iommu/dma: Clean up MSI IOVA allocation

Now that allocation is suitably abstracted, our private alloc/free
helpers can drive the trivial MSI cookie allocator directly as well,
which lets us clean up its exposed guts from iommu_dma_map_msi_msg() and
simplify things quite a bit.

Reviewed-by: Nate Watterson <nwatters@codeaurora.org>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 8e0b684da1ba4f9bd8f7b773f805f87eafbd385b..1b94beb43036a771fad50c4d394e7fd3c2078038 100644 (file)
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -61,15 +61,6 @@ static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
        return PAGE_SIZE;
 }
 
-static inline struct iova_domain *cookie_iovad(struct iommu_domain *domain)
-{
-       struct iommu_dma_cookie *cookie = domain->iova_cookie;
-
-       if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
-               return &cookie->iovad;
-       return NULL;
-}
-
 static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
 {
        struct iommu_dma_cookie *cookie;
@@ -368,11 +359,19 @@ int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
 static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
                size_t size, dma_addr_t dma_limit, struct device *dev)
 {
-       struct iova_domain *iovad = cookie_iovad(domain);
-       unsigned long shift = iova_shift(iovad);
-       unsigned long iova_len = size >> shift;
+       struct iommu_dma_cookie *cookie = domain->iova_cookie;
+       struct iova_domain *iovad = &cookie->iovad;
+       unsigned long shift, iova_len;
        struct iova *iova = NULL;
 
+       if (cookie->type == IOMMU_DMA_MSI_COOKIE) {
+               cookie->msi_iova += size;
+               return cookie->msi_iova - size;
+       }
+
+       shift = iova_shift(iovad);
+       iova_len = size >> shift;
+
        if (domain->geometry.force_aperture)
                dma_limit = min(dma_limit, domain->geometry.aperture_end);
 
@@ -396,6 +395,12 @@ static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
        struct iova_domain *iovad = &cookie->iovad;
        struct iova *iova_rbnode;
 
+       /* The MSI case is only ever cleaning up its most recent allocation */
+       if (cookie->type == IOMMU_DMA_MSI_COOKIE) {
+               cookie->msi_iova -= size;
+               return;
+       }
+
        iova_rbnode = find_iova(iovad, iova_pfn(iovad, iova));
        if (WARN_ON(!iova_rbnode))
                return;
@@ -406,14 +411,15 @@ static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
 static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t dma_addr,
                size_t size)
 {
-       struct iova_domain *iovad = cookie_iovad(domain);
+       struct iommu_dma_cookie *cookie = domain->iova_cookie;
+       struct iova_domain *iovad = &cookie->iovad;
        size_t iova_off = iova_offset(iovad, dma_addr);
 
        dma_addr -= iova_off;
        size = iova_align(iovad, size + iova_off);
 
        WARN_ON(iommu_unmap(domain, dma_addr, size) != size);
-       iommu_dma_free_iova(domain->iova_cookie, dma_addr, size);
+       iommu_dma_free_iova(cookie, dma_addr, size);
 }
 
 static void __iommu_dma_free_pages(struct page **pages, int count)
@@ -838,7 +844,6 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 {
        struct iommu_dma_cookie *cookie = domain->iova_cookie;
        struct iommu_dma_msi_page *msi_page;
-       struct iova_domain *iovad = cookie_iovad(domain);
        dma_addr_t iova;
        int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
        size_t size = cookie_msi_granule(cookie);
@@ -852,29 +857,16 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
        if (!msi_page)
                return NULL;
 
-       msi_page->phys = msi_addr;
-       if (iovad) {
-               iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
-               if (!iova)
-                       goto out_free_page;
-               msi_page->iova = iova;
-       } else {
-               msi_page->iova = cookie->msi_iova;
-               cookie->msi_iova += size;
-       }
-
-       if (iommu_map(domain, msi_page->iova, msi_addr, size, prot))
-               goto out_free_iova;
+       iova = __iommu_dma_map(dev, msi_addr, size, prot);
+       if (iommu_dma_mapping_error(dev, iova))
+               goto out_free_page;
 
        INIT_LIST_HEAD(&msi_page->list);
+       msi_page->phys = msi_addr;
+       msi_page->iova = iova;
        list_add(&msi_page->list, &cookie->msi_page_list);
        return msi_page;
 
-out_free_iova:
-       if (iovad)
-               iommu_dma_free_iova(cookie, iova, size);
-       else
-               cookie->msi_iova -= size;
 out_free_page:
        kfree(msi_page);
        return NULL;