From c2f3011ee697f85ba0166fb3780332aafc66b8f4 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 13 Oct 2020 16:50:03 -0700 Subject: device-dax: add an allocation interface for device-dax instances MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In preparation for a facility that enables dax regions to be sub-divided, introduce infrastructure to track and allocate region capacity. The new dax_region/available_size attribute is only enabled for volatile hmem devices, not pmem devices that are defined by nvdimm namespace boundaries. This is per Jeff's feedback the last time dynamic device-dax capacity allocation support was discussed. Signed-off-by: Dan Williams Signed-off-by: Andrew Morton Cc: Vishal Verma Cc: Brice Goglin Cc: Dave Hansen Cc: Dave Jiang Cc: David Hildenbrand Cc: Ira Weiny Cc: Jia He Cc: Joao Martins Cc: Jonathan Cameron 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: Catalin Marinas Cc: Daniel Vetter Cc: David Airlie Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Hulk Robot Cc: Ingo Molnar Cc: Jason Gunthorpe Cc: Jason Yan Cc: Jeff Moyer Cc: "Jérôme Glisse" 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: Vivek Goyal Cc: Wei Yang Cc: Will Deacon Link: https://lore.kernel.org/linux-nvdimm/x49shpp3zn8.fsf@segfault.boston.devel.redhat.com Link: https://lkml.kernel.org/r/159643101035.4062302.6785857915652647857.stgit@dwillia2-desk3.amr.corp.intel.com Link: https://lkml.kernel.org/r/160106112801.30709.14601438735305335071.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds --- drivers/dax/bus.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 110 insertions(+), 10 deletions(-) (limited to 'drivers/dax/bus.c') diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 96bd64ba95a5..0a48ce378686 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -130,6 +130,11 @@ ATTRIBUTE_GROUPS(dax_drv); static int dax_bus_match(struct device *dev, struct device_driver *drv); +static bool is_static(struct dax_region *dax_region) +{ + return (dax_region->res.flags & IORESOURCE_DAX_STATIC) != 0; +} + static struct bus_type dax_bus_type = { .name = "dax", .uevent = dax_bus_uevent, @@ -185,7 +190,48 @@ static ssize_t align_show(struct device *dev, } static DEVICE_ATTR_RO(align); +#define for_each_dax_region_resource(dax_region, res) \ + for (res = (dax_region)->res.child; res; res = res->sibling) + +static unsigned long long dax_region_avail_size(struct dax_region *dax_region) +{ + resource_size_t size = resource_size(&dax_region->res); + struct resource *res; + + device_lock_assert(dax_region->dev); + + for_each_dax_region_resource(dax_region, res) + size -= resource_size(res); + return size; +} + +static ssize_t available_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_region *dax_region = dev_get_drvdata(dev); + unsigned long long size; + + device_lock(dev); + size = dax_region_avail_size(dax_region); + device_unlock(dev); + + return sprintf(buf, "%llu\n", size); +} +static DEVICE_ATTR_RO(available_size); + +static umode_t dax_region_visible(struct kobject *kobj, struct attribute *a, + int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct dax_region *dax_region = dev_get_drvdata(dev); + + if (is_static(dax_region) && a == &dev_attr_available_size.attr) + return 0; + return a->mode; +} + static struct attribute *dax_region_attributes[] = { + &dev_attr_available_size.attr, &dev_attr_region_size.attr, &dev_attr_align.attr, &dev_attr_id.attr, @@ -195,6 +241,7 @@ static struct attribute *dax_region_attributes[] = { static const struct attribute_group dax_region_attribute_group = { .name = "dax_region", .attrs = dax_region_attributes, + .is_visible = dax_region_visible, }; static const struct attribute_group *dax_region_attribute_groups[] = { @@ -226,7 +273,8 @@ static void dax_region_unregister(void *region) } struct dax_region *alloc_dax_region(struct device *parent, int region_id, - struct resource *res, int target_node, unsigned int align) + struct resource *res, int target_node, unsigned int align, + unsigned long flags) { struct dax_region *dax_region; @@ -249,12 +297,17 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id, return NULL; dev_set_drvdata(parent, dax_region); - memcpy(&dax_region->res, res, sizeof(*res)); kref_init(&dax_region->kref); dax_region->id = region_id; dax_region->align = align; dax_region->dev = parent; dax_region->target_node = target_node; + dax_region->res = (struct resource) { + .start = res->start, + .end = res->end, + .flags = IORESOURCE_MEM | flags, + }; + if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) { kfree(dax_region); return NULL; @@ -267,6 +320,32 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id, } EXPORT_SYMBOL_GPL(alloc_dax_region); +static int alloc_dev_dax_range(struct dev_dax *dev_dax, resource_size_t size) +{ + struct dax_region *dax_region = dev_dax->region; + struct resource *res = &dax_region->res; + struct device *dev = &dev_dax->dev; + struct resource *alloc; + + device_lock_assert(dax_region->dev); + + /* TODO: handle multiple allocations per region */ + if (res->child) + return -ENOMEM; + + alloc = __request_region(res, res->start, size, dev_name(dev), 0); + + if (!alloc) + return -ENOMEM; + + dev_dax->range = (struct range) { + .start = alloc->start, + .end = alloc->end, + }; + + return 0; +} + static ssize_t size_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -361,6 +440,15 @@ void kill_dev_dax(struct dev_dax *dev_dax) } EXPORT_SYMBOL_GPL(kill_dev_dax); +static void free_dev_dax_range(struct dev_dax *dev_dax) +{ + struct dax_region *dax_region = dev_dax->region; + struct range *range = &dev_dax->range; + + device_lock_assert(dax_region->dev); + __release_region(&dax_region->res, range->start, range_len(range)); +} + static void dev_dax_release(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); @@ -385,6 +473,7 @@ static void unregister_dev_dax(void *dev) dev_dbg(dev, "%s\n", __func__); kill_dev_dax(dev_dax); + free_dev_dax_range(dev_dax); device_del(dev); put_device(dev); } @@ -397,7 +486,7 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) struct dev_dax *dev_dax; struct inode *inode; struct device *dev; - int rc = -ENOMEM; + int rc; if (data->id < 0) return ERR_PTR(-EINVAL); @@ -406,11 +495,25 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) if (!dev_dax) return ERR_PTR(-ENOMEM); + dev_dax->region = dax_region; + dev = &dev_dax->dev; + device_initialize(dev); + dev_set_name(dev, "dax%d.%d", dax_region->id, data->id); + + rc = alloc_dev_dax_range(dev_dax, data->size); + if (rc) + goto err_range; + if (data->pgmap) { + dev_WARN_ONCE(parent, !is_static(dax_region), + "custom dev_pagemap requires a static dax_region\n"); + dev_dax->pgmap = kmemdup(data->pgmap, sizeof(struct dev_pagemap), GFP_KERNEL); - if (!dev_dax->pgmap) + if (!dev_dax->pgmap) { + rc = -ENOMEM; goto err_pgmap; + } } /* @@ -427,12 +530,7 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) kill_dax(dax_dev); /* from here on we're committed to teardown via dev_dax_release() */ - dev = &dev_dax->dev; - device_initialize(dev); - dev_dax->dax_dev = dax_dev; - dev_dax->region = dax_region; - dev_dax->range = data->range; dev_dax->target_node = dax_region->target_node; kref_get(&dax_region->kref); @@ -444,7 +542,6 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) dev->class = dax_class; dev->parent = parent; dev->type = &dev_dax_type; - dev_set_name(dev, "dax%d.%d", dax_region->id, data->id); rc = device_add(dev); if (rc) { @@ -458,9 +555,12 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) return ERR_PTR(rc); return dev_dax; + err_alloc_dax: kfree(dev_dax->pgmap); err_pgmap: + free_dev_dax_range(dev_dax); +err_range: kfree(dev_dax); return ERR_PTR(rc); -- cgit v1.2.3-59-g8ed1b