252 lines
7.5 KiB
Diff
252 lines
7.5 KiB
Diff
From 75096579c3ac39ddc2f8b0d9a8924eba31f4d920 Mon Sep 17 00:00:00 2001
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From: Thierry Reding <thierry.reding@avionic-design.de>
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Date: Mon, 21 Jan 2013 11:08:54 +0100
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Subject: [PATCH] lib: devres: Introduce devm_ioremap_resource()
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The devm_request_and_ioremap() function is very useful and helps avoid a
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whole lot of boilerplate. However, one issue that keeps popping up is
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its lack of a specific error code to determine which of the steps that
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it performs failed. Furthermore, while the function gives an example and
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suggests what error code to return on failure, a wide variety of error
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codes are used throughout the tree.
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In an attempt to fix these problems, this patch adds a new function that
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drivers can transition to. The devm_ioremap_resource() returns a pointer
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to the remapped I/O memory on success or an ERR_PTR() encoded error code
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on failure. Callers can check for failure using IS_ERR() and determine
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its cause by extracting the error code using PTR_ERR().
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devm_request_and_ioremap() is implemented as a wrapper around the new
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API and return NULL on failure as before. This ensures that backwards
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compatibility is maintained until all users have been converted to the
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new API, at which point the old devm_request_and_ioremap() function
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should be removed.
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A semantic patch is included which can be used to convert from the old
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devm_request_and_ioremap() API to the new devm_ioremap_resource() API.
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Some non-trivial cases may require manual intervention, though.
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Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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Cc: Arnd Bergmann <arnd@arndb.de>
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Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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---
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Documentation/driver-model/devres.txt | 3 +-
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include/linux/device.h | 1 +
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lib/devres.c | 57 ++++++++++---
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scripts/coccinelle/api/devm_ioremap_resource.cocci | 90 ++++++++++++++++++++
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4 files changed, 137 insertions(+), 14 deletions(-)
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create mode 100644 scripts/coccinelle/api/devm_ioremap_resource.cocci
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--- a/Documentation/driver-model/devres.txt
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+++ b/Documentation/driver-model/devres.txt
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@@ -266,7 +266,8 @@ IOMAP
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devm_ioremap()
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devm_ioremap_nocache()
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devm_iounmap()
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- devm_request_and_ioremap() : checks resource, requests region, ioremaps
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+ devm_ioremap_resource() : checks resource, requests memory region, ioremaps
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+ devm_request_and_ioremap() : obsoleted by devm_ioremap_resource()
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pcim_iomap()
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pcim_iounmap()
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pcim_iomap_table() : array of mapped addresses indexed by BAR
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--- a/include/linux/device.h
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+++ b/include/linux/device.h
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@@ -573,6 +573,7 @@ extern int devres_release_group(struct d
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extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
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extern void devm_kfree(struct device *dev, void *p);
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+void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);
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void __iomem *devm_request_and_ioremap(struct device *dev,
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struct resource *res);
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--- a/lib/devres.c
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+++ b/lib/devres.c
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@@ -86,22 +86,24 @@ void devm_iounmap(struct device *dev, vo
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EXPORT_SYMBOL(devm_iounmap);
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/**
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- * devm_request_and_ioremap() - Check, request region, and ioremap resource
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- * @dev: Generic device to handle the resource for
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+ * devm_ioremap_resource() - check, request region, and ioremap resource
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+ * @dev: generic device to handle the resource for
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* @res: resource to be handled
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*
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- * Takes all necessary steps to ioremap a mem resource. Uses managed device, so
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- * everything is undone on driver detach. Checks arguments, so you can feed
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- * it the result from e.g. platform_get_resource() directly. Returns the
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- * remapped pointer or NULL on error. Usage example:
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+ * Checks that a resource is a valid memory region, requests the memory region
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+ * and ioremaps it either as cacheable or as non-cacheable memory depending on
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+ * the resource's flags. All operations are managed and will be undone on
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+ * driver detach.
