memory.c

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/*
 *  Copyright (c) by Jaroslav Kysela <[email protected]>
 *  Copyright (c) by Takashi Iwai <[email protected]>
 *
 *  EMU10K1 memory page allocation (PTB area)
 *
 *
 *   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/pci.h>
#include <linux/gfp.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <linux/export.h>

#include <sound/core.h>
#include <sound/emu10k1.h>

/* page arguments of these two macros are Emu page (4096 bytes), not like
 * aligned pages in others
 */
#define __set_ptb_entry(emu,page,addr) \
    (((u32 *)(emu)->ptb_pages.area)[page] = cpu_to_le32(((addr) << 1) | (page)))

#define UNIT_PAGES      (PAGE_SIZE / EMUPAGESIZE)
#define MAX_ALIGN_PAGES     (MAXPAGES / UNIT_PAGES)
/* get aligned page from offset address */
#define get_aligned_page(offset)    ((offset) >> PAGE_SHIFT)
/* get offset address from aligned page */
#define aligned_page_offset(page)   ((page) << PAGE_SHIFT)

#if PAGE_SIZE == 4096
/* page size == EMUPAGESIZE */
/* fill PTB entrie(s) corresponding to page with addr */
#define set_ptb_entry(emu,page,addr)    __set_ptb_entry(emu,page,addr)
/* fill PTB entrie(s) corresponding to page with silence pointer */
#define set_silent_ptb(emu,page)    __set_ptb_entry(emu,page,emu->silent_page.addr)
#else
/* fill PTB entries -- we need to fill UNIT_PAGES entries */
static inline void set_ptb_entry(struct snd_emu10k1 *emu, int page, dma_addr_t addr)
{
    int i;
    page *= UNIT_PAGES;
    for (i = 0; i < UNIT_PAGES; i++, page++) {
        __set_ptb_entry(emu, page, addr);
        addr += EMUPAGESIZE;
    }
}
static inline void set_silent_ptb(struct snd_emu10k1 *emu, int page)
{
    int i;
    page *= UNIT_PAGES;
    for (i = 0; i < UNIT_PAGES; i++, page++)
        /* do not increment ptr */
        __set_ptb_entry(emu, page, emu->silent_page.addr);
}
#endif /* PAGE_SIZE */


/*
 */
static int synth_alloc_pages(struct snd_emu10k1 *hw, struct snd_emu10k1_memblk *blk);
static int synth_free_pages(struct snd_emu10k1 *hw, struct snd_emu10k1_memblk *blk);

#define get_emu10k1_memblk(l,member)    list_entry(l, struct snd_emu10k1_memblk, member)


/* initialize emu10k1 part */
static void emu10k1_memblk_init(struct snd_emu10k1_memblk *blk)
{
    blk->mapped_page = -1;
    INIT_LIST_HEAD(&blk->mapped_link);
    INIT_LIST_HEAD(&blk->mapped_order_link);
    blk->map_locked = 0;

    blk->first_page = get_aligned_page(blk->mem.offset);
    blk->last_page = get_aligned_page(blk->mem.offset + blk->mem.size - 1);
    blk->pages = blk->last_page - blk->first_page + 1;
}

/*
 * search empty region on PTB with the given size
 *
 * if an empty region is found, return the page and store the next mapped block
 * in nextp
 * if not found, return a negative error code.
 */
static int search_empty_map_area(struct snd_emu10k1 *emu, int npages, struct list_head **nextp)
{
    int page = 0, found_page = -ENOMEM;
    int max_size = npages;
    int size;
    struct list_head *candidate = &emu->mapped_link_head;
    struct list_head *pos;

    list_for_each (pos, &emu->mapped_link_head) {
        struct snd_emu10k1_memblk *blk = get_emu10k1_memblk(pos, mapped_link);
        if (blk->mapped_page < 0)
            continue;
        size = blk->mapped_page - page;
        if (size == npages) {
            *nextp = pos;
            return page;
        }
        else if (size > max_size) {
            /* we look for the maximum empty hole */
            max_size = size;
            candidate = pos;
            found_page = page;
        }
        page = blk->mapped_page + blk->pages;
    }
    size = MAX_ALIGN_PAGES - page;
    if (size >= max_size) {
        *nextp = pos;
        return page;
    }
    *nextp = candidate;
    return found_page;
}

/*
 * map a memory block onto emu10k1's PTB
 *
 * call with memblk_lock held
 */
static int map_memblk(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
{
    int page, pg;
    struct list_head *next;

    page = search_empty_map_area(emu, blk->pages, &next);
    if (page < 0) /* not found */
        return page;
    /* insert this block in the proper position of mapped list */
    list_add_tail(&blk->mapped_link, next);
    /* append this as a newest block in order list */
    list_add_tail(&blk->mapped_order_link, &emu->mapped_order_link_head);
    blk->mapped_page = page;
    /* fill PTB */
    for (pg = blk->first_page; pg <= blk->last_page; pg++) {
        set_ptb_entry(emu, page, emu->page_addr_table[pg]);
        page++;
    }
    return 0;
}

