[PATCH v2 0/5] drivers: add a new variant of devm_platform_ioremap_resource()

[PATCH v2 0/5] drivers: add a new variant of devm_platform_ioremap_resource()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The new devm_platform_ioremap_resource() helper has now been widely
adopted and used in many drivers. Users of the write-combined ioremap()
variants could benefit from the same code shrinkage. This series provides
a write-combined version of devm_platform_ioremap_resource() and uses it in a
relevant driver with the assumption that - just like was the case
previously - a coccinelle script will be developed to ease the transition
for others.

v1 -> v2:
- dropped everything related to nocache ioremap as this is going away

Bartosz Golaszewski (5):
  Documentation: devres: add missing entry for
    devm_platform_ioremap_resource()
  lib: devres: prepare devm_ioremap_resource() for more variants
  lib: devres: provide devm_ioremap_resource_wc()
  drivers: platform: provide devm_platform_ioremap_resource_wc()
  misc: sram: use devm_platform_ioremap_resource_wc()

 .../driver-api/driver-model/devres.rst        |  3 +
 drivers/base/platform.c                       | 27 ++++++--
 drivers/misc/sram.c                           | 28 +++------
 include/linux/device.h                        |  2 +
 include/linux/platform_device.h               |  3 +
 lib/devres.c                                  | 62 +++++++++++++------
 6 files changed, 80 insertions(+), 45 deletions(-)

-- 
2.23.0

[PATCH v2 1/5] Documentation: devres: add missing entry for devm_platform_ioremap_resource()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

devm_platform_ioremap_resource() should be documented in devres.rst.
Add the missing entry.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 Documentation/driver-api/driver-model/devres.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index a100bef54952..8e3087662daf 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -316,6 +316,7 @@ IOMAP
   devm_ioremap_nocache()
   devm_ioremap_wc()
   devm_ioremap_resource() : checks resource, requests memory region, ioremaps
+  devm_platform_ioremap_resource() : calls devm_ioremap_resource() for platform device
   devm_iounmap()
   pcim_iomap()
   pcim_iomap_regions()	: do request_region() and iomap() on multiple BARs
-- 
2.23.0

[PATCH v2 2/5] lib: devres: prepare devm_ioremap_resource() for more variants

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

We want to add the write-combined variant of devm_ioremap_resource().
Let's first implement __devm_ioremap_resource() which takes
an additional argument type. The types are the same as for
__devm_ioremap(). The existing devm_ioremap_resource() now simply
calls __devm_ioremap_resource() with regular DEVM_IOREMAP type.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 lib/devres.c | 47 +++++++++++++++++++++++++++--------------------
 1 file changed, 27 insertions(+), 20 deletions(-)

diff --git a/lib/devres.c b/lib/devres.c
index 6a0e9bd6524a..a14c727128c1 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -114,25 +114,9 @@ void devm_iounmap(struct device *dev, void __iomem *addr)
 }
 EXPORT_SYMBOL(devm_iounmap);
 
-/**
- * devm_ioremap_resource() - check, request region, and ioremap resource
- * @dev: generic device to handle the resource for
- * @res: resource to be handled
- *
- * Checks that a resource is a valid memory region, requests the memory
- * region and ioremaps it. All operations are managed and will be undone
- * on driver detach.
- *
- * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
- * on failure. Usage example:
- *
- *	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- *	base = devm_ioremap_resource(&pdev->dev, res);
- *	if (IS_ERR(base))
- *		return PTR_ERR(base);
- */
-void __iomem *devm_ioremap_resource(struct device *dev,
-				    const struct resource *res)
+static void __iomem *
+__devm_ioremap_resource(struct device *dev, const struct resource *res,
+			enum devm_ioremap_type type)
 {
 	resource_size_t size;
 	void __iomem *dest_ptr;
@@ -151,7 +135,7 @@ void __iomem *devm_ioremap_resource(struct device *dev,
 		return IOMEM_ERR_PTR(-EBUSY);
 	}
 
-	dest_ptr = devm_ioremap(dev, res->start, size);
+	dest_ptr = __devm_ioremap(dev, res->start, size, type);
 	if (!dest_ptr) {
 		dev_err(dev, "ioremap failed for resource %pR\n", res);
 		devm_release_mem_region(dev, res->start, size);
@@ -160,6 +144,29 @@ void __iomem *devm_ioremap_resource(struct device *dev,
 
 	return dest_ptr;
 }
+
+/**
+ * devm_ioremap_resource() - check, request region, and ioremap resource
+ * @dev: generic device to handle the resource for
+ * @res: resource to be handled
+ *
+ * Checks that a resource is a valid memory region, requests the memory
+ * region and ioremaps it. All operations are managed and will be undone
+ * on driver detach.
+ *
+ * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
+ * on failure. Usage example:
+ *
+ *	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ *	base = devm_ioremap_resource(&pdev->dev, res);
+ *	if (IS_ERR(base))
+ *		return PTR_ERR(base);
+ */
+void __iomem *devm_ioremap_resource(struct device *dev,
+				    const struct resource *res)
+{
+	return __devm_ioremap_resource(dev, res, DEVM_IOREMAP);
+}
 EXPORT_SYMBOL(devm_ioremap_resource);
 
