diff mbox series

[09/12] dma-direct: remove __dma_to_phys

Message ID 20200908164758.3177341-10-hch@lst.de (mailing list archive)
State Superseded
Headers show
Series [01/12] MIPS: make dma_sync_*_for_cpu a little less overzealous | expand

Commit Message

Christoph Hellwig Sept. 8, 2020, 4:47 p.m. UTC
There is no harm in just always clearing the SME encryption bit, while
significantly simplifying the interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/include/asm/dma-direct.h      |  2 +-
 arch/mips/bmips/dma.c                  |  2 +-
 arch/mips/cavium-octeon/dma-octeon.c   |  2 +-
 arch/mips/include/asm/dma-direct.h     |  2 +-
 arch/mips/loongson2ef/fuloong-2e/dma.c |  2 +-
 arch/mips/loongson2ef/lemote-2f/dma.c  |  2 +-
 arch/mips/loongson64/dma.c             |  2 +-
 arch/mips/pci/pci-ar2315.c             |  2 +-
 arch/mips/pci/pci-xtalk-bridge.c       |  2 +-
 arch/mips/sgi-ip32/ip32-dma.c          |  2 +-
 arch/powerpc/include/asm/dma-direct.h  |  2 +-
 include/linux/dma-direct.h             | 14 +++++---------
 kernel/dma/direct.c                    |  6 +-----
 13 files changed, 17 insertions(+), 25 deletions(-)

Comments

Robin Murphy Sept. 10, 2020, 1:26 p.m. UTC | #1
On 2020-09-08 17:47, Christoph Hellwig wrote:
> There is no harm in just always clearing the SME encryption bit, while
> significantly simplifying the interface.

After a 10-minute diversion into "but hang on, force_dma_unencrypted() 
is meaningful on PPC and S390 too..." before realising that it all does 
just come back to __sme_clr(), which is indeed a no-op for everyone 
other than AMD, any simplification of this mess is indeed welcome :)

