On Thu, Mar 24, 2022 at 04:48:26AM +0300, Serge Semin wrote:
> Currently all the DW eDMA DebugFS nodes descriptors are allocated on
> stack, while the DW eDMA driver private data and CSR limits are statically
> preserved. Such design won't work for the multi-eDMA platforms.
Can you please explain why?
> As a
> preparation to adding the multi-eDMA system setups support we need to have
> each DebugFS node separately allocated and described. Afterwards we'll put
> an addition info there like Read/Write channel flag, channel ID, DW eDMA
> private data reference.
>
> Note this conversion is mainly required due to having the legacy DW eDMA
> controllers with indirect Read/Write channels context CSRs access. If we
> didn't need to have a synchronized access to these registers the DebugFS
> code of the driver would have been much simpler.
>
I fail to understand how this change is beneficial or the exact issue.
> Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/dma/dw-edma/dw-edma-v0-debugfs.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
> index afd519d9568b..7eb0147912fa 100644
> --- a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
> +++ b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
> @@ -53,7 +53,8 @@ struct dw_edma_debugfs_entry {
>
> static int dw_edma_debugfs_u32_get(void *data, u64 *val)
> {
> - void __iomem *reg = data;
> + struct dw_edma_debugfs_entry __iomem *entry = data;
Why the entry has to be of __iomem?
Thanks,
Mani
> + void __iomem *reg = entry->reg;
>
> if (dw->chip->mf == EDMA_MF_EDMA_LEGACY &&
> reg >= (void __iomem *)®s->type.legacy.ch) {
> @@ -94,14 +95,22 @@ static int dw_edma_debugfs_u32_get(void *data, u64 *val)
> }
> DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, dw_edma_debugfs_u32_get, NULL, "0x%08llx\n");
>
> -static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry entries[],
> +static void dw_edma_debugfs_create_x32(const struct dw_edma_debugfs_entry ini[],
> int nr_entries, struct dentry *dir)
> {
> + struct dw_edma_debugfs_entry *entries;
> int i;
>
> + entries = devm_kcalloc(dw->chip->dev, nr_entries, sizeof(*entries),
> + GFP_KERNEL);
> + if (!entries)
> + return;
> +
> for (i = 0; i < nr_entries; i++) {
> + entries[i] = ini[i];
> +
> debugfs_create_file_unsafe(entries[i].name, 0444, dir,
> - entries[i].reg, &fops_x32);
> + &entries[i], &fops_x32);
> }
> }
>
> --
> 2.35.1
>
