summaryrefslogtreecommitdiff
path: root/drivers/dax
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/dax')
-rw-r--r--drivers/dax/Kconfig1
-rw-r--r--drivers/dax/dax.c67
-rw-r--r--drivers/dax/dax.h2
-rw-r--r--drivers/dax/pmem.c12
4 files changed, 58 insertions, 24 deletions
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
index 3e2ab3b14eea..9e95bf94eb13 100644
--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -2,6 +2,7 @@ menuconfig DEV_DAX
tristate "DAX: direct access to differentiated memory"
default m if NVDIMM_DAX
depends on TRANSPARENT_HUGEPAGE
+ select SRCU
help
Support raw access to differentiated (persistence, bandwidth,
latency...) memory via an mmap(2) capable character
diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 286447a83dab..40be3747724d 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -24,6 +24,7 @@
#include "dax.h"
static dev_t dax_devt;
+DEFINE_STATIC_SRCU(dax_srcu);
static struct class *dax_class;
static DEFINE_IDA(dax_minor_ida);
static int nr_dax = CONFIG_NR_DEV_DAX;
@@ -59,7 +60,7 @@ struct dax_region {
* @region - parent region
* @dev - device backing the character device
* @cdev - core chardev data
- * @alive - !alive + rcu grace period == no new mappings can be established
+ * @alive - !alive + srcu grace period == no new mappings can be established
* @id - child id in the region
* @num_resources - number of physical address extents in this device
* @res - array of physical address ranges
@@ -334,6 +335,7 @@ static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma,
int rc = VM_FAULT_SIGBUS;
phys_addr_t phys;
pfn_t pfn;
+ unsigned int fault_size = PAGE_SIZE;
if (check_vma(dax_dev, vma, __func__))
return VM_FAULT_SIGBUS;
@@ -344,6 +346,9 @@ static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma,
return VM_FAULT_SIGBUS;
}
+ if (fault_size != dax_region->align)
+ return VM_FAULT_SIGBUS;
+
phys = pgoff_to_phys(dax_dev, vmf->pgoff, PAGE_SIZE);
if (phys == -1) {
dev_dbg(dev, "%s: phys_to_pgoff(%#lx) failed\n", __func__,
@@ -389,6 +394,7 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev,
phys_addr_t phys;
pgoff_t pgoff;
pfn_t pfn;
+ unsigned int fault_size = PMD_SIZE;
if (check_vma(dax_dev, vma, __func__))
return VM_FAULT_SIGBUS;
@@ -405,6 +411,16 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev,
return VM_FAULT_SIGBUS;
}
+ if (fault_size < dax_region->align)
+ return VM_FAULT_SIGBUS;
+ else if (fault_size > dax_region->align)
+ return VM_FAULT_FALLBACK;
+
+ /* if we are outside of the VMA */
+ if (pmd_addr < vma->vm_start ||
+ (pmd_addr + PMD_SIZE) > vma->vm_end)
+ return VM_FAULT_SIGBUS;
+
pgoff = linear_page_index(vma, pmd_addr);
phys = pgoff_to_phys(dax_dev, pgoff, PMD_SIZE);
if (phys == -1) {
@@ -422,7 +438,7 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev,
static int dax_dev_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd, unsigned int flags)
{
- int rc;
+ int rc, id;
struct file *filp = vma->vm_file;
struct dax_dev *dax_dev = filp->private_data;
@@ -430,9 +446,9 @@ static int dax_dev_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
current->comm, (flags & FAULT_FLAG_WRITE)
? "write" : "read", vma->vm_start, vma->vm_end);
- rcu_read_lock();
+ id = srcu_read_lock(&dax_srcu);
rc = __dax_dev_pmd_fault(dax_dev, vma, addr, pmd, flags);
- rcu_read_unlock();
+ srcu_read_unlock(&dax_srcu, id);
return rc;
}
@@ -530,36 +546,43 @@ static void dax_dev_release(struct device *dev)
struct dax_dev *dax_dev = to_dax_dev(dev);
struct dax_region *dax_region = dax_dev->region;
- ida_simple_remove(&dax_region->ida, dax_dev->id);
+ if (dax_dev->id >= 0)
+ ida_simple_remove(&dax_region->ida, dax_dev->id);
ida_simple_remove(&dax_minor_ida, MINOR(dev->devt));
dax_region_put(dax_region);
iput(dax_dev->inode);
kfree(dax_dev);
}
-static void unregister_dax_dev(void *dev)
+static void kill_dax_dev(struct dax_dev *dax_dev)
{
- struct dax_dev *dax_dev = to_dax_dev(dev);
struct cdev *cdev = &dax_dev->cdev;
- dev_dbg(dev, "%s\n", __func__);
-
/*
* Note, rcu is not protecting the liveness of dax_dev, rcu is
* ensuring that any fault handlers that might have seen
* dax_dev->alive == true, have completed. Any fault handlers
- * that start after synchronize_rcu() has started will abort
+ * that start after synchronize_srcu() has started will abort
* upon seeing dax_dev->alive == false.
