From: Andrew Jones <andrew.jones@oss.qualcomm.com>
To: linux-riscv@lists.infradead.org, iommu@lists.linux.dev
Cc: linux-kernel@vger.kernel.org, tomasz.jeznach@linux.dev,
tjeznach@rivosinc.com, jgg@ziepe.ca, jgg@nvidia.com,
joro@8bytes.org, will@kernel.org, robin.murphy@arm.com,
pjw@kernel.org, palmer@dabbelt.com, anup@brainfault.org,
tglx@kernel.org, kevin.tian@intel.com,
fangyu.yu@linux.alibaba.com
Subject: [PATCH v3 03/19] iommu/dma: Add iommu_dma_sw_map_msi()
Date: Fri, 7 Aug 2026 20:16:57 +0200 [thread overview]
Message-ID: <20260807181713.228535-4-andrew.jones@oss.qualcomm.com> (raw)
In-Reply-To: <20260807181713.228535-1-andrew.jones@oss.qualcomm.com>
Add a descriptor-free counterpart to iommu_dma_sw_msi(). The existing
function is tied to a struct msi_desc and stores the result in the
descriptor. This variant returns the IOVA directly so callers can
pre-map MSI targets before any descriptor has been allocated.
Callers may pass a required mapping size so MSI doorbells that must
not share a larger IOMMU leaf, such as RISC-V IMSIC files, can fail
before a mapping is installed.
Signed-off-by: Andrew Jones <andrew.jones@oss.qualcomm.com>
---
drivers/iommu/dma-iommu.c | 48 ++++++++++++++++++++++++++++++++-------
drivers/iommu/dma-iommu.h | 12 ++++++++++
2 files changed, 52 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 9abaec0703ef..56a5072b4dde 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -2234,24 +2234,56 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
return NULL;
}
-int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
- phys_addr_t msi_addr)
+/*
+ * Descriptor-free counterpart to iommu_dma_sw_msi(). Maps an MSI physical
+ * page into the domain and returns the IOVA and mapping granule. Used for
+ * pre-mapping MSI targets before any MSI descriptor has been set.
+ *
+ * The caller must pass a device attached to @domain and hold @dev's IOMMU
+ * group mutex. If @required_size is non-zero then it must exactly match the
+ * domain's MSI mapping granule. @msi_iova and @msi_shift must be non-NULL.
+ */
+int iommu_dma_sw_map_msi(struct iommu_domain *domain,
+ struct device *dev, phys_addr_t msi_addr,
+ size_t required_size, dma_addr_t *msi_iova,
+ unsigned int *msi_shift)
{
- struct device *dev = msi_desc_to_dev(desc);
const struct iommu_dma_msi_page *msi_page;
+ size_t size;
- if (!has_msi_cookie(domain)) {
- msi_desc_set_iommu_msi_iova(desc, 0, 0);
+ *msi_iova = 0;
+ *msi_shift = 0;
+
+ if (!has_msi_cookie(domain))
return 0;
- }
+
+ size = cookie_msi_granule(domain);
+ if (required_size && size != required_size)
+ return -EOPNOTSUPP;
iommu_group_mutex_assert(dev);
msi_page = iommu_dma_get_msi_page(dev, msi_addr, domain);
if (!msi_page)
return -ENOMEM;
- msi_desc_set_iommu_msi_iova(desc, msi_page->iova,
- ilog2(cookie_msi_granule(domain)));
+ *msi_iova = msi_page->iova;
+ *msi_shift = ilog2(size);
+ return 0;
+}
+
+int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+ phys_addr_t msi_addr)
+{
+ struct device *dev = msi_desc_to_dev(desc);
+ dma_addr_t msi_iova;
+ unsigned int msi_shift;
+ int ret;
+
+ ret = iommu_dma_sw_map_msi(domain, dev, msi_addr, 0, &msi_iova, &msi_shift);
+ if (ret)
+ return ret;
+
+ msi_desc_set_iommu_msi_iova(desc, msi_iova, msi_shift);
