1 // SPDX-License-Identifier: (GPL-2.0-only OR B 1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
2 // 2 //
3 // This file is provided under a dual BSD/GPLv 3 // This file is provided under a dual BSD/GPLv2 license. When using or
4 // redistributing this file, you may do so und 4 // redistributing this file, you may do so under either license.
5 // 5 //
6 // Copyright(c) 2018-2022 Intel Corporation 6 // Copyright(c) 2018-2022 Intel Corporation
7 // 7 //
8 // Author: Keyon Jie <yang.jie@linux.intel.com 8 // Author: Keyon Jie <yang.jie@linux.intel.com>
9 // 9 //
10 10
11 #include <linux/unaligned.h> 11 #include <linux/unaligned.h>
12 #include <linux/io-64-nonatomic-lo-hi.h> 12 #include <linux/io-64-nonatomic-lo-hi.h>
13 #include <linux/device.h> 13 #include <linux/device.h>
14 #include <sound/memalloc.h> 14 #include <sound/memalloc.h>
15 #include <linux/module.h> 15 #include <linux/module.h>
16 #include "sof-utils.h" 16 #include "sof-utils.h"
17 17
18 /* 18 /*
19 * Generic buffer page table creation. 19 * Generic buffer page table creation.
20 * Take the each physical page address and dro 20 * Take the each physical page address and drop the least significant unused
21 * bits from each (based on PAGE_SIZE). Then p 21 * bits from each (based on PAGE_SIZE). Then pack valid page address bits
22 * into compressed page table. 22 * into compressed page table.
23 */ 23 */
24 24
25 int snd_sof_create_page_table(struct device *d 25 int snd_sof_create_page_table(struct device *dev,
26 struct snd_dma_b 26 struct snd_dma_buffer *dmab,
27 unsigned char *p 27 unsigned char *page_table, size_t size)
28 { 28 {
29 int i, pages; 29 int i, pages;
30 30
31 pages = snd_sgbuf_aligned_pages(size); 31 pages = snd_sgbuf_aligned_pages(size);
32 32
33 dev_dbg(dev, "generating page table fo 33 dev_dbg(dev, "generating page table for %p size 0x%zx pages %d\n",
34 dmab->area, size, pages); 34 dmab->area, size, pages);
35 35
36 for (i = 0; i < pages; i++) { 36 for (i = 0; i < pages; i++) {
37 /* 37 /*
38 * The number of valid address 38 * The number of valid address bits for each page is 20.
39 * idx determines the byte pos 39 * idx determines the byte position within page_table
40 * where the current page's ad 40 * where the current page's address is stored
41 * in the compressed page_tabl 41 * in the compressed page_table.
42 * This can be calculated by m 42 * This can be calculated by multiplying the page number by 2.5.
43 */ 43 */
44 u32 idx = (5 * i) >> 1; 44 u32 idx = (5 * i) >> 1;
45 u32 pfn = snd_sgbuf_get_addr(d 45 u32 pfn = snd_sgbuf_get_addr(dmab, i * PAGE_SIZE) >> PAGE_SHIFT;
46 u8 *pg_table; 46 u8 *pg_table;
47 47
48 pg_table = (u8 *)(page_table + 48 pg_table = (u8 *)(page_table + idx);
49 49
50 /* 50 /*
51 * pagetable compression: 51 * pagetable compression:
52 * byte 0 byte 1 byte 52 * byte 0 byte 1 byte 2 byte 3 byte 4 byte 5
53 * ___________pfn 0__________ 53 * ___________pfn 0__________ __________pfn 1___________ _pfn 2...
54 * .... .... .... .... .... 54 * .... .... .... .... .... .... .... .... .... .... ....
55 * It is created by: 55 * It is created by:
56 * 1. set current location to 56 * 1. set current location to 0, PFN index i to 0
57 * 2. put pfn[i] at current lo 57 * 2. put pfn[i] at current location in Little Endian byte order
58 * 3. calculate an intermediat 58 * 3. calculate an intermediate value as
59 * x = (pfn[i+1] << 4) | (p 59 * x = (pfn[i+1] << 4) | (pfn[i] & 0xf)
60 * 4. put x at offset (current 60 * 4. put x at offset (current location + 2) in LE byte order
61 * 5. increment current locati 61 * 5. increment current location by 5 bytes, increment i by 2
62 * 6. continue to (2) 62 * 6. continue to (2)
63 */ 63 */
64 if (i & 1) 64 if (i & 1)
65 put_unaligned_le32((pg 65 put_unaligned_le32((pg_table[0] & 0xf) | pfn << 4,
66 pg_ 66 pg_table);
67 else 67 else
68 put_unaligned_le32(pfn 68 put_unaligned_le32(pfn, pg_table);
69 } 69 }
70 70
71 return pages; 71 return pages;
72 } 72 }
73 EXPORT_SYMBOL(snd_sof_create_page_table); 73 EXPORT_SYMBOL(snd_sof_create_page_table);
74 74
75 MODULE_LICENSE("Dual BSD/GPL"); 75 MODULE_LICENSE("Dual BSD/GPL");
76 MODULE_DESCRIPTION("SOF utils"); 76 MODULE_DESCRIPTION("SOF utils");
77 77
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