xref: /openbmc/linux/drivers/dma/ptdma/ptdma-dev.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AMD Passthru DMA device driver
4  * -- Based on the CCP driver
5  *
6  * Copyright (C) 2016,2021 Advanced Micro Devices, Inc.
7  *
8  * Author: Sanjay R Mehta <sanju.mehta@amd.com>
9  * Author: Gary R Hook <gary.hook@amd.com>
10  */
11 
12 #include <linux/bitfield.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/debugfs.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/pci.h>
19 
20 #include "ptdma.h"
21 
22 /* Human-readable error strings */
23 static char *pt_error_codes[] = {
24 	"",
25 	"ERR 01: ILLEGAL_ENGINE",
26 	"ERR 03: ILLEGAL_FUNCTION_TYPE",
27 	"ERR 04: ILLEGAL_FUNCTION_MODE",
28 	"ERR 06: ILLEGAL_FUNCTION_SIZE",
29 	"ERR 08: ILLEGAL_FUNCTION_RSVD",
30 	"ERR 09: ILLEGAL_BUFFER_LENGTH",
31 	"ERR 10: VLSB_FAULT",
32 	"ERR 11: ILLEGAL_MEM_ADDR",
33 	"ERR 12: ILLEGAL_MEM_SEL",
34 	"ERR 13: ILLEGAL_CONTEXT_ID",
35 	"ERR 15: 0xF Reserved",
36 	"ERR 18: CMD_TIMEOUT",
37 	"ERR 19: IDMA0_AXI_SLVERR",
38 	"ERR 20: IDMA0_AXI_DECERR",
39 	"ERR 21: 0x15 Reserved",
40 	"ERR 22: IDMA1_AXI_SLAVE_FAULT",
41 	"ERR 23: IDMA1_AIXI_DECERR",
42 	"ERR 24: 0x18 Reserved",
43 	"ERR 27: 0x1B Reserved",
44 	"ERR 38: ODMA0_AXI_SLVERR",
45 	"ERR 39: ODMA0_AXI_DECERR",
46 	"ERR 40: 0x28 Reserved",
47 	"ERR 41: ODMA1_AXI_SLVERR",
48 	"ERR 42: ODMA1_AXI_DECERR",
49 	"ERR 43: LSB_PARITY_ERR",
50 };
51 
52 static void pt_log_error(struct pt_device *d, int e)
53 {
54 	dev_err(d->dev, "PTDMA error: %s (0x%x)\n", pt_error_codes[e], e);
55 }
56 
57 void pt_start_queue(struct pt_cmd_queue *cmd_q)
58 {
59 	/* Turn on the run bit */
60 	iowrite32(cmd_q->qcontrol | CMD_Q_RUN, cmd_q->reg_control);
61 }
62 
63 void pt_stop_queue(struct pt_cmd_queue *cmd_q)
64 {
65 	/* Turn off the run bit */
66 	iowrite32(cmd_q->qcontrol & ~CMD_Q_RUN, cmd_q->reg_control);
67 }
68 
69 static int pt_core_execute_cmd(struct ptdma_desc *desc, struct pt_cmd_queue *cmd_q)
70 {
71 	bool soc = FIELD_GET(DWORD0_SOC, desc->dw0);
72 	u8 *q_desc = (u8 *)&cmd_q->qbase[cmd_q->qidx];
73 	u32 tail;
74 
75 	if (soc) {
76 		desc->dw0 |= FIELD_PREP(DWORD0_IOC, desc->dw0);
77 		desc->dw0 &= ~DWORD0_SOC;
78 	}
79 	mutex_lock(&cmd_q->q_mutex);
80 
81 	/* Copy 32-byte command descriptor to hw queue. */
82 	memcpy(q_desc, desc, 32);
83 	cmd_q->qidx = (cmd_q->qidx + 1) % CMD_Q_LEN;
84 
85 	/* The data used by this command must be flushed to memory */
86 	wmb();
87 
88 	/* Write the new tail address back to the queue register */
89 	tail = lower_32_bits(cmd_q->qdma_tail + cmd_q->qidx * Q_DESC_SIZE);
90 	iowrite32(tail, cmd_q->reg_control + 0x0004);
91 
92 	/* Turn the queue back on using our cached control register */
93 	pt_start_queue(cmd_q);
94 	mutex_unlock(&cmd_q->q_mutex);
95 
96 	return 0;
97 }
98 
99 int pt_core_perform_passthru(struct pt_cmd_queue *cmd_q,
100 			     struct pt_passthru_engine *pt_engine)
101 {
102 	struct ptdma_desc desc;
103 	struct pt_device *pt = container_of(cmd_q, struct pt_device, cmd_q);
104 
105 	cmd_q->cmd_error = 0;
106 	cmd_q->total_pt_ops++;
107 	memset(&desc, 0, sizeof(desc));
108 	desc.dw0 = CMD_DESC_DW0_VAL;
