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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cldma.c (7941B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2//
      3// Copyright(c) 2021-2022 Intel Corporation. All rights reserved.
      4//
      5// Author: Cezary Rojewski <cezary.rojewski@intel.com>
      6//
      7
      8#include <linux/pci.h>
      9#include <sound/hda_register.h>
     10#include <sound/hdaudio_ext.h>
     11#include "cldma.h"
     12#include "registers.h"
     13
     14/* Stream Registers */
     15#define AZX_CL_SD_BASE			0x80
     16#define AZX_SD_CTL_STRM_MASK		GENMASK(23, 20)
     17#define AZX_SD_CTL_STRM(s)		(((s)->stream_tag << 20) & AZX_SD_CTL_STRM_MASK)
     18#define AZX_SD_BDLPL_BDLPLBA_MASK	GENMASK(31, 7)
     19#define AZX_SD_BDLPL_BDLPLBA(lb)	((lb) & AZX_SD_BDLPL_BDLPLBA_MASK)
     20
     21/* Software Position Based FIFO Capability Registers */
     22#define AZX_CL_SPBFCS			0x20
     23#define AZX_REG_CL_SPBFCTL		(AZX_CL_SPBFCS + 0x4)
     24#define AZX_REG_CL_SD_SPIB		(AZX_CL_SPBFCS + 0x8)
     25
     26#define AVS_CL_OP_INTERVAL_US		3
     27#define AVS_CL_OP_TIMEOUT_US		300
     28#define AVS_CL_IOC_TIMEOUT_MS		300
     29#define AVS_CL_STREAM_INDEX		0
     30
     31struct hda_cldma {
     32	struct device *dev;
     33	struct hdac_bus *bus;
     34	void __iomem *dsp_ba;
     35
     36	unsigned int buffer_size;
     37	unsigned int num_periods;
     38	unsigned int stream_tag;
     39	void __iomem *sd_addr;
     40
     41	struct snd_dma_buffer dmab_data;
     42	struct snd_dma_buffer dmab_bdl;
     43	struct delayed_work memcpy_work;
     44	struct completion completion;
     45
     46	/* runtime */
     47	void *position;
     48	unsigned int remaining;
     49	unsigned int sd_status;
     50};
     51
     52static void cldma_memcpy_work(struct work_struct *work);
     53
     54struct hda_cldma code_loader = {
     55	.stream_tag	= AVS_CL_STREAM_INDEX + 1,
     56	.memcpy_work	= __DELAYED_WORK_INITIALIZER(code_loader.memcpy_work, cldma_memcpy_work, 0),
     57	.completion	= COMPLETION_INITIALIZER(code_loader.completion),
     58};
     59
     60void hda_cldma_fill(struct hda_cldma *cl)
     61{
     62	unsigned int size, offset;
     63
     64	if (cl->remaining > cl->buffer_size)
     65		size = cl->buffer_size;
     66	else
     67		size = cl->remaining;
     68
     69	offset = snd_hdac_stream_readl(cl, CL_SD_SPIB);
     70	if (offset + size > cl->buffer_size) {
     71		unsigned int ss;
     72
     73		ss = cl->buffer_size - offset;
     74		memcpy(cl->dmab_data.area + offset, cl->position, ss);
     75		offset = 0;
     76		size -= ss;
     77		cl->position += ss;
     78		cl->remaining -= ss;
     79	}
     80
     81	memcpy(cl->dmab_data.area + offset, cl->position, size);
     82	cl->position += size;
     83	cl->remaining -= size;
     84
     85	snd_hdac_stream_writel(cl, CL_SD_SPIB, offset + size);
     86}
     87
     88static void cldma_memcpy_work(struct work_struct *work)
     89{
     90	struct hda_cldma *cl = container_of(work, struct hda_cldma, memcpy_work.work);
     91	int ret;
     92
     93	ret = hda_cldma_start(cl);
     94	if (ret < 0) {
     95		dev_err(cl->dev, "cldma set RUN failed: %d\n", ret);
     96		return;
     97	}
     98
     99	while (true) {
    100		ret = wait_for_completion_timeout(&cl->completion,
    101						  msecs_to_jiffies(AVS_CL_IOC_TIMEOUT_MS));
