[PATCH v9 13/27] dmaengine: dw-edma: Convert DebugFS descs to being kz-allocated

Serge Semin
2023-01-13T17:24:21Z

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. 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.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

---

Changelog v2:
- Drop __iomem qualifier from the struct dw_edma_debugfs_entry instance
definition in the dw_edma_debugfs_u32_get() method. (@Manivannan)
---
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 2121ffc33cf3..78f15e4b07ac 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 *entry = data;
+ void __iomem *reg = entry->reg;

if (dw->chip->mf == EDMA_MF_EDMA_LEGACY &&
reg >= (void __iomem *)&regs->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);
}
}

--
2.39.0