109 	desc.length = pt_engine->src_len;
110 	desc.src_lo = lower_32_bits(pt_engine->src_dma);
111 	desc.dw3.src_hi = upper_32_bits(pt_engine->src_dma);
112 	desc.dst_lo = lower_32_bits(pt_engine->dst_dma);
113 	desc.dw5.dst_hi = upper_32_bits(pt_engine->dst_dma);
114 
115 	if (cmd_q->int_en)
116 		pt_core_enable_queue_interrupts(pt);
117 	else
118 		pt_core_disable_queue_interrupts(pt);
119 
120 	return pt_core_execute_cmd(&desc, cmd_q);
121 }
122 
123 static void pt_do_cmd_complete(unsigned long data)
124 {
125 	struct pt_tasklet_data *tdata = (struct pt_tasklet_data *)data;
126 	struct pt_cmd *cmd = tdata->cmd;
127 	struct pt_cmd_queue *cmd_q = &cmd->pt->cmd_q;
128 	u32 tail;
129 
130 	if (cmd_q->cmd_error) {
131 	       /*
132 		* Log the error and flush the queue by
133 		* moving the head pointer
134 		*/
135 		tail = lower_32_bits(cmd_q->qdma_tail + cmd_q->qidx * Q_DESC_SIZE);
136 		pt_log_error(cmd_q->pt, cmd_q->cmd_error);
137 		iowrite32(tail, cmd_q->reg_control + 0x0008);
138 	}
139 
140 	cmd->pt_cmd_callback(cmd->data, cmd->ret);
141 }
142 
143 void pt_check_status_trans(struct pt_device *pt, struct pt_cmd_queue *cmd_q)
144 {
145 	u32 status;
146 
147 	status = ioread32(cmd_q->reg_control + 0x0010);
148 	if (status) {
149 		cmd_q->int_status = status;
150 		cmd_q->q_status = ioread32(cmd_q->reg_control + 0x0100);
151 		cmd_q->q_int_status = ioread32(cmd_q->reg_control + 0x0104);
152 
153 		/* On error, only save the first error value */
154 		if ((status & INT_ERROR) && !cmd_q->cmd_error)
155 			cmd_q->cmd_error = CMD_Q_ERROR(cmd_q->q_status);
156 
157 		/* Acknowledge the completion */
158 		iowrite32(status, cmd_q->reg_control + 0x0010);
159 		pt_do_cmd_complete((ulong)&pt->tdata);
160 	}
161 }
162 
163 static irqreturn_t pt_core_irq_handler(int irq, void *data)
164 {
165 	struct pt_device *pt = data;
166 	struct pt_cmd_queue *cmd_q = &pt->cmd_q;
167 
168 	pt_core_disable_queue_interrupts(pt);
169 	pt->total_interrupts++;
170 	pt_check_status_trans(pt, cmd_q);
171 	pt_core_enable_queue_interrupts(pt);
172 	return IRQ_HANDLED;
173 }
174 
175 int pt_core_init(struct pt_device *pt)
176 {
177 	char dma_pool_name[MAX_DMAPOOL_NAME_LEN];
178 	struct pt_cmd_queue *cmd_q = &pt->cmd_q;
179 	u32 dma_addr_lo, dma_addr_hi;
180 	struct device *dev = pt->dev;
181 	struct dma_pool *dma_pool;
182 	int ret;
183 
184 	/* Allocate a dma pool for the queue */
185 	snprintf(dma_pool_name, sizeof(dma_pool_name), "%s_q", dev_name(pt->dev));
186 
187 	dma_pool = dma_pool_create(dma_pool_name, dev,
188 				   PT_DMAPOOL_MAX_SIZE,
189 				   PT_DMAPOOL_ALIGN, 0);
190 	if (!dma_pool)
191 		return -ENOMEM;
192 
193 	/* ptdma core initialisation */
194 	iowrite32(CMD_CONFIG_VHB_EN, pt->io_regs + CMD_CONFIG_OFFSET);
195 	iowrite32(CMD_QUEUE_PRIO, pt->io_regs + CMD_QUEUE_PRIO_OFFSET);
196 	iowrite32(CMD_TIMEOUT_DISABLE, pt->io_regs + CMD_TIMEOUT_OFFSET);
197 	iowrite32(CMD_CLK_GATE_CONFIG, pt->io_regs + CMD_CLK_GATE_CTL_OFFSET);
198 	iowrite32(CMD_CONFIG_REQID, pt->io_regs + CMD_REQID_CONFIG_OFFSET);
199 
200 	cmd_q->pt = pt;
201 	cmd_q->dma_pool = dma_pool;
202 	mutex_init(&cmd_q->q_mutex);
203 
