xref: /openbmc/linux/drivers/sbus/char/oradax.c (revision 3dc4b6fb)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
4  */
5 
6 /*
7  * Oracle Data Analytics Accelerator (DAX)
8  *
9  * DAX is a coprocessor which resides on the SPARC M7 (DAX1) and M8
10  * (DAX2) processor chips, and has direct access to the CPU's L3
11  * caches as well as physical memory. It can perform several
12  * operations on data streams with various input and output formats.
13  * The driver provides a transport mechanism only and has limited
14  * knowledge of the various opcodes and data formats. A user space
15  * library provides high level services and translates these into low
16  * level commands which are then passed into the driver and
17  * subsequently the hypervisor and the coprocessor.  The library is
18  * the recommended way for applications to use the coprocessor, and
19  * the driver interface is not intended for general use.
20  *
21  * See Documentation/sparc/oradax/oracle-dax.rst for more details.
22  */
23 
24 #include <linux/uaccess.h>
25 #include <linux/module.h>
26 #include <linux/delay.h>
27 #include <linux/cdev.h>
28 #include <linux/slab.h>
29 #include <linux/mm.h>
30 
31 #include <asm/hypervisor.h>
32 #include <asm/mdesc.h>
33 #include <asm/oradax.h>
34 
35 MODULE_LICENSE("GPL");
36 MODULE_DESCRIPTION("Driver for Oracle Data Analytics Accelerator");
37 
38 #define	DAX_DBG_FLG_BASIC	0x01
39 #define	DAX_DBG_FLG_STAT	0x02
40 #define	DAX_DBG_FLG_INFO	0x04
41 #define	DAX_DBG_FLG_ALL		0xff
42 
43 #define	dax_err(fmt, ...)      pr_err("%s: " fmt "\n", __func__, ##__VA_ARGS__)
44 #define	dax_info(fmt, ...)     pr_info("%s: " fmt "\n", __func__, ##__VA_ARGS__)
45 
46 #define	dax_dbg(fmt, ...)	do {					\
47 					if (dax_debug & DAX_DBG_FLG_BASIC)\
48 						dax_info(fmt, ##__VA_ARGS__); \
49 				} while (0)
50 #define	dax_stat_dbg(fmt, ...)	do {					\
51 					if (dax_debug & DAX_DBG_FLG_STAT) \
52 						dax_info(fmt, ##__VA_ARGS__); \
53 				} while (0)
54 #define	dax_info_dbg(fmt, ...)	do { \
55 					if (dax_debug & DAX_DBG_FLG_INFO) \
56 						dax_info(fmt, ##__VA_ARGS__); \
57 				} while (0)
58 
59 #define	DAX1_MINOR		1
60 #define	DAX1_MAJOR		1
61 #define	DAX2_MINOR		0
62 #define	DAX2_MAJOR		2
63 
64 #define	DAX1_STR    "ORCL,sun4v-dax"
65 #define	DAX2_STR    "ORCL,sun4v-dax2"
66 
67 #define	DAX_CA_ELEMS		(DAX_MMAP_LEN / sizeof(struct dax_cca))
68 
69 #define	DAX_CCB_USEC		100
70 #define	DAX_CCB_RETRIES		10000
71 
72 /* stream types */
73 enum {
74 	OUT,
75 	PRI,
76 	SEC,
77 	TBL,
78 	NUM_STREAM_TYPES
79 };
80 
81 /* completion status */
82 #define	CCA_STAT_NOT_COMPLETED	0
83 #define	CCA_STAT_COMPLETED	1
84 #define	CCA_STAT_FAILED		2
85 #define	CCA_STAT_KILLED		3
86 #define	CCA_STAT_NOT_RUN	4
87 #define	CCA_STAT_PIPE_OUT	5
88 #define	CCA_STAT_PIPE_SRC	6
89 #define	CCA_STAT_PIPE_DST	7
90 
91 /* completion err */
92 #define	CCA_ERR_SUCCESS		0x0	/* no error */
93 #define	CCA_ERR_OVERFLOW	0x1	/* buffer overflow */
94 #define	CCA_ERR_DECODE		0x2	/* CCB decode error */
95 #define	CCA_ERR_PAGE_OVERFLOW	0x3	/* page overflow */
96 #define	CCA_ERR_KILLED		0x7	/* command was killed */
97 #define	CCA_ERR_TIMEOUT		0x8	/* Timeout */
98 #define	CCA_ERR_ADI		0x9	/* ADI error */
99 #define	CCA_ERR_DATA_FMT	0xA	/* data format error */
100 #define	CCA_ERR_OTHER_NO_RETRY	0xE	/* Other error, do not retry */
101 #define	CCA_ERR_OTHER_RETRY	0xF	/* Other error, retry */
102 #define	CCA_ERR_PARTIAL_SYMBOL	0x80	/* QP partial symbol warning */
103 
104 /* CCB address types */
105 #define	DAX_ADDR_TYPE_NONE	0
106 #define	DAX_ADDR_TYPE_VA_ALT	1	/* secondary context */
