cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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saa7164-buffer.c (9194B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *  Driver for the NXP SAA7164 PCIe bridge
      4 *
      5 *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
      6 */
      7
      8#include <linux/slab.h>
      9
     10#include "saa7164.h"
     11
     12/* The PCI address space for buffer handling looks like this:
     13 *
     14 * +-u32 wide-------------+
     15 * |                      +
     16 * +-u64 wide------------------------------------+
     17 * +                                             +
     18 * +----------------------+
     19 * | CurrentBufferPtr     + Pointer to current PCI buffer >-+
     20 * +----------------------+                                 |
     21 * | Unused               +                                 |
     22 * +----------------------+                                 |
     23 * | Pitch                + = 188 (bytes)                   |
     24 * +----------------------+                                 |
     25 * | PCI buffer size      + = pitch * number of lines (312) |
     26 * +----------------------+                                 |
     27 * |0| Buf0 Write Offset  +                                 |
     28 * +----------------------+                                 v
     29 * |1| Buf1 Write Offset  +                                 |
     30 * +----------------------+                                 |
     31 * |2| Buf2 Write Offset  +                                 |
     32 * +----------------------+                                 |
     33 * |3| Buf3 Write Offset  +                                 |
     34 * +----------------------+                                 |
     35 * ... More write offsets                                   |
     36 * +---------------------------------------------+          |
     37 * +0| set of ptrs to PCI pagetables             +          |
     38 * +---------------------------------------------+          |
     39 * +1| set of ptrs to PCI pagetables             + <--------+
     40 * +---------------------------------------------+
     41 * +2| set of ptrs to PCI pagetables             +
     42 * +---------------------------------------------+
     43 * +3| set of ptrs to PCI pagetables             + >--+
     44 * +---------------------------------------------+    |
     45 * ... More buffer pointers                           |  +----------------+
     46 *						    +->| pt[0] TS data  |
     47 *						    |  +----------------+
     48 *						    |
     49 *						    |  +----------------+
     50 *						    +->| pt[1] TS data  |
     51 *						    |  +----------------+
     52 *						    | etc
     53 */
     54
     55void saa7164_buffer_display(struct saa7164_buffer *buf)
     56{
     57	struct saa7164_dev *dev = buf->port->dev;
     58	int i;
     59
     60	dprintk(DBGLVL_BUF, "%s()   buffer @ 0x%p nr=%d\n",
     61		__func__, buf, buf->idx);
     62	dprintk(DBGLVL_BUF, "  pci_cpu @ 0x%p    dma @ 0x%08llx len = 0x%x\n",
     63		buf->cpu, (long long)buf->dma, buf->pci_size);
     64	dprintk(DBGLVL_BUF, "   pt_cpu @ 0x%p pt_dma @ 0x%08llx len = 0x%x\n",
     65		buf->pt_cpu, (long long)buf->pt_dma, buf->pt_size);
     66
     67	/* Format the Page Table Entries to point into the data buffer */
     68	for (i = 0 ; i < SAA7164_PT_ENTRIES; i++) {
     69
     70		dprintk(DBGLVL_BUF, "    pt[%02d] = 0x%p -> 0x%llx\n",
     71			i, buf->pt_cpu, (u64)*(buf->pt_cpu));
     72
     73	}
     74}
     75/* Allocate a new buffer structure and associated PCI space in bytes.
