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* [PATCH 0/3] Some minor SWIOTLB cleanups
@ 2022-01-24 16:40 ` Robin Murphy
  0 siblings, 0 replies; 10+ messages in thread
From: Robin Murphy @ 2022-01-24 16:40 UTC (permalink / raw)
  To: hch, konrad; +Cc: iommu, linux-kernel, tientzu, guozhengkui

Hi all,

Here's a little collection of cleanup patches for some annoyances
that have built up while looking at SWIOTLB code recently.

Cheers,
Robin.


Robin Murphy (3):
  swiotlb: Simplify debugfs setup
  swiotlb: Tidy up includes
  swiotlb: Simplify array allocation

 kernel/dma/swiotlb.c | 74 ++++++++++++++------------------------------
 1 file changed, 24 insertions(+), 50 deletions(-)

-- 
2.28.0.dirty


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [PATCH 0/3] Some minor SWIOTLB cleanups
@ 2022-01-24 16:40 ` Robin Murphy
  0 siblings, 0 replies; 10+ messages in thread
From: Robin Murphy @ 2022-01-24 16:40 UTC (permalink / raw)
  To: hch, konrad; +Cc: tientzu, iommu, linux-kernel, guozhengkui

Hi all,

Here's a little collection of cleanup patches for some annoyances
that have built up while looking at SWIOTLB code recently.

Cheers,
Robin.


Robin Murphy (3):
  swiotlb: Simplify debugfs setup
  swiotlb: Tidy up includes
  swiotlb: Simplify array allocation

 kernel/dma/swiotlb.c | 74 ++++++++++++++------------------------------
 1 file changed, 24 insertions(+), 50 deletions(-)

-- 
2.28.0.dirty

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

^ permalink raw reply	[flat|nested] 10+ messages in thread
* [PATCH 1/3] swiotlb: Simplify debugfs setup
  2022-01-24 16:40 ` Robin Murphy
@ 2022-01-24 16:40   ` Robin Murphy
  -1 siblings, 0 replies; 10+ messages in thread
From: Robin Murphy @ 2022-01-24 16:40 UTC (permalink / raw)
  To: hch, konrad; +Cc: iommu, linux-kernel, tientzu, guozhengkui

Debugfs functions are already stubbed out for !CONFIG_DEBUG_FS, so we
can remove most of the #ifdefs, just keeping one to manually optimise
away the initcall when it would do nothing. We can also simplify the
code itself by factoring out the directory creation and realising that
the global io_tlb_default_mem now makes debugfs_dir redundant.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 kernel/dma/swiotlb.c | 40 ++++++++++------------------------------
 1 file changed, 10 insertions(+), 30 deletions(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index f1e7ea160b43..bdce89e053bd 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -36,9 +36,7 @@
 #include <linux/scatterlist.h>
 #include <linux/cc_platform.h>
 #include <linux/set_memory.h>
-#ifdef CONFIG_DEBUG_FS
 #include <linux/debugfs.h>
-#endif
 #ifdef CONFIG_DMA_RESTRICTED_POOL
 #include <linux/io.h>
 #include <linux/of.h>
@@ -758,47 +756,29 @@ bool is_swiotlb_active(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(is_swiotlb_active);
 
-#ifdef CONFIG_DEBUG_FS
-static struct dentry *debugfs_dir;
-
-static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem)
+static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem,
+					 const char *dirname)
 {
+	mem->debugfs = debugfs_create_dir(dirname, io_tlb_default_mem.debugfs);
+	if (!mem->nslabs)
+		return;
+
 	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)
+static int __init __maybe_unused swiotlb_create_default_debugfs(void)
 {
-	struct io_tlb_mem *mem = &io_tlb_default_mem;
-
-	debugfs_dir = debugfs_create_dir("swiotlb", NULL);
-	if (mem->nslabs) {
-		mem->debugfs = debugfs_dir;
-		swiotlb_create_debugfs_files(mem);
-	}
+	swiotlb_create_debugfs_files(&io_tlb_default_mem, "swiotlb");
 	return 0;
 }
 
+#ifdef CONFIG_DEBUG_FS
 late_initcall(swiotlb_create_default_debugfs);
-
 #endif
 