107 #define	DAX_ADDR_TYPE_RA	2	/* real address */
108 #define	DAX_ADDR_TYPE_VA	3	/* virtual address */
109 
110 /* dax_header_t opcode */
111 #define	DAX_OP_SYNC_NOP		0x0
112 #define	DAX_OP_EXTRACT		0x1
113 #define	DAX_OP_SCAN_VALUE	0x2
114 #define	DAX_OP_SCAN_RANGE	0x3
115 #define	DAX_OP_TRANSLATE	0x4
116 #define	DAX_OP_SELECT		0x5
117 #define	DAX_OP_INVERT		0x10	/* OR with translate, scan opcodes */
118 
119 struct dax_header {
120 	u32 ccb_version:4;	/* 31:28 CCB Version */
121 				/* 27:24 Sync Flags */
122 	u32 pipe:1;		/* Pipeline */
123 	u32 longccb:1;		/* Longccb. Set for scan with lu2, lu3, lu4. */
124 	u32 cond:1;		/* Conditional */
125 	u32 serial:1;		/* Serial */
126 	u32 opcode:8;		/* 23:16 Opcode */
127 				/* 15:0 Address Type. */
128 	u32 reserved:3;		/* 15:13 reserved */
129 	u32 table_addr_type:2;	/* 12:11 Huffman Table Address Type */
130 	u32 out_addr_type:3;	/* 10:8 Destination Address Type */
131 	u32 sec_addr_type:3;	/* 7:5 Secondary Source Address Type */
132 	u32 pri_addr_type:3;	/* 4:2 Primary Source Address Type */
133 	u32 cca_addr_type:2;	/* 1:0 Completion Address Type */
134 };
135 
136 struct dax_control {
137 	u32 pri_fmt:4;		/* 31:28 Primary Input Format */
138 	u32 pri_elem_size:5;	/* 27:23 Primary Input Element Size(less1) */
139 	u32 pri_offset:3;	/* 22:20 Primary Input Starting Offset */
140 	u32 sec_encoding:1;	/* 19    Secondary Input Encoding */
141 				/*	 (must be 0 for Select) */
142 	u32 sec_offset:3;	/* 18:16 Secondary Input Starting Offset */
143 	u32 sec_elem_size:2;	/* 15:14 Secondary Input Element Size */
144 				/*	 (must be 0 for Select) */
145 	u32 out_fmt:2;		/* 13:12 Output Format */
146 	u32 out_elem_size:2;	/* 11:10 Output Element Size */
147 	u32 misc:10;		/* 9:0 Opcode specific info */
148 };
149 
150 struct dax_data_access {
151 	u64 flow_ctrl:2;	/* 63:62 Flow Control Type */
152 	u64 pipe_target:2;	/* 61:60 Pipeline Target */
153 	u64 out_buf_size:20;	/* 59:40 Output Buffer Size */
154 				/*	 (cachelines less 1) */
155 	u64 unused1:8;		/* 39:32 Reserved, Set to 0 */
156 	u64 out_alloc:5;	/* 31:27 Output Allocation */
157 	u64 unused2:1;		/* 26	 Reserved */
158 	u64 pri_len_fmt:2;	/* 25:24 Input Length Format */
159 	u64 pri_len:24;		/* 23:0  Input Element/Byte/Bit Count */
160 				/*	 (less 1) */
161 };
162 
163 struct dax_ccb {
164 	struct dax_header hdr;	/* CCB Header */
165 	struct dax_control ctrl;/* Control Word */
166 	void *ca;		/* Completion Address */
167 	void *pri;		/* Primary Input Address */
168 	struct dax_data_access dac; /* Data Access Control */
169 	void *sec;		/* Secondary Input Address */
170 	u64 dword5;		/* depends on opcode */
171 	void *out;		/* Output Address */
172 	void *tbl;		/* Table Address or bitmap */
173 };
174 
175 struct dax_cca {
176 	u8	status;		/* user may mwait on this address */
177 	u8	err;		/* user visible error notification */
178 	u8	rsvd[2];	/* reserved */
179 	u32	n_remaining;	/* for QP partial symbol warning */
180 	u32	output_sz;	/* output in bytes */
181 	u32	rsvd2;		/* reserved */
182 	u64	run_cycles;	/* run time in OCND2 cycles */
183 	u64	run_stats;	/* nothing reported in version 1.0 */
184 	u32	n_processed;	/* number input elements */
185 	u32	rsvd3[5];	/* reserved */
186 	u64	retval;		/* command return value */
187 	u64	rsvd4[8];	/* reserved */
188 };
189 
190 /* per thread CCB context */
191 struct dax_ctx {
192 	struct dax_ccb		*ccb_buf;
193 	u64			ccb_buf_ra;	/* cached RA of ccb_buf  */
194 	struct dax_cca		*ca_buf;
195 	u64			ca_buf_ra;	/* cached RA of ca_buf   */
196 	struct page		*pages[DAX_CA_ELEMS][NUM_STREAM_TYPES];
197 						/* array of locked pages */
