Re: [PATCH 06/13] dma: Let dma_memory_read() propagate MemTxResult

[Li Qiang]

Philippe Mathieu-Daudé <philmd@redhat.com> 于2020年9月4日周五 下午11:50写道：
>
> dma_memory_rw_relaxed() returns a MemTxResult type.
> Do not discard it, return it to the caller.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Reviewed-by: Li Qiang <liq3ea@gmail.com>

> ---
>  include/sysemu/dma.h | 21 +++++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
> index 661d7d0ca88..2961a96ad67 100644
> --- a/include/sysemu/dma.h
> +++ b/include/sysemu/dma.h
> @@ -89,8 +89,9 @@ static inline MemTxResult 
> dma_memory_rw_relaxed(AddressSpace *as,
>                              buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
>  }
>
> -static inline int dma_memory_read_relaxed(AddressSpace *as, dma_addr_t addr,
> -                                          void *buf, dma_addr_t len)
> +static inline MemTxResult dma_memory_read_relaxed(AddressSpace *as,
> +                                                  dma_addr_t addr,
> +                                                  void *buf, dma_addr_t len)
>  {
>      return dma_memory_rw_relaxed(as, addr, buf, len, 
> DMA_DIRECTION_TO_DEVICE);
>  }
> @@ -124,8 +125,20 @@ static inline MemTxResult dma_memory_rw(AddressSpace 
> *as, dma_addr_t addr,
>      return dma_memory_rw_relaxed(as, addr, buf, len, dir);
>  }
>
> -static inline int dma_memory_read(AddressSpace *as, dma_addr_t addr,
> -                                  void *buf, dma_addr_t len)
> +/**
> + * dma_memory_read: Read from an address space from DMA controller.
> + *
> + * Return a MemTxResult indicating whether the operation succeeded
> + * or failed (eg unassigned memory, device rejected the transaction,
> + * IOMMU fault).  Called within RCU critical section.
> + *
> + * @as: #AddressSpace to be accessed
> + * @addr: address within that address space
> + * @buf: buffer with the data transferred
> + * @len: length of the data transferred
> + */
> +static inline MemTxResult dma_memory_read(AddressSpace *as, dma_addr_t addr,
> +                                          void *buf, dma_addr_t len)
>  {
>      return dma_memory_rw(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
>  }
> --
> 2.26.2
>
>