[PATCH 08/10] mm: Inline vm_insert_pfn_prot into caller

From: Matthew Wilcox
Date: Tue Aug 28 2018 - 10:57:51 EST


vm_insert_pfn_prot() is only called from vmf_insert_pfn_prot(),
so inline it and convert some of the errnos into vm_fault codes earlier.

Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
---
mm/memory.c | 55 +++++++++++++++++++++++------------------------------
1 file changed, 24 insertions(+), 31 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index d5ccbadd81c1..9e97926fee19 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1819,36 +1819,6 @@ static int insert_pfn(struct vm_area_struct *vma, unsigned long addr,
return retval;
}

-static int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
- unsigned long pfn, pgprot_t pgprot)
-{
- int ret;
- /*
- * Technically, architectures with pte_special can avoid all these
- * restrictions (same for remap_pfn_range). However we would like
- * consistency in testing and feature parity among all, so we should
- * try to keep these invariants in place for everybody.
- */
- BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
- BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
- (VM_PFNMAP|VM_MIXEDMAP));
- BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
- BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
-
- if (addr < vma->vm_start || addr >= vma->vm_end)
- return -EFAULT;
-
- if (!pfn_modify_allowed(pfn, pgprot))
- return -EACCES;
-
- track_pfn_insert(vma, &pgprot, __pfn_to_pfn_t(pfn, PFN_DEV));
-
- ret = insert_pfn(vma, addr, __pfn_to_pfn_t(pfn, PFN_DEV), pgprot,
- false);
-
- return ret;
-}
-
/**
* vmf_insert_pfn_prot - insert single pfn into user vma with specified pgprot
* @vma: user vma to map to
@@ -1870,7 +1840,30 @@ static int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn, pgprot_t pgprot)
{
- int err = vm_insert_pfn_prot(vma, addr, pfn, pgprot);
+ int err;
+
+ /*
+ * Technically, architectures with pte_special can avoid all these
+ * restrictions (same for remap_pfn_range). However we would like
+ * consistency in testing and feature parity among all, so we should
+ * try to keep these invariants in place for everybody.
+ */
+ BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
+ BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
+ (VM_PFNMAP|VM_MIXEDMAP));
+ BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
+ BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
+
+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return VM_FAULT_SIGBUS;
+
+ if (!pfn_modify_allowed(pfn, pgprot))
+ return VM_FAULT_SIGBUS;
+
+ track_pfn_insert(vma, &pgprot, __pfn_to_pfn_t(pfn, PFN_DEV));
+
+ err = insert_pfn(vma, addr, __pfn_to_pfn_t(pfn, PFN_DEV), pgprot,
+ false);

if (err == -ENOMEM)
return VM_FAULT_OOM;
--
2.18.0