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Message-Id: <20190713044554.28719-3-bauerman@linux.ibm.com>
Date: Sat, 13 Jul 2019 01:45:53 -0300
From: Thiago Jung Bauermann <bauerman@...ux.ibm.com>
To: x86@...nel.org
Cc: iommu@...ts.linux-foundation.org, linux-fsdevel@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org, linux-s390@...r.kernel.org,
linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
"H. Peter Anvin" <hpa@...or.com>, Christoph Hellwig <hch@....de>,
Marek Szyprowski <m.szyprowski@...sung.com>,
Robin Murphy <robin.murphy@....com>,
Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
Alexey Dobriyan <adobriyan@...il.com>,
Thomas Lendacky <Thomas.Lendacky@....com>,
Halil Pasic <pasic@...ux.ibm.com>,
Mike Anderson <andmike@...ux.ibm.com>,
Ram Pai <linuxram@...ibm.com>,
Thiago Jung Bauermann <bauerman@...ux.ibm.com>
Subject: [PATCH 2/3] DMA mapping: Move SME handling to x86-specific files
Secure Memory Encryption is an x86-specific feature, so it shouldn't appear
in generic kernel code.
In DMA mapping code, Christoph Hellwig mentioned that "There is no reason
why we should have a special debug printk just for one specific reason why
there is a requirement for a large DMA mask.", so we just remove
dma_check_mask().
In SWIOTLB code, there's no need to mention which memory encryption feature
is active, so just use a more generic warning. Besides, other architectures
will have different names for similar technology.
Signed-off-by: Thiago Jung Bauermann <bauerman@...ux.ibm.com>
---
arch/s390/include/asm/mem_encrypt.h | 4 +---
arch/x86/include/asm/mem_encrypt.h | 10 ++++++++++
include/linux/mem_encrypt.h | 14 +-------------
kernel/dma/mapping.c | 8 --------
kernel/dma/swiotlb.c | 3 +--
5 files changed, 13 insertions(+), 26 deletions(-)
diff --git a/arch/s390/include/asm/mem_encrypt.h b/arch/s390/include/asm/mem_encrypt.h
index 3eb018508190..ff813a56bc30 100644
--- a/arch/s390/include/asm/mem_encrypt.h
+++ b/arch/s390/include/asm/mem_encrypt.h
@@ -4,9 +4,7 @@
#ifndef __ASSEMBLY__
-#define sme_me_mask 0ULL
-
-static inline bool sme_active(void) { return false; }
+static inline bool mem_encrypt_active(void) { return false; }
extern bool sev_active(void);
int set_memory_encrypted(unsigned long addr, int numpages);
diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index 0c196c47d621..848ce43b9040 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -92,6 +92,16 @@ early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0;
extern char __start_bss_decrypted[], __end_bss_decrypted[], __start_bss_decrypted_unused[];
+static inline bool mem_encrypt_active(void)
+{
+ return sme_me_mask;
+}
+
+static inline u64 sme_get_me_mask(void)
+{
+ return sme_me_mask;
+}
+
#endif /* __ASSEMBLY__ */
#endif /* __X86_MEM_ENCRYPT_H__ */
diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h
index 470bd53a89df..0c5b0ff9eb29 100644
--- a/include/linux/mem_encrypt.h
+++ b/include/linux/mem_encrypt.h
@@ -18,23 +18,11 @@
#else /* !CONFIG_ARCH_HAS_MEM_ENCRYPT */
-#define sme_me_mask 0ULL
-
-static inline bool sme_active(void) { return false; }
+static inline bool mem_encrypt_active(void) { return false; }
static inline bool sev_active(void) { return false; }
#endif /* CONFIG_ARCH_HAS_MEM_ENCRYPT */
-static inline bool mem_encrypt_active(void)
-{
- return sme_me_mask;
-}
-
-static inline u64 sme_get_me_mask(void)
-{
- return sme_me_mask;
-}
-
#ifdef CONFIG_AMD_MEM_ENCRYPT
/*
* The __sme_set() and __sme_clr() macros are useful for adding or removing
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index f7afdadb6770..b53fc7ec4914 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -291,12 +291,6 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
}
EXPORT_SYMBOL(dma_free_attrs);
-static inline void dma_check_mask(struct device *dev, u64 mask)
-{
- if (sme_active() && (mask < (((u64)sme_get_me_mask() << 1) - 1)))
- dev_warn(dev, "SME is active, device will require DMA bounce buffers\n");
-}
-
int dma_supported(struct device *dev, u64 mask)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
@@ -321,7 +315,6 @@ int dma_set_mask(struct device *dev, u64 mask)
return -EIO;
arch_dma_set_mask(dev, mask);
- dma_check_mask(dev, mask);
*dev->dma_mask = mask;
return 0;
}
@@ -333,7 +326,6 @@ int dma_set_coherent_mask(struct device *dev, u64 mask)
if (!dma_supported(dev, mask))
return -EIO;
- dma_check_mask(dev, mask);
dev->coherent_dma_mask = mask;
return 0;
}
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 62fa5a82a065..e52401f94e91 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -459,8 +459,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
if (mem_encrypt_active())
- pr_warn_once("%s is active and system is using DMA bounce buffers\n",
- sme_active() ? "SME" : "SEV");
+ pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n");
mask = dma_get_seg_boundary(hwdev);
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