dmaengine: dw-edma: Convert debugfs descs to being heap-allocated

Currently DW eDMA debugfs node descriptors are allocated on the stack,
which won't work for multi-eDMA platforms. As a preparation to supporting
multi-eDMA systems, allocate each debugfs node separately.  Afterwards
we'll add info 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 synchronize access to these registers, the debugfs code of
the driver would have been much simpler.

Link: https://lore.kernel.org/r/20230113171409.30470-14-Sergey.Semin@baikalelectronics.ru
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/dw-edma/dw-edma-v0-debugfs.c b/drivers/dma/dw-edma/dw-edma-v0-debugfs.c
index 2121ffc33cf3cca0e33bcba8981654f33d2d9902..78f15e4b07acbe44c2b5c2db6cdbd2535b30ae84 100644 (file)
--- 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);
        }
 }