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-rw-r--r--arch/x86/mm/pat.c236
1 files changed, 236 insertions, 0 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index eb1bf000d12e..85cbd3cd3723 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -596,6 +596,242 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
free_memtype(addr, addr + size);
}
+/*
+ * Internal interface to reserve a range of physical memory with prot.
+ * Reserved non RAM regions only and after successful reserve_memtype,
+ * this func also keeps identity mapping (if any) in sync with this new prot.
+ */
+static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t vma_prot)
+{
+ int is_ram = 0;
+ int id_sz, ret;
+ unsigned long flags;
+ unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
+
+ is_ram = pagerange_is_ram(paddr, paddr + size);
+
+ if (is_ram != 0) {
+ /*
+ * For mapping RAM pages, drivers need to call
+ * set_memory_[uc|wc|wb] directly, for reserve and free, before
+ * setting up the PTE.
+ */
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+
+ ret = reserve_memtype(paddr, paddr + size, want_flags, &flags);
+ if (ret)
+ return ret;
+
+ if (flags != want_flags) {
+ free_memtype(paddr, paddr + size);
+ printk(KERN_ERR
+ "%s:%d map pfn expected mapping type %s for %Lx-%Lx, got %s\n",
+ current->comm, current->pid,
+ cattr_name(want_flags),
+ (unsigned long long)paddr,
+ (unsigned long long)(paddr + size),
+ cattr_name(flags));
+ return -EINVAL;
+ }
+
+ /* Need to keep identity mapping in sync */
+ if (paddr >= __pa(high_memory))
+ return 0;
+
+ id_sz = (__pa(high_memory) < paddr + size) ?
+ __pa(high_memory) - paddr :
+ size;
+
+ if (ioremap_change_attr((unsigned long)__va(paddr), id_sz, flags) < 0) {
+ free_memtype(paddr, paddr + size);
+ printk(KERN_ERR
+ "%s:%d reserve_pfn_range ioremap_change_attr failed %s "
+ "for %Lx-%Lx\n",
+ current->comm, current->pid,
+ cattr_name(flags),
+ (unsigned long long)paddr,
+ (unsigned long long)(paddr + size));
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/*
+ * Internal interface to free a range of physical memory.
+ * Frees non RAM regions only.
+ */
+static void free_pfn_range(u64 paddr, unsigned long size)
+{
+ int is_ram;
+
+ is_ram = pagerange_is_ram(paddr, paddr + size);
+ if (is_ram == 0)
+ free_memtype(paddr, paddr + size);
+}
+
+/*
+ * track_pfn_vma_copy is called when vma that is covering the pfnmap gets
+ * copied through copy_page_range().
+ *
+ * If the vma has a linear pfn mapping for the entire range, we get the prot
+ * from pte and reserve the entire vma range with single reserve_pfn_range call.
+ * Otherwise, we reserve the entire vma range, my ging through the PTEs page
+ * by page to get physical address and protection.
+ */
+int track_pfn_vma_copy(struct vm_area_struct *vma)
+{
+ int retval = 0;
+ unsigned long i, j;
+ resource_size_t paddr;
+ unsigned long prot;
+ unsigned long vma_start = vma->vm_start;
+ unsigned long vma_end = vma->vm_end;
+ unsigned long vma_size = vma_end - vma_start;
+
+ if (!pat_enabled)
+ return 0;
+
+ if (is_linear_pfn_mapping(vma)) {
+ /*
+ * reserve the whole chunk covered by vma. We need the
+ * starting address and protection from pte.