     76 * len must be a multiple of sizeof(u64)
     77 */
     78struct saa7164_buffer *saa7164_buffer_alloc(struct saa7164_port *port,
     79	u32 len)
     80{
     81	struct tmHWStreamParameters *params = &port->hw_streamingparams;
     82	struct saa7164_buffer *buf = NULL;
     83	struct saa7164_dev *dev = port->dev;
     84	int i;
     85
     86	if ((len == 0) || (len >= 65536) || (len % sizeof(u64))) {
     87		log_warn("%s() SAA_ERR_BAD_PARAMETER\n", __func__);
     88		goto ret;
     89	}
     90
     91	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
     92	if (!buf)
     93		goto ret;
     94
     95	buf->idx = -1;
     96	buf->port = port;
     97	buf->flags = SAA7164_BUFFER_FREE;
     98	buf->pos = 0;
     99	buf->actual_size = params->pitch * params->numberoflines;
    100	buf->crc = 0;
    101	/* TODO: arg len is being ignored */
    102	buf->pci_size = SAA7164_PT_ENTRIES * 0x1000;
    103	buf->pt_size = (SAA7164_PT_ENTRIES * sizeof(u64)) + 0x1000;
    104
    105	/* Allocate contiguous memory */
    106	buf->cpu = dma_alloc_coherent(&port->dev->pci->dev, buf->pci_size,
    107				      &buf->dma, GFP_KERNEL);
    108	if (!buf->cpu)
    109		goto fail1;
    110
    111	buf->pt_cpu = dma_alloc_coherent(&port->dev->pci->dev, buf->pt_size,
    112					 &buf->pt_dma, GFP_KERNEL);
    113	if (!buf->pt_cpu)
    114		goto fail2;
    115
    116	/* init the buffers to a known pattern, easier during debugging */
    117	memset(buf->cpu, 0xff, buf->pci_size);
    118	buf->crc = crc32(0, buf->cpu, buf->actual_size);
    119	memset(buf->pt_cpu, 0xff, buf->pt_size);
    120
    121	dprintk(DBGLVL_BUF, "%s()   allocated buffer @ 0x%p (%d pageptrs)\n",
    122		__func__, buf, params->numpagetables);
    123	dprintk(DBGLVL_BUF, "  pci_cpu @ 0x%p    dma @ 0x%08lx len = 0x%x\n",
    124		buf->cpu, (long)buf->dma, buf->pci_size);
    125	dprintk(DBGLVL_BUF, "   pt_cpu @ 0x%p pt_dma @ 0x%08lx len = 0x%x\n",
    126		buf->pt_cpu, (long)buf->pt_dma, buf->pt_size);
    127
    128	/* Format the Page Table Entries to point into the data buffer */
    129	for (i = 0 ; i < params->numpagetables; i++) {
    130
    131		*(buf->pt_cpu + i) = buf->dma + (i * 0x1000); /* TODO */
    132		dprintk(DBGLVL_BUF, "    pt[%02d] = 0x%p -> 0x%llx\n",
    133			i, buf->pt_cpu, (u64)*(buf->pt_cpu));
    134
    135	}
    136
    137	goto ret;
    138
    139fail2:
    140	dma_free_coherent(&port->dev->pci->dev, buf->pci_size, buf->cpu,
    141			  buf->dma);
    142fail1:
    143	kfree(buf);
    144
    145	buf = NULL;
    146ret:
    147	return buf;
    148}
    149
    150int saa7164_buffer_dealloc(struct saa7164_buffer *buf)
    151{
    152	struct saa7164_dev *dev;
    153
    154	if (!buf || !buf->port)
    155		return SAA_ERR_BAD_PARAMETER;
    156	dev = buf->port->dev;
    157
    158	dprintk(DBGLVL_BUF, "%s() deallocating buffer @ 0x%p\n",
    159		__func__, buf);
    160
    161	if (buf->flags != SAA7164_BUFFER_FREE)
    162		log_warn(" freeing a non-free buffer\n");
    163
    164	dma_free_coherent(&dev->pci->dev, buf->pci_size, buf->cpu, buf->dma);
    165	dma_free_coherent(&dev->pci->dev, buf->pt_size, buf->pt_cpu,
    166			  buf->pt_dma);
    167
    168	kfree(buf);
    169
    170	return SAA_OK;
    171}
    172
    173int saa7164_buffer_zero_offsets(struct saa7164_port *port, int i)
    174{
    175	struct saa7164_dev *dev = port->dev;
    176
    177	if ((i < 0) || (i >= port->hwcfg.buffercount))
    178		return -EINVAL;
    179
    180	dprintk(DBGLVL_BUF, "%s(idx = %d)\n", __func__, i);
    181
    182	saa7164_writel(port->bufoffset + (sizeof(u32) * i), 0);
    183
    184	return 0;
    185}
    186
    187/* Write a buffer into the hardware */
    188int saa7164_buffer_activate(struct saa7164_buffer *buf, int i)
    189{
    190	struct saa7164_port *port = buf->port;
    191	struct saa7164_dev *dev = port->dev;
    192