 #ifdef CONFIG_DMA_RESTRICTED_POOL
 
-#ifdef CONFIG_DEBUG_FS
-static void rmem_swiotlb_debugfs_init(struct reserved_mem *rmem)
-{
-	struct io_tlb_mem *mem = rmem->priv;
-
-	mem->debugfs = debugfs_create_dir(rmem->name, debugfs_dir);
-	swiotlb_create_debugfs_files(mem);
-}
-#else
-static void rmem_swiotlb_debugfs_init(struct reserved_mem *rmem)
-{
-}
-#endif
-
 struct page *swiotlb_alloc(struct device *dev, size_t size)
 {
 	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
@@ -860,7 +840,7 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
 
 		rmem->priv = mem;
 
-		rmem_swiotlb_debugfs_init(rmem);
+		swiotlb_create_debugfs_files(mem, rmem->name);
 	}
 
 	dev->dma_io_tlb_mem = mem;
-- 
2.28.0.dirty


^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH 1/3] swiotlb: Simplify debugfs setup
@ 2022-01-24 16:40   ` Robin Murphy
  0 siblings, 0 replies; 10+ messages in thread
From: Robin Murphy @ 2022-01-24 16:40 UTC (permalink / raw)
  To: hch, konrad; +Cc: tientzu, iommu, linux-kernel, guozhengkui

Debugfs functions are already stubbed out for !CONFIG_DEBUG_FS, so we
can remove most of the #ifdefs, just keeping one to manually optimise
away the initcall when it would do nothing. We can also simplify the
code itself by factoring out the directory creation and realising that
the global io_tlb_default_mem now makes debugfs_dir redundant.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 kernel/dma/swiotlb.c | 40 ++++++++++------------------------------
 1 file changed, 10 insertions(+), 30 deletions(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index f1e7ea160b43..bdce89e053bd 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -36,9 +36,7 @@
 #include <linux/scatterlist.h>
 #include <linux/cc_platform.h>
 #include <linux/set_memory.h>
-#ifdef CONFIG_DEBUG_FS
 #include <linux/debugfs.h>
-#endif
 #ifdef CONFIG_DMA_RESTRICTED_POOL
 #include <linux/io.h>
 #include <linux/of.h>
@@ -758,47 +756,29 @@ bool is_swiotlb_active(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(is_swiotlb_active);
 
-#ifdef CONFIG_DEBUG_FS
-static struct dentry *debugfs_dir;
-
-static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem)
+static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem,
+					 const char *dirname)
 {
+	mem->debugfs = debugfs_create_dir(dirname, io_tlb_default_mem.debugfs);
+	if (!mem->nslabs)
+		return;
+
 	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)
+static int __init __maybe_unused swiotlb_create_default_debugfs(void)
 {
-	struct io_tlb_mem *mem = &io_tlb_default_mem;
-
-	debugfs_dir = debugfs_create_dir("swiotlb", NULL);
-	if (mem->nslabs) {
-		mem->debugfs = debugfs_dir;
-		swiotlb_create_debugfs_files(mem);
-	}
+	swiotlb_create_debugfs_files(&io_tlb_default_mem, "swiotlb");
 	return 0;
 }
 
+#ifdef CONFIG_DEBUG_FS
 late_initcall(swiotlb_create_default_debugfs);
-
 #endif
 
 #ifdef CONFIG_DMA_RESTRICTED_POOL
 
-#ifdef CONFIG_DEBUG_FS
-static void rmem_swiotlb_debugfs_init(struct reserved_mem *rmem)
-{
-	struct io_tlb_mem *mem = rmem->priv;
-
-	mem->debugfs = debugfs_create_dir(rmem->name, debugfs_dir);
-	swiotlb_create_debugfs_files(mem);
-}
-#else
-static void rmem_swiotlb_debugfs_init(struct reserved_mem *rmem)
-{
-}
-#endif
-
 struct page *swiotlb_alloc(struct device *dev, size_t size)
 {
 	struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
@@ -860,7 +840,7 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
 
 		rmem->priv = mem;
 