+ */
+ if (follow_phys(vma, vma_start, 0, &prot, &paddr)) {
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+ return reserve_pfn_range(paddr, vma_size, __pgprot(prot));
+ }
+
+ /* reserve entire vma page by page, using pfn and prot from pte */
+ for (i = 0; i < vma_size; i += PAGE_SIZE) {
+ if (follow_phys(vma, vma_start + i, 0, &prot, &paddr))
+ continue;
+
+ retval = reserve_pfn_range(paddr, PAGE_SIZE, __pgprot(prot));
+ if (retval)
+ goto cleanup_ret;
+ }
+ return 0;
+
+cleanup_ret:
+ /* Reserve error: Cleanup partial reservation and return error */
+ for (j = 0; j < i; j += PAGE_SIZE) {
+ if (follow_phys(vma, vma_start + j, 0, &prot, &paddr))
+ continue;
+
+ free_pfn_range(paddr, PAGE_SIZE);
+ }
+
+ return retval;
+}
+
+/*
+ * track_pfn_vma_new is called when a _new_ pfn mapping is being established
+ * for physical range indicated by pfn and size.
+ *
+ * prot is passed in as a parameter for the new mapping. If the vma has a
+ * linear pfn mapping for the entire range reserve the entire vma range with
+ * single reserve_pfn_range call.
+ * Otherwise, we look t the pfn and size and reserve only the specified range
+ * page by page.
+ *
+ * Note that this function can be called with caller trying to map only a
+ * subrange/page inside the vma.
+ */
+int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
+ unsigned long pfn, unsigned long size)
+{
+ int retval = 0;
+ unsigned long i, j;
+ resource_size_t base_paddr;
+ resource_size_t paddr;
+ unsigned long vma_start = vma->vm_start;
+ unsigned long vma_end = vma->vm_end;
+ unsigned long vma_size = vma_end - vma_start;
+
+ if (!pat_enabled)
+ return 0;
+
+ if (is_linear_pfn_mapping(vma)) {
+ /* reserve the whole chunk starting from vm_pgoff */
+ paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT;
+ return reserve_pfn_range(paddr, vma_size, prot);
+ }
+
+ /* reserve page by page using pfn and size */
+ base_paddr = (resource_size_t)pfn << PAGE_SHIFT;
+ for (i = 0; i < size; i += PAGE_SIZE) {
+ paddr = base_paddr + i;
+ retval = reserve_pfn_range(paddr, PAGE_SIZE, prot);
+ if (retval)
+ goto cleanup_ret;
+ }
+ return 0;
+
+cleanup_ret:
+ /* Reserve error: Cleanup partial reservation and return error */
+ for (j = 0; j < i; j += PAGE_SIZE) {
+ paddr = base_paddr + j;
+ free_pfn_range(paddr, PAGE_SIZE);
+ }
+
+ return retval;
+}
+
+/*
+ * untrack_pfn_vma is called while unmapping a pfnmap for a region.
+ * untrack can be called for a specific region indicated by pfn and size or
+ * can be for the entire vma (in which case size can be zero).
+ */
+void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
+ unsigned long size)
+{
+ unsigned long i;
+ resource_size_t paddr;
+ unsigned long prot;
+ unsigned long vma_start = vma->vm_start;
+ unsigned long vma_end = vma->vm_end;
+ unsigned long vma_size = vma_end - vma_start;
+
+ if (!pat_enabled)
+ return;
+
+ if (is_linear_pfn_mapping(vma)) {
+ /* free the whole chunk starting from vm_pgoff */
+ paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT;
+ free_pfn_range(paddr, vma_size);
+ return;
+ }
+
+ if (size != 0 && size != vma_size) {
+ /* free page by page, using pfn and size */
+ paddr = (resource_size_t)pfn << PAGE_SHIFT;
+ for (i = 0; i < size; i += PAGE_SIZE) {
+ paddr = paddr + i;
+ free_pfn_range(paddr, PAGE_SIZE);
+ }
+ } else {
+ /* free entire vma, page by page, using the pfn from pte */
+ for (i = 0; i < vma_size; i += PAGE_SIZE) {
+ if (follow_phys(vma, vma_start + i, 0, &prot, &paddr))
+ continue;
+
+ free_pfn_range(paddr, PAGE_SIZE);
+ }
+ }
+}
+
+pgprot_t pgprot_writecombine(pgprot_t prot)
+{
+ if (pat_enabled)
+ return __pgprot(pgprot_val(prot) | _PAGE_CACHE_WC);
+ else
+ return pgprot_noncached(prot);
+}
+
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
/* get Nth element of the linked list */