device-dax: improve fault handler debug output

A couple of minor improvements to the debug output in the fault handlers:

a) Print the region alignment and fault size when we sent a SIGBUS
   because the region alignment is greater than the fault size.
b) Fix the message in the PFN_{DEV|MAP} check.
c) Additionally print the fault size enum value in the huge fault handler.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 94036d9..352cc54 100644 (file)
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -435,7 +435,8 @@ static int __dax_dev_pte_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
 
        dax_region = dax_dev->region;
        if (dax_region->align > PAGE_SIZE) {
-               dev_dbg(dev, "%s: alignment > fault size\n", __func__);
+               dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n",
+                       __func__, dax_region->align, fault_size);
                return VM_FAULT_SIGBUS;
        }
 
@@ -476,13 +477,14 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
 
        dax_region = dax_dev->region;
        if (dax_region->align > PMD_SIZE) {
-               dev_dbg(dev, "%s: alignment > fault size\n", __func__);
+               dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n",
+                       __func__, dax_region->align, fault_size);
                return VM_FAULT_SIGBUS;
        }
 
        /* dax pmd mappings require pfn_t_devmap() */
        if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
-               dev_dbg(dev, "%s: alignment > fault size\n", __func__);
+               dev_dbg(dev, "%s: region lacks devmap flags\n", __func__);
                return VM_FAULT_SIGBUS;
        }
 
@@ -527,13 +529,14 @@ static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
 
        dax_region = dax_dev->region;
        if (dax_region->align > PUD_SIZE) {
-               dev_dbg(dev, "%s: alignment > fault size\n", __func__);
+               dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n",
+                       __func__, dax_region->align, fault_size);
                return VM_FAULT_SIGBUS;
        }
 
        /* dax pud mappings require pfn_t_devmap() */
        if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
-               dev_dbg(dev, "%s: alignment > fault size\n", __func__);
+               dev_dbg(dev, "%s: region lacks devmap flags\n", __func__);
                return VM_FAULT_SIGBUS;
        }
 
@@ -574,10 +577,10 @@ static int dax_dev_huge_fault(struct vm_fault *vmf,
        struct file *filp = vmf->vma->vm_file;
        struct dax_dev *dax_dev = filp->private_data;
 
-       dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__,
+       dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx) size = %d\n", __func__,
                        current->comm, (vmf->flags & FAULT_FLAG_WRITE)
                        ? "write" : "read",
-                       vmf->vma->vm_start, vmf->vma->vm_end);
+                       vmf->vma->vm_start, vmf->vma->vm_end, pe_size);
 
        id = srcu_read_lock(&dax_srcu);
        switch (pe_size) {