    102		if (!ret) {
    103			dev_err(cl->dev, "cldma IOC timeout\n");
    104			break;
    105		}
    106
    107		if (!(cl->sd_status & SD_INT_COMPLETE)) {
    108			dev_err(cl->dev, "cldma transfer error, SD status: 0x%08x\n",
    109				cl->sd_status);
    110			break;
    111		}
    112
    113		if (!cl->remaining)
    114			break;
    115
    116		reinit_completion(&cl->completion);
    117		hda_cldma_fill(cl);
    118		/* enable CLDMA interrupt */
    119		snd_hdac_adsp_updatel(cl, AVS_ADSP_REG_ADSPIC, AVS_ADSP_ADSPIC_CLDMA,
    120				      AVS_ADSP_ADSPIC_CLDMA);
    121	}
    122}
    123
    124void hda_cldma_transfer(struct hda_cldma *cl, unsigned long start_delay)
    125{
    126	if (!cl->remaining)
    127		return;
    128
    129	reinit_completion(&cl->completion);
    130	/* fill buffer with the first chunk before scheduling run */
    131	hda_cldma_fill(cl);
    132
    133	schedule_delayed_work(&cl->memcpy_work, start_delay);
    134}
    135
    136int hda_cldma_start(struct hda_cldma *cl)
    137{
    138	unsigned int reg;
    139
    140	/* enable interrupts */
    141	snd_hdac_adsp_updatel(cl, AVS_ADSP_REG_ADSPIC, AVS_ADSP_ADSPIC_CLDMA,
    142			      AVS_ADSP_ADSPIC_CLDMA);
    143	snd_hdac_stream_updateb(cl, SD_CTL, SD_INT_MASK | SD_CTL_DMA_START,
    144				SD_INT_MASK | SD_CTL_DMA_START);
    145
    146	/* await DMA engine start */
    147	return snd_hdac_stream_readb_poll(cl, SD_CTL, reg, reg & SD_CTL_DMA_START,
    148					  AVS_CL_OP_INTERVAL_US, AVS_CL_OP_TIMEOUT_US);
    149}
    150
    151int hda_cldma_stop(struct hda_cldma *cl)
    152{
    153	unsigned int reg;
    154	int ret;
    155
    156	/* disable interrupts */
    157	snd_hdac_adsp_updatel(cl, AVS_ADSP_REG_ADSPIC, AVS_ADSP_ADSPIC_CLDMA, 0);
    158	snd_hdac_stream_updateb(cl, SD_CTL, SD_INT_MASK | SD_CTL_DMA_START, 0);
    159
    160	/* await DMA engine stop */
    161	ret = snd_hdac_stream_readb_poll(cl, SD_CTL, reg, !(reg & SD_CTL_DMA_START),
    162					 AVS_CL_OP_INTERVAL_US, AVS_CL_OP_TIMEOUT_US);
    163	cancel_delayed_work_sync(&cl->memcpy_work);
    164
    165	return ret;
    166}
    167
    168int hda_cldma_reset(struct hda_cldma *cl)
    169{
    170	unsigned int reg;
    171	int ret;
    172
    173	ret = hda_cldma_stop(cl);
    174	if (ret < 0) {
    175		dev_err(cl->dev, "cldma stop failed: %d\n", ret);
    176		return ret;
    177	}
    178
    179	snd_hdac_stream_updateb(cl, SD_CTL, 1, 1);
    180	ret = snd_hdac_stream_readb_poll(cl, SD_CTL, reg, (reg & 1), AVS_CL_OP_INTERVAL_US,
    181					 AVS_CL_OP_TIMEOUT_US);
    182	if (ret < 0) {
    183		dev_err(cl->dev, "cldma set SRST failed: %d\n", ret);
    184		return ret;
    185	}
    186
    187	snd_hdac_stream_updateb(cl, SD_CTL, 1, 0);
    188	ret = snd_hdac_stream_readb_poll(cl, SD_CTL, reg, !(reg & 1), AVS_CL_OP_INTERVAL_US,
    189					 AVS_CL_OP_TIMEOUT_US);
    190	if (ret < 0) {
    191		dev_err(cl->dev, "cldma unset SRST failed: %d\n", ret);
    192		return ret;
    193	}
    194
    195	return 0;
    196}
    197
    198void hda_cldma_set_data(struct hda_cldma *cl, void *data, unsigned int size)
    199{
    200	/* setup runtime */
    201	cl->position = data;
    202	cl->remaining = size;
    203}
    204
    205static void cldma_setup_bdle(struct hda_cldma *cl, u32 bdle_size)
    206{
    207	struct snd_dma_buffer *dmab = &cl->dmab_data;
    208	__le32 *bdl = (__le32 *)cl->dmab_bdl.area;
