[PATCH v7 05/10] selftests: Add additional kernel functions to tools/include/
From: Jason Gunthorpe <jgg@nvidia.com>
Date: 2026-09-21 22:36:04
Also in:
kvm, kvmarm, linux-arm-kernel, linux-kselftest, linux-patches, netdev
Subsystem:
kernel selftest framework, kernel virtual machine (kvm), the rest · Maintainers:
Shuah Khan, Shuah Khan, Paolo Bonzini, Linus Torvalds
These are needed by the VFIO mlx5 selftest in the following patches, which includes some headers from mlx5 and also needs a few more MMIO-related features. - DECLARE_FLEX_ARRAY in new tools/include/linux/stddef.h (wraps existing __DECLARE_FLEX_ARRAY from uapi/linux/stddef.h) - dma_wmb/dma_rmb barriers: x86 uses compiler barrier (DMA-coherent), arm64 uses dmb oshst/oshld (outer-shareable for device visibility), generic fallback uses wmb/rmb - ioread32be/iowrite32be in tools/include/asm-generic/io.h for big-endian MMIO register access Assisted-by: Claude:claude-opus-4.6 Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- tools/arch/arm64/include/asm/barrier.h | 4 +++ tools/arch/x86/include/asm/barrier.h | 5 ++++ tools/include/asm-generic/io.h | 28 +++++++++++++++++++ tools/include/asm/barrier.h | 8 ++++++ tools/include/linux/stddef.h | 10 +++++++ .../selftests/kvm/include/arm64/processor.h | 4 +-- 6 files changed, 56 insertions(+), 3 deletions(-) create mode 100644 tools/include/linux/stddef.h
diff --git a/tools/arch/arm64/include/asm/barrier.h b/tools/arch/arm64/include/asm/barrier.h
index 3b9b41331c4f16..abdc64fc3c70f0 100644
--- a/tools/arch/arm64/include/asm/barrier.h
+++ b/tools/arch/arm64/include/asm/barrier.h@@ -24,6 +24,10 @@ #define smp_wmb() asm volatile("dmb ishst" ::: "memory") #define smp_rmb() asm volatile("dmb ishld" ::: "memory") +/* DMA barriers use outer-shareable (osh) for device visibility */ +#define dma_rmb() asm volatile("dmb oshld" ::: "memory") +#define dma_wmb() asm volatile("dmb oshst" ::: "memory") + #define smp_store_release(p, v) \ do { \ union { typeof(*p) __val; char __c[1]; } __u = \
diff --git a/tools/arch/x86/include/asm/barrier.h b/tools/arch/x86/include/asm/barrier.h
index 0adf295dd5b6aa..0b51431fa530ea 100644
--- a/tools/arch/x86/include/asm/barrier.h
+++ b/tools/arch/x86/include/asm/barrier.h@@ -43,4 +43,9 @@ do { \ ___p1; \ }) #endif /* defined(__x86_64__) */ + +/* x86 is DMA-coherent so DMA barriers are just compiler barriers */ +#define dma_rmb() barrier() +#define dma_wmb() barrier() + #endif /* _TOOLS_LINUX_ASM_X86_BARRIER_H */
diff --git a/tools/include/asm-generic/io.h b/tools/include/asm-generic/io.h
index e5a0b07ad452a6..0d89decdafb818 100644
--- a/tools/include/asm-generic/io.h
+++ b/tools/include/asm-generic/io.h@@ -479,4 +479,32 @@ static inline void writesq(volatile void __iomem *addr, const void *buffer, } #endif +/* + * ioread/iowrite for big-endian MMIO registers. + */ + +#ifndef ioread32be +#define ioread32be ioread32be +static inline u32 ioread32be(const volatile void __iomem *addr) +{ + return bswap_32(readl(addr)); +} +#endif + +#ifndef iowrite32be +#define iowrite32be iowrite32be +static inline void iowrite32be(u32 value, volatile void __iomem *addr) +{ + writel(bswap_32(value), addr); +} +#endif + +#ifndef iowrite64be +#define iowrite64be iowrite64be +static inline void iowrite64be(u64 value, volatile void __iomem *addr) +{ + writeq(bswap_64(value), addr); +} +#endif + #endif /* _TOOLS_ASM_GENERIC_IO_H */
diff --git a/tools/include/asm/barrier.h b/tools/include/asm/barrier.h
index 0c21678ac5e65f..e7e0c7de5a2ffe 100644
--- a/tools/include/asm/barrier.h
+++ b/tools/include/asm/barrier.h@@ -47,6 +47,14 @@ # define smp_mb() mb() #endif +#ifndef dma_rmb +# define dma_rmb() rmb() +#endif + +#ifndef dma_wmb +# define dma_wmb() wmb() +#endif + #ifndef smp_store_release # define smp_store_release(p, v) \ do { \
diff --git a/tools/include/linux/stddef.h b/tools/include/linux/stddef.h
new file mode 100644
index 00000000000000..99182ea4a1419b
--- /dev/null
+++ b/tools/include/linux/stddef.h@@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _TOOLS_LINUX_STDDEF_H +#define _TOOLS_LINUX_STDDEF_H + +#include_next <linux/stddef.h> + +#define DECLARE_FLEX_ARRAY(TYPE, NAME) \ + __DECLARE_FLEX_ARRAY(TYPE, NAME) + +#endif /* _TOOLS_LINUX_STDDEF_H */
diff --git a/tools/testing/selftests/kvm/include/arm64/processor.h b/tools/testing/selftests/kvm/include/arm64/processor.h
index b8a902ba8573da..5878a6abdf20e1 100644
--- a/tools/testing/selftests/kvm/include/arm64/processor.h
+++ b/tools/testing/selftests/kvm/include/arm64/processor.h@@ -12,6 +12,7 @@ #include <linux/stringify.h> #include <linux/types.h> +#include <asm/barrier.h> #include <asm/brk-imm.h> #include <asm/esr.h> #include <asm/sysreg.h>
@@ -191,11 +192,8 @@ static inline void cpu_relax(void) #define dsb(opt) asm volatile("dsb " #opt : : : "memory") #define dmb(opt) asm volatile("dmb " #opt : : : "memory") -#define dma_wmb() dmb(oshst) #define __iowmb() dma_wmb() -#define dma_rmb() dmb(oshld) - #define __iormb(v) \ ({ \ unsigned long tmp; \
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2.43.0