Re: [PATCH v22 3/6] iomap: introduce io{read|write}64_{lo_hi|hi_lo}

From: Michael Ellerman
Date: Sat Oct 06 2018 - 07:56:21 EST


Logan Gunthorpe <logang@xxxxxxxxxxxx> writes:

> In order to provide non-atomic functions for io{read|write}64 that will
> use readq and writeq when appropriate. We define a number of variants
> of these functions in the generic iomap that will do non-atomic
> operations on pio but atomic operations on mmio.
>
> These functions are only defined if readq and writeq are defined. If
> they are not, then the wrappers that always use non-atomic operations
> from include/linux/io-64-nonatomic*.h will be used.
>
> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Suresh Warrier <warrier@xxxxxxxxxxxxxxxxxx>
> Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
> ---
> arch/powerpc/include/asm/io.h | 2 +
> include/asm-generic/iomap.h | 22 ++++++
> lib/iomap.c | 132 ++++++++++++++++++++++++++++++++++
> 3 files changed, 156 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
> index e0331e754568..20fe5d7515db 100644
> --- a/arch/powerpc/include/asm/io.h
> +++ b/arch/powerpc/include/asm/io.h
> @@ -798,8 +798,10 @@ extern void __iounmap_at(void *ea, unsigned long size);
>
> #define mmio_read16be(addr) readw_be(addr)
> #define mmio_read32be(addr) readl_be(addr)
> +#define mmio_read64be(addr) readq_be(addr)
> #define mmio_write16be(val, addr) writew_be(val, addr)
> #define mmio_write32be(val, addr) writel_be(val, addr)
> +#define mmio_write64be(val, addr) writeq_be(val, addr)
> #define mmio_insb(addr, dst, count) readsb(addr, dst, count)
> #define mmio_insw(addr, dst, count) readsw(addr, dst, count)
> #define mmio_insl(addr, dst, count) readsl(addr, dst, count)

For the powerpc part:

Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc)

cheers