unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
1
Fork 0
Code Pull requests 5 Wiki Activity

lib: devres: Add managed arch_phys_wc_add()

Browse source 
Add devm_arch_phys_wc_add() as managed wrapper around arch_phys_wc_add().
Useful for several graphics drivers that set framebuffer memory to write
combining.

v2:
	* fix typo in commit description

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210916181601.9146-2-tzimmermann@suse.de
This commit is contained in:
Thomas Zimmermann 2021-09-16 20:15:57 +02:00
parent 9c2fce1378
commit 3229b906fb
2 changed files with 38 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
include/linux/io.h
View file

@ -132,6 +132,8 @@ static inline int arch_phys_wc_index(int handle)
#endif
#endif
int devm_arch_phys_wc_add(struct device *dev, unsigned long base, unsigned long size);
enum {
/* See memremap() kernel-doc for usage description... */
MEMREMAP_WB = 1 << 0,

36
lib/devres.c
View file

@ -528,3 +528,39 @@ void pcim_iounmap_regions(struct pci_dev *pdev, int mask)
}
EXPORT_SYMBOL(pcim_iounmap_regions);
#endif /* CONFIG_PCI */
static void devm_arch_phys_ac_add_release(struct device *dev, void *res)
{
arch_phys_wc_del(*((int *)res));
}
/**
* devm_arch_phys_wc_add - Managed arch_phys_wc_add()
* @dev: Managed device
* @base: Memory base address
* @size: Size of memory range
*
* Adds a WC MTRR using arch_phys_wc_add() and sets up a release callback.
* See arch_phys_wc_add() for more information.
*/
int devm_arch_phys_wc_add(struct device *dev, unsigned long base, unsigned long size)
{
int *mtrr;
int ret;
mtrr = devres_alloc(devm_arch_phys_ac_add_release, sizeof(*mtrr), GFP_KERNEL);
if (!mtrr)
return -ENOMEM;
ret = arch_phys_wc_add(base, size);
if (ret < 0) {
devres_free(mtrr);
return ret;
}
*mtrr = ret;
devres_add(dev, mtrr);
return ret;
}
EXPORT_SYMBOL(devm_arch_phys_wc_add);