
--- a/drivers/iommu/iommu-priv.h
+++ b/drivers/iommu/iommu-priv.h
@@ -54,10 +54,11 @@ int iommu_replace_group_handle(struct iommu_group *group,
#if IS_ENABLED(CONFIG_IOMMUFD_DRIVER_CORE) && IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
- phys_addr_t msi_addr);
+ const phys_addr_t *phys_addrs, unsigned int nr_addrs, size_t granule);
#else /* !CONFIG_IOMMUFD_DRIVER_CORE || !CONFIG_IRQ_MSI_IOMMU */
-static inline int iommufd_sw_msi(struct iommu_domain *domain,
- struct msi_desc *desc, phys_addr_t msi_addr)
+static inline int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+ const phys_addr_t *phys_addrs, unsigned int nr_addrs,
+ size_t granule)
{
return -EOPNOTSUPP;
}
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index a3dea7353500..692e793c624e 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -4223,42 +4223,115 @@ void pci_dev_reset_iommu_done(struct pci_dev *pdev)
EXPORT_SYMBOL_GPL(pci_dev_reset_iommu_done);
#if IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
+static int __iommu_dma_prepare_msi_list(struct iommu_group *group, struct msi_desc *desc,
+ const phys_addr_t *phys_addrs, unsigned int nr_addrs,
+ size_t granule)
+{
+ if (!group->domain || group->domain->type == IOMMU_DOMAIN_IDENTITY)
+ return 0;
+
+ switch (group->domain->cookie_type) {
+ case IOMMU_COOKIE_DMA_MSI:
+ case IOMMU_COOKIE_DMA_IOVA:
+ return iommu_dma_sw_msi(group->domain, desc, phys_addrs, nr_addrs, granule);
+ case IOMMU_COOKIE_IOMMUFD:
+ return iommufd_sw_msi(group->domain, desc, phys_addrs, nr_addrs, granule);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int iommu_dma_validate_msi_list(const phys_addr_t *phys_addrs, unsigned int nr_addrs,
+ size_t granule)
+{
+ unsigned int i;
+
+ if (!nr_addrs || granule < PAGE_SIZE || !is_power_of_2(granule) ||
+ nr_addrs > SIZE_MAX / granule)
+ return -EINVAL;
+
+ for (i = 0; i < nr_addrs; i++)
+ if (!IS_ALIGNED(phys_addrs[i], granule))
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * iommu_dma_prepare_msi_list() - Map MSI pages in the IOMMU domain
+ * @desc: MSI descriptor to update with the base IOVA
+ * @phys_addrs: Ordered MSI target physical addresses
+ * @nr_addrs: Number of addresses in @phys_addrs
+ * @granule: Mapping granule for every address
+ *
+ * @nr_addrs must be nonzero and @granule must be a power of two no smaller than
+ * PAGE_SIZE. Every address must be aligned to @granule. The addresses are mapped
+ * in order to one contiguous IOVA range and may repeat. The list is consumed
+ * synchronously and is not retained.
+ *
+ * When a software MSI mapping is required, the backend records the base IOVA
+ * and granule shift in @desc. Otherwise, @desc is left unchanged.
+ *
+ * Return: 0 on success, -EINVAL if the parameters are invalid, -EOPNOTSUPP if
+ * the domain backend cannot provide the mapping, or another negative error
+ * code from the backend.
+ */
+int iommu_dma_prepare_msi_list(struct msi_desc *desc, const phys_addr_t *phys_addrs,
+ unsigned int nr_addrs, size_t granule)
+{
+ struct device *dev = msi_desc_to_dev(desc);
+ struct iommu_group *group = dev->iommu_group;
+ int ret;
+
+ ret = iommu_dma_validate_msi_list(phys_addrs, nr_addrs, granule);
+ if (ret || !group)
+ return ret;
+
+ mutex_lock(&group->mutex);
+ ret = __iommu_dma_prepare_msi_list(group, desc, phys_addrs, nr_addrs, granule);
+ mutex_unlock(&group->mutex);
+ return ret;
+}
+
/**
* iommu_dma_prepare_msi() - Map the MSI page in the IOMMU domain
* @desc: MSI descriptor, will store the MSI page
* @msi_addr: MSI target address to be mapped
*
- * The implementation of sw_msi() should take msi_addr and map it to
- * an IOVA in the domain and call msi_desc_set_iommu_msi_iova() with the
- * mapping information.