198 	struct task_struct	*owner;		/* thread that owns ctx  */
199 	struct task_struct	*client;	/* requesting thread     */
200 	union ccb_result	result;
201 	u32			ccb_count;
202 	u32			fail_count;
203 };
204 
205 /* driver public entry points */
206 static int dax_open(struct inode *inode, struct file *file);
207 static ssize_t dax_read(struct file *filp, char __user *buf,
208 			size_t count, loff_t *ppos);
209 static ssize_t dax_write(struct file *filp, const char __user *buf,
210 			 size_t count, loff_t *ppos);
211 static int dax_devmap(struct file *f, struct vm_area_struct *vma);
212 static int dax_close(struct inode *i, struct file *f);
213 
214 static const struct file_operations dax_fops = {
215 	.owner	=	THIS_MODULE,
216 	.open	=	dax_open,
217 	.read	=	dax_read,
218 	.write	=	dax_write,
219 	.mmap	=	dax_devmap,
220 	.release =	dax_close,
221 };
222 
223 static int dax_ccb_exec(struct dax_ctx *ctx, const char __user *buf,
224 			size_t count, loff_t *ppos);
225 static int dax_ccb_info(u64 ca, struct ccb_info_result *info);
226 static int dax_ccb_kill(u64 ca, u16 *kill_res);
227 
228 static struct cdev c_dev;
229 static struct class *cl;
230 static dev_t first;
231 
232 static int max_ccb_version;
233 static int dax_debug;
234 module_param(dax_debug, int, 0644);
235 MODULE_PARM_DESC(dax_debug, "Debug flags");
236 
237 static int __init dax_attach(void)
238 {
239 	unsigned long dummy, hv_rv, major, minor, minor_requested, max_ccbs;
240 	struct mdesc_handle *hp = mdesc_grab();
241 	char *prop, *dax_name;
242 	bool found = false;
243 	int len, ret = 0;
244 	u64 pn;
245 
246 	if (hp == NULL) {
247 		dax_err("Unable to grab mdesc");
248 		return -ENODEV;
249 	}
250 
251 	mdesc_for_each_node_by_name(hp, pn, "virtual-device") {
252 		prop = (char *)mdesc_get_property(hp, pn, "name", &len);
253 		if (prop == NULL)
254 			continue;
255 		if (strncmp(prop, "dax", strlen("dax")))
256 			continue;
257 		dax_dbg("Found node 0x%llx = %s", pn, prop);
258 
259 		prop = (char *)mdesc_get_property(hp, pn, "compatible", &len);
260 		if (prop == NULL)
261 			continue;
262 		dax_dbg("Found node 0x%llx = %s", pn, prop);
263 		found = true;
264 		break;
265 	}
266 
267 	if (!found) {
268 		dax_err("No DAX device found");
269 		ret = -ENODEV;
270 		goto done;
271 	}
272 
273 	if (strncmp(prop, DAX2_STR, strlen(DAX2_STR)) == 0) {
274 		dax_name = DAX_NAME "2";
275 		major = DAX2_MAJOR;
276 		minor_requested = DAX2_MINOR;
277 		max_ccb_version = 1;
278 		dax_dbg("MD indicates DAX2 coprocessor");
279 	} else if (strncmp(prop, DAX1_STR, strlen(DAX1_STR)) == 0) {
280 		dax_name = DAX_NAME "1";
281 		major = DAX1_MAJOR;
282 		minor_requested = DAX1_MINOR;
283 		max_ccb_version = 0;
284 		dax_dbg("MD indicates DAX1 coprocessor");
285 	} else {
286 		dax_err("Unknown dax type: %s", prop);
287 		ret = -ENODEV;
288 		goto done;
289 	}
290 
291 	minor = minor_requested;
292 	dax_dbg("Registering DAX HV api with major %ld minor %ld", major,
293 		minor);
294 	if (sun4v_hvapi_register(HV_GRP_DAX, major, &minor)) {
295 		dax_err("hvapi_register failed");
296 		ret = -ENODEV;
297 		goto done;
298 	} else {
299 		dax_dbg("Max minor supported by HV = %ld (major %ld)", minor,
300 			major);
301 		minor = min(minor, minor_requested);
302 		dax_dbg("registered DAX major %ld minor %ld", major, minor);
303 	}
304 
305 	/* submit a zero length ccb array to query coprocessor queue size */
306 	hv_rv = sun4v_ccb_submit(0, 0, HV_CCB_QUERY_CMD, 0, &max_ccbs, &dummy);
307 	if (hv_rv != 0) {
308 		dax_err("get_hwqueue_size failed with status=%ld and max_ccbs=%ld",
309 			hv_rv, max_ccbs);
