* [PATCH v7 1/3] devres: provide devm_krealloc()
2020-08-17 17:05 [PATCH v7 0/3] devres: provide and use devm_krealloc() Bartosz Golaszewski
@ 2020-08-17 17:05 ` Bartosz Golaszewski
2020-08-17 17:39 ` Andy Shevchenko
2020-08-17 17:05 ` [PATCH v7 2/3] hwmon: pmbus: use more devres helpers Bartosz Golaszewski
2020-08-17 17:05 ` [PATCH v7 3/3] iio: adc: xilinx-xadc: use devm_krealloc() Bartosz Golaszewski
2 siblings, 1 reply; 11+ messages in thread
From: Bartosz Golaszewski @ 2020-08-17 17:05 UTC (permalink / raw)
To: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, Andy Shevchenko
Cc: linux-iio, linux-arm-kernel, linux-kernel, Bartosz Golaszewski
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Implement the managed variant of krealloc(). This function works with
all memory allocated by devm_kmalloc() (or devres functions using it
implicitly like devm_kmemdup(), devm_kstrdup() etc.).
Managed realloc'ed chunks can be manually released with devm_kfree().
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
.../driver-api/driver-model/devres.rst | 1 +
drivers/base/devres.c | 93 +++++++++++++++++++
include/linux/device.h | 2 +
3 files changed, 96 insertions(+)
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index eaaaafc21134..f318a5c0033c 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -354,6 +354,7 @@ MEM
devm_kmalloc()
devm_kmalloc_array()
devm_kmemdup()
+ devm_krealloc()
devm_kstrdup()
devm_kvasprintf()
devm_kzalloc()
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index ed615d3b9cf1..bfe46e83147e 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -36,6 +36,17 @@ struct devres {
u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];
};
+static struct devres *to_devres(void *data)
+{
+ return (struct devres *)((u8 *)data - ALIGN(sizeof(struct devres),
+ ARCH_KMALLOC_MINALIGN));
+}
+
+static size_t devres_data_size(size_t total_size)
+{
+ return total_size - ALIGN(sizeof(struct devres), ARCH_KMALLOC_MINALIGN);
+}
+
struct devres_group {
struct devres_node node[2];
void *id;
@@ -126,6 +137,14 @@ static void add_dr(struct device *dev, struct devres_node *node)
list_add_tail(&node->entry, &dev->devres_head);
}
+static void replace_dr(struct device *dev,
+ struct devres_node *old, struct devres_node *new)
+{
+ devres_log(dev, old, "REPLACE");
+ BUG_ON(!list_empty(&new->entry));
+ list_replace(&old->entry, &new->entry);
+}
+
#ifdef CONFIG_DEBUG_DEVRES
void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
const char *name)
@@ -837,6 +856,80 @@ void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
}
EXPORT_SYMBOL_GPL(devm_kmalloc);
+/**
+ * devm_krealloc - Resource-managed krealloc()
+ * @dev: Device to re-allocate memory for
+ * @ptr: Pointer to the memory chunk to re-allocate
+ * @new_size: New allocation size
+ * @gfp: Allocation gfp flags
+ *
+ * Managed krealloc(). Resizes the memory chunk allocated with devm_kmalloc().
+ * Behaves similarly to regular krealloc(): if @ptr is NULL or ZERO_SIZE_PTR,
+ * it's the equivalent of devm_kmalloc(). If new_size is zero, it frees the
+ * previously allocated memory and returns ZERO_SIZE_PTR. This function doesn't
+ * change the order in which the release callback for the re-alloc'ed devres
+ * will be called (except when falling back to devm_kmalloc() or when freeing
+ * resources when new_size is zero). The contents of the memory are preserved
+ * up to the lesser of new and old sizes.
+ */
+void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
+{
+ size_t total_new_size, total_old_size;
+ struct devres *old_dr, *new_dr;
+ unsigned long flags;
+
+ if (unlikely(!new_size)) {
+ devm_kfree(dev, ptr);
+ return ZERO_SIZE_PTR;
+ }
+
+ if (unlikely(ZERO_OR_NULL_PTR(ptr)))
+ return devm_kmalloc(dev, new_size, gfp);
+
+ if (WARN_ON(is_kernel_rodata((unsigned long)ptr)))
+ /*
+ * We cannot reliably realloc a const string returned by
+ * devm_kstrdup_const().
