Teach dma_capable() about DMA_ATTR_CC_SHARED so the capability
check can reject encrypted DMA addresses for devices that require
unencrypted/shared DMA.

Also propagate DMA_ATTR_CC_SHARED in swiotlb_map() when the selected
SWIOTLB pool is decrypted so the capability check sees the correct DMA
address attribute.

Signed-off-by: Aneesh Kumar K.V (Arm) <[email protected]>
---
 arch/x86/kernel/amd_gart_64.c | 30 ++++++++++++++++--------------
 drivers/xen/swiotlb-xen.c     | 10 +++++++---
 include/linux/dma-direct.h    |  9 ++++++++-
 kernel/dma/direct.h           |  6 +++---
 kernel/dma/swiotlb.c          |  8 +++++---
 5 files changed, 39 insertions(+), 24 deletions(-)

diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index e8000a56732e..b5f1f031d45b 100644
--- a/arch/x86/kernel/amd_gart_64.c
+++ b/arch/x86/kernel/amd_gart_64.c
@@ -180,22 +180,23 @@ static void iommu_full(struct device *dev, size_t size, 
int dir)
 }
 
 static inline int
-need_iommu(struct device *dev, unsigned long addr, size_t size)
+need_iommu(struct device *dev, unsigned long addr, size_t size, unsigned long 
attrs)
 {
-       return force_iommu || !dma_capable(dev, addr, size, true);
+       return force_iommu || !dma_capable(dev, addr, size, true, attrs);
 }
 
 static inline int
-nonforced_iommu(struct device *dev, unsigned long addr, size_t size)
+nonforced_iommu(struct device *dev, unsigned long addr, size_t size,
+               unsigned long attrs)
 {
-       return !dma_capable(dev, addr, size, true);
+       return !dma_capable(dev, addr, size, true, attrs);
 }
 
 /* Map a single continuous physical area into the IOMMU.
  * Caller needs to check if the iommu is needed and flush.
  */
 static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem,
-                               size_t size, int dir, unsigned long align_mask)
+               size_t size, int dir, unsigned long align_mask, unsigned long 
attrs)
 {
        unsigned long npages = iommu_num_pages(phys_mem, size, PAGE_SIZE);
        unsigned long iommu_page;
@@ -206,7 +207,7 @@ static dma_addr_t dma_map_area(struct device *dev, 
dma_addr_t phys_mem,
 
        iommu_page = alloc_iommu(dev, npages, align_mask);
        if (iommu_page == -1) {
-               if (!nonforced_iommu(dev, phys_mem, size))
+               if (!nonforced_iommu(dev, phys_mem, size, attrs))
                        return phys_mem;
                if (panic_on_overflow)
                        panic("dma_map_area overflow %lu bytes\n", size);
@@ -231,10 +232,10 @@ static dma_addr_t gart_map_phys(struct device *dev, 
phys_addr_t paddr,
        if (unlikely(attrs & DMA_ATTR_MMIO))
                return DMA_MAPPING_ERROR;
 
-       if (!need_iommu(dev, paddr, size))
+       if (!need_iommu(dev, paddr, size, attrs))
                return paddr;
 
-       bus = dma_map_area(dev, paddr, size, dir, 0);
+       bus = dma_map_area(dev, paddr, size, dir, 0, attrs);
        flush_gart();
 
        return bus;
@@ -289,7 +290,7 @@ static void gart_unmap_sg(struct device *dev, struct 
scatterlist *sg, int nents,
 
 /* Fallback for dma_map_sg in case of overflow */
 static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
-                              int nents, int dir)
+               int nents, int dir, unsigned long attrs)
 {
        struct scatterlist *s;
        int i;
@@ -301,8 +302,8 @@ static int dma_map_sg_nonforce(struct device *dev, struct 
scatterlist *sg,
        for_each_sg(sg, s, nents, i) {
                unsigned long addr = sg_phys(s);
 
-               if (nonforced_iommu(dev, addr, s->length)) {
-                       addr = dma_map_area(dev, addr, s->length, dir, 0);
+               if (nonforced_iommu(dev, addr, s->length, attrs)) {
+                       addr = dma_map_area(dev, addr, s->length, dir, 0, 
attrs);
                        if (addr == DMA_MAPPING_ERROR) {
                                if (i > 0)
                                        gart_unmap_sg(dev, sg, i, dir, 0);
@@ -401,7 +402,7 @@ static int gart_map_sg(struct device *dev, struct 
scatterlist *sg, int nents,
                s->dma_address = addr;
                BUG_ON(s->length == 0);
 
-               nextneed = need_iommu(dev, addr, s->length);
+               nextneed = need_iommu(dev, addr, s->length, attrs);
 
                /* Handle the previous not yet processed entries */
                if (i > start) {
@@ -449,7 +450,7 @@ static int gart_map_sg(struct device *dev, struct 
scatterlist *sg, int nents,
 
        /* When it was forced or merged try again in a dumb way */
        if (force_iommu || iommu_merge) {
-               out = dma_map_sg_nonforce(dev, sg, nents, dir);
+               out = dma_map_sg_nonforce(dev, sg, nents, dir, attrs);
                if (out > 0)
                        return out;
        }
@@ -473,7 +474,8 @@ gart_alloc_coherent(struct device *dev, size_t size, 
dma_addr_t *dma_addr,
                return vaddr;
 
