| Message ID | 20190617122733.22432-7-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/25] mm: remove the unused ARCH_HAS_HMM_DEVICE Kconfig option | expand |
On Mon, Jun 17, 2019 at 5:27 AM Christoph Hellwig <hch@lst.de> wrote: > > Keep the physical address allocation that hmm_add_device does with the > rest of the resource code, and allow future reuse of it without the hmm > wrapper. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> > Reviewed-by: John Hubbard <jhubbard@nvidia.com> > --- > include/linux/ioport.h | 2 ++ > kernel/resource.c | 39 +++++++++++++++++++++++++++++++++++++++ > mm/hmm.c | 33 ++++----------------------------- > 3 files changed, 45 insertions(+), 29 deletions(-) > > diff --git a/include/linux/ioport.h b/include/linux/ioport.h > index da0ebaec25f0..76a33ae3bf6c 100644 > --- a/include/linux/ioport.h > +++ b/include/linux/ioport.h > @@ -286,6 +286,8 @@ static inline bool resource_overlaps(struct resource *r1, struct resource *r2) > return (r1->start <= r2->end && r1->end >= r2->start); > } > > +struct resource *devm_request_free_mem_region(struct device *dev, > + struct resource *base, unsigned long size); This appears to need a 'static inline' helper stub in the CONFIG_DEVICE_PRIVATE=n case, otherwise this compile error triggers: ld: mm/hmm.o: in function `hmm_devmem_add': /home/dwillia2/git/linux/mm/hmm.c:1427: undefined reference to `devm_request_free_mem_region'
On Mon, Jun 17, 2019 at 10:37:12AM -0700, Dan Williams wrote: > > +struct resource *devm_request_free_mem_region(struct device *dev, > > + struct resource *base, unsigned long size); > > This appears to need a 'static inline' helper stub in the > CONFIG_DEVICE_PRIVATE=n case, otherwise this compile error triggers: > > ld: mm/hmm.o: in function `hmm_devmem_add': > /home/dwillia2/git/linux/mm/hmm.c:1427: undefined reference to > `devm_request_free_mem_region' *sigh* - hmm_devmem_add already only works for device private memory, so it shouldn't be built if that option is not enabled, but in the current code it is. And a few patches later in the series we just kill it off entirely, and the only real caller of this function already depends on CONFIG_DEVICE_PRIVATE. So I'm tempted to just ignore the strict bisectability requirement here instead of making things messy by either adding the proper ifdefs in hmm.c or providing a stub we don't really need.
On Mon, Jun 17, 2019 at 07:40:18PM +0200, Christoph Hellwig wrote: > On Mon, Jun 17, 2019 at 10:37:12AM -0700, Dan Williams wrote: > > > +struct resource *devm_request_free_mem_region(struct device *dev, > > > + struct resource *base, unsigned long size); > > > > This appears to need a 'static inline' helper stub in the > > CONFIG_DEVICE_PRIVATE=n case, otherwise this compile error triggers: > > > > ld: mm/hmm.o: in function `hmm_devmem_add': > > /home/dwillia2/git/linux/mm/hmm.c:1427: undefined reference to > > `devm_request_free_mem_region' > > *sigh* - hmm_devmem_add already only works for device private memory, > so it shouldn't be built if that option is not enabled, but in the > current code it is. And a few patches later in the series we just > kill it off entirely, and the only real caller of this function > already depends on CONFIG_DEVICE_PRIVATE. So I'm tempted to just > ignore the strict bisectability requirement here instead of making > things messy by either adding the proper ifdefs in hmm.c or providing > a stub we don't really need. Actually, I could just move the patch to mark CONFIG_DEVICE_PUBLIC broken earlier, which would force hmm_devmem_add to only be built when CONFIG_DEVICE_PRIVATE ist set.
diff --git a/include/linux/ioport.h b/include/linux/ioport.h index da0ebaec25f0..76a33ae3bf6c 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -286,6 +286,8 @@ static inline bool resource_overlaps(struct resource *r1, struct resource *r2) return (r1->start <= r2->end && r1->end >= r2->start); } +struct resource *devm_request_free_mem_region(struct device *dev, + struct resource *base, unsigned long size); #endif /* __ASSEMBLY__ */ #endif /* _LINUX_IOPORT_H */ diff --git a/kernel/resource.c b/kernel/resource.c index 158f04ec1d4f..d22423e85cf8 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1628,6 +1628,45 @@ void resource_list_free(struct list_head *head) } EXPORT_SYMBOL(resource_list_free); +#ifdef CONFIG_DEVICE_PRIVATE +/** + * devm_request_free_mem_region - find free region for device private memory + * + * @dev: device struct to bind the resource to + * @size: size in bytes of the device memory to add + * @base: resource tree to look in + * + * This function tries to find an empty range of physical address big enough to + * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE + * memory, which in turn allocates struct pages. + */ +struct resource *devm_request_free_mem_region(struct device *dev, + struct resource *base, unsigned long size) +{ + resource_size_t end, addr; + struct resource *res; + + size = ALIGN(size, 1UL << PA_SECTION_SHIFT); + end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1); + addr = end - size + 1UL; + + for (; addr > size && addr >= base->start; addr -= size) { + if (region_intersects(addr, size, 0, IORES_DESC_NONE) != + REGION_DISJOINT) + continue; + + res = devm_request_mem_region(dev, addr, size, dev_name(dev)); + if (!res) + return ERR_PTR(-ENOMEM); + res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY; + return res; + } + + return ERR_PTR(-ERANGE); +} +EXPORT_SYMBOL_GPL(devm_request_free_mem_region); +#endif /* CONFIG_DEVICE_PRIVATE */ + static int __init strict_iomem(char *str) { if (strstr(str, "relaxed")) diff --git a/mm/hmm.c b/mm/hmm.c index 64e788bb1211..172d695dcb8b 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -25,8 +25,6 @@ #include <linux/mmu_notifier.h> #include <linux/memory_hotplug.h> -#define PA_SECTION_SIZE (1UL << PA_SECTION_SHIFT) - #if IS_ENABLED(CONFIG_HMM_MIRROR) static const struct mmu_notifier_ops hmm_mmu_notifier_ops; @@ -1405,7 +1403,6 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, unsigned long size) { struct hmm_devmem *devmem; - resource_size_t addr; void *result; int ret; @@ -1427,32 +1424,10 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, if (ret) return ERR_PTR(ret); - size = ALIGN(size, PA_SECTION_SIZE); - addr = min((unsigned long)iomem_resource.end, - (1UL << MAX_PHYSMEM_BITS) - 1); - addr = addr - size + 1UL; - - /* - * FIXME add a new helper to quickly walk resource tree and find free - * range - * - * FIXME what about ioport_resource resource ? - */ - for (; addr > size && addr >= iomem_resource.start; addr -= size) { - ret = region_intersects(addr, size, 0, IORES_DESC_NONE); - if (ret != REGION_DISJOINT) - continue; - - devmem->resource = devm_request_mem_region(device, addr, size, - dev_name(device)); - if (!devmem->resource) - return ERR_PTR(-ENOMEM); - break; - } - if (!devmem->resource) - return ERR_PTR(-ERANGE); - - devmem->resource->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY; + devmem->resource = devm_request_free_mem_region(device, &iomem_resource, + size); + if (IS_ERR(devmem->resource)) + return ERR_CAST(devmem->resource); devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT; devmem->pfn_last = devmem->pfn_first + (resource_size(devmem->resource) >> PAGE_SHIFT);