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+ *
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+ * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
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+ * on failure. Usage example:
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*
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* res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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- * base = devm_request_and_ioremap(&pdev->dev, res);
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- * if (!base)
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- * return -EADDRNOTAVAIL;
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+ * base = devm_ioremap_resource(&pdev->dev, res);
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+ * if (IS_ERR(base))
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+ * return PTR_ERR(base);
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*/
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-void __iomem *devm_request_and_ioremap(struct device *dev,
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- struct resource *res)
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+void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
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{
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resource_size_t size;
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const char *name;
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@@ -111,7 +113,7 @@ void __iomem *devm_request_and_ioremap(s
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if (!res || resource_type(res) != IORESOURCE_MEM) {
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dev_err(dev, "invalid resource\n");
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- return NULL;
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+ return ERR_PTR(-EINVAL);
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}
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size = resource_size(res);
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@@ -119,7 +121,7 @@ void __iomem *devm_request_and_ioremap(s
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if (!devm_request_mem_region(dev, res->start, size, name)) {
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dev_err(dev, "can't request region for resource %pR\n", res);
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- return NULL;
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+ return ERR_PTR(-EBUSY);
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}
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if (res->flags & IORESOURCE_CACHEABLE)
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@@ -130,10 +132,39 @@ void __iomem *devm_request_and_ioremap(s
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if (!dest_ptr) {
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dev_err(dev, "ioremap failed for resource %pR\n", res);
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devm_release_mem_region(dev, res->start, size);
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+ dest_ptr = ERR_PTR(-ENOMEM);
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}
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return dest_ptr;
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}
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+EXPORT_SYMBOL(devm_ioremap_resource);
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+
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+/**
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+ * devm_request_and_ioremap() - Check, request region, and ioremap resource
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+ * @dev: Generic device to handle the resource for
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+ * @res: resource to be handled
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+ *
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+ * Takes all necessary steps to ioremap a mem resource. Uses managed device, so
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+ * everything is undone on driver detach. Checks arguments, so you can feed
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+ * it the result from e.g. platform_get_resource() directly. Returns the
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+ * remapped pointer or NULL on error. Usage example:
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+ *
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+ * res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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+ * base = devm_request_and_ioremap(&pdev->dev, res);
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+ * if (!base)
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+ * return -EADDRNOTAVAIL;
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+ */
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+void __iomem *devm_request_and_ioremap(struct device *device,
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+ struct resource *res)
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+{
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+ void __iomem *dest_ptr;
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+
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+ dest_ptr = devm_ioremap_resource(device, res);
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+ if (IS_ERR(dest_ptr))
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+ return NULL;
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+
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+ return dest_ptr;
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+}
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EXPORT_SYMBOL(devm_request_and_ioremap);
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#ifdef CONFIG_HAS_IOPORT
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--- /dev/null
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+++ b/scripts/coccinelle/api/devm_ioremap_resource.cocci
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@@ -0,0 +1,90 @@
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+virtual patch
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+virtual report
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+
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+@depends on patch@
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+expression base, dev, res;
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+@@
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+
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+-base = devm_request_and_ioremap(dev, res);
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++base = devm_ioremap_resource(dev, res);
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+ ...
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+ if (
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+-base == NULL
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++IS_ERR(base)
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+ || ...) {
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+<...
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+- return ...;
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++ return PTR_ERR(base);
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+...>
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+ }
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+
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+@depends on patch@
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+expression e, E, ret;
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+identifier l;
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+@@
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+
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+ e = devm_ioremap_resource(...);
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+ ...
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+ if (IS_ERR(e) || ...) {
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+ ... when any
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+- ret = E;
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++ ret = PTR_ERR(e);
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+ ...
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+(
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+ return ret;
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+|
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+ goto l;
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+)
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+ }
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+
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+@depends on patch@
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+expression e;
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+@@
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+
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+ e = devm_ioremap_resource(...);
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+ ...
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+ if (IS_ERR(e) || ...) {
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+ ...
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+- \(dev_dbg\|dev_err\|pr_debug\|pr_err\|DRM_ERROR\)(...);
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+ ...
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+ }
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+
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+@depends on patch@
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+expression e;
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+identifier l;
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+@@
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+
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+ e = devm_ioremap_resource(...);
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+ ...
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+ if (IS_ERR(e) || ...)
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+-{
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+(
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+ return ...;
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+|
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+ goto l;
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+)
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+-}
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+
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+@r depends on report@
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+expression e;
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+identifier l;
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+position p1;
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+@@
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+
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+*e = devm_request_and_ioremap@p1(...);
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+ ...
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+ if (e == NULL || ...) {
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+ ...
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+(
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+ return ...;
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+|
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+ goto l;
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+)
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+ }
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+
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+@script:python depends on r@
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+p1 << r.p1;
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+@@
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+
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+msg = "ERROR: deprecated devm_request_and_ioremap() API used on line %s" % (p1[0].line)
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+coccilib.report.print_report(p1[0], msg)
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