/*
 * unmap the block
 * return the size of resultant empty pages
 *
 * call with memblk_lock held
 */
static int unmap_memblk(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
{
    int start_page, end_page, mpage, pg;
    struct list_head *p;
    struct snd_emu10k1_memblk *q;

    /* calculate the expected size of empty region */
    if ((p = blk->mapped_link.prev) != &emu->mapped_link_head) {
        q = get_emu10k1_memblk(p, mapped_link);
        start_page = q->mapped_page + q->pages;
    } else
        start_page = 0;
    if ((p = blk->mapped_link.next) != &emu->mapped_link_head) {
        q = get_emu10k1_memblk(p, mapped_link);
        end_page = q->mapped_page;
    } else
        end_page = MAX_ALIGN_PAGES;

    /* remove links */
    list_del(&blk->mapped_link);
    list_del(&blk->mapped_order_link);
    /* clear PTB */
    mpage = blk->mapped_page;
    for (pg = blk->first_page; pg <= blk->last_page; pg++) {
        set_silent_ptb(emu, mpage);
        mpage++;
    }
    blk->mapped_page = -1;
    return end_page - start_page; /* return the new empty size */
}

/*
 * search empty pages with the given size, and create a memory block
 *
 * unlike synth_alloc the memory block is aligned to the page start
 */
static struct snd_emu10k1_memblk *
search_empty(struct snd_emu10k1 *emu, int size)
{
    struct list_head *p;
    struct snd_emu10k1_memblk *blk;
    int page, psize;

    psize = get_aligned_page(size + PAGE_SIZE -1);
    page = 0;
    list_for_each(p, &emu->memhdr->block) {
        blk = get_emu10k1_memblk(p, mem.list);
        if (page + psize <= blk->first_page)
            goto __found_pages;
        page = blk->last_page + 1;
    }
    if (page + psize > emu->max_cache_pages)
        return NULL;

__found_pages:
    /* create a new memory block */
    blk = (struct snd_emu10k1_memblk *)__snd_util_memblk_new(emu->memhdr, psize << PAGE_SHIFT, p->prev);
    if (blk == NULL)
        return NULL;
    blk->mem.offset = aligned_page_offset(page); /* set aligned offset */
    emu10k1_memblk_init(blk);
    return blk;
}


/*
 * check if the given pointer is valid for pages
 */
static int is_valid_page(struct snd_emu10k1 *emu, dma_addr_t addr)
{
    if (addr & ~emu->dma_mask) {
        snd_printk(KERN_ERR "max memory size is 0x%lx (addr = 0x%lx)!!\n", emu->dma_mask, (unsigned long)addr);
        return 0;
    }
    if (addr & (EMUPAGESIZE-1)) {
        snd_printk(KERN_ERR "page is not aligned\n");
        return 0;
    }
    return 1;
}

/*
 * map the given memory block on PTB.
 * if the block is already mapped, update the link order.
 * if no empty pages are found, tries to release unused memory blocks
 * and retry the mapping.
 */
int snd_emu10k1_memblk_map(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
{
    int err;
    int size;
    struct list_head *p, *nextp;
    struct snd_emu10k1_memblk *deleted;
    unsigned long flags;

    spin_lock_irqsave(&emu->memblk_lock, flags);
    if (blk->mapped_page >= 0) {
        /* update order link */
        list_move_tail(&blk->mapped_order_link,
                   &emu->mapped_order_link_head);
        spin_unlock_irqrestore(&emu->memblk_lock, flags);
        return 0;
    }
    if ((err = map_memblk(emu, blk)) < 0) {
        /* no enough page - try to unmap some blocks */
        /* starting from the oldest block */
        p = emu->mapped_order_link_head.next;
        for (; p != &emu->mapped_order_link_head; p = nextp) {
            nextp = p->next;
            deleted = get_emu10k1_memblk(p, mapped_order_link);
            if (deleted->map_locked)
                continue;
            size = unmap_memblk(emu, deleted);
            if (size >= blk->pages) {
                /* ok the empty region is enough large */
                err = map_memblk(emu, blk);
                break;
            }
        }
    }
    spin_unlock_irqrestore(&emu->memblk_lock, flags);
    return err;
}

EXPORT_SYMBOL(snd_emu10k1_memblk_map);

