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memalloc.c

/*
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *                   Takashi Iwai <tiwai@suse.de>
 * 
 *  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>
#ifdef CONFIG_SBUS
#include <asm/sbus.h>
#endif


MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Memory allocator for ALSA system.");
MODULE_LICENSE("GPL");


/*
 */

void *snd_malloc_sgbuf_pages(struct device *device,
                             size_t size, struct snd_dma_buffer *dmab,
                       size_t *res_size);
int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab);

/*
 */

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

#ifdef CONFIG_SND_DEBUG
#define __ASTRING__(x) #x
#define snd_assert(expr, args...) do {\
      if (!(expr)) {\
            printk(KERN_ERR "snd-malloc: BUG? (%s) (called from %p)\n", __ASTRING__(expr), __builtin_return_address(0));\
            args;\
      }\
} while (0)
#else
#define snd_assert(expr, args...) /**/
#endif

/*
 *  Hacks
 */

#if defined(__i386__)
/*
 * A hack to allocate large buffers via dma_alloc_coherent()
 *
 * since dma_alloc_coherent always tries GFP_DMA when the requested
 * pci memory region is below 32bit, it happens quite often that even
 * 2 order of pages cannot be allocated.
 *
 * so in the following, we allocate at first without dma_mask, so that
 * allocation will be done without GFP_DMA.  if the area doesn't match
 * with the requested region, then realloate with the original dma_mask
 * again.
 *
 * Really, we want to move this type of thing into dma_alloc_coherent()
 * so dma_mask doesn't have to be messed with.
 */

static void *snd_dma_hack_alloc_coherent(struct device *dev, size_t size,
                               dma_addr_t *dma_handle,
                               gfp_t flags)
{
      void *ret;
      u64 dma_mask, coherent_dma_mask;

      if (dev == NULL || !dev->dma_mask)
            return dma_alloc_coherent(dev, size, dma_handle, flags);
      dma_mask = *dev->dma_mask;
      coherent_dma_mask = dev->coherent_dma_mask;
      *dev->dma_mask = 0xffffffff;  /* do without masking */
      dev->coherent_dma_mask = 0xffffffff;      /* do without masking */
      ret = dma_alloc_coherent(dev, size, dma_handle, flags);
      *dev->dma_mask = dma_mask;    /* restore */
      dev->coherent_dma_mask = coherent_dma_mask;     /* restore */
      if (ret) {
            /* obtained address is out of range? */
            if (((unsigned long)*dma_handle + size - 1) & ~dma_mask) {
                  /* reallocate with the proper mask */
                  dma_free_coherent(dev, size, ret, *dma_handle);
                  ret = dma_alloc_coherent(dev, size, dma_handle, flags);
            }
      } else {
            /* wish to success now with the proper mask... */
            if (dma_mask != 0xffffffffUL) {
                  /* allocation with GFP_ATOMIC to avoid the long stall */
                  flags &= ~GFP_KERNEL;
                  flags |= GFP_ATOMIC;
                  ret = dma_alloc_coherent(dev, size, dma_handle, flags);
            }
      }
      return ret;
}

/* redefine dma_alloc_coherent for some architectures */
#undef dma_alloc_coherent
#define dma_alloc_coherent snd_dma_hack_alloc_coherent

#endif /* arch */

/*
 *
 *  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;
}

/**
 * snd_malloc_pages - allocate pages with the given size
 * @size: the size to allocate in bytes
 * @gfp_flags: the allocation conditions, GFP_XXX
 *
 * Allocates the physically contiguous pages with the given size.
 *
 * Returns the pointer of the buffer, or NULL if no enoguh memory.
 */
void *snd_malloc_pages(size_t size, gfp_t gfp_flags)
{
      int pg;
      void *res;

      snd_assert(size > 0, return NULL);
      snd_assert(gfp_flags != 0, 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;
}

/**
 * snd_free_pages - release the pages
 * @ptr: the buffer pointer to release
 * @size: the allocated buffer size
 *
 * Releases the buffer allocated via snd_malloc_pages().
 */
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;

      snd_assert(size > 0, return NULL);
      snd_assert(dma != NULL, 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 */