-		rmem_swiotlb_debugfs_init(rmem);
+		swiotlb_create_debugfs_files(mem, rmem->name);
 	}
 
 	dev->dma_io_tlb_mem = mem;
-- 
2.28.0.dirty

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH 2/3] swiotlb: Tidy up includes
  2022-01-24 16:40 ` Robin Murphy
@ 2022-01-24 16:40   ` Robin Murphy
  -1 siblings, 0 replies; 10+ messages in thread
From: Robin Murphy @ 2022-01-24 16:40 UTC (permalink / raw)
  To: hch, konrad; +Cc: tientzu, iommu, linux-kernel, guozhengkui

SWIOTLB's includes have become a great big mess. Restore some order by
consolidating the random different blocks, sorting alphabetically, and
purging some clearly unnecessary entries - linux/io.h is now included
unconditionally, so need not be duplicated in the restricted DMA pool
case; similarly, linux/io.h subsumes asm/io.h; and by now it's a
mystery why asm/dma.h was ever here at all.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 kernel/dma/swiotlb.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index bdce89e053bd..f56d6504903c 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -21,38 +21,33 @@
 #define pr_fmt(fmt) "software IO TLB: " fmt
 
 #include <linux/cache.h>
+#include <linux/cc_platform.h>
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
 #include <linux/dma-direct.h>
 #include <linux/dma-map-ops.h>
-#include <linux/mm.h>
 #include <linux/export.h>
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/iommu-helper.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/mm.h>
+#include <linux/pfn.h>
+#include <linux/scatterlist.h>
+#include <linux/set_memory.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/swiotlb.h>
-#include <linux/pfn.h>
 #include <linux/types.h>
-#include <linux/ctype.h>
-#include <linux/highmem.h>
-#include <linux/gfp.h>
-#include <linux/scatterlist.h>
-#include <linux/cc_platform.h>
-#include <linux/set_memory.h>
-#include <linux/debugfs.h>
 #ifdef CONFIG_DMA_RESTRICTED_POOL
-#include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/of_reserved_mem.h>
 #include <linux/slab.h>
 #endif
 
-#include <asm/io.h>
-#include <asm/dma.h>
-
-#include <linux/io.h>
-#include <linux/init.h>
-#include <linux/memblock.h>
-#include <linux/iommu-helper.h>
-
 #define CREATE_TRACE_POINTS
 #include <trace/events/swiotlb.h>
 
-- 
2.28.0.dirty

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH 2/3] swiotlb: Tidy up includes
@ 2022-01-24 16:40   ` Robin Murphy
  0 siblings, 0 replies; 10+ messages in thread
From: Robin Murphy @ 2022-01-24 16:40 UTC (permalink / raw)
  To: hch, konrad; +Cc: iommu, linux-kernel, tientzu, guozhengkui

SWIOTLB's includes have become a great big mess. Restore some order by
consolidating the random different blocks, sorting alphabetically, and
purging some clearly unnecessary entries - linux/io.h is now included
unconditionally, so need not be duplicated in the restricted DMA pool
case; similarly, linux/io.h subsumes asm/io.h; and by now it's a
mystery why asm/dma.h was ever here at all.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 kernel/dma/swiotlb.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index bdce89e053bd..f56d6504903c 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -21,38 +21,33 @@
 #define pr_fmt(fmt) "software IO TLB: " fmt
 
 #include <linux/cache.h>
+#include <linux/cc_platform.h>
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
 #include <linux/dma-direct.h>
 #include <linux/dma-map-ops.h>
-#include <linux/mm.h>
 #include <linux/export.h>
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/iommu-helper.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/mm.h>
+#include <linux/pfn.h>
+#include <linux/scatterlist.h>
+#include <linux/set_memory.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/swiotlb.h>
-#include <linux/pfn.h>
 #include <linux/types.h>
-#include <linux/ctype.h>
-#include <linux/highmem.h>
-#include <linux/gfp.h>
-#include <linux/scatterlist.h>
-#include <linux/cc_platform.h>
-#include <linux/set_memory.h>
-#include <linux/debugfs.h>
 #ifdef CONFIG_DMA_RESTRICTED_POOL
-#include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/of_reserved_mem.h>
 #include <linux/slab.h>
 #endif
 