- *
* Return: 0 on success or negative error code if the mapping failed.
*/
int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr)
{
struct device *dev = msi_desc_to_dev(desc);
struct iommu_group *group = dev->iommu_group;
+ phys_addr_t phys_addr;
+ size_t granule;
int ret = 0;
if (!group)
return 0;
mutex_lock(&group->mutex);
- /* An IDENTITY domain must pass through */
- if (group->domain && group->domain->type != IOMMU_DOMAIN_IDENTITY) {
- switch (group->domain->cookie_type) {
- case IOMMU_COOKIE_DMA_MSI:
- case IOMMU_COOKIE_DMA_IOVA:
- ret = iommu_dma_sw_msi(group->domain, desc, msi_addr);
- break;
- case IOMMU_COOKIE_IOMMUFD:
- ret = iommufd_sw_msi(group->domain, desc, msi_addr);
- break;
- default:
- ret = -EOPNOTSUPP;
- break;
- }
+ if (!group->domain || group->domain->type == IOMMU_DOMAIN_IDENTITY)
+ goto out_unlock;
+
+ switch (group->domain->cookie_type) {
+ case IOMMU_COOKIE_DMA_MSI:
+ case IOMMU_COOKIE_DMA_IOVA:
+ granule = iommu_dma_msi_granule(group->domain);
+ break;
+ case IOMMU_COOKIE_IOMMUFD:
+ granule = PAGE_SIZE;
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ goto out_unlock;
}
+
+ phys_addr = ALIGN_DOWN(msi_addr, granule);
+ ret = __iommu_dma_prepare_msi_list(group, desc, &phys_addr, 1, granule);
+
+out_unlock:
mutex_unlock(&group->mutex);
return ret;
}
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index 45278c11c688..72e9ce63a5ee 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c
@@ -419,9 +419,14 @@ static void iommufd_sw_msi_set_required(struct iommufd_group *igroup,
}
}
-static int iommufd_sw_msi_list(struct iommu_domain *domain, struct msi_desc *desc,
- const phys_addr_t *phys_addrs, unsigned int nr_addrs,
- size_t granule)
+/*
+ * Called by the irq code if the platform translates the MSI addresses through the
+ * IOMMU. phys_addrs are the physical addresses of the MSI pages. iommufd will
+ * allocate contiguous fd global iovas for the physical pages that are the same on
+ * all domains and devices.
+ */
+int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+ const phys_addr_t *phys_addrs, unsigned int nr_addrs, size_t granule)
{
struct device *dev = msi_desc_to_dev(desc);
struct iommufd_hwpt_paging *hwpt_paging;
@@ -505,19 +510,6 @@ static int iommufd_sw_msi_list(struct iommu_domain *domain, struct msi_desc *des
return rc;
}
-/*
- * Called by the irq code if the platform translates the MSI address through the
- * IOMMU. msi_addr is the physical address of the MSI page. iommufd will
- * allocate a fd global iova for the physical page that is the same on all
- * domains and devices.
- */
-int iommufd_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
- phys_addr_t msi_addr)
-{
- phys_addr_t phys_addr = msi_addr & PAGE_MASK;
-
- return iommufd_sw_msi_list(domain, desc, &phys_addr, 1, PAGE_SIZE);
-}
EXPORT_SYMBOL_NS_GPL(iommufd_sw_msi, "IOMMUFD");
#endif
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index ac43b8b93f14..bf08be172e40 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -1561,8 +1561,16 @@ static inline void pci_dev_reset_iommu_done(struct pci_dev *pdev)
#ifdef CONFIG_IRQ_MSI_IOMMU
#ifdef CONFIG_IOMMU_API
+int iommu_dma_prepare_msi_list(struct msi_desc *desc, const phys_addr_t *phys_addrs,
+ unsigned int nr_addrs, size_t granule);
int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr);
#else
+static inline int iommu_dma_prepare_msi_list(struct msi_desc *desc, const phys_addr_t *phys_addrs,
+ unsigned int nr_addrs, size_t granule)
+{
+ return 0;
+}
+
static inline int iommu_dma_prepare_msi(struct msi_desc *desc,
phys_addr_t msi_addr)
{
--
2.43.0
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