/*
 * page allocation for DMA
 */
struct snd_util_memblk *
snd_emu10k1_alloc_pages(struct snd_emu10k1 *emu, struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct snd_util_memhdr *hdr;
    struct snd_emu10k1_memblk *blk;
    int page, err, idx;

    if (snd_BUG_ON(!emu))
        return NULL;
    if (snd_BUG_ON(runtime->dma_bytes <= 0 ||
               runtime->dma_bytes >= MAXPAGES * EMUPAGESIZE))
        return NULL;
    hdr = emu->memhdr;
    if (snd_BUG_ON(!hdr))
        return NULL;

    idx = runtime->period_size >= runtime->buffer_size ?
                    (emu->delay_pcm_irq * 2) : 0;
    mutex_lock(&hdr->block_mutex);
    blk = search_empty(emu, runtime->dma_bytes + idx);
    if (blk == NULL) {
        mutex_unlock(&hdr->block_mutex);
        return NULL;
    }
    /* fill buffer addresses but pointers are not stored so that
     * snd_free_pci_page() is not called in in synth_free()
     */
    idx = 0;
    for (page = blk->first_page; page <= blk->last_page; page++, idx++) {
        unsigned long ofs = idx << PAGE_SHIFT;
        dma_addr_t addr;
        if (ofs >= runtime->dma_bytes)
            addr = emu->silent_page.addr;
        else
            addr = snd_pcm_sgbuf_get_addr(substream, ofs);
        if (! is_valid_page(emu, addr)) {
            printk(KERN_ERR "emu: failure page = %d\n", idx);
            mutex_unlock(&hdr->block_mutex);
            return NULL;
        }
        emu->page_addr_table[page] = addr;
        emu->page_ptr_table[page] = NULL;
    }

    /* set PTB entries */
    blk->map_locked = 1; /* do not unmap this block! */
    err = snd_emu10k1_memblk_map(emu, blk);
    if (err < 0) {
        __snd_util_mem_free(hdr, (struct snd_util_memblk *)blk);
        mutex_unlock(&hdr->block_mutex);
        return NULL;
    }
    mutex_unlock(&hdr->block_mutex);
    return (struct snd_util_memblk *)blk;
}


/*
 * release DMA buffer from page table
 */
int snd_emu10k1_free_pages(struct snd_emu10k1 *emu, struct snd_util_memblk *blk)
{
    if (snd_BUG_ON(!emu || !blk))
        return -EINVAL;
    return snd_emu10k1_synth_free(emu, blk);
}


/*
 * memory allocation using multiple pages (for synth)
 * Unlike the DMA allocation above, non-contiguous pages are assined.
 */

/*
 * allocate a synth sample area
 */
struct snd_util_memblk *
snd_emu10k1_synth_alloc(struct snd_emu10k1 *hw, unsigned int size)
{
    struct snd_emu10k1_memblk *blk;
    struct snd_util_memhdr *hdr = hw->memhdr; 

    mutex_lock(&hdr->block_mutex);
    blk = (struct snd_emu10k1_memblk *)__snd_util_mem_alloc(hdr, size);
    if (blk == NULL) {
        mutex_unlock(&hdr->block_mutex);
        return NULL;
    }
    if (synth_alloc_pages(hw, blk)) {
        __snd_util_mem_free(hdr, (struct snd_util_memblk *)blk);
        mutex_unlock(&hdr->block_mutex);
        return NULL;
    }
    snd_emu10k1_memblk_map(hw, blk);
    mutex_unlock(&hdr->block_mutex);
    return (struct snd_util_memblk *)blk;
}

EXPORT_SYMBOL(snd_emu10k1_synth_alloc);

/*
 * free a synth sample area
 */
int
snd_emu10k1_synth_free(struct snd_emu10k1 *emu, struct snd_util_memblk *memblk)
{
    struct snd_util_memhdr *hdr = emu->memhdr; 
    struct snd_emu10k1_memblk *blk = (struct snd_emu10k1_memblk *)memblk;
    unsigned long flags;

    mutex_lock(&hdr->block_mutex);
    spin_lock_irqsave(&emu->memblk_lock, flags);
    if (blk->mapped_page >= 0)
        unmap_memblk(emu, blk);
    spin_unlock_irqrestore(&emu->memblk_lock, flags);
    synth_free_pages(emu, blk);
     __snd_util_mem_free(hdr, memblk);
    mutex_unlock(&hdr->block_mutex);
    return 0;
}

EXPORT_SYMBOL(snd_emu10k1_synth_free);