 /*
-- 
2.23.0

[PATCH v2 3/5] lib: devres: provide devm_ioremap_resource_wc()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Provide a variant of devm_ioremap_resource() for write-combined ioremap.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 Documentation/driver-api/driver-model/devres.rst |  1 +
 include/linux/device.h                           |  2 ++
 lib/devres.c                                     | 15 +++++++++++++++
 3 files changed, 18 insertions(+)

diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index 8e3087662daf..e605bb9df6e1 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -316,6 +316,7 @@ IOMAP
   devm_ioremap_nocache()
   devm_ioremap_wc()
   devm_ioremap_resource() : checks resource, requests memory region, ioremaps
+  devm_ioremap_resource_wc()
   devm_platform_ioremap_resource() : calls devm_ioremap_resource() for platform device
   devm_iounmap()
   pcim_iomap()
diff --git a/include/linux/device.h b/include/linux/device.h
index 297239a08bb7..1f4aaf2d4b2a 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -946,6 +946,8 @@ extern void devm_free_pages(struct device *dev, unsigned long addr);
 
 void __iomem *devm_ioremap_resource(struct device *dev,
 				    const struct resource *res);
+void __iomem *devm_ioremap_resource_wc(struct device *dev,
+				       const struct resource *res);
 
 void __iomem *devm_of_iomap(struct device *dev,
 			    struct device_node *node, int index,
diff --git a/lib/devres.c b/lib/devres.c
index a14c727128c1..97fb44e5b4d6 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -169,6 +169,21 @@ void __iomem *devm_ioremap_resource(struct device *dev,
 }
 EXPORT_SYMBOL(devm_ioremap_resource);
 
+/**
+ * devm_ioremap_resource_wc() - write-combined variant of
+ *				devm_ioremap_resource()
+ * @dev: generic device to handle the resource for
+ * @res: resource to be handled
+ *
+ * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
+ * on failure. Usage example:
+ */
+void __iomem *devm_ioremap_resource_wc(struct device *dev,
+				       const struct resource *res)
+{
+	return __devm_ioremap_resource(dev, res, DEVM_IOREMAP_WC);
+}
+
 /*
  * devm_of_iomap - Requests a resource and maps the memory mapped IO
  *		   for a given device_node managed by a given device
-- 
2.23.0

[PATCH v2 4/5] drivers: platform: provide devm_platform_ioremap_resource_wc()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Provide a write-combined variant of devm_platform_ioremap_resource().

While at it: in order not to duplicate code - pass the resource
retrieved by platform_get_resource() directly to the appropriate
devm_ioremap_resource() variant.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 .../driver-api/driver-model/devres.rst        |  1 +
 drivers/base/platform.c                       | 27 +++++++++++++++----
 include/linux/platform_device.h               |  3 +++
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index e605bb9df6e1..480b78ca3871 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -318,6 +318,7 @@ IOMAP
   devm_ioremap_resource() : checks resource, requests memory region, ioremaps
   devm_ioremap_resource_wc()
   devm_platform_ioremap_resource() : calls devm_ioremap_resource() for platform device
+  devm_platform_ioremap_resource_wc()
   devm_iounmap()
   pcim_iomap()
   pcim_iomap_regions()	: do request_region() and iomap() on multiple BARs
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index b6c6c7d97d5b..8fdf3eb23bda 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -60,6 +60,7 @@ struct resource *platform_get_resource(struct platform_device *dev,
 }
 EXPORT_SYMBOL_GPL(platform_get_resource);
 
+#ifdef CONFIG_HAS_IOMEM
 /**
  * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
  *				    device
@@ -68,16 +69,32 @@ EXPORT_SYMBOL_GPL(platform_get_resource);
  *        resource management
  * @index: resource index
  */
-#ifdef CONFIG_HAS_IOMEM
 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
 					     unsigned int index)
 {
-	struct resource *res;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
-	return devm_ioremap_resource(&pdev->dev, res);
+	return devm_ioremap_resource(&pdev->dev,
+				     platform_get_resource(pdev,
+							   IORESOURCE_MEM,
+							   index));
 }
 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
+
+/**
+ * devm_platform_ioremap_resource_wc - write-combined variant of
+ *                                     devm_platform_ioremap_resource()
+ *
+ * @pdev: platform device to use both for memory resource lookup as well as
+ *        resource management
+ * @index: resource index
+ */
+void __iomem *devm_platform_ioremap_resource_wc(struct platform_device *pdev,
+						unsigned int index)
+{
+	return devm_ioremap_resource_wc(&pdev->dev,
+					platform_get_resource(pdev,
+							      IORESOURCE_MEM,
+							      index));
+}
 #endif /* CONFIG_HAS_IOMEM */
 
