diff options
| -rw-r--r-- | drivers/dax/bus.c | 301 | ||||
| -rw-r--r-- | drivers/dax/dax-private.h | 9 | ||||
| -rw-r--r-- | drivers/dax/hmem/hmem.c | 2 |
3 files changed, 272 insertions, 40 deletions
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 9549f11ebed0..dce9413a4394 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -139,8 +139,26 @@ static int dax_bus_probe(struct device *dev) { struct dax_device_driver *dax_drv = to_dax_drv(dev->driver); struct dev_dax *dev_dax = to_dev_dax(dev); + struct dax_region *dax_region = dev_dax->region; + struct range *range = &dev_dax->range; + int rc; + + if (range_len(range) == 0 || dev_dax->id < 0) + return -ENXIO; + + rc = dax_drv->probe(dev_dax); + + if (rc || is_static(dax_region)) + return rc; + + /* + * Track new seed creation only after successful probe of the + * previous seed. + */ + if (dax_region->seed == dev) + dax_region->seed = NULL; - return dax_drv->probe(dev_dax); + return 0; } static int dax_bus_remove(struct device *dev) @@ -237,14 +255,216 @@ static ssize_t available_size_show(struct device *dev, } static DEVICE_ATTR_RO(available_size); +static ssize_t seed_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_region *dax_region = dev_get_drvdata(dev); + struct device *seed; + ssize_t rc; + + if (is_static(dax_region)) + return -EINVAL; + + device_lock(dev); + seed = dax_region->seed; + rc = sprintf(buf, "%s\n", seed ? dev_name(seed) : ""); + device_unlock(dev); + + return rc; +} +static DEVICE_ATTR_RO(seed); + +static ssize_t create_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dax_region *dax_region = dev_get_drvdata(dev); + struct device *youngest; + ssize_t rc; + + if (is_static(dax_region)) + return -EINVAL; + + device_lock(dev); + youngest = dax_region->youngest; + rc = sprintf(buf, "%s\n", youngest ? dev_name(youngest) : ""); + device_unlock(dev); + + return rc; +} + +static ssize_t create_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct dax_region *dax_region = dev_get_drvdata(dev); + unsigned long long avail; + ssize_t rc; + int val; + + if (is_static(dax_region)) + return -EINVAL; + + rc = kstrtoint(buf, 0, &val); + if (rc) + return rc; + if (val != 1) + return -EINVAL; + + device_lock(dev); + avail = dax_region_avail_size(dax_region); + if (avail == 0) + rc = -ENOSPC; + else { + struct dev_dax_data data = { + .dax_region = dax_region, + .size = 0, + .id = -1, + }; + struct dev_dax *dev_dax = devm_create_dev_dax(&data); + + if (IS_ERR(dev_dax)) + rc = PTR_ERR(dev_dax); + else { + /* + * In support of crafting multiple new devices + * simultaneously multiple seeds can be created, + * but only the first one that has not been + * successfully bound is tracked as the region + * seed. + */ + if (!dax_region->seed) + dax_region->seed = &dev_dax->dev; + dax_region->youngest = &dev_dax->dev; + rc = len; + } + } + device_unlock(dev); + + return rc; +} +static DEVICE_ATTR_RW(create); + +void kill_dev_dax(struct dev_dax *dev_dax) +{ + struct dax_device *dax_dev = dev_dax->dax_dev; + struct inode *inode = dax_inode(dax_dev); + + kill_dax(dax_dev); + unmap_mapping_range(inode->i_mapping, 0, 0, 1); +} +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); + if (range_len(range)) + __release_region(&dax_region->res, range->start, + range_len(range)); +} + +static void unregister_dev_dax(void *dev) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + + dev_dbg(dev, "%s\n", __func__); + + kill_dev_dax(dev_dax); + free_dev_dax_range(dev_dax); + device_del(dev); + put_device(dev); +} + +/* a return value >= 0 indicates this invocation invalidated the id */ +static int __free_dev_dax_id(struct dev_dax *dev_dax) +{ + struct dax_region *dax_region = dev_dax->region; + struct device *dev = &dev_dax->dev; + int rc = dev_dax->id; + + device_lock_assert(dev); + + if (is_static(dax_region) || dev_dax->id < 0) + return -1; + ida_free(&dax_region->ida, dev_dax->id); + dev_dax->id = -1; + return rc; +} + +static int free_dev_dax_id(struct dev_dax *dev_dax) +{ + struct device *dev = &dev_dax->dev; + int rc; + + device_lock(dev); + rc = __free_dev_dax_id(dev_dax); + device_unlock(dev); + return rc; +} + +static ssize_t delete_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct dax_region *dax_region = dev_get_drvdata(dev); + struct dev_dax *dev_dax; + struct device *victim; + bool do_del = false; + int rc; + + if (is_static(dax_region)) + return -EINVAL; + + victim = device_find_child_by_name(dax_region->dev, buf); + if (!victim) + return -ENXIO; + + device_lock(dev); + device_lock(victim); + dev_dax = to_dev_dax(victim); + if (victim->driver || range_len(&dev_dax->range)) + rc = -EBUSY; + else { + /* + * Invalidate the device so it does not become active + * again, but always preserve device-id-0 so that + * /sys/bus/dax/ is guaranteed to be populated while any + * dax_region is registered. + */ + if (dev_dax->id > 0) { + do_del = __free_dev_dax_id(dev_dax) >= 0; + rc = len; + if (dax_region->seed == victim) + dax_region->seed = NULL; + if (dax_region->youngest == victim) + dax_region->youngest = NULL; + } else + rc = -EBUSY; + } + device_unlock(victim); + + /* won the race to invalidate the device, clean it up */ + if (do_del) + devm_release_action(dev, unregister_dev_dax, victim); + device_unlock(dev); + put_device(victim); + + return rc; +} +static DEVICE_ATTR_WO(delete); + 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; + if (is_static(dax_region)) + if (a == &dev_attr_available_size.attr + || a == &dev_attr_create.attr + || a == &dev_attr_seed.attr + || a == &dev_attr_delete.attr) + return 0; return a->mode; } @@ -252,6 +472,9 @@ static struct attribute *dax_region_attributes[] = { &dev_attr_available_size.attr, &dev_attr_region_size.attr, &dev_attr_align.attr, + &dev_attr_create.attr, + &dev_attr_seed.attr, + &dev_attr_delete.attr, &dev_attr_id.attr, NULL, }; @@ -320,6 +543,7 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id, dax_region->align = align; dax_region->dev = parent; dax_region->target_node = target_node; + ida_init(&dax_region->ida); dax_region->res = (struct resource) { .start = res->start, .end = res->end, @@ -347,6 +571,15 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, resource_size_t size) device_lock_assert(dax_region->dev); + /* handle the seed alloc special case */ + if (!size) { + dev_dax->range = (struct range) { + .start = res->start, + .end = res->start - 1, + }; + return 0; + } + /* TODO: handle multiple allocations per region */ if (res->child) return -ENOMEM; @@ -448,33 +681,15 @@ static const struct attribute_group *dax_attribute_groups[] = { NULL, }; -void kill_dev_dax(struct dev_dax *dev_dax) -{ - struct dax_device *dax_dev = dev_dax->dax_dev; - struct inode *inode = dax_inode(dax_dev); - - kill_dax(dax_dev); - unmap_mapping_range(inode->i_mapping, 0, 0, 1); -} -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); struct dax_region *dax_region = dev_dax->region; struct dax_device *dax_dev = dev_dax->dax_dev; - dax_region_put(dax_region); put_dax(dax_dev); + free_dev_dax_id(dev_dax); + dax_region_put(dax_region); kfree(dev_dax->pgmap); kfree(dev_dax); } @@ -484,18 +699,6 @@ static const struct device_type dev_dax_type = { .groups = dax_attribute_groups, }; -static void unregister_dev_dax(void *dev) -{ - struct dev_dax *dev_dax = to_dev_dax(dev); - - dev_dbg(dev, "%s\n", __func__); - - kill_dev_dax(dev_dax); - free_dev_dax_range(dev_dax); - device_del(dev); - put_device(dev); -} - struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) { struct dax_region *dax_region = data->dax_region; @@ -506,17 +709,35 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data) struct device *dev; int rc; - if (data->id < 0) - return ERR_PTR(-EINVAL); - dev_dax = kzalloc(sizeof(*dev_dax), GFP_KERNEL); if (!dev_dax) return ERR_PTR(-ENOMEM); + if (is_static(dax_region)) { + if (dev_WARN_ONCE(parent, data->id < 0, + "dynamic id specified to static region\n")) { + rc = -EINVAL; + goto err_id; + } + + dev_dax->id = data->id; + } else { + if (dev_WARN_ONCE(parent, data->id >= 0, + "static id specified to dynamic region\n")) { + rc = -EINVAL; + goto err_id; + } + + rc = ida_alloc(&dax_region->ida, GFP_KERNEL); + if (rc < 0) + goto err_id; + dev_dax->id = rc; + } + dev_dax->region = dax_region; dev = &dev_dax->dev; device_initialize(dev); - dev_set_name(dev, "dax%d.%d", dax_region->id, data->id); + dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id); rc = alloc_dev_dax_range(dev_dax, data->size); if (rc) @@ -579,6 +800,8 @@ err_alloc_dax: err_pgmap: free_dev_dax_range(dev_dax); err_range: + free_dev_dax_id(dev_dax); +err_id: kfree(dev_dax); return ERR_PTR(rc); diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index 99b1273bb232..b81a1494d82b 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -7,6 +7,7 @@ #include <linux/device.h> #include <linux/cdev.h> +#include <linux/idr.h> /* private routines between core files */ struct dax_device; @@ -22,7 +23,10 @@ void dax_bus_exit(void); * @kref: to pin while other agents have a need to do lookups * @dev: parent device backing this region * @align: allocation and mapping alignment for child dax devices + * @ida: instance id allocator * @res: resource tree to track instance allocations + * @seed: allow userspace to find the first unbound seed device + * @youngest: allow userspace to find the most recently created device */ struct dax_region { int id; @@ -30,7 +34,10 @@ struct dax_region { struct kref kref; struct device *dev; unsigned int align; + struct ida ida; struct resource res; + struct device *seed; + struct device *youngest; }; /** @@ -39,6 +46,7 @@ struct dax_region { * @region - parent region * @dax_dev - core dax functionality * @target_node: effective numa node if dev_dax memory range is onlined + * @id: ida allocated id * @dev - device core * @pgmap - pgmap for memmap setup / lifetime (driver owned) * @range: resource range for the instance @@ -47,6 +55,7 @@ struct dev_dax { struct dax_region *region; struct dax_device *dax_dev; int target_node; + int id; struct device dev; struct dev_pagemap *pgmap; struct range range; diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c index e7b64539e23e..aa260009dfc7 100644 --- a/drivers/dax/hmem/hmem.c +++ b/drivers/dax/hmem/hmem.c @@ -26,7 +26,7 @@ static int dax_hmem_probe(struct platform_device *pdev) data = (struct dev_dax_data) { .dax_region = dax_region, - .id = 0, + .id = -1, .size = resource_size(res), }; dev_dax = devm_create_dev_dax(&data); |