+ */
+ return NULL;
+
+ if (!check_dr_size(new_size, &total_new_size))
+ return NULL;
+
+ total_old_size = ksize(to_devres(ptr));
+
+ /*
+ * If new size is smaller or equal to the actual number of bytes
+ * allocated previously - just return the same pointer.
+ */
+ if (total_new_size <= total_old_size)
+ return ptr;
+
+ new_dr = alloc_dr(devm_kmalloc_release,
+ total_new_size, gfp, dev_to_node(dev));
+ if (!new_dr)
+ return NULL;
+
+ spin_lock_irqsave(&dev->devres_lock, flags);
+
+ old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
+ if (!old_dr) {
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+ devres_free(new_dr);
+ WARN(1, "Memory chunk not managed or managed by a different device.");
+ return NULL;
+ }
+
+ replace_dr(dev, &old_dr->node, &new_dr->node);
+
+ spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+ memcpy(new_dr->data, old_dr->data, devres_data_size(total_old_size));
+ kfree(old_dr);
+ return new_dr->data;
+}
+EXPORT_SYMBOL_GPL(devm_krealloc);
+
/**
* devm_kstrdup - Allocate resource managed space and
* copy an existing string into that.
diff --git a/include/linux/device.h b/include/linux/device.h
index ca18da4768e3..5da7d5f0a7ff 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -206,6 +206,8 @@ int devres_release_group(struct device *dev, void *id);
/* managed devm_k.alloc/kfree for device drivers */
void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
+void *devm_krealloc(struct device *dev, void *ptr, size_t size,
+ gfp_t gfp) __must_check;
__printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
const char *fmt, va_list ap) __malloc;
__printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
--
2.26.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH v7 1/3] devres: provide devm_krealloc()
2020-08-17 17:05 ` [PATCH v7 1/3] devres: provide devm_krealloc() Bartosz Golaszewski
@ 2020-08-17 17:39 ` Andy Shevchenko
2020-08-17 20:02 ` Bartosz Golaszewski
0 siblings, 1 reply; 11+ messages in thread
From: Andy Shevchenko @ 2020-08-17 17:39 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, linux-iio, linux-arm-kernel, linux-kernel,
Bartosz Golaszewski
On Mon, Aug 17, 2020 at 07:05:33PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>
> Implement the managed variant of krealloc(). This function works with
> all memory allocated by devm_kmalloc() (or devres functions using it
> implicitly like devm_kmemdup(), devm_kstrdup() etc.).
>
> Managed realloc'ed chunks can be manually released with devm_kfree().
Thanks for an update! My comments / questions below.
...
> +static struct devres *to_devres(void *data)
> +{
> + return (struct devres *)((u8 *)data - ALIGN(sizeof(struct devres),
> + ARCH_KMALLOC_MINALIGN));
Do you really need both explicit castings?
> +}
...
> + total_old_size = ksize(to_devres(ptr));
But how you can guarantee this pointer:
- belongs to devres,
- hasn't gone while you run a ksize()?
...
> + new_dr = alloc_dr(devm_kmalloc_release,
> + total_new_size, gfp, dev_to_node(dev));
Can you move some parameters to the previous line?
> + if (!new_dr)
> + return NULL;
...
> + spin_lock_irqsave(&dev->devres_lock, flags);
> +
> + old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
> + if (!old_dr) {
> + spin_unlock_irqrestore(&dev->devres_lock, flags);
> + devres_free(new_dr);
> + WARN(1, "Memory chunk not managed or managed by a different device.");
> + return NULL;
> + }
> +
> + replace_dr(dev, &old_dr->node, &new_dr->node);
> +
> + spin_unlock_irqrestore(&dev->devres_lock, flags);
> +
> + memcpy(new_dr->data, old_dr->data, devres_data_size(total_old_size));
But new_dr may concurrently gone at this point, no? It means memcpy() should be
under spin lock.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v7 1/3] devres: provide devm_krealloc()
2020-08-17 17:39 ` Andy Shevchenko
@ 2020-08-17 20:02 ` Bartosz Golaszewski
2020-08-18 8:25 ` Andy Shevchenko
0 siblings, 1 reply; 11+ messages in thread
From: Bartosz Golaszewski @ 2020-08-17 20:02 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, linux-iio, Linux ARM, Linux Kernel Mailing List,
Bartosz Golaszewski
On Mon, Aug 17, 2020 at 7:43 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Mon, Aug 17, 2020 at 07:05:33PM +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> >
> > Implement the managed variant of krealloc(). This function works with
> > all memory allocated by devm_kmalloc() (or devres functions using it
> > implicitly like devm_kmemdup(), devm_kstrdup() etc.).