    209	int remaining = cl->buffer_size;
    210	int offset = 0;
    211
    212	cl->num_periods = 0;
    213
    214	while (remaining > 0) {
    215		phys_addr_t addr;
    216		int chunk;
    217
    218		addr = snd_sgbuf_get_addr(dmab, offset);
    219		bdl[0] = cpu_to_le32(lower_32_bits(addr));
    220		bdl[1] = cpu_to_le32(upper_32_bits(addr));
    221		chunk = snd_sgbuf_get_chunk_size(dmab, offset, bdle_size);
    222		bdl[2] = cpu_to_le32(chunk);
    223
    224		remaining -= chunk;
    225		/* set IOC only for the last entry */
    226		bdl[3] = (remaining > 0) ? 0 : cpu_to_le32(0x01);
    227
    228		bdl += 4;
    229		offset += chunk;
    230		cl->num_periods++;
    231	}
    232}
    233
    234void hda_cldma_setup(struct hda_cldma *cl)
    235{
    236	dma_addr_t bdl_addr = cl->dmab_bdl.addr;
    237
    238	cldma_setup_bdle(cl, cl->buffer_size / 2);
    239
    240	snd_hdac_stream_writel(cl, SD_BDLPL, AZX_SD_BDLPL_BDLPLBA(lower_32_bits(bdl_addr)));
    241	snd_hdac_stream_writel(cl, SD_BDLPU, upper_32_bits(bdl_addr));
    242
    243	snd_hdac_stream_writel(cl, SD_CBL, cl->buffer_size);
    244	snd_hdac_stream_writeb(cl, SD_LVI, cl->num_periods - 1);
    245
    246	snd_hdac_stream_updatel(cl, SD_CTL, AZX_SD_CTL_STRM_MASK, AZX_SD_CTL_STRM(cl));
    247	/* enable spib */
    248	snd_hdac_stream_writel(cl, CL_SPBFCTL, 1);
    249}
    250
    251static irqreturn_t cldma_irq_handler(int irq, void *dev_id)
    252{
    253	struct hda_cldma *cl = dev_id;
    254	u32 adspis;
    255
    256	adspis = snd_hdac_adsp_readl(cl, AVS_ADSP_REG_ADSPIS);
    257	if (adspis == UINT_MAX)
    258		return IRQ_NONE;
    259	if (!(adspis & AVS_ADSP_ADSPIS_CLDMA))
    260		return IRQ_NONE;
    261
    262	cl->sd_status = snd_hdac_stream_readb(cl, SD_STS);
    263	dev_warn(cl->dev, "%s sd_status: 0x%08x\n", __func__, cl->sd_status);
    264
    265	/* disable CLDMA interrupt */
    266	snd_hdac_adsp_updatel(cl, AVS_ADSP_REG_ADSPIC, AVS_ADSP_ADSPIC_CLDMA, 0);
    267
    268	complete(&cl->completion);
    269
    270	return IRQ_HANDLED;
    271}
    272
    273int hda_cldma_init(struct hda_cldma *cl, struct hdac_bus *bus, void __iomem *dsp_ba,
    274		   unsigned int buffer_size)
    275{
    276	struct pci_dev *pci = to_pci_dev(bus->dev);
    277	int ret;
    278
    279	ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV_SG, bus->dev, buffer_size, &cl->dmab_data);
    280	if (ret < 0)
    281		return ret;
    282
    283	ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, bus->dev, BDL_SIZE, &cl->dmab_bdl);
    284	if (ret < 0)
    285		goto alloc_err;
    286
    287	cl->dev = bus->dev;
    288	cl->bus = bus;
    289	cl->dsp_ba = dsp_ba;
    290	cl->buffer_size = buffer_size;
    291	cl->sd_addr = dsp_ba + AZX_CL_SD_BASE;
    292
    293	ret = pci_request_irq(pci, 0, cldma_irq_handler, NULL, cl, "CLDMA");
    294	if (ret < 0) {
    295		dev_err(cl->dev, "Failed to request CLDMA IRQ handler: %d\n", ret);
    296		goto req_err;
    297	}
    298
    299	return 0;
    300
    301req_err:
    302	snd_dma_free_pages(&cl->dmab_bdl);
    303alloc_err:
    304	snd_dma_free_pages(&cl->dmab_data);
    305
    306	return ret;
    307}
    308
    309void hda_cldma_free(struct hda_cldma *cl)
    310{
    311	struct pci_dev *pci = to_pci_dev(cl->dev);
    312
    313	pci_free_irq(pci, 0, cl);
    314	snd_dma_free_pages(&cl->dmab_data);
    315	snd_dma_free_pages(&cl->dmab_bdl);
    316}