Unless I've massively misunderstood how SME is supposed to work,

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   arch/arm/include/asm/dma-direct.h      |  2 +-
>   arch/mips/bmips/dma.c                  |  2 +-
>   arch/mips/cavium-octeon/dma-octeon.c   |  2 +-
>   arch/mips/include/asm/dma-direct.h     |  2 +-
>   arch/mips/loongson2ef/fuloong-2e/dma.c |  2 +-
>   arch/mips/loongson2ef/lemote-2f/dma.c  |  2 +-
>   arch/mips/loongson64/dma.c             |  2 +-
>   arch/mips/pci/pci-ar2315.c             |  2 +-
>   arch/mips/pci/pci-xtalk-bridge.c       |  2 +-
>   arch/mips/sgi-ip32/ip32-dma.c          |  2 +-
>   arch/powerpc/include/asm/dma-direct.h  |  2 +-
>   include/linux/dma-direct.h             | 14 +++++---------
>   kernel/dma/direct.c                    |  6 +-----
>   13 files changed, 17 insertions(+), 25 deletions(-)
> 
> diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
> index 7c3001a6a775bf..a8cee87a93e8ab 100644
> --- a/arch/arm/include/asm/dma-direct.h
> +++ b/arch/arm/include/asm/dma-direct.h
> @@ -8,7 +8,7 @@ static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return pfn_to_dma(dev, __phys_to_pfn(paddr)) + offset;
>   }
>   
> -static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
> +static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
>   {
>   	unsigned int offset = dev_addr & ~PAGE_MASK;
>   	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
> diff --git a/arch/mips/bmips/dma.c b/arch/mips/bmips/dma.c
> index df56bf4179e347..ba2a5d33dfd3fa 100644
> --- a/arch/mips/bmips/dma.c
> +++ b/arch/mips/bmips/dma.c
> @@ -52,7 +52,7 @@ dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t pa)
>   	return pa;
>   }
>   
> -phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
>   {
>   	struct bmips_dma_range *r;
>   
> diff --git a/arch/mips/cavium-octeon/dma-octeon.c b/arch/mips/cavium-octeon/dma-octeon.c
> index 14ea680d180e07..388b13ba2558c2 100644
> --- a/arch/mips/cavium-octeon/dma-octeon.c
> +++ b/arch/mips/cavium-octeon/dma-octeon.c
> @@ -177,7 +177,7 @@ dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return paddr;
>   }
>   
> -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)
>   {
>   #ifdef CONFIG_PCI
>   	if (dev && dev_is_pci(dev))
> diff --git a/arch/mips/include/asm/dma-direct.h b/arch/mips/include/asm/dma-direct.h
> index 14e352651ce946..8e178651c638c2 100644
> --- a/arch/mips/include/asm/dma-direct.h
> +++ b/arch/mips/include/asm/dma-direct.h
> @@ -3,6 +3,6 @@
>   #define _MIPS_DMA_DIRECT_H 1
>   
>   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);
> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
>   
>   #endif /* _MIPS_DMA_DIRECT_H */
> diff --git a/arch/mips/loongson2ef/fuloong-2e/dma.c b/arch/mips/loongson2ef/fuloong-2e/dma.c
> index e122292bf6660a..83fadeb3fd7d56 100644
> --- a/arch/mips/loongson2ef/fuloong-2e/dma.c
> +++ b/arch/mips/loongson2ef/fuloong-2e/dma.c
> @@ -6,7 +6,7 @@ dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return paddr | 0x80000000;
>   }
>   
> -phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
>   {
>   	return dma_addr & 0x7fffffff;
>   }
> diff --git a/arch/mips/loongson2ef/lemote-2f/dma.c b/arch/mips/loongson2ef/lemote-2f/dma.c
> index abf0e39d7e4696..302b43a14eee74 100644
> --- a/arch/mips/loongson2ef/lemote-2f/dma.c
> +++ b/arch/mips/loongson2ef/lemote-2f/dma.c
> @@ -6,7 +6,7 @@ dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return paddr | 0x80000000;
>   }
>   
> -phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
>   {
>   	if (dma_addr > 0x8fffffff)
>   		return dma_addr;
> diff --git a/arch/mips/loongson64/dma.c b/arch/mips/loongson64/dma.c
> index dbfe6e82fddd1c..b3dc5d0bd2b113 100644
> --- a/arch/mips/loongson64/dma.c
> +++ b/arch/mips/loongson64/dma.c
> @@ -13,7 +13,7 @@ dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return ((nid << 44) ^ paddr) | (nid << node_id_offset);
>   }
>   
> -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)
>   {
>   	/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
>   	 * Loongson-3's 48bit address space and embed it into 40bit */
> diff --git a/arch/mips/pci/pci-ar2315.c b/arch/mips/pci/pci-ar2315.c
> index 490953f515282a..d88395684f487d 100644
> --- a/arch/mips/pci/pci-ar2315.c
> +++ b/arch/mips/pci/pci-ar2315.c
> @@ -175,7 +175,7 @@ dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return paddr + ar2315_dev_offset(dev);
>   }
>   
> -phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
>   {
>   	return dma_addr - ar2315_dev_offset(dev);
