memalloc.c

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/*
 *  Copyright (c) by Jaroslav Kysela <[email protected]>
 *                   Takashi Iwai <[email protected]>
 * 
 *  Generic memory allocators
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
#include <linux/dma-mapping.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <sound/memalloc.h>


MODULE_AUTHOR("Takashi Iwai <[email protected]>, Jaroslav Kysela <[email protected]>");
MODULE_DESCRIPTION("Memory allocator for ALSA system.");
MODULE_LICENSE("GPL");


/*
 */

static DEFINE_MUTEX(list_mutex);
static LIST_HEAD(mem_list_head);

/* buffer preservation list */
struct snd_mem_list {
    struct snd_dma_buffer buffer;
    unsigned int id;
    struct list_head list;
};

/* id for pre-allocated buffers */
#define SNDRV_DMA_DEVICE_UNUSED (unsigned int)-1

/*
 *
 *  Generic memory allocators
 *
 */

static long snd_allocated_pages; /* holding the number of allocated pages */

static inline void inc_snd_pages(int order)
{
    snd_allocated_pages += 1 << order;
}

static inline void dec_snd_pages(int order)
{
    snd_allocated_pages -= 1 << order;
}

void *snd_malloc_pages(size_t size, gfp_t gfp_flags)
{
    int pg;
    void *res;

    if (WARN_ON(!size))
        return NULL;
    if (WARN_ON(!gfp_flags))
        return NULL;
    gfp_flags |= __GFP_COMP;    /* compound page lets parts be mapped */
    pg = get_order(size);
    if ((res = (void *) __get_free_pages(gfp_flags, pg)) != NULL)
        inc_snd_pages(pg);
    return res;
}

void snd_free_pages(void *ptr, size_t size)
{
    int pg;

    if (ptr == NULL)
        return;
    pg = get_order(size);
    dec_snd_pages(pg);
    free_pages((unsigned long) ptr, pg);
}

/*
 *
 *  Bus-specific memory allocators
 *
 */

#ifdef CONFIG_HAS_DMA
/* allocate the coherent DMA pages */
static void *snd_malloc_dev_pages(struct device *dev, size_t size, dma_addr_t *dma)
{
    int pg;
    void *res;
    gfp_t gfp_flags;

    if (WARN_ON(!dma))
        return NULL;
    pg = get_order(size);
    gfp_flags = GFP_KERNEL
        | __GFP_COMP    /* compound page lets parts be mapped */
        | __GFP_NORETRY /* don't trigger OOM-killer */
        | __GFP_NOWARN; /* no stack trace print - this call is non-critical */
    res = dma_alloc_coherent(dev, PAGE_SIZE << pg, dma, gfp_flags);
    if (res != NULL)
        inc_snd_pages(pg);

    return res;
}

/* free the coherent DMA pages */
static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
                   dma_addr_t dma)
{
    int pg;

    if (ptr == NULL)
        return;
    pg = get_order(size);
    dec_snd_pages(pg);
    dma_free_coherent(dev, PAGE_SIZE << pg, ptr, dma);
}
#endif /* CONFIG_HAS_DMA */

/*
 *
 *  ALSA generic memory management
 *
 */


int snd_dma_alloc_pages(int type, struct device *device, size_t size,
            struct snd_dma_buffer *dmab)
{
    if (WARN_ON(!size))
        return -ENXIO;
    if (WARN_ON(!dmab))
        return -ENXIO;

    dmab->dev.type = type;
    dmab->dev.dev = device;
    dmab->bytes = 0;
    switch (type) {
    case SNDRV_DMA_TYPE_CONTINUOUS:
        dmab->area = snd_malloc_pages(size,
                    (__force gfp_t)(unsigned long)device);
        dmab->addr = 0;
        break;
#ifdef CONFIG_HAS_DMA
    case SNDRV_DMA_TYPE_DEV:
        dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
        break;
#endif
#ifdef CONFIG_SND_DMA_SGBUF
    case SNDRV_DMA_TYPE_DEV_SG:
        snd_malloc_sgbuf_pages(device, size, dmab, NULL);
        break;
#endif
    default:
        printk(KERN_ERR "snd-malloc: invalid device type %d\n", type);
        dmab->area = NULL;
        dmab->addr = 0;
        return -ENXIO;
    }
    if (! dmab->area)
        return -ENOMEM;
    dmab->bytes = size;
    return 0;
}

int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
                 struct snd_dma_buffer *dmab)
{
    int err;