/* check new allocation range */
static void get_single_page_range(struct snd_util_memhdr *hdr,
                  struct snd_emu10k1_memblk *blk,
                  int *first_page_ret, int *last_page_ret)
{
    struct list_head *p;
    struct snd_emu10k1_memblk *q;
    int first_page, last_page;
    first_page = blk->first_page;
    if ((p = blk->mem.list.prev) != &hdr->block) {
        q = get_emu10k1_memblk(p, mem.list);
        if (q->last_page == first_page)
            first_page++;  /* first page was already allocated */
    }
    last_page = blk->last_page;
    if ((p = blk->mem.list.next) != &hdr->block) {
        q = get_emu10k1_memblk(p, mem.list);
        if (q->first_page == last_page)
            last_page--; /* last page was already allocated */
    }
    *first_page_ret = first_page;
    *last_page_ret = last_page;
}

/* release allocated pages */
static void __synth_free_pages(struct snd_emu10k1 *emu, int first_page,
                   int last_page)
{
    int page;

    for (page = first_page; page <= last_page; page++) {
        free_page((unsigned long)emu->page_ptr_table[page]);
        emu->page_addr_table[page] = 0;
        emu->page_ptr_table[page] = NULL;
    }
}

/*
 * allocate kernel pages
 */
static int synth_alloc_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
{
    int page, first_page, last_page;

    emu10k1_memblk_init(blk);
    get_single_page_range(emu->memhdr, blk, &first_page, &last_page);
    /* allocate kernel pages */
    for (page = first_page; page <= last_page; page++) {
        /* first try to allocate from <4GB zone */
        struct page *p = alloc_page(GFP_KERNEL | GFP_DMA32 |
                        __GFP_NOWARN);
        if (!p || (page_to_pfn(p) & ~(emu->dma_mask >> PAGE_SHIFT))) {
            if (p)
                __free_page(p);
            /* try to allocate from <16MB zone */
            p = alloc_page(GFP_ATOMIC | GFP_DMA |
                       __GFP_NORETRY | /* no OOM-killer */
                       __GFP_NOWARN);
        }
        if (!p) {
            __synth_free_pages(emu, first_page, page - 1);
            return -ENOMEM;
        }
        emu->page_addr_table[page] = page_to_phys(p);
        emu->page_ptr_table[page] = page_address(p);
    }
    return 0;
}

/*
 * free pages
 */
static int synth_free_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
{
    int first_page, last_page;

    get_single_page_range(emu->memhdr, blk, &first_page, &last_page);
    __synth_free_pages(emu, first_page, last_page);
    return 0;
}

/* calculate buffer pointer from offset address */
static inline void *offset_ptr(struct snd_emu10k1 *emu, int page, int offset)
{
    char *ptr;
    if (snd_BUG_ON(page < 0 || page >= emu->max_cache_pages))
        return NULL;
    ptr = emu->page_ptr_table[page];
    if (! ptr) {
        printk(KERN_ERR "emu10k1: access to NULL ptr: page = %d\n", page);
        return NULL;
    }
    ptr += offset & (PAGE_SIZE - 1);
    return (void*)ptr;
}

/*
 * bzero(blk + offset, size)
 */
int snd_emu10k1_synth_bzero(struct snd_emu10k1 *emu, struct snd_util_memblk *blk,
                int offset, int size)
{
    int page, nextofs, end_offset, temp, temp1;
    void *ptr;
    struct snd_emu10k1_memblk *p = (struct snd_emu10k1_memblk *)blk;

    offset += blk->offset & (PAGE_SIZE - 1);
    end_offset = offset + size;
    page = get_aligned_page(offset);
    do {
        nextofs = aligned_page_offset(page + 1);
        temp = nextofs - offset;
        temp1 = end_offset - offset;
        if (temp1 < temp)
            temp = temp1;
        ptr = offset_ptr(emu, page + p->first_page, offset);
        if (ptr)
            memset(ptr, 0, temp);
        offset = nextofs;
        page++;
    } while (offset < end_offset);
    return 0;
}

EXPORT_SYMBOL(snd_emu10k1_synth_bzero);

/*
 * copy_from_user(blk + offset, data, size)
 */
int snd_emu10k1_synth_copy_from_user(struct snd_emu10k1 *emu, struct snd_util_memblk *blk,
                     int offset, const char __user *data, int size)
{
    int page, nextofs, end_offset, temp, temp1;
    void *ptr;
    struct snd_emu10k1_memblk *p = (struct snd_emu10k1_memblk *)blk;

    offset += blk->offset & (PAGE_SIZE - 1);
    end_offset = offset + size;
    page = get_aligned_page(offset);
    do {
        nextofs = aligned_page_offset(page + 1);
        temp = nextofs - offset;
        temp1 = end_offset - offset;
        if (temp1 < temp)
            temp = temp1;
        ptr = offset_ptr(emu, page + p->first_page, offset);
        if (ptr && copy_from_user(ptr, data, temp))
            return -EFAULT;
        offset = nextofs;
        data += temp;
        page++;
    } while (offset < end_offset);
    return 0;
}

EXPORT_SYMBOL(snd_emu10k1_synth_copy_from_user);