        *dma_addr = dma_map_area(dev, virt_to_phys(vaddr), size,
-                       DMA_BIDIRECTIONAL, (1UL << get_order(size)) - 1);
+                                DMA_BIDIRECTIONAL,
+                                (1UL << get_order(size)) - 1, attrs);
        flush_gart();
        if (unlikely(*dma_addr == DMA_MAPPING_ERROR))
                goto out_free;
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 2cbf2b588f5b..fa6734461d4c 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -212,7 +212,7 @@ static dma_addr_t xen_swiotlb_map_phys(struct device *dev, 
phys_addr_t phys,
        BUG_ON(dir == DMA_NONE);
 
        if (attrs & DMA_ATTR_MMIO) {
-               if (unlikely(!dma_capable(dev, phys, size, false))) {
+               if (unlikely(!dma_capable(dev, phys, size, false, attrs))) {
                        dev_err_once(
                                dev,
                                "DMA addr %pa+%zu overflow (mask %llx, bus 
limit %llx).\n",
@@ -231,7 +231,7 @@ static dma_addr_t xen_swiotlb_map_phys(struct device *dev, 
phys_addr_t phys,
         * we can safely return the device addr and not worry about bounce
         * buffering it.
         */
-       if (dma_capable(dev, dev_addr, size, true) &&
+       if (dma_capable(dev, dev_addr, size, true, attrs) &&
            !dma_kmalloc_needs_bounce(dev, size, dir) &&
            !range_straddles_page_boundary(phys, size) &&
                !xen_arch_need_swiotlb(dev, phys, dev_addr) &&
@@ -248,12 +248,16 @@ static dma_addr_t xen_swiotlb_map_phys(struct device 
*dev, phys_addr_t phys,
                return DMA_MAPPING_ERROR;
 
        phys = map;
+       /* This always return an encrypted addr */
        dev_addr = xen_phys_to_dma(dev, map);
 
+       if (WARN_ON(dev->dma_io_tlb_mem->unencrypted))
+               attrs |= DMA_ATTR_CC_SHARED;
+
        /*
         * Ensure that the address returned is DMA'ble
         */
-       if (unlikely(!dma_capable(dev, dev_addr, size, true))) {
+       if (unlikely(!dma_capable(dev, dev_addr, size, true, attrs))) {
                __swiotlb_tbl_unmap_single(dev, map, size, dir,
                                attrs | DMA_ATTR_SKIP_CPU_SYNC,
                                swiotlb_find_pool(dev, map));
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 94fad4e7c11e..9dbe198b2c4a 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -135,12 +135,19 @@ static inline bool force_dma_unencrypted(struct device 
*dev)
 #endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */
 
 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t 
size,
-               bool is_ram)
+               bool is_ram, unsigned long attrs)
 {
        dma_addr_t end = addr + size - 1;
 
        if (addr == DMA_MAPPING_ERROR)
                return false;
+       /*
+        * if phys addr attribute is encrypted but the
+        * device is forcing an unencrypted dma addr
+        */
+       if (!(attrs & DMA_ATTR_CC_SHARED) && force_dma_unencrypted(dev))
+               return false;
+
        if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
            min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
                return false;
diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
index 7140c208c123..e05dc7649366 100644
--- a/kernel/dma/direct.h
+++ b/kernel/dma/direct.h
@@ -101,15 +101,15 @@ static inline dma_addr_t dma_direct_map_phys(struct 
device *dev,
 
        if (attrs & DMA_ATTR_MMIO) {
                dma_addr = phys;
-               if (unlikely(!dma_capable(dev, dma_addr, size, false)))
+               if (unlikely(!dma_capable(dev, dma_addr, size, false, attrs)))
                        goto err_overflow;
        } else if (attrs & DMA_ATTR_CC_SHARED) {
                dma_addr = phys_to_dma_unencrypted(dev, phys);
-               if (unlikely(!dma_capable(dev, dma_addr, size, false)))
+               if (unlikely(!dma_capable(dev, dma_addr, size, false, attrs)))
                        goto err_overflow;
        } else {
                dma_addr = phys_to_dma(dev, phys);
-               if (unlikely(!dma_capable(dev, dma_addr, size, true)) ||
+               if (unlikely(!dma_capable(dev, dma_addr, size, true, attrs)) ||
                    dma_kmalloc_needs_bounce(dev, size, dir)) {
                        if (is_swiotlb_active(dev) &&
                            !(attrs & DMA_ATTR_REQUIRE_COHERENT))
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 065663be282c..9f87ebe42797 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -1646,12 +1646,14 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t 
paddr, size_t size,
        /*
         * Use the allocated io_tlb_mem encryption type to determine dma addr.
         */
-       if (dev->dma_io_tlb_mem->unencrypted)
+       if (dev->dma_io_tlb_mem->unencrypted) {
                dma_addr = phys_to_dma_unencrypted(dev, swiotlb_addr);
-       else
+               attrs |= DMA_ATTR_CC_SHARED;
+       } else {
                dma_addr = phys_to_dma_encrypted(dev, swiotlb_addr);
+       }
 
-       if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
+       if (unlikely(!dma_capable(dev, dma_addr, size, true, attrs))) {
                __swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, dir,
                        attrs | DMA_ATTR_SKIP_CPU_SYNC,
                        swiotlb_find_pool(dev, swiotlb_addr));
-- 
2.43.0


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