#ifdef CONFIG_SBUS

static void *snd_malloc_sbus_pages(struct device *dev, size_t size,
                           dma_addr_t *dma_addr)
{
      struct sbus_dev *sdev = (struct sbus_dev *)dev;
      int pg;
      void *res;

      snd_assert(size > 0, return NULL);
      snd_assert(dma_addr != NULL, return NULL);
      pg = get_order(size);
      res = sbus_alloc_consistent(sdev, PAGE_SIZE * (1 << pg), dma_addr);
      if (res != NULL)
            inc_snd_pages(pg);
      return res;
}

static void snd_free_sbus_pages(struct device *dev, size_t size,
                        void *ptr, dma_addr_t dma_addr)
{
      struct sbus_dev *sdev = (struct sbus_dev *)dev;
      int pg;

      if (ptr == NULL)
            return;
      pg = get_order(size);
      dec_snd_pages(pg);
      sbus_free_consistent(sdev, PAGE_SIZE * (1 << pg), ptr, dma_addr);
}

#endif /* CONFIG_SBUS */

/*
 *
 *  ALSA generic memory management
 *
 */


/**
 * snd_dma_alloc_pages - allocate the buffer area according to the given type
 * @type: the DMA buffer type
 * @device: the device pointer
 * @size: the buffer size to allocate
 * @dmab: buffer allocation record to store the allocated data
 *
 * Calls the memory-allocator function for the corresponding
 * buffer type.
 * 
 * Returns zero if the buffer with the given size is allocated successfuly,
 * other a negative value at error.
 */
int snd_dma_alloc_pages(int type, struct device *device, size_t size,
                  struct snd_dma_buffer *dmab)
{
      snd_assert(size > 0, return -ENXIO);
      snd_assert(dmab != NULL, 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, (unsigned long)device);
            dmab->addr = 0;
            break;
#ifdef CONFIG_SBUS
      case SNDRV_DMA_TYPE_SBUS:
            dmab->area = snd_malloc_sbus_pages(device, size, &dmab->addr);
            break;
#endif
#ifdef CONFIG_HAS_DMA
      case SNDRV_DMA_TYPE_DEV:
            dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
            break;
      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;
}

/**
 * snd_dma_alloc_pages_fallback - allocate the buffer area according to the given type with fallback
 * @type: the DMA buffer type
 * @device: the device pointer
 * @size: the buffer size to allocate
 * @dmab: buffer allocation record to store the allocated data
 *
 * Calls the memory-allocator function for the corresponding
 * buffer type.  When no space is left, this function reduces the size and
 * tries to allocate again.  The size actually allocated is stored in
 * res_size argument.
 * 
 * Returns zero if the buffer with the given size is allocated successfuly,
 * other a negative value at error.
 */
int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
                         struct snd_dma_buffer *dmab)
{
      int err;

      snd_assert(size > 0, return -ENXIO);
      snd_assert(dmab != NULL, return -ENXIO);

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


/**
 * snd_dma_free_pages - release the allocated buffer
 * @dmab: the buffer allocation record to release
 *
 * Releases the allocated buffer via snd_dma_alloc_pages().
 */
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_SBUS
      case SNDRV_DMA_TYPE_SBUS:
            snd_free_sbus_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
            break;
#endif
#ifdef CONFIG_HAS_DMA
      case SNDRV_DMA_TYPE_DEV:
            snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
            break;
      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);
      }
}


/**
 * snd_dma_get_reserved - get the reserved buffer for the given device
 * @dmab: the buffer allocation record to store
 * @id: the buffer id
 *
 * Looks for the reserved-buffer list and re-uses if the same buffer
 * is found in the list.  When the buffer is found, it's removed from the free list.
 *
 * Returns the size of buffer if the buffer is found, or zero if not found.
 */
size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *dmab, unsigned int id)
{
      struct snd_mem_list *mem;

      snd_assert(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;
}

/**
 * snd_dma_reserve_buf - reserve the buffer
 * @dmab: the buffer to reserve
 * @id: the buffer id
 *
 * Reserves the given buffer as a reserved buffer.
 * 
 * Returns zero if successful, or a negative code at error.
 */
int snd_dma_reserve_buf(struct snd_dma_buffer *dmab, unsigned int id)
{
      struct snd_mem_list *mem;

      snd_assert(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", "SBUS" };

      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 = create_proc_entry(SND_MEM_PROC_FILE, 0644, NULL);
      if (snd_mem_proc)
            snd_mem_proc->proc_fops = &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);

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