From 6d82120f41561426dd67c86380d779b4599d070d Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 13 Oct 2020 16:50:55 -0700 Subject: [PATCH] device-dax: add an 'align' attribute MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Introduce a device align attribute. While doing so, rename the region align attribute to be more explicitly named as so, but keep it named as @align to retain the API for tools like daxctl. Changes on align may not always be valid, when say certain mappings were created with 2M and then we switch to 1G. So, we validate all ranges against the new value being attempted, post resizing. Signed-off-by: Joao Martins Signed-off-by: Dan Williams Signed-off-by: Andrew Morton Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Ard Biesheuvel Cc: Benjamin Herrenschmidt Cc: Ben Skeggs Cc: Bjorn Helgaas Cc: Borislav Petkov Cc: Boris Ostrovsky Cc: Brice Goglin Cc: Catalin Marinas Cc: Daniel Vetter Cc: Dave Hansen Cc: Dave Jiang Cc: David Airlie Cc: David Hildenbrand Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Hulk Robot Cc: Ingo Molnar Cc: Ira Weiny Cc: Jason Gunthorpe Cc: Jason Yan Cc: Jeff Moyer Cc: "Jérôme Glisse" Cc: Jia He Cc: Jonathan Cameron Cc: Juergen Gross Cc: kernel test robot Cc: Michael Ellerman Cc: Mike Rapoport Cc: Paul Mackerras Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: "Rafael J. Wysocki" Cc: Randy Dunlap Cc: Stefano Stabellini Cc: Thomas Gleixner Cc: Tom Lendacky Cc: Vishal Verma Cc: Vivek Goyal Cc: Wei Yang Cc: Will Deacon Link: https://lkml.kernel.org/r/159643105944.4062302.3131761052969132784.stgit@dwillia2-desk3.amr.corp.intel.com Link: https://lore.kernel.org/r/20200716172913.19658-3-joao.m.martins@oracle.com Link: https://lkml.kernel.org/r/160106118486.30709.13012322227204800596.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds --- drivers/dax/bus.c | 93 ++++++++++++++++++++++++++++++++++++++++++----- drivers/dax/dax-private.h | 18 +++++++++ 2 files changed, 101 insertions(+), 10 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 852899084d13..0ac4a9c0fd18 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -230,14 +230,15 @@ static ssize_t region_size_show(struct device *dev, static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, region_size_show, NULL); -static ssize_t align_show(struct device *dev, +static ssize_t region_align_show(struct device *dev, struct device_attribute *attr, char *buf) { struct dax_region *dax_region = dev_get_drvdata(dev); return sprintf(buf, "%u\n", dax_region->align); } -static DEVICE_ATTR_RO(align); +static struct device_attribute dev_attr_region_align = + __ATTR(align, 0400, region_align_show, NULL); #define for_each_dax_region_resource(dax_region, res) \ for (res = (dax_region)->res.child; res; res = res->sibling) @@ -488,7 +489,7 @@ static umode_t dax_region_visible(struct kobject *kobj, struct attribute *a, static struct attribute *dax_region_attributes[] = { &dev_attr_available_size.attr, &dev_attr_region_size.attr, - &dev_attr_align.attr, + &dev_attr_region_align.attr, &dev_attr_create.attr, &dev_attr_seed.attr, &dev_attr_delete.attr, @@ -858,15 +859,13 @@ static ssize_t size_show(struct device *dev, return sprintf(buf, "%llu\n", size); } -static bool alloc_is_aligned(struct dax_region *dax_region, - resource_size_t size) +static bool alloc_is_aligned(struct dev_dax *dev_dax, resource_size_t size) { /* * The minimum mapping granularity for a device instance is a * single subsection, unless the arch says otherwise. */ - return IS_ALIGNED(size, max_t(unsigned long, dax_region->align, - memremap_compat_align())); + return IS_ALIGNED(size, max_t(unsigned long, dev_dax->align, memremap_compat_align())); } static int