> >
> > Managed realloc'ed chunks can be manually released with devm_kfree().
>
> Thanks for an update! My comments / questions below.
>
> ...
>
> > +static struct devres *to_devres(void *data)
> > +{
> > + return (struct devres *)((u8 *)data - ALIGN(sizeof(struct devres),
> > + ARCH_KMALLOC_MINALIGN));
>
> Do you really need both explicit castings?
>
Yeah, we can probably drop the (struct devres *) here.
> > +}
>
> ...
>
> > + total_old_size = ksize(to_devres(ptr));
>
> But how you can guarantee this pointer:
> - belongs to devres,
We can only check if a chunk is dynamically allocated with ksize() -
it will return 0 if it isn't and I'll add a check for that in the next
iteration. We check whether it's a managed chunk later after taking
the lock.
> - hasn't gone while you run a ksize()?
>
At some point you need to draw a line. In the end: how do you
guarantee a devres buffer hasn't been freed when you're using it? In
my comment to the previous version of this patch I clarified that we
need to protect all modifications of the devres linked list - we must
not realloc a chunk that contains the links without taking the
spinlock but also we must not call alloc() funcs with GFP_KERNEL with
spinlock taken. The issue we could run into is: someone modifies the
linked list by adding/removing other managed resources, not modifying
this one.
The way this function works now guarantees it but other than that:
it's up to the users to not free memory they're actively using.
> ...
>
> > + new_dr = alloc_dr(devm_kmalloc_release,
> > + total_new_size, gfp, dev_to_node(dev));
>
> Can you move some parameters to the previous line?
>
Why though? It's fine this way.
> > + if (!new_dr)
> > + return NULL;
>
> ...
>
> > + spin_lock_irqsave(&dev->devres_lock, flags);
> > +
> > + old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
> > + if (!old_dr) {
> > + spin_unlock_irqrestore(&dev->devres_lock, flags);
> > + devres_free(new_dr);
> > + WARN(1, "Memory chunk not managed or managed by a different device.");
> > + return NULL;
> > + }
> > +
> > + replace_dr(dev, &old_dr->node, &new_dr->node);
> > +
> > + spin_unlock_irqrestore(&dev->devres_lock, flags);
> > +
> > + memcpy(new_dr->data, old_dr->data, devres_data_size(total_old_size));
>
> But new_dr may concurrently gone at this point, no? It means memcpy() should be
> under spin lock.
>
Just as I explained above: we're protecting the linked list, not the
resource itself.
Bartosz
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v7 1/3] devres: provide devm_krealloc()
2020-08-17 20:02 ` Bartosz Golaszewski
@ 2020-08-18 8:25 ` Andy Shevchenko
2020-08-18 16:27 ` Bartosz Golaszewski
0 siblings, 1 reply; 11+ messages in thread
From: Andy Shevchenko @ 2020-08-18 8:25 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, linux-iio, Linux ARM, Linux Kernel Mailing List,
Bartosz Golaszewski
On Mon, Aug 17, 2020 at 10:02:05PM +0200, Bartosz Golaszewski wrote:
> On Mon, Aug 17, 2020 at 7:43 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > On Mon, Aug 17, 2020 at 07:05:33PM +0200, Bartosz Golaszewski wrote:
> > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
...
> > > +static struct devres *to_devres(void *data)
> > > +{
> > > + return (struct devres *)((u8 *)data - ALIGN(sizeof(struct devres),
> > > + ARCH_KMALLOC_MINALIGN));
> >
> > Do you really need both explicit castings?
> >
>
> Yeah, we can probably drop the (struct devres *) here.
void * -> u8 * here is also not needed, it is considered byte access IIRC.
> > > +}
...
> > - hasn't gone while you run a ksize()?