310 		ret = -ENODEV;
311 		goto done;
312 	}
313 
314 	if (max_ccbs != DAX_MAX_CCBS) {
315 		dax_err("HV reports unsupported max_ccbs=%ld", max_ccbs);
316 		ret = -ENODEV;
317 		goto done;
318 	}
319 
320 	if (alloc_chrdev_region(&first, 0, 1, DAX_NAME) < 0) {
321 		dax_err("alloc_chrdev_region failed");
322 		ret = -ENXIO;
323 		goto done;
324 	}
325 
326 	cl = class_create(THIS_MODULE, DAX_NAME);
327 	if (IS_ERR(cl)) {
328 		dax_err("class_create failed");
329 		ret = PTR_ERR(cl);
330 		goto class_error;
331 	}
332 
333 	if (device_create(cl, NULL, first, NULL, dax_name) == NULL) {
334 		dax_err("device_create failed");
335 		ret = -ENXIO;
336 		goto device_error;
337 	}
338 
339 	cdev_init(&c_dev, &dax_fops);
340 	if (cdev_add(&c_dev, first, 1) == -1) {
341 		dax_err("cdev_add failed");
342 		ret = -ENXIO;
343 		goto cdev_error;
344 	}
345 
346 	pr_info("Attached DAX module\n");
347 	goto done;
348 
349 cdev_error:
350 	device_destroy(cl, first);
351 device_error:
352 	class_destroy(cl);
353 class_error:
354 	unregister_chrdev_region(first, 1);
355 done:
356 	mdesc_release(hp);
357 	return ret;
358 }
359 module_init(dax_attach);
360 
361 static void __exit dax_detach(void)
362 {
363 	pr_info("Cleaning up DAX module\n");
364 	cdev_del(&c_dev);
365 	device_destroy(cl, first);
366 	class_destroy(cl);
367 	unregister_chrdev_region(first, 1);
368 }
369 module_exit(dax_detach);
370 
371 /* map completion area */
372 static int dax_devmap(struct file *f, struct vm_area_struct *vma)
373 {
374 	struct dax_ctx *ctx = (struct dax_ctx *)f->private_data;
375 	size_t len = vma->vm_end - vma->vm_start;
376 
377 	dax_dbg("len=0x%lx, flags=0x%lx", len, vma->vm_flags);
378 
379 	if (ctx->owner != current) {
380 		dax_dbg("devmap called from wrong thread");
381 		return -EINVAL;
382 	}
383 
384 	if (len != DAX_MMAP_LEN) {
385 		dax_dbg("len(%lu) != DAX_MMAP_LEN(%d)", len, DAX_MMAP_LEN);
386 		return -EINVAL;
387 	}
388 
389 	/* completion area is mapped read-only for user */
390 	if (vma->vm_flags & VM_WRITE)
391 		return -EPERM;
392 	vma->vm_flags &= ~VM_MAYWRITE;
393 
394 	if (remap_pfn_range(vma, vma->vm_start, ctx->ca_buf_ra >> PAGE_SHIFT,
395 			    len, vma->vm_page_prot))
396 		return -EAGAIN;
397 
398 	dax_dbg("mmapped completion area at uva 0x%lx", vma->vm_start);
399 	return 0;
400 }
401 
402 /* Unlock user pages. Called during dequeue or device close */
403 static void dax_unlock_pages(struct dax_ctx *ctx, int ccb_index, int nelem)
404 {
405 	int i, j;
406 
407 	for (i = ccb_index; i < ccb_index + nelem; i++) {
408 		for (j = 0; j < NUM_STREAM_TYPES; j++) {
409 			struct page *p = ctx->pages[i][j];
410 
411 			if (p) {
412 				dax_dbg("freeing page %p", p);
413 				if (j == OUT)
414 					set_page_dirty(p);
415 				put_page(p);
416 				ctx->pages[i][j] = NULL;
417 			}
418 		}
419 	}
420 }
421 
422 static int dax_lock_page(void *va, struct page **p)
423 {
424 	int ret;
425 
426 	dax_dbg("uva %p", va);
427 
428 	ret = get_user_pages_fast((unsigned long)va, 1, FOLL_WRITE, p);
429 	if (ret == 1) {
430 		dax_dbg("locked page %p, for VA %p", *p, va);
431 		return 0;
432 	}
433 
434 	dax_dbg("get_user_pages failed, va=%p, ret=%d", va, ret);
435 	return -1;
436 }
437 
438 static int dax_lock_pages(struct dax_ctx *ctx, int idx,
439 			  int nelem, u64 *err_va)
440 {
441 	int i;
442 
443 	for (i = 0; i < nelem; i++) {
444 		struct dax_ccb *ccbp = &ctx->ccb_buf[i];
445 
446 		/*
447 		 * For each address in the CCB whose type is virtual,
448 		 * lock the page and change the type to virtual alternate
449 		 * context. On error, return the offending address in
450 		 * err_va.