    while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
        size_t aligned_size;
        if (err != -ENOMEM)
            return err;
        if (size <= PAGE_SIZE)
            return -ENOMEM;
        aligned_size = PAGE_SIZE << get_order(size);
        if (size != aligned_size)
            size = aligned_size;
        else
            size >>= 1;
    }
    if (! dmab->area)
        return -ENOMEM;
    return 0;
}


void snd_dma_free_pages(struct snd_dma_buffer *dmab)
{
    switch (dmab->dev.type) {
    case SNDRV_DMA_TYPE_CONTINUOUS:
        snd_free_pages(dmab->area, dmab->bytes);
        break;
#ifdef CONFIG_HAS_DMA
    case SNDRV_DMA_TYPE_DEV:
        snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
        break;
#endif
#ifdef CONFIG_SND_DMA_SGBUF
    case SNDRV_DMA_TYPE_DEV_SG:
        snd_free_sgbuf_pages(dmab);
        break;
#endif
    default:
        printk(KERN_ERR "snd-malloc: invalid device type %d\n", dmab->dev.type);
    }
}


size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *dmab, unsigned int id)
{
    struct snd_mem_list *mem;

    if (WARN_ON(!dmab))
        return 0;

    mutex_lock(&list_mutex);
    list_for_each_entry(mem, &mem_list_head, list) {
        if (mem->id == id &&
            (mem->buffer.dev.dev == NULL || dmab->dev.dev == NULL ||
             ! memcmp(&mem->buffer.dev, &dmab->dev, sizeof(dmab->dev)))) {
            struct device *dev = dmab->dev.dev;
            list_del(&mem->list);
            *dmab = mem->buffer;
            if (dmab->dev.dev == NULL)
                dmab->dev.dev = dev;
            kfree(mem);
            mutex_unlock(&list_mutex);
            return dmab->bytes;
        }
    }
    mutex_unlock(&list_mutex);
    return 0;
}

int snd_dma_reserve_buf(struct snd_dma_buffer *dmab, unsigned int id)
{
    struct snd_mem_list *mem;

    if (WARN_ON(!dmab))
        return -EINVAL;
    mem = kmalloc(sizeof(*mem), GFP_KERNEL);
    if (! mem)
        return -ENOMEM;
    mutex_lock(&list_mutex);
    mem->buffer = *dmab;
    mem->id = id;
    list_add_tail(&mem->list, &mem_list_head);
    mutex_unlock(&list_mutex);
    return 0;
}

/*
 * purge all reserved buffers
 */
static void free_all_reserved_pages(void)
{
    struct list_head *p;
    struct snd_mem_list *mem;

    mutex_lock(&list_mutex);
    while (! list_empty(&mem_list_head)) {
        p = mem_list_head.next;
        mem = list_entry(p, struct snd_mem_list, list);
        list_del(p);
        snd_dma_free_pages(&mem->buffer);
        kfree(mem);
    }
    mutex_unlock(&list_mutex);
}


#ifdef CONFIG_PROC_FS
/*
 * proc file interface
 */
#define SND_MEM_PROC_FILE   "driver/snd-page-alloc"
static struct proc_dir_entry *snd_mem_proc;

static int snd_mem_proc_read(struct seq_file *seq, void *offset)
{
    long pages = snd_allocated_pages >> (PAGE_SHIFT-12);
    struct snd_mem_list *mem;
    int devno;
    static char *types[] = { "UNKNOWN", "CONT", "DEV", "DEV-SG" };

    mutex_lock(&list_mutex);
    seq_printf(seq, "pages  : %li bytes (%li pages per %likB)\n",
           pages * PAGE_SIZE, pages, PAGE_SIZE / 1024);
    devno = 0;
    list_for_each_entry(mem, &mem_list_head, list) {
        devno++;
        seq_printf(seq, "buffer %d : ID %08x : type %s\n",
               devno, mem->id, types[mem->buffer.dev.type]);
        seq_printf(seq, "  addr = 0x%lx, size = %d bytes\n",
               (unsigned long)mem->buffer.addr,
               (int)mem->buffer.bytes);
    }
    mutex_unlock(&list_mutex);
    return 0;
}

static int snd_mem_proc_open(struct inode *inode, struct file *file)
{
    return single_open(file, snd_mem_proc_read, NULL);
}