    193	if ((i < 0) || (i >= port->hwcfg.buffercount))
    194		return -EINVAL;
    195
    196	dprintk(DBGLVL_BUF, "%s(idx = %d)\n", __func__, i);
    197
    198	buf->idx = i; /* Note of which buffer list index position we occupy */
    199	buf->flags = SAA7164_BUFFER_BUSY;
    200	buf->pos = 0;
    201
    202	/* TODO: Review this in light of 32v64 assignments */
    203	saa7164_writel(port->bufoffset + (sizeof(u32) * i), 0);
    204	saa7164_writel(port->bufptr32h + ((sizeof(u32) * 2) * i), buf->pt_dma);
    205	saa7164_writel(port->bufptr32l + ((sizeof(u32) * 2) * i), 0);
    206
    207	dprintk(DBGLVL_BUF, "	buf[%d] offset 0x%llx (0x%x) buf 0x%llx/%llx (0x%x/%x) nr=%d\n",
    208		buf->idx,
    209		(u64)port->bufoffset + (i * sizeof(u32)),
    210		saa7164_readl(port->bufoffset + (sizeof(u32) * i)),
    211		(u64)port->bufptr32h + ((sizeof(u32) * 2) * i),
    212		(u64)port->bufptr32l + ((sizeof(u32) * 2) * i),
    213		saa7164_readl(port->bufptr32h + ((sizeof(u32) * i) * 2)),
    214		saa7164_readl(port->bufptr32l + ((sizeof(u32) * i) * 2)),
    215		buf->idx);
    216
    217	return 0;
    218}
    219
    220int saa7164_buffer_cfg_port(struct saa7164_port *port)
    221{
    222	struct tmHWStreamParameters *params = &port->hw_streamingparams;
    223	struct saa7164_dev *dev = port->dev;
    224	struct saa7164_buffer *buf;
    225	struct list_head *c, *n;
    226	int i = 0;
    227
    228	dprintk(DBGLVL_BUF, "%s(port=%d)\n", __func__, port->nr);
    229
    230	saa7164_writel(port->bufcounter, 0);
    231	saa7164_writel(port->pitch, params->pitch);
    232	saa7164_writel(port->bufsize, params->pitch * params->numberoflines);
    233
    234	dprintk(DBGLVL_BUF, " configured:\n");
    235	dprintk(DBGLVL_BUF, "   lmmio       0x%p\n", dev->lmmio);
    236	dprintk(DBGLVL_BUF, "   bufcounter  0x%x = 0x%x\n", port->bufcounter,
    237		saa7164_readl(port->bufcounter));
    238
    239	dprintk(DBGLVL_BUF, "   pitch       0x%x = %d\n", port->pitch,
    240		saa7164_readl(port->pitch));
    241
    242	dprintk(DBGLVL_BUF, "   bufsize     0x%x = %d\n", port->bufsize,
    243		saa7164_readl(port->bufsize));
    244
    245	dprintk(DBGLVL_BUF, "   buffercount = %d\n", port->hwcfg.buffercount);
    246	dprintk(DBGLVL_BUF, "   bufoffset = 0x%x\n", port->bufoffset);
    247	dprintk(DBGLVL_BUF, "   bufptr32h = 0x%x\n", port->bufptr32h);
    248	dprintk(DBGLVL_BUF, "   bufptr32l = 0x%x\n", port->bufptr32l);
    249
    250	/* Poke the buffers and offsets into PCI space */
    251	mutex_lock(&port->dmaqueue_lock);
    252	list_for_each_safe(c, n, &port->dmaqueue.list) {
    253		buf = list_entry(c, struct saa7164_buffer, list);
    254
    255		BUG_ON(buf->flags != SAA7164_BUFFER_FREE);
    256
    257		/* Place the buffer in the h/w queue */
    258		saa7164_buffer_activate(buf, i);
    259
    260		/* Don't exceed the device maximum # bufs */
    261		BUG_ON(i > port->hwcfg.buffercount);
    262		i++;
    263
    264	}
    265	mutex_unlock(&port->dmaqueue_lock);
    266
    267	return 0;
    268}
    269
    270struct saa7164_user_buffer *saa7164_buffer_alloc_user(struct saa7164_dev *dev,
    271	u32 len)
    272{
    273	struct saa7164_user_buffer *buf;
    274
    275	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
    276	if (!buf)
    277		return NULL;
    278
    279	buf->data = kzalloc(len, GFP_KERNEL);
    280
    281	if (!buf->data) {
    282		kfree(buf);
    283		return NULL;
    284	}
    285
    286	buf->actual_size = len;
    287	buf->pos = 0;
    288	buf->crc = 0;
    289
    290	dprintk(DBGLVL_BUF, "%s()   allocated user buffer @ 0x%p\n",
    291		__func__, buf);
    292
    293	return buf;
    294}
    295
    296void saa7164_buffer_dealloc_user(struct saa7164_user_buffer *buf)
    297{
    298	if (!buf)
    299		return;
    300
    301	kfree(buf->data);
    302	buf->data = NULL;
    303
    304	kfree(buf);
    305}