451 		 */
452 		if (ccbp->hdr.out_addr_type == DAX_ADDR_TYPE_VA) {
453 			dax_dbg("output");
454 			if (dax_lock_page(ccbp->out,
455 					  &ctx->pages[i + idx][OUT]) != 0) {
456 				*err_va = (u64)ccbp->out;
457 				goto error;
458 			}
459 			ccbp->hdr.out_addr_type = DAX_ADDR_TYPE_VA_ALT;
460 		}
461 
462 		if (ccbp->hdr.pri_addr_type == DAX_ADDR_TYPE_VA) {
463 			dax_dbg("input");
464 			if (dax_lock_page(ccbp->pri,
465 					  &ctx->pages[i + idx][PRI]) != 0) {
466 				*err_va = (u64)ccbp->pri;
467 				goto error;
468 			}
469 			ccbp->hdr.pri_addr_type = DAX_ADDR_TYPE_VA_ALT;
470 		}
471 
472 		if (ccbp->hdr.sec_addr_type == DAX_ADDR_TYPE_VA) {
473 			dax_dbg("sec input");
474 			if (dax_lock_page(ccbp->sec,
475 					  &ctx->pages[i + idx][SEC]) != 0) {
476 				*err_va = (u64)ccbp->sec;
477 				goto error;
478 			}
479 			ccbp->hdr.sec_addr_type = DAX_ADDR_TYPE_VA_ALT;
480 		}
481 
482 		if (ccbp->hdr.table_addr_type == DAX_ADDR_TYPE_VA) {
483 			dax_dbg("tbl");
484 			if (dax_lock_page(ccbp->tbl,
485 					  &ctx->pages[i + idx][TBL]) != 0) {
486 				*err_va = (u64)ccbp->tbl;
487 				goto error;
488 			}
489 			ccbp->hdr.table_addr_type = DAX_ADDR_TYPE_VA_ALT;
490 		}
491 
492 		/* skip over 2nd 64 bytes of long CCB */
493 		if (ccbp->hdr.longccb)
494 			i++;
495 	}
496 	return DAX_SUBMIT_OK;
497 
498 error:
499 	dax_unlock_pages(ctx, idx, nelem);
500 	return DAX_SUBMIT_ERR_NOACCESS;
501 }
502 
503 static void dax_ccb_wait(struct dax_ctx *ctx, int idx)
504 {
505 	int ret, nretries;
506 	u16 kill_res;
507 
508 	dax_dbg("idx=%d", idx);
509 
510 	for (nretries = 0; nretries < DAX_CCB_RETRIES; nretries++) {
511 		if (ctx->ca_buf[idx].status == CCA_STAT_NOT_COMPLETED)
512 			udelay(DAX_CCB_USEC);
513 		else
514 			return;
515 	}
516 	dax_dbg("ctx (%p): CCB[%d] timed out, wait usec=%d, retries=%d. Killing ccb",
517 		(void *)ctx, idx, DAX_CCB_USEC, DAX_CCB_RETRIES);
518 
519 	ret = dax_ccb_kill(ctx->ca_buf_ra + idx * sizeof(struct dax_cca),
520 			   &kill_res);
521 	dax_dbg("Kill CCB[%d] %s", idx, ret ? "failed" : "succeeded");
522 }
523 
524 static int dax_close(struct inode *ino, struct file *f)
525 {
526 	struct dax_ctx *ctx = (struct dax_ctx *)f->private_data;
527 	int i;
528 
529 	f->private_data = NULL;
530 
531 	for (i = 0; i < DAX_CA_ELEMS; i++) {
532 		if (ctx->ca_buf[i].status == CCA_STAT_NOT_COMPLETED) {
533 			dax_dbg("CCB[%d] not completed", i);
534 			dax_ccb_wait(ctx, i);
535 		}
536 		dax_unlock_pages(ctx, i, 1);
537 	}
538 
539 	kfree(ctx->ccb_buf);
540 	kfree(ctx->ca_buf);
541 	dax_stat_dbg("CCBs: %d good, %d bad", ctx->ccb_count, ctx->fail_count);
542 	kfree(ctx);
543 
544 	return 0;
545 }
546 
547 static ssize_t dax_read(struct file *f, char __user *buf,
548 			size_t count, loff_t *ppos)
549 {
550 	struct dax_ctx *ctx = f->private_data;
551 
552 	if (ctx->client != current)
553 		return -EUSERS;
554 
555 	ctx->client = NULL;
556 
557 	if (count != sizeof(union ccb_result))
558 		return -EINVAL;
559 	if (copy_to_user(buf, &ctx->result, sizeof(union ccb_result)))
560 		return -EFAULT;
561 	return count;
562 }
563 
564 static ssize_t dax_write(struct file *f, const char __user *buf,
565 			 size_t count, loff_t *ppos)
566 {
567 	struct dax_ctx *ctx = f->private_data;
568 	struct dax_command hdr;
569 	unsigned long ca;
570 	int i, idx, ret;
571 
572 	if (ctx->client != NULL)
573 		return -EINVAL;
574 
575 	if (count == 0 || count > DAX_MAX_CCBS * sizeof(struct dax_ccb))
