Commit 9717c1ce authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'drm-next-2020-02-04' of git://anongit.freedesktop.org/drm/drm

Pull drm ttm/mm updates from Dave Airlie:
 "Thomas Hellstrom has some more changes to the TTM layer that needed a
  patch to the mm subsystem.

  This adds a new mm API vmf_insert_mixed_prot to avoid an ugly hack
  that has limitations in the TTM layer"

* tag 'drm-next-2020-02-04' of git://anongit.freedesktop.org/drm/drm:
  mm, drm/ttm: Fix vm page protection handling
  mm: Add a vmf_insert_mixed_prot() function
parents 79703e01 b45f1b3b
...@@ -179,7 +179,6 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, ...@@ -179,7 +179,6 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
pgoff_t num_prefault) pgoff_t num_prefault)
{ {
struct vm_area_struct *vma = vmf->vma; struct vm_area_struct *vma = vmf->vma;
struct vm_area_struct cvma = *vma;
struct ttm_buffer_object *bo = vma->vm_private_data; struct ttm_buffer_object *bo = vma->vm_private_data;
struct ttm_bo_device *bdev = bo->bdev; struct ttm_bo_device *bdev = bo->bdev;
unsigned long page_offset; unsigned long page_offset;
...@@ -250,7 +249,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, ...@@ -250,7 +249,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
goto out_io_unlock; goto out_io_unlock;
} }
cvma.vm_page_prot = ttm_io_prot(bo->mem.placement, prot); prot = ttm_io_prot(bo->mem.placement, prot);
if (!bo->mem.bus.is_iomem) { if (!bo->mem.bus.is_iomem) {
struct ttm_operation_ctx ctx = { struct ttm_operation_ctx ctx = {
.interruptible = false, .interruptible = false,
...@@ -266,7 +265,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, ...@@ -266,7 +265,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
} }
} else { } else {
/* Iomem should not be marked encrypted */ /* Iomem should not be marked encrypted */
cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); prot = pgprot_decrypted(prot);
} }
/* /*
...@@ -289,11 +288,20 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, ...@@ -289,11 +288,20 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
pfn = page_to_pfn(page); pfn = page_to_pfn(page);
} }
/*
* Note that the value of @prot at this point may differ from
* the value of @vma->vm_page_prot in the caching- and
* encryption bits. This is because the exact location of the
* data may not be known at mmap() time and may also change
* at arbitrary times while the data is mmap'ed.
* See vmf_insert_mixed_prot() for a discussion.
*/
if (vma->vm_flags & VM_MIXEDMAP) if (vma->vm_flags & VM_MIXEDMAP)
ret = vmf_insert_mixed(&cvma, address, ret = vmf_insert_mixed_prot(vma, address,
__pfn_to_pfn_t(pfn, PFN_DEV)); __pfn_to_pfn_t(pfn, PFN_DEV),
prot);
else else
ret = vmf_insert_pfn(&cvma, address, pfn); ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
/* Never error on prefaulted PTEs */ /* Never error on prefaulted PTEs */
if (unlikely((ret & VM_FAULT_ERROR))) { if (unlikely((ret & VM_FAULT_ERROR))) {
...@@ -325,7 +333,7 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) ...@@ -325,7 +333,7 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
if (ret) if (ret)
return ret; return ret;
prot = vm_get_page_prot(vma->vm_flags); prot = vma->vm_page_prot;
ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT); ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT);
if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
return ret; return ret;
......
...@@ -2535,6 +2535,8 @@ vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr, ...@@ -2535,6 +2535,8 @@ vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn, pgprot_t pgprot); unsigned long pfn, pgprot_t pgprot);
vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr, vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn); pfn_t pfn);
vm_fault_t vmf_insert_mixed_prot(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn, pgprot_t pgprot);
vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma, vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
unsigned long addr, pfn_t pfn); unsigned long addr, pfn_t pfn);
int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len); int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
......
...@@ -312,7 +312,12 @@ struct vm_area_struct { ...@@ -312,7 +312,12 @@ struct vm_area_struct {