/* FIXME: for pci only - other bus? */
#ifdef CONFIG_PCI
#define gettoken(bufp) strsep(bufp, " \t\n")

static ssize_t snd_mem_proc_write(struct file *file, const char __user * buffer,
                  size_t count, loff_t * ppos)
{
    char buf[128];
    char *token, *p;

    if (count > sizeof(buf) - 1)
        return -EINVAL;
    if (copy_from_user(buf, buffer, count))
        return -EFAULT;
    buf[count] = '\0';

    p = buf;
    token = gettoken(&p);
    if (! token || *token == '#')
        return count;
    if (strcmp(token, "add") == 0) {
        char *endp;
        int vendor, device, size, buffers;
        long mask;
        int i, alloced;
        struct pci_dev *pci;

        if ((token = gettoken(&p)) == NULL ||
            (vendor = simple_strtol(token, NULL, 0)) <= 0 ||
            (token = gettoken(&p)) == NULL ||
            (device = simple_strtol(token, NULL, 0)) <= 0 ||
            (token = gettoken(&p)) == NULL ||
            (mask = simple_strtol(token, NULL, 0)) < 0 ||
            (token = gettoken(&p)) == NULL ||
            (size = memparse(token, &endp)) < 64*1024 ||
            size > 16*1024*1024 /* too big */ ||
            (token = gettoken(&p)) == NULL ||
            (buffers = simple_strtol(token, NULL, 0)) <= 0 ||
            buffers > 4) {
            printk(KERN_ERR "snd-page-alloc: invalid proc write format\n");
            return count;
        }
        vendor &= 0xffff;
        device &= 0xffff;

        alloced = 0;
        pci = NULL;
        while ((pci = pci_get_device(vendor, device, pci)) != NULL) {
            if (mask > 0 && mask < 0xffffffff) {
                if (pci_set_dma_mask(pci, mask) < 0 ||
                    pci_set_consistent_dma_mask(pci, mask) < 0) {
                    printk(KERN_ERR "snd-page-alloc: cannot set DMA mask %lx for pci %04x:%04x\n", mask, vendor, device);
                    pci_dev_put(pci);
                    return count;
                }
            }
            for (i = 0; i < buffers; i++) {
                struct snd_dma_buffer dmab;
                memset(&dmab, 0, sizeof(dmab));
                if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(pci),
                            size, &dmab) < 0) {
                    printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
                    pci_dev_put(pci);
                    return count;
                }
                snd_dma_reserve_buf(&dmab, snd_dma_pci_buf_id(pci));
            }
            alloced++;
        }
        if (! alloced) {
            for (i = 0; i < buffers; i++) {
                struct snd_dma_buffer dmab;
                memset(&dmab, 0, sizeof(dmab));
                /* FIXME: We can allocate only in ZONE_DMA
                 * without a device pointer!
                 */
                if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, NULL,
                            size, &dmab) < 0) {
                    printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
                    break;
                }
                snd_dma_reserve_buf(&dmab, (unsigned int)((vendor << 16) | device));
            }
        }
    } else if (strcmp(token, "erase") == 0)
        /* FIXME: need for releasing each buffer chunk? */
        free_all_reserved_pages();
    else
        printk(KERN_ERR "snd-page-alloc: invalid proc cmd\n");
    return count;
}
#endif /* CONFIG_PCI */

static const struct file_operations snd_mem_proc_fops = {
    .owner      = THIS_MODULE,
    .open       = snd_mem_proc_open,
    .read       = seq_read,
#ifdef CONFIG_PCI
    .write      = snd_mem_proc_write,
#endif
    .llseek     = seq_lseek,
    .release    = single_release,
};

#endif /* CONFIG_PROC_FS */

/*
 * module entry
 */

static int __init snd_mem_init(void)
{
#ifdef CONFIG_PROC_FS
    snd_mem_proc = proc_create(SND_MEM_PROC_FILE, 0644, NULL,
                   &snd_mem_proc_fops);
#endif
    return 0;
}

static void __exit snd_mem_exit(void)
{
    remove_proc_entry(SND_MEM_PROC_FILE, NULL);
    free_all_reserved_pages();
    if (snd_allocated_pages > 0)
        printk(KERN_ERR "snd-malloc: Memory leak?  pages not freed = %li\n", snd_allocated_pages);
}


module_init(snd_mem_init)
module_exit(snd_mem_exit)


/*
 * exports
 */
EXPORT_SYMBOL(snd_dma_alloc_pages);
EXPORT_SYMBOL(snd_dma_alloc_pages_fallback);
EXPORT_SYMBOL(snd_dma_free_pages);

EXPORT_SYMBOL(snd_dma_get_reserved_buf);
EXPORT_SYMBOL(snd_dma_reserve_buf);

EXPORT_SYMBOL(snd_malloc_pages);
EXPORT_SYMBOL(snd_free_pages);