dev_dax_shrink(struct dev_dax *dev_dax, resource_size_t size) @@ -961,7 +960,7 @@ static ssize_t dev_dax_resize(struct dax_region *dax_region, return dev_dax_shrink(dev_dax, size); to_alloc = size - dev_size; - if (dev_WARN_ONCE(dev, !alloc_is_aligned(dax_region, to_alloc), + if (dev_WARN_ONCE(dev, !alloc_is_aligned(dev_dax, to_alloc), "resize of %pa misaligned\n", &to_alloc)) return -ENXIO; @@ -1025,7 +1024,7 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr, if (rc) return rc; - if (!alloc_is_aligned(dax_region, val)) { + if (!alloc_is_aligned(dev_dax, val)) { dev_dbg(dev, "%s: size: %lld misaligned\n", __func__, val); return -EINVAL; } @@ -1044,6 +1043,78 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RW(size); +static ssize_t align_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + + return sprintf(buf, "%d\n", dev_dax->align); +} + +static ssize_t dev_dax_validate_align(struct dev_dax *dev_dax) +{ + resource_size_t dev_size = dev_dax_size(dev_dax); + struct device *dev = &dev_dax->dev; + int i; + + if (dev_size > 0 && !alloc_is_aligned(dev_dax, dev_size)) { + dev_dbg(dev, "%s: align %u invalid for size %pa\n", + __func__, dev_dax->align, &dev_size); + return -EINVAL; + } + + for (i = 0; i < dev_dax->nr_range; i++) { + size_t len = range_len(&dev_dax->ranges[i].range); + + if (!alloc_is_aligned(dev_dax, len)) { + dev_dbg(dev, "%s: align %u invalid for range %d\n", + __func__, dev_dax->align, i); + return -EINVAL; + } + } + + return 0; +} + +static ssize_t align_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_region *dax_region = dev_dax->region; + unsigned long val, align_save; + ssize_t rc; + + rc = kstrtoul(buf, 0, &val); + if (rc) + return -ENXIO; + + if (!dax_align_valid(val)) + return -EINVAL; + + device_lock(dax_region->dev); + if (!dax_region->dev->driver) { + device_unlock(dax_region->dev); + return -ENXIO; + } + + device_lock(dev); + if (dev->driver) { + rc = -EBUSY; + goto out_unlock; + } + + align_save = dev_dax->align; + dev_dax->align = val; + rc = dev_dax_validate_align(dev_dax); + if (rc) + dev_dax->align = align_save; +out_unlock: + device_unlock(dev); + device_unlock(dax_region->dev); + return rc == 0 ? len : rc; +} +static DEVICE_ATTR_RW(align); + static int dev_dax_target_node(struct dev_dax *dev_dax) { struct dax_region *dax_region = dev_dax->region; @@ -1104,7 +1175,8 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) return 0; if (a == &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA)) return 0; - if (a == &dev_attr_size.attr && is_static(dax_region)) + if ((a == &dev_attr_align.attr || + a == &dev_attr_size.attr) && is_static(dax_region)) return 0444; return a->mode; } @@ -1113,6 +1185,7 @@ static struct attribute *dev_dax_attributes[] = { &dev_attr_modalias.attr, &dev_attr_size.attr, &dev_attr_target_node.attr, + &dev_attr_align.attr, &dev_attr_resource.attr, &dev_attr_numa_node.attr, NULL, diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index 5fd3a26cfcea..1c974b7caae6 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -87,4 +87,22 @@ static inline struct dax_mapping *to_dax_mapping(struct device *dev) } phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff, unsigned long size); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline bool dax_align_valid(unsigned long align) +{ + if (align == PUD_SIZE && IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)) + return true; + if (align == PMD_SIZE && has_transparent_hugepage()) + return true; + if (align == PAGE_SIZE) + return true; + return false; +} +#else +static inline bool dax_align_valid(unsigned long align) +{ + return align == PAGE_SIZE; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ #endif -- 2.11.0