> At some point you need to draw a line. In the end: how do you
> guarantee a devres buffer hasn't been freed when you're using it? In
> my comment to the previous version of this patch I clarified that we
> need to protect all modifications of the devres linked list - we must
> not realloc a chunk that contains the links without taking the
> spinlock but also we must not call alloc() funcs with GFP_KERNEL with
> spinlock taken. The issue we could run into is: someone modifies the
> linked list by adding/removing other managed resources, not modifying
> this one.
>
> The way this function works now guarantees it but other than that:
> it's up to the users to not free memory they're actively using.
Thanks for clarification. I agree.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v7 1/3] devres: provide devm_krealloc()
2020-08-18 8:25 ` Andy Shevchenko
@ 2020-08-18 16:27 ` Bartosz Golaszewski
2020-08-18 17:10 ` Andy Shevchenko
0 siblings, 1 reply; 11+ messages in thread
From: Bartosz Golaszewski @ 2020-08-18 16:27 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, linux-iio, Linux ARM, Linux Kernel Mailing List,
Bartosz Golaszewski
On Tue, Aug 18, 2020 at 10:40 AM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Mon, Aug 17, 2020 at 10:02:05PM +0200, Bartosz Golaszewski wrote:
> > On Mon, Aug 17, 2020 at 7:43 PM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > On Mon, Aug 17, 2020 at 07:05:33PM +0200, Bartosz Golaszewski wrote:
> > > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>
> ...
>
> > > > +static struct devres *to_devres(void *data)
> > > > +{
> > > > + return (struct devres *)((u8 *)data - ALIGN(sizeof(struct devres),
> > > > + ARCH_KMALLOC_MINALIGN));
> > >
> > > Do you really need both explicit castings?
> > >
> >
> > Yeah, we can probably drop the (struct devres *) here.
>
> void * -> u8 * here is also not needed, it is considered byte access IIRC.
>
Actually it turns out that while we don't need the (void *) -> (u8 *)
casting, we must cast to (struct devres *) or the following error is
produced:
drivers/base/devres.c: In function ‘to_devres’:
drivers/base/devres.c:41:21: error: returning ‘u8 *’ {aka ‘unsigned
char *’} from a function with incompatible return type ‘struct devres
*’ [-Werror=incompatible-pointer-types]
return ((u8 *)data - ALIGN(sizeof(struct devres),
~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ARCH_KMALLOC_MINALIGN));
~~~~~~~~~~~~~~~~~~~~~~~
Bart
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v7 1/3] devres: provide devm_krealloc()
2020-08-18 16:27 ` Bartosz Golaszewski
@ 2020-08-18 17:10 ` Andy Shevchenko
2020-08-18 18:13 ` Bartosz Golaszewski
0 siblings, 1 reply; 11+ messages in thread
From: Andy Shevchenko @ 2020-08-18 17:10 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, linux-iio, Linux ARM, Linux Kernel Mailing List,
Bartosz Golaszewski
On Tue, Aug 18, 2020 at 06:27:12PM +0200, Bartosz Golaszewski wrote:
> On Tue, Aug 18, 2020 at 10:40 AM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> >
> > On Mon, Aug 17, 2020 at 10:02:05PM +0200, Bartosz Golaszewski wrote:
> > > On Mon, Aug 17, 2020 at 7:43 PM Andy Shevchenko
> > > <andriy.shevchenko@linux.intel.com> wrote:
> > > > On Mon, Aug 17, 2020 at 07:05:33PM +0200, Bartosz Golaszewski wrote:
> > > > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> >
> > ...
> >
> > > > > +static struct devres *to_devres(void *data)
> > > > > +{
> > > > > + return (struct devres *)((u8 *)data - ALIGN(sizeof(struct devres),
> > > > > + ARCH_KMALLOC_MINALIGN));
> > > >
> > > > Do you really need both explicit castings?
> > > >
> > >
> > > Yeah, we can probably drop the (struct devres *) here.
> >
> > void * -> u8 * here is also not needed, it is considered byte access IIRC.
