diff mbox series

[v7,02/15] swiotlb: Refactor swiotlb_create_debugfs

Message ID 20210518064215.2856977-3-tientzu@chromium.org (mailing list archive)
State Superseded
Headers show
Series Restricted DMA | expand

Commit Message

Claire Chang May 18, 2021, 6:42 a.m. UTC
Split the debugfs creation to make the code reusable for supporting
different bounce buffer pools, e.g. restricted DMA pool.

Signed-off-by: Claire Chang <tientzu@chromium.org>
---
 kernel/dma/swiotlb.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

Comments

Florian Fainelli May 19, 2021, 7:24 p.m. UTC | #1
On 5/17/2021 11:42 PM, Claire Chang wrote:
> Split the debugfs creation to make the code reusable for supporting
> different bounce buffer pools, e.g. restricted DMA pool.
> 
> Signed-off-by: Claire Chang <tientzu@chromium.org>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Christoph Hellwig May 27, 2021, 1:24 p.m. UTC | #2
On Tue, May 18, 2021 at 02:42:02PM +0800, Claire Chang wrote:
>  struct io_tlb_mem *io_tlb_default_mem;
> +static struct dentry *debugfs_dir;
>  
>  /*
>   * Max segment that we can provide which (if pages are contingous) will
> @@ -662,18 +663,30 @@ EXPORT_SYMBOL_GPL(is_swiotlb_active);
>  
>  #ifdef CONFIG_DEBUG_FS
>  
> +static void swiotlb_create_debugfs(struct io_tlb_mem *mem, const char *name)
>  {
>  	if (!mem)
> +		return;

I don't think this check makes much sense here.

> +}
> +
> +static int __init swiotlb_create_default_debugfs(void)
> +{
> +	struct io_tlb_mem *mem = io_tlb_default_mem;
> +
> +	if (mem) {
> +		swiotlb_create_debugfs(mem, "swiotlb");
> +		debugfs_dir = mem->debugfs;
> +	} else {
> +		debugfs_dir = debugfs_create_dir("swiotlb", NULL);
> +	}

This also looks rather strange.  I'd much rather create move the
directory creation of out swiotlb_create_debugfs.  E.g. something like:

static void swiotlb_create_debugfs_file(struct io_tlb_mem *mem)
{
	debugfs_create_ulong("io_tlb_nslabs", 0400, mem->debugfs, &mem->nslabs);
	debugfs_create_ulong("io_tlb_used", 0400, mem->debugfs, &mem->used);
}

static int __init swiotlb_init_debugfs(void)
{
	debugfs_dir = debugfs_create_dir("swiotlb", NULL);
	if (io_tlb_default_mem) {
		io_tlb_default_mem->debugfs = debugfs_dir;
		swiotlb_create_debugfs_files(io_tlb_default_mem);
	}
	return 0;
}
late_initcall(swiotlb_init_debugfs);

...

static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
                                    struct device *dev)
{
	...
		mem->debugfs = debugfs_create_dir(rmem->name, debugfs_dir);
		swiotlb_create_debugfs_files(mem->debugfs);

			
}
diff mbox series

Patch

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index d3232fc19385..b849b01a446f 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -64,6 +64,7 @@ 
 enum swiotlb_force swiotlb_force;
 
 struct io_tlb_mem *io_tlb_default_mem;
+static struct dentry *debugfs_dir;
 
 /*
  * Max segment that we can provide which (if pages are contingous) will
@@ -662,18 +663,30 @@  EXPORT_SYMBOL_GPL(is_swiotlb_active);
 
 #ifdef CONFIG_DEBUG_FS
 
-static int __init swiotlb_create_debugfs(void)
+static void swiotlb_create_debugfs(struct io_tlb_mem *mem, const char *name)
 {
-	struct io_tlb_mem *mem = io_tlb_default_mem;
-
 	if (!mem)
-		return 0;
-	mem->debugfs = debugfs_create_dir("swiotlb", NULL);
+		return;
+
+	mem->debugfs = debugfs_create_dir(name, debugfs_dir);
 	debugfs_create_ulong("io_tlb_nslabs", 0400, mem->debugfs, &mem->nslabs);
 	debugfs_create_ulong("io_tlb_used", 0400, mem->debugfs, &mem->used);
+}
+
+static int __init swiotlb_create_default_debugfs(void)
+{
+	struct io_tlb_mem *mem = io_tlb_default_mem;
+
+	if (mem) {
+		swiotlb_create_debugfs(mem, "swiotlb");
+		debugfs_dir = mem->debugfs;
+	} else {
+		debugfs_dir = debugfs_create_dir("swiotlb", NULL);
+	}
+
 	return 0;
 }
 
-late_initcall(swiotlb_create_debugfs);
+late_initcall(swiotlb_create_default_debugfs);
 
 #endif