On Mon, Mar 07, 2022 at 04:47:49PM -0600, Frank Li wrote:
> Allow PCI EP probe DMA locally and prevent use of remote MSI
> to remote PCI host.
>
> Add option to force 32bit DBI register access even on
> 64-bit systems. i.MX8 hardware only allowed 32bit register
> access.
>
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> ---
>
> Resend added dmaengine@xxxxxxxxxxxxxxx
>
> Change from v2 to v3
> - rework commit message
> - Change to DW_EDMA_CHIP_32BIT_DBI
> - using DW_EDMA_CHIP_LOCAL control msi
> - Apply Bjorn's comments,
> if (!j) {
> control |= DW_EDMA_V0_LIE;
> if (!(chan->chip->flags & DW_EDMA_CHIP_LOCAL))
> control |= DW_EDMA_V0_RIE;
> }
>
> if ((chan->chip->flags & DW_EDMA_CHIP_REG32BIT) ||
> !IS_ENABLED(CONFIG_64BIT)) {
> SET_CH_32(...);
> SET_CH_32(...);
> } else {
> SET_CH_64(...);
> }
>
>
> Change from v1 to v2
> - none
>
> drivers/dma/dw-edma/dw-edma-v0-core.c | 20 ++++++++++++--------
> include/linux/dma/edma.h | 9 +++++++++
> 2 files changed, 21 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
> index 6e2f83e31a03a..081cd7997348d 100644
> --- a/drivers/dma/dw-edma/dw-edma-v0-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
> @@ -307,6 +307,7 @@ u32 dw_edma_v0_core_status_abort_int(struct dw_edma_chip *chip, enum dw_edma_dir
> static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
> {
> struct dw_edma_burst *child;
> + struct dw_edma_chan *chan = chunk->chan;
> struct dw_edma_v0_lli __iomem *lli;
> struct dw_edma_v0_llp __iomem *llp;
> u32 control = 0, i = 0;
> @@ -320,9 +321,11 @@ static void dw_edma_v0_core_write_chunk(struct dw_edma_chunk *chunk)
> j = chunk->bursts_alloc;
> list_for_each_entry(child, &chunk->burst->list, list) {
> j--;
> - if (!j)
> - control |= (DW_EDMA_V0_LIE | DW_EDMA_V0_RIE);
> -
> + if (!j) {
> + control |= DW_EDMA_V0_LIE;
> + if (!(chan->chip->flags & DW_EDMA_CHIP_LOCAL))
> + control |= DW_EDMA_V0_RIE;
> + }
> /* Channel control */
> SET_LL_32(&lli[i].control, control);
> /* Transfer size */
> @@ -420,15 +423,16 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
> SET_CH_32(chip, chan->dir, chan->id, ch_control1,
> (DW_EDMA_V0_CCS | DW_EDMA_V0_LLE));
> /* Linked list */
> - #ifdef CONFIG_64BIT
> - SET_CH_64(chip, chan->dir, chan->id, llp.reg,
> - chunk->ll_region.paddr);
> - #else /* CONFIG_64BIT */
> + if ((chan->chip->flags & DW_EDMA_CHIP_32BIT_DBI) ||
> + !IS_ENABLED(CONFIG_64BIT)) {
> SET_CH_32(chip, chan->dir, chan->id, llp.lsb,
> lower_32_bits(chunk->ll_region.paddr));
> SET_CH_32(chip, chan->dir, chan->id, llp.msb,
> upper_32_bits(chunk->ll_region.paddr));
> - #endif /* CONFIG_64BIT */
> + } else {
> + SET_CH_64(chip, chan->dir, chan->id, llp.reg,
> + chunk->ll_region.paddr);
> + }
> }
> /* Doorbell */
> SET_RW_32(chip, chan->dir, doorbell,
> diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
> index fcfbc0f47f83d..4321f6378ef66 100644
> --- a/include/linux/dma/edma.h
> +++ b/include/linux/dma/edma.h
> @@ -33,6 +33,12 @@ enum dw_edma_map_format {
> EDMA_MF_HDMA_COMPAT = 0x5
> };
>
> +/* Probe EDMA engine locally and prevent generate MSI to host side*/
> +#define DW_EDMA_CHIP_LOCAL BIT(0)
> +
> +/* Only support 32bit DBI register access */
> +#define DW_EDMA_CHIP_32BIT_DBI BIT(1)
> +
How about using an enum for defining the flags? This would help us organize the
flags in a more coherent way and also will give the benefit of kdoc.
/**
* enum dw_edma_chip_flags - Flags specific to an eDMA chip
* @DW_EDMA_CHIP_LOCAL: eDMA is used locally by an endpoint
* @DW_EDMA_CHIP_32BIT_DBI: eDMA only supports 32bit DBI access
*/
enum dw_edma_chip_flags {
DW_EDMA_CHIP_LOCAL = BIT(0),
DW_EDMA_CHIP_32BIT_DBI = BIT(1),
};
> /**
> * struct dw_edma_chip - representation of DesignWare eDMA controller hardware
> * @dev: struct device of the eDMA controller
> @@ -40,6 +46,8 @@ enum dw_edma_map_format {
> * @nr_irqs: total dma irq number
> * reg64bit if support 64bit write to register
> * @ops DMA channel to IRQ number mapping
> + * @flags - DW_EDMA_CHIP_LOCAL
> + * - DW_EDMA_CHIP_32BIT_DBI
No need to mention the flags here if you use the enum I suggested above.
> * @wr_ch_cnt DMA write channel number
> * @rd_ch_cnt DMA read channel number
> * @rg_region DMA register region
> @@ -53,6 +61,7 @@ struct dw_edma_chip {
> int id;
> int nr_irqs;
> const struct dw_edma_core_ops *ops;
> + u32 flags;
enum dw_edma_chip_flags flags;
Thanks,
Mani
>
> void __iomem *reg_base;
>
> --
> 2.24.0.rc1
>