> >
>
> Actually it turns out that while we don't need the (void *) -> (u8 *)
> casting, we must cast to (struct devres *) or the following error is
> produced:
>
> drivers/base/devres.c: In function ‘to_devres’:
> drivers/base/devres.c:41:21: error: returning ‘u8 *’ {aka ‘unsigned
> char *’} from a function with incompatible return type ‘struct devres
> *’ [-Werror=incompatible-pointer-types]
> return ((u8 *)data - ALIGN(sizeof(struct devres),
> ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ARCH_KMALLOC_MINALIGN));
> ~~~~~~~~~~~~~~~~~~~~~~~
Of course, you have to drop u8 * casting as well.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v7 1/3] devres: provide devm_krealloc()
2020-08-18 17:10 ` Andy Shevchenko
@ 2020-08-18 18:13 ` Bartosz Golaszewski
2020-08-19 9:14 ` Andy Shevchenko
0 siblings, 1 reply; 11+ messages in thread
From: Bartosz Golaszewski @ 2020-08-18 18:13 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, linux-iio, Linux ARM, Linux Kernel Mailing List,
Bartosz Golaszewski
On Tue, Aug 18, 2020 at 7:19 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Tue, Aug 18, 2020 at 06:27:12PM +0200, Bartosz Golaszewski wrote:
> > On Tue, Aug 18, 2020 at 10:40 AM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > >
> > > On Mon, Aug 17, 2020 at 10:02:05PM +0200, Bartosz Golaszewski wrote:
> > > > On Mon, Aug 17, 2020 at 7:43 PM Andy Shevchenko
> > > > <andriy.shevchenko@linux.intel.com> wrote:
> > > > > On Mon, Aug 17, 2020 at 07:05:33PM +0200, Bartosz Golaszewski wrote:
> > > > > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > >
> > > ...
> > >
> > > > > > +static struct devres *to_devres(void *data)
> > > > > > +{
> > > > > > + return (struct devres *)((u8 *)data - ALIGN(sizeof(struct devres),
> > > > > > + ARCH_KMALLOC_MINALIGN));
> > > > >
> > > > > Do you really need both explicit castings?
> > > > >
> > > >
> > > > Yeah, we can probably drop the (struct devres *) here.
> > >
> > > void * -> u8 * here is also not needed, it is considered byte access IIRC.
> > >
> >
> > Actually it turns out that while we don't need the (void *) -> (u8 *)
> > casting, we must cast to (struct devres *) or the following error is
> > produced:
> >
> > drivers/base/devres.c: In function ‘to_devres’:
> > drivers/base/devres.c:41:21: error: returning ‘u8 *’ {aka ‘unsigned
> > char *’} from a function with incompatible return type ‘struct devres
> > *’ [-Werror=incompatible-pointer-types]
> > return ((u8 *)data - ALIGN(sizeof(struct devres),
> > ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > ARCH_KMALLOC_MINALIGN));
> > ~~~~~~~~~~~~~~~~~~~~~~~
>
> Of course, you have to drop u8 * casting as well.
>
Yes, of course. Duh
Bart
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v7 1/3] devres: provide devm_krealloc()
2020-08-18 18:13 ` Bartosz Golaszewski
@ 2020-08-19 9:14 ` Andy Shevchenko
0 siblings, 0 replies; 11+ messages in thread
From: Andy Shevchenko @ 2020-08-19 9:14 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, linux-iio, Linux ARM, Linux Kernel Mailing List,
Bartosz Golaszewski
On Tue, Aug 18, 2020 at 08:13:10PM +0200, Bartosz Golaszewski wrote:
> On Tue, Aug 18, 2020 at 7:19 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > On Tue, Aug 18, 2020 at 06:27:12PM +0200, Bartosz Golaszewski wrote:
> > > On Tue, Aug 18, 2020 at 10:40 AM Andy Shevchenko
> > > <andriy.shevchenko@linux.intel.com> wrote:
> > > > On Mon, Aug 17, 2020 at 10:02:05PM +0200, Bartosz Golaszewski wrote:
> > > > > On Mon, Aug 17, 2020 at 7:43 PM Andy Shevchenko
> > > > > <andriy.shevchenko@linux.intel.com> wrote:
> > > > > > On Mon, Aug 17, 2020 at 07:05:33PM +0200, Bartosz Golaszewski wrote:
> > > > > > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
...
> > > > > > > +static struct devres *to_devres(void *data)
> > > > > > > +{
> > > > > > > + return (struct devres *)((u8 *)data - ALIGN(sizeof(struct devres),
> > > > > > > + ARCH_KMALLOC_MINALIGN));
> > > > > >
> > > > > > Do you really need both explicit castings?
