linux/sound/pci/emu10k1/memory.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) by Jaroslav Kysela <[email protected]>
 *  Copyright (c) by Takashi Iwai <[email protected]>
 *
 *  EMU10K1 memory page allocation (PTB area)
 */

#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) …
#define __get_ptb_entry(emu, page) …

#define UNIT_PAGES …
#define MAX_ALIGN_PAGES0 …
#define MAX_ALIGN_PAGES1 …
/* get aligned page from offset address */
#define get_aligned_page(offset) …
/* get offset address from aligned page */
#define aligned_page_offset(page) …

#if PAGE_SIZE == EMUPAGESIZE && !IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
/* fill PTB entrie(s) corresponding to page with addr */
#define set_ptb_entry …
/* fill PTB entrie(s) corresponding to page with silence pointer */
#define set_silent_ptb …
#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)
{ … }
static inline void set_silent_ptb(struct snd_emu10k1 *emu, int page)
{ … }
#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) …


/* initialize emu10k1 part */
static void emu10k1_memblk_init(struct snd_emu10k1_memblk *blk)
{ … }

/*
 * 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)
{ … }

/*
 * 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)
{ … }

/*
 * 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)
{ … }

/*
 * 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)
{ … }


/*
 * check if the given pointer is valid for pages
 */
static int is_valid_page(struct snd_emu10k1 *emu, dma_addr_t addr)
{ … }

/*
 * 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)
{ … }

EXPORT_SYMBOL(…);

/*
 * page allocation for DMA
 */
struct snd_util_memblk *
snd_emu10k1_alloc_pages(struct snd_emu10k1 *emu, struct snd_pcm_substream *substream)
{ … }


/*
 * release DMA buffer from page table
 */
int snd_emu10k1_free_pages(struct snd_emu10k1 *emu, struct snd_util_memblk *blk)
{ … }

/*
 * allocate DMA pages, widening the allocation if necessary
 *
 * See the comment above snd_emu10k1_detect_iommu() in emu10k1_main.c why
 * this might be needed.
 *
 * If you modify this function check whether __synth_free_pages() also needs
 * changes.
 */
int snd_emu10k1_alloc_pages_maybe_wider(struct snd_emu10k1 *emu, size_t size,
					struct snd_dma_buffer *dmab)
{ … }

/*
 * 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)
{ … }

EXPORT_SYMBOL(…);

/*
 * free a synth sample area
 */
int
snd_emu10k1_synth_free(struct snd_emu10k1 *emu, struct snd_util_memblk *memblk)
{ … }

EXPORT_SYMBOL(…);

/* 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)
{ … }

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

/*
 * allocate kernel pages
 */
static int synth_alloc_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
{ … }

/*
 * free pages
 */
static int synth_free_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
{ … }

/* calculate buffer pointer from offset address */
static inline void *offset_ptr(struct snd_emu10k1 *emu, int page, int offset)
{ … }

/*
 * memset(blk + offset, value, size)
 */
int snd_emu10k1_synth_memset(struct snd_emu10k1 *emu, struct snd_util_memblk *blk,
			     int offset, int size, u8 value)
{ … }

EXPORT_SYMBOL(…);

// Note that the value is assumed to be suitably repetitive.
static void xor_range(void *ptr, int size, u32 value)
{ … }

/*
 * copy_from_user(blk + offset, data, size) ^ xor
 */
int snd_emu10k1_synth_copy_from_user(struct snd_emu10k1 *emu, struct snd_util_memblk *blk,
				     int offset, const char __user *data, int size, u32 xor)
{ … }

EXPORT_SYMBOL(…);