-#include <asm/io.h>
-#include <asm/dma.h>
-
-#include <linux/io.h>
-#include <linux/init.h>
-#include <linux/memblock.h>
-#include <linux/iommu-helper.h>
-
 #define CREATE_TRACE_POINTS
 #include <trace/events/swiotlb.h>
 
-- 
2.28.0.dirty


^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH 3/3] swiotlb: Simplify array allocation
  2022-01-24 16:40 ` Robin Murphy
@ 2022-01-24 16:40   ` Robin Murphy
  -1 siblings, 0 replies; 10+ messages in thread
From: Robin Murphy @ 2022-01-24 16:40 UTC (permalink / raw)
  To: hch, konrad; +Cc: tientzu, iommu, linux-kernel, guozhengkui

Prefer kcalloc() to kzalloc(array_size()) for allocating an array.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 kernel/dma/swiotlb.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index f56d6504903c..44c49c3616fe 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -820,8 +820,7 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
 		if (!mem)
 			return -ENOMEM;
 
-		mem->slots = kzalloc(array_size(sizeof(*mem->slots), nslabs),
-				     GFP_KERNEL);
+		mem->slots = kcalloc(nslabs, sizeof(*mem->slots), GFP_KERNEL);
 		if (!mem->slots) {
 			kfree(mem);
 			return -ENOMEM;
-- 
2.28.0.dirty

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH 3/3] swiotlb: Simplify array allocation
@ 2022-01-24 16:40   ` Robin Murphy
  0 siblings, 0 replies; 10+ messages in thread
From: Robin Murphy @ 2022-01-24 16:40 UTC (permalink / raw)
  To: hch, konrad; +Cc: iommu, linux-kernel, tientzu, guozhengkui

Prefer kcalloc() to kzalloc(array_size()) for allocating an array.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 kernel/dma/swiotlb.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index f56d6504903c..44c49c3616fe 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -820,8 +820,7 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
 		if (!mem)
 			return -ENOMEM;
 
-		mem->slots = kzalloc(array_size(sizeof(*mem->slots), nslabs),
-				     GFP_KERNEL);
+		mem->slots = kcalloc(nslabs, sizeof(*mem->slots), GFP_KERNEL);
 		if (!mem->slots) {
 			kfree(mem);
 			return -ENOMEM;
-- 
2.28.0.dirty


^ permalink raw reply related	[flat|nested] 10+ messages in thread
* Re: [PATCH 0/3] Some minor SWIOTLB cleanups
  2022-01-24 16:40 ` Robin Murphy
@ 2022-01-26 16:21   ` Christoph Hellwig
  -1 siblings, 0 replies; 10+ messages in thread
From: Christoph Hellwig @ 2022-01-26 16:21 UTC (permalink / raw)
  To: Robin Murphy; +Cc: hch, konrad, iommu, linux-kernel, tientzu, guozhengkui

Thanks,

applied to the dma-mapping for-next tree.

^ permalink raw reply	[flat|nested] 10+ messages in thread
* Re: [PATCH 0/3] Some minor SWIOTLB cleanups
@ 2022-01-26 16:21   ` Christoph Hellwig
  0 siblings, 0 replies; 10+ messages in thread
From: Christoph Hellwig @ 2022-01-26 16:21 UTC (permalink / raw)
  To: Robin Murphy; +Cc: guozhengkui, linux-kernel, iommu, tientzu, hch

Thanks,

applied to the dma-mapping for-next tree.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

^ permalink raw reply	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2022-01-26 16:22 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-24 16:40 [PATCH 0/3] Some minor SWIOTLB cleanups Robin Murphy
2022-01-24 16:40 ` Robin Murphy
2022-01-24 16:40 ` [PATCH 1/3] swiotlb: Simplify debugfs setup Robin Murphy
2022-01-24 16:40   ` Robin Murphy
2022-01-24 16:40 ` [PATCH 2/3] swiotlb: Tidy up includes Robin Murphy
2022-01-24 16:40   ` Robin Murphy
2022-01-24 16:40 ` [PATCH 3/3] swiotlb: Simplify array allocation Robin Murphy
2022-01-24 16:40   ` Robin Murphy
2022-01-26 16:21 ` [PATCH 0/3] Some minor SWIOTLB cleanups Christoph Hellwig
2022-01-26 16:21   ` Christoph Hellwig

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