> > > > > >
> > > > >
> > > > > Yeah, we can probably drop the (struct devres *) here.
> > > >
> > > > void * -> u8 * here is also not needed, it is considered byte access IIRC.
> > > >
> > >
> > > Actually it turns out that while we don't need the (void *) -> (u8 *)
> > > casting, we must cast to (struct devres *) or the following error is
> > > produced:
> > >
> > > drivers/base/devres.c: In function ‘to_devres’:
> > > drivers/base/devres.c:41:21: error: returning ‘u8 *’ {aka ‘unsigned
> > > char *’} from a function with incompatible return type ‘struct devres
> > > *’ [-Werror=incompatible-pointer-types]
> > > return ((u8 *)data - ALIGN(sizeof(struct devres),
> > > ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > ARCH_KMALLOC_MINALIGN));
> > > ~~~~~~~~~~~~~~~~~~~~~~~
> >
> > Of course, you have to drop u8 * casting as well.
> >
>
> Yes, of course. Duh
With this addressed (and don't forget to remove also unneeded parentheses),
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Thanks!
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH v7 2/3] hwmon: pmbus: use more devres helpers
2020-08-17 17:05 [PATCH v7 0/3] devres: provide and use devm_krealloc() Bartosz Golaszewski
2020-08-17 17:05 ` [PATCH v7 1/3] devres: provide devm_krealloc() Bartosz Golaszewski
@ 2020-08-17 17:05 ` Bartosz Golaszewski
2020-08-17 17:05 ` [PATCH v7 3/3] iio: adc: xilinx-xadc: use devm_krealloc() Bartosz Golaszewski
2 siblings, 0 replies; 11+ messages in thread
From: Bartosz Golaszewski @ 2020-08-17 17:05 UTC (permalink / raw)
To: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, Andy Shevchenko
Cc: linux-iio, linux-arm-kernel, linux-kernel, Bartosz Golaszewski
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Shrink pmbus code by using devm_hwmon_device_register_with_groups()
and devm_krealloc() instead of their non-managed variants.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
---
drivers/hwmon/pmbus/pmbus_core.c | 28 +++++++++-------------------
1 file changed, 9 insertions(+), 19 deletions(-)
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 44535add3a4a..91839979cf6c 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -1018,9 +1018,9 @@ static int pmbus_add_attribute(struct pmbus_data *data, struct attribute *attr)
{
if (data->num_attributes >= data->max_attributes - 1) {
int new_max_attrs = data->max_attributes + PMBUS_ATTR_ALLOC_SIZE;
- void *new_attrs = krealloc(data->group.attrs,
- new_max_attrs * sizeof(void *),
- GFP_KERNEL);
+ void *new_attrs = devm_krealloc(data->dev, data->group.attrs,
+ new_max_attrs * sizeof(void *),
+ GFP_KERNEL);
if (!new_attrs)
return -ENOMEM;
data->group.attrs = new_attrs;
@@ -2534,7 +2534,7 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
ret = pmbus_find_attributes(client, data);
if (ret)
- goto out_kfree;
+ return ret;
/*
* If there are no attributes, something is wrong.
