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authorDan Williams <dan.j.williams@intel.com>2017-04-13 06:59:01 +0200
committerDan Williams <dan.j.williams@intel.com>2017-04-13 06:59:01 +0200
commitbfca9acf1a5df0ff98fbf47e363adb48612bb7ec (patch)
treea50287c88fdc60a73912d205d7bce41b7af53827 /drivers/dax
parentdevice-dax: utilize new cdev_device_add helper function (diff)
parentx86, pmem: fix broken __copy_user_nocache cache-bypass assumptions (diff)
downloadlinux-bfca9acf1a5df0ff98fbf47e363adb48612bb7ec.tar.xz
linux-bfca9acf1a5df0ff98fbf47e363adb48612bb7ec.zip
Merge branch 'for-4.11/libnvdimm' into for-4.12/dax
Diffstat (limited to 'drivers/dax')
-rw-r--r--drivers/dax/Kconfig1
-rw-r--r--drivers/dax/dax.c46
2 files changed, 38 insertions, 9 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 e5f85550dc25..19795eb35579 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -25,6 +25,7 @@
#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;
@@ -60,7 +61,7 @@ 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
@@ -427,6 +428,7 @@ static int __dax_dev_pte_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
int rc = VM_FAULT_SIGBUS;
phys_addr_t phys;
pfn_t pfn;
+ unsigned int fault_size = PAGE_SIZE;
if (check_vma(dax_dev, vmf->vma, __func__))
return VM_FAULT_SIGBUS;
@@ -437,9 +439,12 @@ static int __dax_dev_pte_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
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__,
+ dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
vmf->pgoff);
return VM_FAULT_SIGBUS;
}
@@ -464,6 +469,7 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
phys_addr_t phys;
pgoff_t pgoff;
pfn_t pfn;
+ unsigned int fault_size = PMD_SIZE;
if (check_vma(dax_dev, vmf->vma, __func__))
return VM_FAULT_SIGBUS;
@@ -480,10 +486,20 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
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 < vmf->vma->vm_start ||
+ (pmd_addr + PMD_SIZE) > vmf->vma->vm_end)
+ return VM_FAULT_SIGBUS;
+
pgoff = linear_page_index(vmf->vma, pmd_addr);
phys = pgoff_to_phys(dax_dev, pgoff, PMD_SIZE);
if (phys == -1) {
- dev_dbg(dev, "%s: phys_to_pgoff(%#lx) failed\n", __func__,
+ dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
pgoff);
return VM_FAULT_SIGBUS;
}
@@ -503,6 +519,8 @@ static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
phys_addr_t phys;
pgoff_t pgoff;
pfn_t pfn;
+ unsigned int fault_size = PUD_SIZE;
+
if (check_vma(dax_dev, vmf->vma, __func__))
return VM_FAULT_SIGBUS;
@@ -519,10 +537,20 @@ static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
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 (pud_addr < vmf->vma->vm_start ||
+ (pud_addr + PUD_SIZE) > vmf->vma->vm_end)
+ return VM_FAULT_SIGBUS;
+
pgoff = linear_page_index(vmf->vma, pud_addr);
phys = pgoff_to_phys(dax_dev, pgoff, PUD_SIZE);
if (phys == -1) {
- dev_dbg(dev, "%s: phys_to_pgoff(%#lx) failed\n", __func__,
+ dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
pgoff);
return VM_FAULT_SIGBUS;
}
@@ -542,7 +570,7 @@ static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
static int dax_dev_huge_fault(struct vm_fault *vmf,
enum page_entry_size pe_size)
{
- int rc;
+ int rc, id;
struct file *filp = vmf->vma->vm_file;
struct dax_dev *dax_dev = filp->private_data;
@@ -551,7 +579,7 @@ static int dax_dev_huge_fault(struct vm_fault *vmf,
? "write" : "read",
vmf->vma->vm_start, vmf->vma->vm_end);
- rcu_read_lock();
+ id = srcu_read_lock(&dax_srcu);
switch (pe_size) {
case PE_SIZE_PTE:
rc = __dax_dev_pte_fault(dax_dev, vmf);
@@ -565,7 +593,7 @@ static int dax_dev_huge_fault(struct vm_fault *vmf,
default:
return VM_FAULT_FALLBACK;
}
- rcu_read_unlock();
+ srcu_read_unlock(&dax_srcu, id);
return rc;
}
@@ -681,11 +709,11 @@ static void kill_dax_dev(struct dax_dev *dax_dev)
* 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);
}