204 	/* Page alignment satisfies our needs for N <= 128 */
205 	cmd_q->qsize = Q_SIZE(Q_DESC_SIZE);
206 	cmd_q->qbase = dma_alloc_coherent(dev, cmd_q->qsize,
207 					  &cmd_q->qbase_dma,
208 					  GFP_KERNEL);
209 	if (!cmd_q->qbase) {
210 		dev_err(dev, "unable to allocate command queue\n");
211 		ret = -ENOMEM;
212 		goto e_destroy_pool;
213 	}
214 
215 	cmd_q->qidx = 0;
216 
217 	/* Preset some register values */
218 	cmd_q->reg_control = pt->io_regs + CMD_Q_STATUS_INCR;
219 
220 	/* Turn off the queues and disable interrupts until ready */
221 	pt_core_disable_queue_interrupts(pt);
222 
223 	cmd_q->qcontrol = 0; /* Start with nothing */
224 	iowrite32(cmd_q->qcontrol, cmd_q->reg_control);
225 
226 	ioread32(cmd_q->reg_control + 0x0104);
227 	ioread32(cmd_q->reg_control + 0x0100);
228 
229 	/* Clear the interrupt status */
230 	iowrite32(SUPPORTED_INTERRUPTS, cmd_q->reg_control + 0x0010);
231 
232 	/* Request an irq */
233 	ret = request_irq(pt->pt_irq, pt_core_irq_handler, 0, dev_name(pt->dev), pt);
234 	if (ret) {
235 		dev_err(dev, "unable to allocate an IRQ\n");
236 		goto e_free_dma;
237 	}
238 
239 	/* Update the device registers with queue information. */
240 	cmd_q->qcontrol &= ~CMD_Q_SIZE;
241 	cmd_q->qcontrol |= FIELD_PREP(CMD_Q_SIZE, QUEUE_SIZE_VAL);
242 
243 	cmd_q->qdma_tail = cmd_q->qbase_dma;
244 	dma_addr_lo = lower_32_bits(cmd_q->qdma_tail);
245 	iowrite32((u32)dma_addr_lo, cmd_q->reg_control + 0x0004);
246 	iowrite32((u32)dma_addr_lo, cmd_q->reg_control + 0x0008);
247 
248 	dma_addr_hi = upper_32_bits(cmd_q->qdma_tail);
249 	cmd_q->qcontrol |= (dma_addr_hi << 16);
250 	iowrite32(cmd_q->qcontrol, cmd_q->reg_control);
251 
252 	pt_core_enable_queue_interrupts(pt);
253 
254 	/* Register the DMA engine support */
255 	ret = pt_dmaengine_register(pt);
256 	if (ret)
257 		goto e_free_irq;
258 
259 	/* Set up debugfs entries */
260 	ptdma_debugfs_setup(pt);
261 
262 	return 0;
263 
264 e_free_irq:
265 	free_irq(pt->pt_irq, pt);
266 
267 e_free_dma:
268 	dma_free_coherent(dev, cmd_q->qsize, cmd_q->qbase, cmd_q->qbase_dma);
269 
270 e_destroy_pool:
271 	dma_pool_destroy(pt->cmd_q.dma_pool);
272 
273 	return ret;
274 }
275 
276 void pt_core_destroy(struct pt_device *pt)
277 {
278 	struct device *dev = pt->dev;
279 	struct pt_cmd_queue *cmd_q = &pt->cmd_q;
280 	struct pt_cmd *cmd;
281 
282 	/* Unregister the DMA engine */
283 	pt_dmaengine_unregister(pt);
284 
285 	/* Disable and clear interrupts */
286 	pt_core_disable_queue_interrupts(pt);
287 
288 	/* Turn off the run bit */
289 	pt_stop_queue(cmd_q);
290 
291 	/* Clear the interrupt status */
292 	iowrite32(SUPPORTED_INTERRUPTS, cmd_q->reg_control + 0x0010);
293 	ioread32(cmd_q->reg_control + 0x0104);
294 	ioread32(cmd_q->reg_control + 0x0100);
295 
296 	free_irq(pt->pt_irq, pt);
297 
298 	dma_free_coherent(dev, cmd_q->qsize, cmd_q->qbase,
299 			  cmd_q->qbase_dma);
300 
301 	/* Flush the cmd queue */
302 	while (!list_empty(&pt->cmd)) {
303 		/* Invoke the callback directly with an error code */
304 		cmd = list_first_entry(&pt->cmd, struct pt_cmd, entry);
305 		list_del(&cmd->entry);
306 		cmd->pt_cmd_callback(cmd->data, -ENODEV);
307 	}
308 }
309