return 0;
}
diff --git a/drivers/iommu/dma-iommu.h b/drivers/iommu/dma-iommu.h
index 040d00252563..3e1adeafdcac 100644
--- a/drivers/iommu/dma-iommu.h
+++ b/drivers/iommu/dma-iommu.h
@@ -19,6 +19,10 @@ int iommu_dma_init_fq(struct iommu_domain *domain);
void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
+int iommu_dma_sw_map_msi(struct iommu_domain *domain,
+ struct device *dev, phys_addr_t msi_addr,
+ size_t required_size, dma_addr_t *msi_iova,
+ unsigned int *msi_shift);
int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
phys_addr_t msi_addr);
@@ -53,6 +57,14 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he
{
}
+static inline int iommu_dma_sw_map_msi(struct iommu_domain *domain,
+ struct device *dev, phys_addr_t msi_addr,
+ size_t required_size, dma_addr_t *msi_iova,
+ unsigned int *msi_shift)
+{
+ return -ENODEV;
+}
+
static inline int iommu_dma_sw_msi(struct iommu_domain *domain,
struct msi_desc *desc, phys_addr_t msi_addr)
{
--
2.43.0
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next prev parent reply other threads:[~2026-08-07 18:17 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-07 18:16 [PATCH v3 00/19] iommu/riscv: Enable MSI remapping, IOMMU_DMA and VFIO Andrew Jones
2026-08-07 18:16 ` [PATCH v3 01/19] iommufd: Convert struct iommufd_sw_msi_maps to a growable bitmap Andrew Jones
2026-08-07 18:16 ` [PATCH v3 02/19] iommufd: Add iommufd_sw_map_msi() Andrew Jones
2026-08-07 18:16 ` Andrew Jones [this message]
2026-08-07 18:16 ` [PATCH v3 04/19] iommu/dma: Add iommu_dma_map_msi() Andrew Jones
2026-08-07 18:16 ` [PATCH v3 05/19] genirq/msi: Provide DOMAIN_BUS_MSI_REMAP Andrew Jones
2026-08-07 18:17 ` [PATCH v3 06/19] irqchip/riscv-imsic: Compose MSI updates through the hierarchy Andrew Jones
2026-08-07 20:25 ` Thomas Gleixner
2026-08-07 18:17 ` [PATCH v3 07/19] iommu/riscv: Add IRQ domain for interrupt remapping Andrew Jones
2026-08-07 20:32 ` Thomas Gleixner
2026-08-07 20:36 ` Thomas Gleixner
2026-08-07 18:17 ` [PATCH v3 08/19] iommu/riscv: Prepare info->domain for concurrent RCU read access Andrew Jones
2026-08-07 18:17 ` [PATCH v3 09/19] iommu/riscv: Publish IOMMU_RESV_SW_MSI region for iommufd MSI remapping Andrew Jones
2026-08-07 18:17 ` [PATCH v3 10/19] iommu/riscv: Pre-map IMSIC MSI targets Andrew Jones
2026-08-07 18:17 ` [PATCH v3 11/19] iommu/riscv: Copy MSI IOVA table when replacing an iommufd domain Andrew Jones
2026-08-07 18:17 ` [PATCH v3 12/19] iommu/riscv: Gate identity boundary switches with live MSIs Andrew Jones
2026-08-07 18:17 ` [PATCH v3 13/19] iommu/riscv: Implement irq_compose_msi_msg for IMSIC remapping Andrew Jones
2026-08-07 18:17 ` [PATCH v3 14/19] iommu/dma: Enable IOMMU_DMA for 64-bit RISC-V Andrew Jones
2026-08-07 18:17 ` [PATCH v3 15/19] iommu/riscv: report iommu capabilities Andrew Jones
2026-08-07 18:17 ` [PATCH v3 16/19] vfio: enable IOMMU_TYPE1 for RISC-V Andrew Jones
2026-08-07 18:17 ` [PATCH v3 17/19] RISC-V: KVM: Enable KVM_VFIO interfaces on RISC-V arch Andrew Jones
2026-08-07 18:17 ` [PATCH v3 18/19] riscv: defconfig: Enable IOMMUFD and VFIO Andrew Jones
2026-08-07 18:17 ` [PATCH v3 19/19] selftests/vfio: Allow building on RISC-V Andrew Jones
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