3 files changed, 63 insertions, 9 deletions

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 6f07f3b21816..eb1c8cd243f9 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -94,6 +94,7 @@ config IOMMU_DMA
         bool
         select IOMMU_API
         select IOMMU_IOVA
+        select IRQ_MSI_IOMMU
         select NEED_SG_DMA_LENGTH
 
 config FSL_PAMU
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 77aabe637a60..f847904098f7 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -888,17 +888,18 @@ out_free_page:
         return NULL;
 }
 
-void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg)
+int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr)
 {
-        struct device *dev = msi_desc_to_dev(irq_get_msi_desc(irq));
+        struct device *dev = msi_desc_to_dev(desc);
         struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
         struct iommu_dma_cookie *cookie;
         struct iommu_dma_msi_page *msi_page;
-        phys_addr_t msi_addr = (u64)msg->address_hi << 32 | msg->address_lo;
         unsigned long flags;
 
-        if (!domain || !domain->iova_cookie)
-                return;
+        if (!domain || !domain->iova_cookie) {
+                desc->iommu_cookie = NULL;
+                return 0;
+        }
 
         cookie = domain->iova_cookie;
 
@@ -911,7 +912,36 @@ void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg)
         msi_page = iommu_dma_get_msi_page(dev, msi_addr, domain);
         spin_unlock_irqrestore(&cookie->msi_lock, flags);
 
-        if (WARN_ON(!msi_page)) {
+        msi_desc_set_iommu_cookie(desc, msi_page);
+
+        if (!msi_page)
+                return -ENOMEM;
+        return 0;
+}
+
+void iommu_dma_compose_msi_msg(struct msi_desc *desc,
+                               struct msi_msg *msg)
+{
+        struct device *dev = msi_desc_to_dev(desc);
+        const struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+        const struct iommu_dma_msi_page *msi_page;
+
+        msi_page = msi_desc_get_iommu_cookie(desc);
+
+        if (!domain || !domain->iova_cookie || WARN_ON(!msi_page))
+                return;
+
+        msg->address_hi = upper_32_bits(msi_page->iova);
+        msg->address_lo &= cookie_msi_granule(domain->iova_cookie) - 1;
+        msg->address_lo += lower_32_bits(msi_page->iova);
+}
+
+void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg)
+{
+        struct msi_desc *desc = irq_get_msi_desc(irq);
+        phys_addr_t msi_addr = (u64)msg->address_hi << 32 | msg->address_lo;
+
+        if (WARN_ON(iommu_dma_prepare_msi(desc, msi_addr))) {
                 /*
                  * We're called from a void callback, so the best we can do is
                  * 'fail' by filling the message with obviously bogus values.
@@ -922,8 +952,6 @@ void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg)
                 msg->address_lo = ~0U;
                 msg->data = ~0U;
         } else {
-                msg->address_hi = upper_32_bits(msi_page->iova);
-                msg->address_lo &= cookie_msi_granule(cookie) - 1;
-                msg->address_lo += lower_32_bits(msi_page->iova);
+                iommu_dma_compose_msi_msg(desc, msg);
         }
 }
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index e760dc5d1fa8..0b781a98ee73 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -71,12 +71,26 @@ void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
                 size_t size, enum dma_data_direction dir, unsigned long attrs);
 
 /* The DMA API isn't _quite_ the whole story, though... */
+/*
+ * iommu_dma_prepare_msi() - Map the MSI page in the IOMMU device
+ *
+ * The MSI page will be stored in @desc.
+ *
+ * Return: 0 on success otherwise an error describing the failure.
+ */
+int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr);
+
+/* Update the MSI message if required. */
+void iommu_dma_compose_msi_msg(struct msi_desc *desc,
+                               struct msi_msg *msg);
+
 void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
 #else
 
 struct iommu_domain;
+struct msi_desc;
 struct msi_msg;
 struct device;
 
@@ -99,6 +113,17 @@ static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
 {
 }
 
+static inline int iommu_dma_prepare_msi(struct msi_desc *desc,
+                                        phys_addr_t msi_addr)
+{
+        return 0;
+}
+
+static inline void iommu_dma_compose_msi_msg(struct msi_desc *desc,
+                                             struct msi_msg *msg)
+{
+}
+
 static inline void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg)
 {
 }