diff options
Diffstat (limited to 'drivers/dax')
| -rw-r--r-- | drivers/dax/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/dax/dax.c | 46 |
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 8d9829ff2a78..806f180c80d8 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; } @@ -686,11 +714,11 @@ static void unregister_dax_dev(void *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); cdev_del(cdev); device_unregister(dev); |