linux-imx

// SPDX-License-Identifier: GPL-2.0

/* bounce buffer handling for block devices

 *

 * - Split from highmem.c

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/mm.h>

#include <linux/export.h>

#include <linux/swap.h>

#include <linux/gfp.h>

#include <linux/bio.h>

#include <linux/pagemap.h>

#include <linux/mempool.h>

#include <linux/blkdev.h>

#include <linux/backing-dev.h>

#include <linux/init.h>

#include <linux/hash.h>

#include <linux/highmem.h>

#include <linux/memblock.h>

#include <linux/printk.h>

#include <asm/tlbflush.h>

​

#include <trace/events/block.h>

#include "blk.h"

​

#define POOL_SIZE   64

#define ISA_POOL_SIZE   16

​

static struct bio_set bounce_bio_set, bounce_bio_split;

static mempool_t page_pool, isa_page_pool;

​

static void init_bounce_bioset(void)

{

    static bool bounce_bs_setup;

    int ret;

​

    if (bounce_bs_setup)

        return;

​

    ret = bioset_init(&bounce_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);

    BUG_ON(ret);

    if (bioset_integrity_create(&bounce_bio_set, BIO_POOL_SIZE))

        BUG_ON(1);

​

    ret = bioset_init(&bounce_bio_split, BIO_POOL_SIZE, 0, 0);

    BUG_ON(ret);

    bounce_bs_setup = true;

}

​

#if defined(CONFIG_HIGHMEM)

static __init int init_emergency_pool(void)

{

    int ret;

#if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG)

    if (max_pfn <= max_low_pfn)

        return 0;

#endif

​

    ret = mempool_init_page_pool(&page_pool, POOL_SIZE, 0);

    BUG_ON(ret);

    pr_info("pool size: %d pages\n", POOL_SIZE);

​

    init_bounce_bioset();

    return 0;

}

​

__initcall(init_emergency_pool);

#endif

​

#ifdef CONFIG_HIGHMEM

/*

 * highmem version, map in to vec

 */

static void bounce_copy_vec(struct bio_vec *to, unsigned char *vfrom)

{

    unsigned char *vto;

​

    vto = kmap_atomic(to->bv_page);

    memcpy(vto + to->bv_offset, vfrom, to->bv_len);

    kunmap_atomic(vto);

}

​

#else /* CONFIG_HIGHMEM */

​

#define bounce_copy_vec(to, vfrom)  \

    memcpy(page_address((to)->bv_page) + (to)->bv_offset, vfrom, (to)->bv_len)

​

#endif /* CONFIG_HIGHMEM */

​

/*