 static int __platform_get_irq(struct platform_device *dev, unsigned int num)
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 1b5cec067533..83930790c701 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -57,6 +57,9 @@ platform_find_device_by_driver(struct device *start,
 extern void __iomem *
 devm_platform_ioremap_resource(struct platform_device *pdev,
 			       unsigned int index);
+extern void __iomem *
+devm_platform_ioremap_resource_wc(struct platform_device *pdev,
+				  unsigned int index);
 extern int platform_get_irq(struct platform_device *, unsigned int);
 extern int platform_get_irq_optional(struct platform_device *, unsigned int);
 extern int platform_irq_count(struct platform_device *);
-- 
2.23.0

[PATCH v2 5/5] misc: sram: use devm_platform_ioremap_resource_wc()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Use the new devm_platform_ioremap_resource_wc() helper instead of
devm_ioremap_wc() combinded with a call to platform_get_resource().
Also use devm_platform_ioremap_resource() where applicable.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/misc/sram.c | 28 ++++++++--------------------
 1 file changed, 8 insertions(+), 20 deletions(-)

diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index f30448bf3a63..6c1a23cb3e8c 100644
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -340,8 +340,6 @@ static const struct of_device_id sram_dt_ids[] = {
 static int sram_probe(struct platform_device *pdev)
 {
 	struct sram_dev *sram;
-	struct resource *res;
-	size_t size;
 	int ret;
 	int (*init_func)(void);
 
@@ -351,25 +349,14 @@ static int sram_probe(struct platform_device *pdev)
 
 	sram->dev = &pdev->dev;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(sram->dev, "found no memory resource\n");
-		return -EINVAL;
-	}
-
-	size = resource_size(res);
-
-	if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) {
-		dev_err(sram->dev, "could not request region for resource\n");
-		return -EBUSY;
-	}
-
 	if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc"))
-		sram->virt_base = devm_ioremap(sram->dev, res->start, size);
+		sram->virt_base = devm_platform_ioremap_resource(pdev, 0);
 	else
-		sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size);
-	if (!sram->virt_base)
-		return -ENOMEM;
+		sram->virt_base = devm_platform_ioremap_resource_wc(pdev, 0);
+	if (IS_ERR(sram->virt_base)) {
+		dev_err(&pdev->dev, "could not map SRAM registers\n");
+		return PTR_ERR(sram->virt_base);
+	}
 
 	sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
 					  NUMA_NO_NODE, NULL);
@@ -382,7 +369,8 @@ static int sram_probe(struct platform_device *pdev)
 	else
 		clk_prepare_enable(sram->clk);
 
-	ret = sram_reserve_regions(sram, res);
+	ret = sram_reserve_regions(sram,
+			platform_get_resource(pdev, IORESOURCE_MEM, 0));
 	if (ret)
 		goto err_disable_clk;
 
-- 
2.23.0

Re: [PATCH v2 0/5] drivers: add a new variant of devm_platform_ioremap_resource()

[Bartosz Golaszewski]

śr., 2 paź 2019 o 18:25 Bartosz Golaszewski <brgl@bgdev.pl> napisał(a):
>
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>
> The new devm_platform_ioremap_resource() helper has now been widely
> adopted and used in many drivers. Users of the write-combined ioremap()
> variants could benefit from the same code shrinkage. This series provides
> a write-combined version of devm_platform_ioremap_resource() and uses it in a
> relevant driver with the assumption that - just like was the case
> previously - a coccinelle script will be developed to ease the transition
> for others.
>
> v1 -> v2:
> - dropped everything related to nocache ioremap as this is going away
>
> Bartosz Golaszewski (5):
>   Documentation: devres: add missing entry for
>     devm_platform_ioremap_resource()
>   lib: devres: prepare devm_ioremap_resource() for more variants
>   lib: devres: provide devm_ioremap_resource_wc()
>   drivers: platform: provide devm_platform_ioremap_resource_wc()
>   misc: sram: use devm_platform_ioremap_resource_wc()
>
>  .../driver-api/driver-model/devres.rst        |  3 +
>  drivers/base/platform.c                       | 27 ++++++--
>  drivers/misc/sram.c                           | 28 +++------
>  include/linux/device.h                        |  2 +
>  include/linux/platform_device.h               |  3 +
>  lib/devres.c                                  | 62 +++++++++++++------
>  6 files changed, 80 insertions(+), 45 deletions(-)
>
> --
> 2.23.0
>

Superseded by v3 which adds another variant that might be useful.

Bart