576 		return -EINVAL;
577 
578 	if (count % sizeof(struct dax_ccb) == 0)
579 		return dax_ccb_exec(ctx, buf, count, ppos); /* CCB EXEC */
580 
581 	if (count != sizeof(struct dax_command))
582 		return -EINVAL;
583 
584 	/* immediate command */
585 	if (ctx->owner != current)
586 		return -EUSERS;
587 
588 	if (copy_from_user(&hdr, buf, sizeof(hdr)))
589 		return -EFAULT;
590 
591 	ca = ctx->ca_buf_ra + hdr.ca_offset;
592 
593 	switch (hdr.command) {
594 	case CCB_KILL:
595 		if (hdr.ca_offset >= DAX_MMAP_LEN) {
596 			dax_dbg("invalid ca_offset (%d) >= ca_buflen (%d)",
597 				hdr.ca_offset, DAX_MMAP_LEN);
598 			return -EINVAL;
599 		}
600 
601 		ret = dax_ccb_kill(ca, &ctx->result.kill.action);
602 		if (ret != 0) {
603 			dax_dbg("dax_ccb_kill failed (ret=%d)", ret);
604 			return ret;
605 		}
606 
607 		dax_info_dbg("killed (ca_offset %d)", hdr.ca_offset);
608 		idx = hdr.ca_offset / sizeof(struct dax_cca);
609 		ctx->ca_buf[idx].status = CCA_STAT_KILLED;
610 		ctx->ca_buf[idx].err = CCA_ERR_KILLED;
611 		ctx->client = current;
612 		return count;
613 
614 	case CCB_INFO:
615 		if (hdr.ca_offset >= DAX_MMAP_LEN) {
616 			dax_dbg("invalid ca_offset (%d) >= ca_buflen (%d)",
617 				hdr.ca_offset, DAX_MMAP_LEN);
618 			return -EINVAL;
619 		}
620 
621 		ret = dax_ccb_info(ca, &ctx->result.info);
622 		if (ret != 0) {
623 			dax_dbg("dax_ccb_info failed (ret=%d)", ret);
624 			return ret;
625 		}
626 
627 		dax_info_dbg("info succeeded on ca_offset %d", hdr.ca_offset);
628 		ctx->client = current;
629 		return count;
630 
631 	case CCB_DEQUEUE:
632 		for (i = 0; i < DAX_CA_ELEMS; i++) {
633 			if (ctx->ca_buf[i].status !=
634 			    CCA_STAT_NOT_COMPLETED)
635 				dax_unlock_pages(ctx, i, 1);
636 		}
637 		return count;
638 
639 	default:
640 		return -EINVAL;
641 	}
642 }
643 
644 static int dax_open(struct inode *inode, struct file *f)
645 {
646 	struct dax_ctx *ctx = NULL;
647 	int i;
648 
649 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
650 	if (ctx == NULL)
651 		goto done;
652 
653 	ctx->ccb_buf = kcalloc(DAX_MAX_CCBS, sizeof(struct dax_ccb),
654 			       GFP_KERNEL);
655 	if (ctx->ccb_buf == NULL)
656 		goto done;
657 
658 	ctx->ccb_buf_ra = virt_to_phys(ctx->ccb_buf);
659 	dax_dbg("ctx->ccb_buf=0x%p, ccb_buf_ra=0x%llx",
660 		(void *)ctx->ccb_buf, ctx->ccb_buf_ra);
661 
662 	/* allocate CCB completion area buffer */
663 	ctx->ca_buf = kzalloc(DAX_MMAP_LEN, GFP_KERNEL);
664 	if (ctx->ca_buf == NULL)
665 		goto alloc_error;
666 	for (i = 0; i < DAX_CA_ELEMS; i++)
667 		ctx->ca_buf[i].status = CCA_STAT_COMPLETED;
668 
669 	ctx->ca_buf_ra = virt_to_phys(ctx->ca_buf);
670 	dax_dbg("ctx=0x%p, ctx->ca_buf=0x%p, ca_buf_ra=0x%llx",
671 		(void *)ctx, (void *)ctx->ca_buf, ctx->ca_buf_ra);
672 
673 	ctx->owner = current;
674 	f->private_data = ctx;
675 	return 0;
676 
677 alloc_error:
678 	kfree(ctx->ccb_buf);
679 done:
680 	kfree(ctx);
681 	return -ENOMEM;
682 }
683 
684 static char *dax_hv_errno(unsigned long hv_ret, int *ret)
685 {
686 	switch (hv_ret) {
687 	case HV_EBADALIGN:
688 		*ret = -EFAULT;
689 		return "HV_EBADALIGN";
690 	case HV_ENORADDR:
691 		*ret = -EFAULT;
692 		return "HV_ENORADDR";
693 	case HV_EINVAL:
694 		*ret = -EINVAL;
695 		return "HV_EINVAL";
696 	case HV_EWOULDBLOCK:
697 		*ret = -EAGAIN;
698 		return "HV_EWOULDBLOCK";
699 	case HV_ENOACCESS:
700 		*ret = -EPERM;
701 		return "HV_ENOACCESS";
702 	default:
703 		break;
704 	}
705 
706 	*ret = -EIO;