>   }
> diff --git a/arch/mips/pci/pci-xtalk-bridge.c b/arch/mips/pci/pci-xtalk-bridge.c
> index 9b3cc775c55e05..f1b37f32b55395 100644
> --- a/arch/mips/pci/pci-xtalk-bridge.c
> +++ b/arch/mips/pci/pci-xtalk-bridge.c
> @@ -33,7 +33,7 @@ dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return bc->baddr + paddr;
>   }
>   
> -phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
>   {
>   	return dma_addr & ~(0xffUL << 56);
>   }
> diff --git a/arch/mips/sgi-ip32/ip32-dma.c b/arch/mips/sgi-ip32/ip32-dma.c
> index fa7b17cb53853e..160317294d97a9 100644
> --- a/arch/mips/sgi-ip32/ip32-dma.c
> +++ b/arch/mips/sgi-ip32/ip32-dma.c
> @@ -27,7 +27,7 @@ dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return dma_addr;
>   }
>   
> -phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
>   {
>   	phys_addr_t paddr = dma_addr & RAM_OFFSET_MASK;
>   
> diff --git a/arch/powerpc/include/asm/dma-direct.h b/arch/powerpc/include/asm/dma-direct.h
> index abc154d784b078..95b09313d2a4cf 100644
> --- a/arch/powerpc/include/asm/dma-direct.h
> +++ b/arch/powerpc/include/asm/dma-direct.h
> @@ -7,7 +7,7 @@ static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return paddr + dev->archdata.dma_offset;
>   }
>   
> -static inline 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 daddr - dev->archdata.dma_offset;
>   }
> diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
> index 20eceb2e4f91f8..f00e262ab6b154 100644
> --- a/include/linux/dma-direct.h
> +++ b/include/linux/dma-direct.h
> @@ -24,11 +24,12 @@ static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
>   }
>   
> -static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
> +static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
>   {
> -	phys_addr_t paddr = (phys_addr_t)dev_addr;
> +	phys_addr_t paddr = (phys_addr_t)dev_addr +
> +		((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
>   
> -	return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
> +	return __sme_clr(paddr);
>   }
>   #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
>   
> @@ -44,7 +45,7 @@ static inline bool force_dma_unencrypted(struct device *dev)
>   /*
>    * If memory encryption is supported, phys_to_dma will set the memory encryption
>    * bit in the DMA address, and dma_to_phys will clear it.  The raw __phys_to_dma
> - * and __dma_to_phys versions should only be used on non-encrypted memory for
> + * version should only be used on non-encrypted memory for
>    * special occasions like DMA coherent buffers.
>    */
>   static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
> @@ -52,11 +53,6 @@ static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
>   	return __sme_set(__phys_to_dma(dev, paddr));
>   }
>   
> -static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
> -{
> -	return __sme_clr(__dma_to_phys(dev, daddr));
> -}
> -
>   static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
>   		bool is_ram)
>   {
> diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
> index 57a6e7d7cf8f16..bfb479c8a370fa 100644
> --- a/kernel/dma/direct.c
> +++ b/kernel/dma/direct.c
> @@ -48,11 +48,6 @@ static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
>   {
>   	u64 dma_limit = min_not_zero(dma_mask, dev->bus_dma_limit);
>   
> -	if (force_dma_unencrypted(dev))
> -		*phys_limit = __dma_to_phys(dev, dma_limit);
> -	else
> -		*phys_limit = dma_to_phys(dev, dma_limit);
> -
>   	/*
>   	 * Optimistically try the zone that the physical address mask falls
>   	 * into first.  If that returns memory that isn't actually addressable
> @@ -61,6 +56,7 @@ static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
>   	 * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding
>   	 * zones.
>   	 */
> +	*phys_limit = dma_to_phys(dev, dma_limit);
>   	if (*phys_limit <= DMA_BIT_MASK(zone_dma_bits))
>   		return GFP_DMA;
>   	if (*phys_limit <= DMA_BIT_MASK(32))
>
Christoph Hellwig Sept. 11, 2020, 7:14 a.m. UTC | #2
On Thu, Sep 10, 2020 at 02:26:03PM +0100, Robin Murphy wrote:
> On 2020-09-08 17:47, Christoph Hellwig wrote:
>> There is no harm in just always clearing the SME encryption bit, while
>> significantly simplifying the interface.
>
> After a 10-minute diversion into "but hang on, force_dma_unencrypted() is 
> meaningful on PPC and S390 too..." before realising that it all does just 
> come back to __sme_clr(), which is indeed a no-op for everyone other than 
> AMD, any simplification of this mess is indeed welcome :)
>
> Unless I've massively misunderstood how SME is supposed to work,

