mirror of
https://github.com/torvalds/linux.git
synced 2024-11-15 00:21:59 +00:00
3ff78451b8
MODULE_DESCRIPTION() was optional until it became mandatory and flagged as an error by 'make W=1'. Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com> Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com> Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com> Link: https://msgid.link/r/20240527194414.166156-5-pierre-louis.bossart@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
77 lines
2.3 KiB
C
77 lines
2.3 KiB
C
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
|
|
//
|
|
// This file is provided under a dual BSD/GPLv2 license. When using or
|
|
// redistributing this file, you may do so under either license.
|
|
//
|
|
// Copyright(c) 2018-2022 Intel Corporation
|
|
//
|
|
// Author: Keyon Jie <yang.jie@linux.intel.com>
|
|
//
|
|
|
|
#include <asm/unaligned.h>
|
|
#include <linux/io-64-nonatomic-lo-hi.h>
|
|
#include <linux/device.h>
|
|
#include <sound/memalloc.h>
|
|
#include <linux/module.h>
|
|
#include "sof-utils.h"
|
|
|
|
/*
|
|
* Generic buffer page table creation.
|
|
* Take the each physical page address and drop the least significant unused
|
|
* bits from each (based on PAGE_SIZE). Then pack valid page address bits
|
|
* into compressed page table.
|
|
*/
|
|
|
|
int snd_sof_create_page_table(struct device *dev,
|
|
struct snd_dma_buffer *dmab,
|
|
unsigned char *page_table, size_t size)
|
|
{
|
|
int i, pages;
|
|
|
|
pages = snd_sgbuf_aligned_pages(size);
|
|
|
|
dev_dbg(dev, "generating page table for %p size 0x%zx pages %d\n",
|
|
dmab->area, size, pages);
|
|
|
|
for (i = 0; i < pages; i++) {
|
|
/*
|
|
* The number of valid address bits for each page is 20.
|
|
* idx determines the byte position within page_table
|
|
* where the current page's address is stored
|
|
* in the compressed page_table.
|
|
* This can be calculated by multiplying the page number by 2.5.
|
|
*/
|
|
u32 idx = (5 * i) >> 1;
|
|
u32 pfn = snd_sgbuf_get_addr(dmab, i * PAGE_SIZE) >> PAGE_SHIFT;
|
|
u8 *pg_table;
|
|
|
|
pg_table = (u8 *)(page_table + idx);
|
|
|
|
/*
|
|
* pagetable compression:
|
|
* byte 0 byte 1 byte 2 byte 3 byte 4 byte 5
|
|
* ___________pfn 0__________ __________pfn 1___________ _pfn 2...
|
|
* .... .... .... .... .... .... .... .... .... .... ....
|
|
* It is created by:
|
|
* 1. set current location to 0, PFN index i to 0
|
|
* 2. put pfn[i] at current location in Little Endian byte order
|
|
* 3. calculate an intermediate value as
|
|
* x = (pfn[i+1] << 4) | (pfn[i] & 0xf)
|
|
* 4. put x at offset (current location + 2) in LE byte order
|
|
* 5. increment current location by 5 bytes, increment i by 2
|
|
* 6. continue to (2)
|
|
*/
|
|
if (i & 1)
|
|
put_unaligned_le32((pg_table[0] & 0xf) | pfn << 4,
|
|
pg_table);
|
|
else
|
|
put_unaligned_le32(pfn, pg_table);
|
|
}
|
|
|
|
return pages;
|
|
}
|
|
EXPORT_SYMBOL(snd_sof_create_page_table);
|
|
|
|
MODULE_LICENSE("Dual BSD/GPL");
|
|
MODULE_DESCRIPTION("SOF utils");
|