707 	return "UNKNOWN";
708 }
709 
710 static int dax_ccb_kill(u64 ca, u16 *kill_res)
711 {
712 	unsigned long hv_ret;
713 	int count, ret = 0;
714 	char *err_str;
715 
716 	for (count = 0; count < DAX_CCB_RETRIES; count++) {
717 		dax_dbg("attempting kill on ca_ra 0x%llx", ca);
718 		hv_ret = sun4v_ccb_kill(ca, kill_res);
719 
720 		if (hv_ret == HV_EOK) {
721 			dax_info_dbg("HV_EOK (ca_ra 0x%llx): %d", ca,
722 				     *kill_res);
723 		} else {
724 			err_str = dax_hv_errno(hv_ret, &ret);
725 			dax_dbg("%s (ca_ra 0x%llx)", err_str, ca);
726 		}
727 
728 		if (ret != -EAGAIN)
729 			return ret;
730 		dax_info_dbg("ccb_kill count = %d", count);
731 		udelay(DAX_CCB_USEC);
732 	}
733 
734 	return -EAGAIN;
735 }
736 
737 static int dax_ccb_info(u64 ca, struct ccb_info_result *info)
738 {
739 	unsigned long hv_ret;
740 	char *err_str;
741 	int ret = 0;
742 
743 	dax_dbg("attempting info on ca_ra 0x%llx", ca);
744 	hv_ret = sun4v_ccb_info(ca, info);
745 
746 	if (hv_ret == HV_EOK) {
747 		dax_info_dbg("HV_EOK (ca_ra 0x%llx): %d", ca, info->state);
748 		if (info->state == DAX_CCB_ENQUEUED) {
749 			dax_info_dbg("dax_unit %d, queue_num %d, queue_pos %d",
750 				     info->inst_num, info->q_num, info->q_pos);
751 		}
752 	} else {
753 		err_str = dax_hv_errno(hv_ret, &ret);
754 		dax_dbg("%s (ca_ra 0x%llx)", err_str, ca);
755 	}
756 
757 	return ret;
758 }
759 
760 static void dax_prt_ccbs(struct dax_ccb *ccb, int nelem)
761 {
762 	int i, j;
763 	u64 *ccbp;
764 
765 	dax_dbg("ccb buffer:");
766 	for (i = 0; i < nelem; i++) {
767 		ccbp = (u64 *)&ccb[i];
768 		dax_dbg(" %sccb[%d]", ccb[i].hdr.longccb ? "long " : "",  i);
769 		for (j = 0; j < 8; j++)
770 			dax_dbg("\tccb[%d].dwords[%d]=0x%llx",
771 				i, j, *(ccbp + j));
772 	}
773 }
774 
775 /*
776  * Validates user CCB content.  Also sets completion address and address types
777  * for all addresses contained in CCB.
778  */
779 static int dax_preprocess_usr_ccbs(struct dax_ctx *ctx, int idx, int nelem)
780 {
781 	int i;
782 
783 	/*
784 	 * The user is not allowed to specify real address types in
785 	 * the CCB header.  This must be enforced by the kernel before
786 	 * submitting the CCBs to HV.  The only allowed values for all
787 	 * address fields are VA or IMM
788 	 */
789 	for (i = 0; i < nelem; i++) {
790 		struct dax_ccb *ccbp = &ctx->ccb_buf[i];
791 		unsigned long ca_offset;
792 
793 		if (ccbp->hdr.ccb_version > max_ccb_version)
794 			return DAX_SUBMIT_ERR_CCB_INVAL;
795 
796 		switch (ccbp->hdr.opcode) {
797 		case DAX_OP_SYNC_NOP:
798 		case DAX_OP_EXTRACT:
799 		case DAX_OP_SCAN_VALUE:
800 		case DAX_OP_SCAN_RANGE:
801 		case DAX_OP_TRANSLATE:
802 		case DAX_OP_SCAN_VALUE | DAX_OP_INVERT:
803 		case DAX_OP_SCAN_RANGE | DAX_OP_INVERT:
804 		case DAX_OP_TRANSLATE | DAX_OP_INVERT:
805 		case DAX_OP_SELECT:
806 			break;
807 		default:
808 			return DAX_SUBMIT_ERR_CCB_INVAL;
809 		}
810 
811 		if (ccbp->hdr.out_addr_type != DAX_ADDR_TYPE_VA &&
812 		    ccbp->hdr.out_addr_type != DAX_ADDR_TYPE_NONE) {
813 			dax_dbg("invalid out_addr_type in user CCB[%d]", i);
814 			return DAX_SUBMIT_ERR_CCB_INVAL;
815 		}
816 
817 		if (ccbp->hdr.pri_addr_type != DAX_ADDR_TYPE_VA &&
818 		    ccbp->hdr.pri_addr_type != DAX_ADDR_TYPE_NONE) {
819 			dax_dbg("invalid pri_addr_type in user CCB[%d]", i);
820 			return DAX_SUBMIT_ERR_CCB_INVAL;
821 		}
822 
823 		if (ccbp->hdr.sec_addr_type != DAX_ADDR_TYPE_VA &&
