Merge tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:
 "Fix various regressions:

   - force unencrypted dma-coherent buffers if encryption bit can't fit
     into the dma coherent mask (Tom Lendacky)

   - avoid limiting request size if swiotlb is not used (me)

   - fix swiotlb handling in dma_direct_sync_sg_for_cpu/device (Fugang
     Duan)"

* tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/device
  dma-direct: only limit the mapping size if swiotlb could be used
  dma-mapping: add a dma_addressing_limited helper
  dma-direct: Force unencrypted DMA under SME for certain DMA masks

4 files changed, 38 insertions, 1 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 5d8570ed6cab..a4ad2733eedf 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -189,6 +189,7 @@ config S390
 	select VIRT_CPU_ACCOUNTING
 	select ARCH_HAS_SCALED_CPUTIME
 	select HAVE_NMI
+	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
 	select SWIOTLB
 	select GENERIC_ALLOCATOR
 
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 4e5bbe328594..20340a03ad90 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -30,7 +30,7 @@
 #include <linux/export.h>
 #include <linux/cma.h>
 #include <linux/gfp.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <asm/processor.h>
 #include <linux/uaccess.h>
 #include <asm/pgtable.h>
@@ -161,6 +161,11 @@ bool sev_active(void)
 	return is_prot_virt_guest();
 }
 
+bool force_dma_unencrypted(struct device *dev)
+{
+	return sev_active();
+}
+
 /* protected virtualization */
 static void pv_init(void)
 {
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 78772870facd..222855cc0158 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1526,6 +1526,7 @@ config AMD_MEM_ENCRYPT
 	depends on X86_64 && CPU_SUP_AMD
 	select DYNAMIC_PHYSICAL_MASK
 	select ARCH_USE_MEMREMAP_PROT
+	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
 	---help---
 	  Say yes to enable support for the encryption of system memory.
 	  This requires an AMD processor that supports Secure Memory
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index e94e0a62ba92..fece30ca8b0c 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -15,6 +15,10 @@
 #include <linux/dma-direct.h>
 #include <linux/swiotlb.h>
 #include <linux/mem_encrypt.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/dma-mapping.h>
 
 #include <asm/tlbflush.h>
 #include <asm/fixmap.h>
@@ -348,6 +352,32 @@ bool sev_active(void)
 }
 EXPORT_SYMBOL(sev_active);
 
+/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
+bool force_dma_unencrypted(struct device *dev)
+{
+	/*
+	 * For SEV, all DMA must be to unencrypted addresses.
+	 */
+	if (sev_active())
+		return true;
+
+	/*
+	 * For SME, all DMA must be to unencrypted addresses if the
+	 * device does not support DMA to addresses that include the
+	 * encryption mask.
+	 */
+	if (sme_active()) {
+		u64 dma_enc_mask = DMA_BIT_MASK(__ffs64(sme_me_mask));
+		u64 dma_dev_mask = min_not_zero(dev->coherent_dma_mask,
+						dev->bus_dma_mask);
+
+		if (dma_dev_mask <= dma_enc_mask)
+			return true;
+	}
+
+	return false;
+}
+
 /* Architecture __weak replacement functions */
 void __init mem_encrypt_free_decrypted_mem(void)
 {