*/
dax_dev->alive = false;
- synchronize_rcu();
+ synchronize_srcu(&dax_srcu);
unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1);
cdev_del(cdev);
+}
+
+static void unregister_dax_dev(void *dev)
+{
+ struct dax_dev *dax_dev = to_dax_dev(dev);
+
+ dev_dbg(dev, "%s\n", __func__);
+
+ kill_dax_dev(dax_dev);
device_unregister(dev);
}
struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
- struct resource *res, int count)
+ int id, struct resource *res, int count)
{
struct device *parent = dax_region->dev;
struct dax_dev *dax_dev;
@@ -586,10 +609,16 @@ struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
if (i < count)
goto err_id;
- dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
- if (dax_dev->id < 0) {
- rc = dax_dev->id;
- goto err_id;
+ if (id < 0) {
+ id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
+ dax_dev->id = id;
+ if (id < 0) {
+ rc = id;
+ goto err_id;
+ }
+ } else {
+ /* region provider owns @id lifetime */
+ dax_dev->id = -1;
}
minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL);
@@ -628,9 +657,10 @@ struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
dev->parent = parent;
dev->groups = dax_attribute_groups;
dev->release = dax_dev_release;
- dev_set_name(dev, "dax%d.%d", dax_region->id, dax_dev->id);
+ dev_set_name(dev, "dax%d.%d", dax_region->id, id);
rc = device_add(dev);
if (rc) {
+ kill_dax_dev(dax_dev);
put_device(dev);
return ERR_PTR(rc);
}
@@ -646,7 +676,8 @@ struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
err_inode:
ida_simple_remove(&dax_minor_ida, minor);
err_minor:
- ida_simple_remove(&dax_region->ida, dax_dev->id);
+ if (dax_dev->id >= 0)
+ ida_simple_remove(&dax_region->ida, dax_dev->id);
err_id:
kfree(dax_dev);
diff --git a/drivers/dax/dax.h b/drivers/dax/dax.h
index ddd829ab58c0..b5ed85036b2a 100644
--- a/drivers/dax/dax.h
+++ b/drivers/dax/dax.h
@@ -21,5 +21,5 @@ struct dax_region *alloc_dax_region(struct device *parent,
int region_id, struct resource *res, unsigned int align,
void *addr, unsigned long flags);
struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
- struct resource *res, int count);
+ int id, struct resource *res, int count);
#endif /* __DAX_H__ */
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c
index 73c6ce93a0d9..eebb35720398 100644
--- a/drivers/dax/pmem.c
+++ b/drivers/dax/pmem.c
@@ -58,13 +58,12 @@ static void dax_pmem_percpu_kill(void *data)
static int dax_pmem_probe(struct device *dev)
{
- int rc;
void *addr;
struct resource res;
struct dax_dev *dax_dev;
+ int rc, id, region_id;
struct nd_pfn_sb *pfn_sb;
struct dax_pmem *dax_pmem;
- struct nd_region *nd_region;
struct nd_namespace_io *nsio;
struct dax_region *dax_region;
struct nd_namespace_common *ndns;
@@ -122,14 +121,17 @@ static int dax_pmem_probe(struct device *dev)
/* adjust the dax_region resource to the start of data */
res.start += le64_to_cpu(pfn_sb->dataoff);
- nd_region = to_nd_region(dev->parent);
- dax_region = alloc_dax_region(dev, nd_region->id, &res,
+ rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", &region_id, &id);
+ if (rc != 2)
+ return -EINVAL;
+
+ dax_region = alloc_dax_region(dev, region_id, &res,
le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP);
if (!dax_region)
return -ENOMEM;
/* TODO: support for subdividing a dax region... */
- dax_dev = devm_create_dax_dev(dax_region, &res, 1);
+ dax_dev = devm_create_dax_dev(dax_region, id, &res, 1);
/* child dax_dev instances now own the lifetime of the dax_region */
dax_region_put(dax_region);
generated by cgit v1.2.3 (git 2.0.4) at 2024-06-21 22:22:50 +0000