[PATCH 1/5] mm/vmalloc: remove map_kernel_range

Nicholas Piggin
2021-01-26T23:17:33Z

This is a shim around vmap_pages_range, get rid of it.

Move the main API comment from the _noflush variant to the normal
variant, and make _noflush internal to mm/.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
Documentation/core-api/cachetlb.rst | 2 +-
include/linux/vmalloc.h | 11 -----
mm/internal.h | 6 +++
mm/percpu-vm.c | 5 ++-
mm/vmalloc.c | 65 +++++++++++++----------------
5 files changed, 38 insertions(+), 51 deletions(-)

diff --git a/Documentation/core-api/cachetlb.rst b/Documentation/core-api/cachetlb.rst
index a1582cc79f0f..756f7bcf8191 100644
--- a/Documentation/core-api/cachetlb.rst
+++ b/Documentation/core-api/cachetlb.rst
@@ -213,7 +213,7 @@ Here are the routines, one by one:
there will be no entries in the cache for the kernel address
space for virtual addresses in the range 'start' to 'end-1'.

- The first of these two routines is invoked after map_kernel_range()
+ The first of these two routines is invoked after vmap_range()
has installed the page table entries. The second is invoked
before unmap_kernel_range() deletes the page table entries.

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 93270adf5db5..913c9d4f5e03 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -217,10 +217,6 @@ static inline bool is_vm_area_hugepages(const void *addr)
int vmap_range(unsigned long addr, unsigned long end,
phys_addr_t phys_addr, pgprot_t prot,
unsigned int max_page_shift);
-extern int map_kernel_range_noflush(unsigned long start, unsigned long size,
- pgprot_t prot, struct page **pages);
-int map_kernel_range(unsigned long start, unsigned long size, pgprot_t prot,
- struct page **pages);
extern void unmap_kernel_range_noflush(unsigned long addr, unsigned long size);
extern void unmap_kernel_range(unsigned long addr, unsigned long size);
static inline void set_vm_flush_reset_perms(void *addr)
@@ -232,13 +228,6 @@ static inline void set_vm_flush_reset_perms(void *addr)
}

#else
-static inline int
-map_kernel_range_noflush(unsigned long start, unsigned long size,
- pgprot_t prot, struct page **pages)
-{
- return size >> PAGE_SHIFT;
-}
-#define map_kernel_range map_kernel_range_noflush
static inline void
unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
{
diff --git a/mm/internal.h b/mm/internal.h
index 25d2b2439f19..3ce246945882 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -623,4 +623,10 @@ struct migration_target_control {
gfp_t gfp_mask;
};

+/*
+ * mm/vmalloc.c
+ */
+int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
+ pgprot_t prot, struct page **pages, unsigned int page_shift);
+
#endif /* __MM_INTERNAL_H */
diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c
index e46f7a6917f9..88a53eb68a94 100644
--- a/mm/percpu-vm.c
+++ b/mm/percpu-vm.c
@@ -8,6 +8,7 @@
* Chunks are mapped into vmalloc areas and populated page by page.
* This is the default chunk allocator.
*/
+#include "internal.h"

static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk,
unsigned int cpu, int page_idx)
@@ -192,8 +193,8 @@ static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk,
static int __pcpu_map_pages(unsigned long addr, struct page **pages,
int nr_pages)
{
- return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT,
- PAGE_KERNEL, pages);
+ return vmap_pages_range_noflush(addr, addr + (nr_pages << PAGE_SHIFT),
+ PAGE_KERNEL, pages, PAGE_SHIFT);
}

/**
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e9a28de04182..78dc3ec457ef 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -523,7 +523,16 @@ static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
return 0;
}

-static int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
+/*
+ * vmap_pages_range_noflush is similar to vmap_pages_range, but does not
+ * flush caches.
+ *
+ * The caller is responsible for calling flush_cache_vmap() after this
+ * function returns successfully and before the addresses are accessed.
+ *
+ * This is an internal function only. Do not use outside mm/.
+ */
+int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
pgprot_t prot, struct page **pages, unsigned int page_shift)
{
unsigned int i, nr = (end - addr) >> PAGE_SHIFT;
@@ -549,48 +558,26 @@ static int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
return 0;
}

-static int vmap_pages_range(unsigned long addr, unsigned long end,
- pgprot_t prot, struct page **pages, unsigned int page_shift)
-{
- int err;
-
- err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
- flush_cache_vmap(addr, end);
- return err;
-}
-
/**
- * map_kernel_range_noflush - map kernel VM area with the specified pages
+ * vmap_pages_range - map pages to a kernel virtual address
* @addr: start of the VM area to map
- * @size: size of the VM area to map
+ * @end: end of the VM area to map (non-inclusive)
* @prot: page protection flags to use
- * @pages: pages to map
- *
- * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size specify should
- * have been allocated using get_vm_area() and its friends.
- *
- * NOTE:
- * This function does NOT do any cache flushing. The caller is responsible for
- * calling flush_cache_vmap() on to-be-mapped areas before calling this
- * function.
+ * @pages: pages to map (always PAGE_SIZE pages)
+ * @page_shift: maximum shift that the pages may be mapped with, @pages must
+ * be aligned and contiguous up to at least this shift.
*
* RETURNS:
* 0 on success, -errno on failure.
*/
-int map_kernel_range_noflush(unsigned long addr, unsigned long size,
- pgprot_t prot, struct page **pages)
-{
- return vmap_pages_range_noflush(addr, addr + size, prot, pages, PAGE_SHIFT);
-}
-
-int map_kernel_range(unsigned long start, unsigned long size, pgprot_t prot,
- struct page **pages)
+static int vmap_pages_range(unsigned long addr, unsigned long end,
+ pgprot_t prot, struct page **pages, unsigned int page_shift)
{
- int ret;
+ int err;

- ret = map_kernel_range_noflush(start, size, prot, pages);
- flush_cache_vmap(start, start + size);
- return ret;
+ err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
+ flush_cache_vmap(addr, end);
+ return err;
}

int is_vmalloc_or_module_addr(const void *x)
@@ -2156,10 +2143,12 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node)

kasan_unpoison_vmalloc(mem, size);

- if (map_kernel_range(addr, size, PAGE_KERNEL, pages) < 0) {
+ if (vmap_pages_range(addr, addr + size, PAGE_KERNEL,
+ pages, PAGE_SHIFT) < 0) {
vm_unmap_ram(mem, count);
return NULL;
}
+
return mem;
}
EXPORT_SYMBOL(vm_map_ram);
@@ -2703,6 +2692,7 @@ void *vmap(struct page **pages, unsigned int count,
unsigned long flags, pgprot_t prot)
{
struct vm_struct *area;
+ unsigned long addr;
unsigned long size; /* In bytes */

might_sleep();
@@ -2715,8 +2705,9 @@ void *vmap(struct page **pages, unsigned int count,
if (!area)
return NULL;

- if (map_kernel_range((unsigned long)area->addr, size, pgprot_nx(prot),
- pages) < 0) {
+ addr = (unsigned long)area->addr;
+ if (vmap_pages_range(addr, addr + size, pgprot_nx(prot),
+ pages, PAGE_SHIFT) < 0) {
vunmap(area->addr);
return NULL;
}
--
2.23.0