On Wed, Sep 01, 2021 at 09:14:01PM +0000, Raghavendra Rao Ananta wrote:
> Define the readl() and writel() functions for the guests to
> access (4-byte) the MMIO region.
>
> The routines, and their dependents, are inspired from the kernel's
> arch/arm64/include/asm/io.h and arch/arm64/include/asm/barrier.h.
>
> Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
> ---
> .../selftests/kvm/include/aarch64/processor.h | 45 ++++++++++++++++++-
> 1 file changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index c0273aefa63d..3cbaf5c1e26b 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -130,6 +130,49 @@ void vm_install_sync_handler(struct kvm_vm *vm,
> val; \
> })
>
> -#define isb() asm volatile("isb" : : : "memory")
> +#define isb() asm volatile("isb" : : : "memory")
> +#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; \
> + \
> + dma_rmb(); \
> + \
> + /* \
> + * Courtesy of arch/arm64/include/asm/io.h: \
> + * Create a dummy control dependency from the IO read to any \
> + * later instructions. This ensures that a subsequent call \
> + * to udelay() will be ordered due to the ISB in __delay(). \
We don't have udelay or __delay yet, but I assume they're coming soon.
> + */ \
> + asm volatile("eor %0, %1, %1\n" \
> + "cbnz %0, ." \
> + : "=r" (tmp) : "r" ((unsigned long)(v)) \
> + : "memory"); \
> +})
> +
> +static __always_inline void __raw_writel(u32 val, volatile void *addr)
> +{
> + asm volatile("str %w0, [%1]" : : "rZ" (val), "r" (addr));
> +}
> +
> +static __always_inline u32 __raw_readl(const volatile void *addr)
> +{
> + u32 val;
> + asm volatile("ldr %w0, [%1]" : "=r" (val) : "r" (addr));
> + return val;
> +}
> +
> +#define writel_relaxed(v,c) ((void)__raw_writel((__force u32)cpu_to_le32(v),(c)))
> +#define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; })
Might want to explicitly include linux/types.h for these __force symbols.
> +
> +#define writel(v,c) ({ __iowmb(); writel_relaxed((v),(c));})
> +#define readl(c) ({ u32 __v = readl_relaxed(c); __iormb(__v); __v; })
>
> #endif /* SELFTEST_KVM_PROCESSOR_H */
> --
> 2.33.0.153.gba50c8fa24-goog
Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
Thanks,
drew
>
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