Exactly.  This weird encryption bit in AMD SME causes all kinds of harm,
and I'm glad no one picked it up.  I've also been wondering if we
should change the interface to explicit set/clear the bit, but I'll
leave that for another pass as fixing up the SME interfaces would turn
into a massive disgression.
diff mbox series

Patch

diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
index 7c3001a6a775bf..a8cee87a93e8ab 100644
--- a/arch/arm/include/asm/dma-direct.h
+++ b/arch/arm/include/asm/dma-direct.h
@@ -8,7 +8,7 @@  static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return pfn_to_dma(dev, __phys_to_pfn(paddr)) + offset;
 }
 
-static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
 {
 	unsigned int offset = dev_addr & ~PAGE_MASK;
 	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
diff --git a/arch/mips/bmips/dma.c b/arch/mips/bmips/dma.c
index df56bf4179e347..ba2a5d33dfd3fa 100644
--- a/arch/mips/bmips/dma.c
+++ b/arch/mips/bmips/dma.c
@@ -52,7 +52,7 @@  dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t pa)
 	return pa;
 }
 
-phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
 {
 	struct bmips_dma_range *r;
 
diff --git a/arch/mips/cavium-octeon/dma-octeon.c b/arch/mips/cavium-octeon/dma-octeon.c
index 14ea680d180e07..388b13ba2558c2 100644
--- a/arch/mips/cavium-octeon/dma-octeon.c
+++ b/arch/mips/cavium-octeon/dma-octeon.c
@@ -177,7 +177,7 @@  dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return paddr;
 }
 
-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)
 {
 #ifdef CONFIG_PCI
 	if (dev && dev_is_pci(dev))
diff --git a/arch/mips/include/asm/dma-direct.h b/arch/mips/include/asm/dma-direct.h
index 14e352651ce946..8e178651c638c2 100644
--- a/arch/mips/include/asm/dma-direct.h
+++ b/arch/mips/include/asm/dma-direct.h
@@ -3,6 +3,6 @@ 
 #define _MIPS_DMA_DIRECT_H 1
 
 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);
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
 
 #endif /* _MIPS_DMA_DIRECT_H */
diff --git a/arch/mips/loongson2ef/fuloong-2e/dma.c b/arch/mips/loongson2ef/fuloong-2e/dma.c
index e122292bf6660a..83fadeb3fd7d56 100644
--- a/arch/mips/loongson2ef/fuloong-2e/dma.c
+++ b/arch/mips/loongson2ef/fuloong-2e/dma.c
@@ -6,7 +6,7 @@  dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return paddr | 0x80000000;
 }
 
-phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
 {
 	return dma_addr & 0x7fffffff;
 }
diff --git a/arch/mips/loongson2ef/lemote-2f/dma.c b/arch/mips/loongson2ef/lemote-2f/dma.c
index abf0e39d7e4696..302b43a14eee74 100644
--- a/arch/mips/loongson2ef/lemote-2f/dma.c
+++ b/arch/mips/loongson2ef/lemote-2f/dma.c
@@ -6,7 +6,7 @@  dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return paddr | 0x80000000;
 }
 
-phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
 {
 	if (dma_addr > 0x8fffffff)
 		return dma_addr;
diff --git a/arch/mips/loongson64/dma.c b/arch/mips/loongson64/dma.c
index dbfe6e82fddd1c..b3dc5d0bd2b113 100644
--- a/arch/mips/loongson64/dma.c
+++ b/arch/mips/loongson64/dma.c
@@ -13,7 +13,7 @@  dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return ((nid << 44) ^ paddr) | (nid << node_id_offset);
 }
 
