dma/direct: Handle the memory encryption bit in common code

Give the basic phys_to_dma() and dma_to_phys() helpers a __-prefix and add
the memory encryption mask to the non-prefixed versions.  Use the
__-prefixed versions directly instead of clearing the mask again in
various places.

Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Muli Ben-Yehuda <mulix@mulix.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20180319103826.12853-13-hch@lst.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

4 files changed, 7 insertions, 28 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7dc347217d3a..5b4899de076f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -54,7 +54,6 @@ config X86
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_KCOV			if X86_64
-	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PMEM_API		if X86_64
 	select ARCH_HAS_REFCOUNT
@@ -692,6 +691,7 @@ config X86_SUPPORTS_MEMORY_FAILURE
 config STA2X11
 	bool "STA2X11 Companion Chip Support"
 	depends on X86_32_NON_STANDARD && PCI
+	select ARCH_HAS_PHYS_TO_DMA
 	select X86_DEV_DMA_OPS
 	select X86_DMA_REMAP
 	select SWIOTLB
diff --git a/arch/x86/include/asm/dma-direct.h b/arch/x86/include/asm/dma-direct.h
index 1295bc622ebe..1a19251eaac9 100644
--- a/arch/x86/include/asm/dma-direct.h
+++ b/arch/x86/include/asm/dma-direct.h
@@ -2,29 +2,8 @@
 #ifndef ASM_X86_DMA_DIRECT_H
 #define ASM_X86_DMA_DIRECT_H 1
 
-#include <linux/mem_encrypt.h>
-
-#ifdef CONFIG_X86_DMA_REMAP /* Platform code defines bridge-specific code */
 bool dma_capable(struct device *dev, dma_addr_t addr, size_t size);
-dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
-phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
-#else
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return 0;
-
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	return __sme_set(paddr);
-}
+dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr);
+phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr);
 
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
-{
-	return __sme_clr(daddr);
-}
-#endif /* CONFIG_X86_DMA_REMAP */
 #endif /* ASM_X86_DMA_DIRECT_H */
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index d243e8d80d89..1b396422d26f 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -211,7 +211,7 @@ static void *sev_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		 * Since we will be clearing the encryption bit, check the
 		 * mask with it already cleared.
 		 */
-		addr = __sme_clr(phys_to_dma(dev, page_to_phys(page)));
+		addr = __phys_to_dma(dev, page_to_phys(page));
 		if ((addr + size) > dev->coherent_dma_mask) {
 			__free_pages(page, get_order(size));
 		} else {
diff --git a/arch/x86/pci/sta2x11-fixup.c b/arch/x86/pci/sta2x11-fixup.c
index eac58e03f43c..7a5bafb76d77 100644
--- a/arch/x86/pci/sta2x11-fixup.c
+++ b/arch/x86/pci/sta2x11-fixup.c
@@ -207,11 +207,11 @@ bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 }
 
 /**
- * phys_to_dma - Return the DMA AMBA address used for this STA2x11 device
+ * __phys_to_dma - Return the DMA AMBA address used for this STA2x11 device
  * @dev: device for a PCI device
  * @paddr: Physical address
  */
-dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 {
 	if (!dev->archdata.is_sta2x11)
 		return paddr;
@@ -223,7 +223,7 @@ dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
  * @dev: device for a PCI device
  * @daddr: STA2x11 AMBA DMA address
  */
-phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
+phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr)
 {
 	if (!dev->archdata.is_sta2x11)
 		return daddr;