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-rw-r--r--arch/x86/include/asm/pgtable.h10
-rw-r--r--arch/x86/mm/pat.c236
2 files changed, 246 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index c012f3b1167..7dcd94c2904 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -219,6 +219,11 @@ static inline unsigned long pte_pfn(pte_t pte)
return (pte_val(pte) & PTE_PFN_MASK) >> PAGE_SHIFT;
}
+static inline u64 pte_pa(pte_t pte)
+{
+ return pte_val(pte) & PTE_PFN_MASK;
+}
+
#define pte_page(pte) pfn_to_page(pte_pfn(pte))
static inline int pmd_large(pmd_t pte)
@@ -328,6 +333,11 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
#define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask)
+/* Indicate that x86 has its own track and untrack pfn vma functions */
+#define track_pfn_vma_new track_pfn_vma_new
+#define track_pfn_vma_copy track_pfn_vma_copy
+#define untrack_pfn_vma untrack_pfn_vma
+
#ifndef __ASSEMBLY__
#define __HAVE_PHYS_MEM_ACCESS_PROT
struct file;
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index eb1bf000d12..1069ffecf77 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;
+ u64 paddr;
+ pgprot_t prot;
+ pte_t pte;
+ 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,
+ * But, we have to get the protection from pte.
+ */
+ if (follow_pfnmap_pte(vma, vma_start, &pte)) {
+ WARN_ON_ONCE(1);
+ return -1;
+ }
+ prot = pte_pgprot(pte);
+ paddr = (u64)vma->vm_pgoff << PAGE_SHIFT;
+ return reserve_pfn_range(paddr, vma_size, prot);
+ }
+
+ /* reserve entire vma page by page, using pfn and prot from pte */
+ for (i = 0; i < vma_size; i += PAGE_SIZE) {
+ if (follow_pfnmap_pte(vma, vma_start + i, &pte))
+ continue;
+
+ paddr = pte_pa(pte);
+ prot = pte_pgprot(pte);
+ 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) {
+ if (follow_pfnmap_pte(vma, vma_start + j, &pte))
+ continue;
+
+ paddr = pte_pa(pte);
+ 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;
+ u64 base_paddr;
+ u64 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 = (u64)vma->vm_pgoff << PAGE_SHIFT;
+ return reserve_pfn_range(paddr, vma_size, prot);
+ }
+
+ /* reserve page by page using pfn and size */
+ base_paddr = (u64)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;
+ u64 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;
+
+ if (is_linear_pfn_mapping(vma)) {
+ /* free the whole chunk starting from vm_pgoff */
+ paddr = (u64)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 = (u64)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) {
+ pte_t pte;
+
+ if (follow_pfnmap_pte(vma, vma_start + i, &pte))
+ continue;
+
+ paddr = pte_pa(pte);
+ free_pfn_range(paddr, PAGE_SIZE);
+ }
+ }
+}
+
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
/* get Nth element of the linked list */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 16:22:29 +0000