-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)
 {
 	/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
 	 * Loongson-3's 48bit address space and embed it into 40bit */
diff --git a/arch/mips/pci/pci-ar2315.c b/arch/mips/pci/pci-ar2315.c
index 490953f515282a..d88395684f487d 100644
--- a/arch/mips/pci/pci-ar2315.c
+++ b/arch/mips/pci/pci-ar2315.c
@@ -175,7 +175,7 @@  dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return paddr + ar2315_dev_offset(dev);
 }
 
-phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
 {
 	return dma_addr - ar2315_dev_offset(dev);
 }
diff --git a/arch/mips/pci/pci-xtalk-bridge.c b/arch/mips/pci/pci-xtalk-bridge.c
index 9b3cc775c55e05..f1b37f32b55395 100644
--- a/arch/mips/pci/pci-xtalk-bridge.c
+++ b/arch/mips/pci/pci-xtalk-bridge.c
@@ -33,7 +33,7 @@  dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return bc->baddr + paddr;
 }
 
-phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
 {
 	return dma_addr & ~(0xffUL << 56);
 }
diff --git a/arch/mips/sgi-ip32/ip32-dma.c b/arch/mips/sgi-ip32/ip32-dma.c
index fa7b17cb53853e..160317294d97a9 100644
--- a/arch/mips/sgi-ip32/ip32-dma.c
+++ b/arch/mips/sgi-ip32/ip32-dma.c
@@ -27,7 +27,7 @@  dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return dma_addr;
 }
 
-phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
 {
 	phys_addr_t paddr = dma_addr & RAM_OFFSET_MASK;
 
diff --git a/arch/powerpc/include/asm/dma-direct.h b/arch/powerpc/include/asm/dma-direct.h
index abc154d784b078..95b09313d2a4cf 100644
--- a/arch/powerpc/include/asm/dma-direct.h
+++ b/arch/powerpc/include/asm/dma-direct.h
@@ -7,7 +7,7 @@  static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return paddr + dev->archdata.dma_offset;
 }
 
-static inline 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 daddr - dev->archdata.dma_offset;
 }
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 20eceb2e4f91f8..f00e262ab6b154 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -24,11 +24,12 @@  static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
 }
 
-static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
 {
-	phys_addr_t paddr = (phys_addr_t)dev_addr;
+	phys_addr_t paddr = (phys_addr_t)dev_addr +
+		((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
 
-	return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
+	return __sme_clr(paddr);
 }
 #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
 
@@ -44,7 +45,7 @@  static inline bool force_dma_unencrypted(struct device *dev)
 /*
  * If memory encryption is supported, phys_to_dma will set the memory encryption
  * bit in the DMA address, and dma_to_phys will clear it.  The raw __phys_to_dma
- * and __dma_to_phys versions should only be used on non-encrypted memory for
+ * version should only be used on non-encrypted memory for
  * special occasions like DMA coherent buffers.
  */
 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
@@ -52,11 +53,6 @@  static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
 	return __sme_set(__phys_to_dma(dev, paddr));
 }
 
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
-{
-	return __sme_clr(__dma_to_phys(dev, daddr));
-}
-
 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
 		bool is_ram)
 {
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 57a6e7d7cf8f16..bfb479c8a370fa 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -48,11 +48,6 @@  static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
 {
 	u64 dma_limit = min_not_zero(dma_mask, dev->bus_dma_limit);
 
-	if (force_dma_unencrypted(dev))
-		*phys_limit = __dma_to_phys(dev, dma_limit);
-	else
-		*phys_limit = dma_to_phys(dev, dma_limit);
-
 	/*
 	 * Optimistically try the zone that the physical address mask falls
 	 * into first.  If that returns memory that isn't actually addressable
@@ -61,6 +56,7 @@  static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
 	 * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding
 	 * zones.
 	 */
+	*phys_limit = dma_to_phys(dev, dma_limit);
 	if (*phys_limit <= DMA_BIT_MASK(zone_dma_bits))
 		return GFP_DMA;
 	if (*phys_limit <= DMA_BIT_MASK(32))