[U-Boot] [PATCH] bouncebuf: add feature to support buffer only available in DRAM

[Peng Fan <peng.fan@nxp.com>]

Hi Kever,

> Subject: [PATCH] bouncebuf: add feature to support buffer only available in
> DRAM
> 
> Some DMA which inside peripheral controller can only access space in DRAM
> area, the target address outside DRAM is not available.
> eg. Rockchip MMC contrller's internal DMA can only access DRAM area.
> 
> Add Kconfig option and driver for people who need it.
> 
> Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
> ---
> 
>  common/bouncebuf.c  | 9 +++++++++
>  drivers/mmc/Kconfig | 6 ++++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/common/bouncebuf.c b/common/bouncebuf.c index
> a7098e2caf..7ff2f488a4 100644
> --- a/common/bouncebuf.c
> +++ b/common/bouncebuf.c
> @@ -10,6 +10,8 @@
>  #include <errno.h>
>  #include <bouncebuf.h>
> 
> +DECLARE_GLOBAL_DATA_PTR;
> +
>  static int addr_aligned(struct bounce_buffer *state)  {
>  	const ulong align_mask = ARCH_DMA_MINALIGN - 1; @@ -26,6 +28,13
> @@ static int addr_aligned(struct bounce_buffer *state)
>  		return 0;
>  	}
> 
> +#ifdef MMC_BUF_IN_DRAM
> +	if (((ulong)state->user_buffer < CONFIG_SYS_SDRAM_BASE) ||
> +	    ((ulong)state->user_buffer > gd->ram_top)) {
> +		debug("Not support buffer address %p\n", state->user_buffer);
> +		return 0;
> +	}
> +#endif
>  	/* Aligned */
>  	return 1;
>  }
> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig index
> c23299ea96..e852ee6175 100644
> --- a/drivers/mmc/Kconfig
> +++ b/drivers/mmc/Kconfig
> @@ -671,6 +671,12 @@ config FSL_ESDHC
>  	  This selects support for the eSDHC (enhanced secure digital host
>  	  controller) found on numerous Freescale/NXP SoCs.
> 
> +config MMC_BUF_IN_DRAM
> +	bool "Only buffer in DRAM is available"
> +	help
> +	  This selects support those controller whose internal DMA can only
> +	  access SDRAM spaces and other spaces are not available.
> +

I think introduce a new GEN_BB_FORCE flags might be better, no need to
introduce new kconfig entry, and it will be easier for others to use, if
there are other controllers has same limitation.

Regards,
Peng.

>  endmenu
> 
>  config SYS_FSL_ERRATUM_ESDHC111
> --
> 2.20.1