/* Second cache line starts here. */ /* Second cache line starts here. */
struct mm_struct *vm_mm; /* The address space we belong to. */ struct mm_struct *vm_mm; /* The address space we belong to. */
pgprot_t vm_page_prot; /* Access permissions of this VMA. */
/*
* Access permissions of this VMA.
* See vmf_insert_mixed_prot() for discussion.
*/
pgprot_t vm_page_prot;
unsigned long vm_flags; /* Flags, see mm.h. */ unsigned long vm_flags; /* Flags, see mm.h. */
/* /*
......
...@@ -1664,6 +1664,9 @@ static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr, ...@@ -1664,6 +1664,9 @@ static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
* vmf_insert_pfn_prot should only be used if using multiple VMAs is * vmf_insert_pfn_prot should only be used if using multiple VMAs is
* impractical. * impractical.
* *
* See vmf_insert_mixed_prot() for a discussion of the implication of using
* a value of @pgprot different from that of @vma->vm_page_prot.
*
* Context: Process context. May allocate using %GFP_KERNEL. * Context: Process context. May allocate using %GFP_KERNEL.
* Return: vm_fault_t value. * Return: vm_fault_t value.
*/ */
...@@ -1737,9 +1740,9 @@ static bool vm_mixed_ok(struct vm_area_struct *vma, pfn_t pfn) ...@@ -1737,9 +1740,9 @@ static bool vm_mixed_ok(struct vm_area_struct *vma, pfn_t pfn)
} }
static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma, static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
unsigned long addr, pfn_t pfn, bool mkwrite) unsigned long addr, pfn_t pfn, pgprot_t pgprot,
bool mkwrite)
{ {
pgprot_t pgprot = vma->vm_page_prot;
int err; int err;
BUG_ON(!vm_mixed_ok(vma, pfn)); BUG_ON(!vm_mixed_ok(vma, pfn));
...@@ -1782,10 +1785,43 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma, ...@@ -1782,10 +1785,43 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
return VM_FAULT_NOPAGE; return VM_FAULT_NOPAGE;
} }
/**
* vmf_insert_mixed_prot - insert single pfn into user vma with specified pgprot
* @vma: user vma to map to
* @addr: target user address of this page
* @pfn: source kernel pfn
* @pgprot: pgprot flags for the inserted page
*
* This is exactly like vmf_insert_mixed(), except that it allows drivers to
* to override pgprot on a per-page basis.
*
* Typically this function should be used by drivers to set caching- and
* encryption bits different than those of @vma->vm_page_prot, because
* the caching- or encryption mode may not be known at mmap() time.
* This is ok as long as @vma->vm_page_prot is not used by the core vm
* to set caching and encryption bits for those vmas (except for COW pages).
* This is ensured by core vm only modifying these page table entries using
* functions that don't touch caching- or encryption bits, using pte_modify()
* if needed. (See for example mprotect()).
* Also when new page-table entries are created, this is only done using the
* fault() callback, and never using the value of vma->vm_page_prot,
* except for page-table entries that point to anonymous pages as the result
* of COW.
*
* Context: Process context. May allocate using %GFP_KERNEL.
* Return: vm_fault_t value.
*/
vm_fault_t vmf_insert_mixed_prot(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn, pgprot_t pgprot)
{
return __vm_insert_mixed(vma, addr, pfn, pgprot, false);
}
EXPORT_SYMBOL(vmf_insert_mixed_prot);
vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr, vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn) pfn_t pfn)
{ {
return __vm_insert_mixed(vma, addr, pfn, false); return __vm_insert_mixed(vma, addr, pfn, vma->vm_page_prot, false);
} }
EXPORT_SYMBOL(vmf_insert_mixed); EXPORT_SYMBOL(vmf_insert_mixed);
...@@ -1797,7 +1833,7 @@ EXPORT_SYMBOL(vmf_insert_mixed); ...@@ -1797,7 +1833,7 @@ EXPORT_SYMBOL(vmf_insert_mixed);
vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma, vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
unsigned long addr, pfn_t pfn) unsigned long addr, pfn_t pfn)
{ {
return __vm_insert_mixed(vma, addr, pfn, true); return __vm_insert_mixed(vma, addr, pfn, vma->vm_page_prot, true);
} }
EXPORT_SYMBOL(vmf_insert_mixed_mkwrite); EXPORT_SYMBOL(vmf_insert_mixed_mkwrite);
......
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