linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Virtual Memory Map support

 *

 * (C) 2007 sgi. Christoph Lameter.

 *

 * Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,

 * virt_to_page, page_address() to be implemented as a base offset

 * calculation without memory access.

 *

 * However, virtual mappings need a page table and TLBs. Many Linux

 * architectures already map their physical space using 1-1 mappings

 * via TLBs. For those arches the virtual memory map is essentially

 * for free if we use the same page size as the 1-1 mappings. In that

 * case the overhead consists of a few additional pages that are

 * allocated to create a view of memory for vmemmap.

 *

 * The architecture is expected to provide a vmemmap_populate() function

 * to instantiate the mapping.

 */

#include <linux/mm.h>

#include <linux/mmzone.h>

#include <linux/memblock.h>

#include <linux/memremap.h>

#include <linux/highmem.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/vmalloc.h>

#include <linux/sched.h>

#include <asm/dma.h>

#include <asm/pgalloc.h>

#include <asm/pgtable.h>

​

/*

 * Allocate a block of memory to be used to back the virtual memory map

 * or to back the page tables that are used to create the mapping.

 * Uses the main allocators if they are available, else bootmem.

 */

​

static void * __ref __earlyonly_bootmem_alloc(int node,

                unsigned long size,

                unsigned long align,

                unsigned long goal)

{

    return memblock_alloc_try_nid_raw(size, align, goal,

                           MEMBLOCK_ALLOC_ACCESSIBLE, node);

}

​

void * __meminit vmemmap_alloc_block(unsigned long size, int node)

{

    /* If the main allocator is up use that, fallback to bootmem. */

    if (slab_is_available()) {

        gfp_t gfp_mask = GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN;

        int order = get_order(size);

        static bool warned;

        struct page *page;

​

        page = alloc_pages_node(node, gfp_mask, order);

        if (page)

            return page_address(page);

​

        if (!warned) {

            warn_alloc(gfp_mask & ~__GFP_NOWARN, NULL,