@@ -2542,35 +2542,27 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
*/
if (!data->num_attributes) {
dev_err(dev, "No attributes found\n");
- ret = -ENODEV;
- goto out_kfree;
+ return -ENODEV;
}
data->groups[0] = &data->group;
memcpy(data->groups + 1, info->groups, sizeof(void *) * groups_num);
- data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
- data, data->groups);
+ data->hwmon_dev = devm_hwmon_device_register_with_groups(dev,
+ client->name, data, data->groups);
if (IS_ERR(data->hwmon_dev)) {
- ret = PTR_ERR(data->hwmon_dev);
dev_err(dev, "Failed to register hwmon device\n");
- goto out_kfree;
+ return PTR_ERR(data->hwmon_dev);
}
ret = pmbus_regulator_register(data);
if (ret)
- goto out_unregister;
+ return ret;
ret = pmbus_init_debugfs(client, data);
if (ret)
dev_warn(dev, "Failed to register debugfs\n");
return 0;
-
-out_unregister:
- hwmon_device_unregister(data->hwmon_dev);
-out_kfree:
- kfree(data->group.attrs);
- return ret;
}
EXPORT_SYMBOL_GPL(pmbus_do_probe);
@@ -2580,8 +2572,6 @@ int pmbus_do_remove(struct i2c_client *client)
debugfs_remove_recursive(data->debugfs);
- hwmon_device_unregister(data->hwmon_dev);
- kfree(data->group.attrs);
return 0;
}
EXPORT_SYMBOL_GPL(pmbus_do_remove);
--
2.26.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH v7 3/3] iio: adc: xilinx-xadc: use devm_krealloc()
2020-08-17 17:05 [PATCH v7 0/3] devres: provide and use devm_krealloc() Bartosz Golaszewski
2020-08-17 17:05 ` [PATCH v7 1/3] devres: provide devm_krealloc() Bartosz Golaszewski
2020-08-17 17:05 ` [PATCH v7 2/3] hwmon: pmbus: use more devres helpers Bartosz Golaszewski
@ 2020-08-17 17:05 ` Bartosz Golaszewski
2 siblings, 0 replies; 11+ messages in thread
From: Bartosz Golaszewski @ 2020-08-17 17:05 UTC (permalink / raw)
To: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Michal Simek, Greg Kroah-Hartman,
Guenter Roeck, Andy Shevchenko
Cc: linux-iio, linux-arm-kernel, linux-kernel, Bartosz Golaszewski,
Jonathan Cameron
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Use the managed variant of krealloc() and shrink the code a bit.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
drivers/iio/adc/xilinx-xadc-core.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c
index d0b7ef296afb..f93c34fe5873 100644
--- a/drivers/iio/adc/xilinx-xadc-core.c
+++ b/drivers/iio/adc/xilinx-xadc-core.c
@@ -1092,6 +1092,7 @@ MODULE_DEVICE_TABLE(of, xadc_of_match_table);
static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
unsigned int *conf)
{
+ struct device *dev = indio_dev->dev.parent;
struct xadc *xadc = iio_priv(indio_dev);
struct iio_chan_spec *channels, *chan;
struct device_node *chan_node, *child;
@@ -1136,7 +1137,8 @@ static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
*conf |= XADC_CONF0_MUX | XADC_CONF0_CHAN(ext_mux_chan);
}
- channels = kmemdup(xadc_channels, sizeof(xadc_channels), GFP_KERNEL);
+ channels = devm_kmemdup(dev, xadc_channels,
+ sizeof(xadc_channels), GFP_KERNEL);
if (!channels)
return -ENOMEM;
@@ -1172,8 +1174,9 @@ static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
of_node_put(chan_node);
indio_dev->num_channels = num_channels;
- indio_dev->channels = krealloc(channels, sizeof(*channels) *
- num_channels, GFP_KERNEL);
+ indio_dev->channels = devm_krealloc(dev, channels,
+ sizeof(*channels) * num_channels,
+ GFP_KERNEL);
/* If we can't resize the channels array, just use the original */
if (!indio_dev->channels)
indio_dev->channels = channels;
@@ -1225,14 +1228,14 @@ static int xadc_probe(struct platform_device *pdev)
ret = xadc_parse_dt(indio_dev, pdev->dev.of_node, &conf0);
if (ret)
- goto err_device_free;
+ return ret;
if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
ret = iio_triggered_buffer_setup(indio_dev,
&iio_pollfunc_store_time, &xadc_trigger_handler,
&xadc_buffer_ops);
if (ret)
- goto err_device_free;
+ return ret;
xadc->convst_trigger = xadc_alloc_trigger(indio_dev, "convst");
if (IS_ERR(xadc->convst_trigger)) {
@@ -1350,8 +1353,6 @@ static int xadc_probe(struct platform_device *pdev)
err_triggered_buffer_cleanup:
if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
iio_triggered_buffer_cleanup(indio_dev);
-err_device_free:
- kfree(indio_dev->channels);
return ret;
}
@@ -1371,7 +1372,6 @@ static int xadc_remove(struct platform_device *pdev)
cancel_delayed_work_sync(&xadc->zynq_unmask_work);
clk_disable_unprepare(xadc->clk);
kfree(xadc->data);
- kfree(indio_dev->channels);
return 0;
}
--
2.26.1
^ permalink raw reply related [flat|nested] 11+ messages in thread