824 		    ccbp->hdr.sec_addr_type != DAX_ADDR_TYPE_NONE) {
825 			dax_dbg("invalid sec_addr_type in user CCB[%d]", i);
826 			return DAX_SUBMIT_ERR_CCB_INVAL;
827 		}
828 
829 		if (ccbp->hdr.table_addr_type != DAX_ADDR_TYPE_VA &&
830 		    ccbp->hdr.table_addr_type != DAX_ADDR_TYPE_NONE) {
831 			dax_dbg("invalid table_addr_type in user CCB[%d]", i);
832 			return DAX_SUBMIT_ERR_CCB_INVAL;
833 		}
834 
835 		/* set completion (real) address and address type */
836 		ccbp->hdr.cca_addr_type = DAX_ADDR_TYPE_RA;
837 		ca_offset = (idx + i) * sizeof(struct dax_cca);
838 		ccbp->ca = (void *)ctx->ca_buf_ra + ca_offset;
839 		memset(&ctx->ca_buf[idx + i], 0, sizeof(struct dax_cca));
840 
841 		dax_dbg("ccb[%d]=%p, ca_offset=0x%lx, compl RA=0x%llx",
842 			i, ccbp, ca_offset, ctx->ca_buf_ra + ca_offset);
843 
844 		/* skip over 2nd 64 bytes of long CCB */
845 		if (ccbp->hdr.longccb)
846 			i++;
847 	}
848 
849 	return DAX_SUBMIT_OK;
850 }
851 
852 static int dax_ccb_exec(struct dax_ctx *ctx, const char __user *buf,
853 			size_t count, loff_t *ppos)
854 {
855 	unsigned long accepted_len, hv_rv;
856 	int i, idx, nccbs, naccepted;
857 
858 	ctx->client = current;
859 	idx = *ppos;
860 	nccbs = count / sizeof(struct dax_ccb);
861 
862 	if (ctx->owner != current) {
863 		dax_dbg("wrong thread");
864 		ctx->result.exec.status = DAX_SUBMIT_ERR_THR_INIT;
865 		return 0;
866 	}
867 	dax_dbg("args: ccb_buf_len=%ld, idx=%d", count, idx);
868 
869 	/* for given index and length, verify ca_buf range exists */
870 	if (idx < 0 || idx > (DAX_CA_ELEMS - nccbs)) {
871 		ctx->result.exec.status = DAX_SUBMIT_ERR_NO_CA_AVAIL;
872 		return 0;
873 	}
874 
875 	/*
876 	 * Copy CCBs into kernel buffer to prevent modification by the
877 	 * user in between validation and submission.
878 	 */
879 	if (copy_from_user(ctx->ccb_buf, buf, count)) {
880 		dax_dbg("copyin of user CCB buffer failed");
881 		ctx->result.exec.status = DAX_SUBMIT_ERR_CCB_ARR_MMU_MISS;
882 		return 0;
883 	}
884 
885 	/* check to see if ca_buf[idx] .. ca_buf[idx + nccbs] are available */
886 	for (i = idx; i < idx + nccbs; i++) {
887 		if (ctx->ca_buf[i].status == CCA_STAT_NOT_COMPLETED) {
888 			dax_dbg("CA range not available, dequeue needed");
889 			ctx->result.exec.status = DAX_SUBMIT_ERR_NO_CA_AVAIL;
890 			return 0;
891 		}
892 	}
893 	dax_unlock_pages(ctx, idx, nccbs);
894 
895 	ctx->result.exec.status = dax_preprocess_usr_ccbs(ctx, idx, nccbs);
896 	if (ctx->result.exec.status != DAX_SUBMIT_OK)
897 		return 0;
898 
899 	ctx->result.exec.status = dax_lock_pages(ctx, idx, nccbs,
900 						 &ctx->result.exec.status_data);
901 	if (ctx->result.exec.status != DAX_SUBMIT_OK)
902 		return 0;
903 
904 	if (dax_debug & DAX_DBG_FLG_BASIC)
905 		dax_prt_ccbs(ctx->ccb_buf, nccbs);
906 
907 	hv_rv = sun4v_ccb_submit(ctx->ccb_buf_ra, count,
908 				 HV_CCB_QUERY_CMD | HV_CCB_VA_SECONDARY, 0,
909 				 &accepted_len, &ctx->result.exec.status_data);
910 
911 	switch (hv_rv) {
912 	case HV_EOK:
913 		/*
914 		 * Hcall succeeded with no errors but the accepted
915 		 * length may be less than the requested length.  The
916 		 * only way the driver can resubmit the remainder is
917 		 * to wait for completion of the submitted CCBs since
918 		 * there is no way to guarantee the ordering semantics
919 		 * required by the client applications.  Therefore we
920 		 * let the user library deal with resubmissions.
921 		 */
922 		ctx->result.exec.status = DAX_SUBMIT_OK;
923 		break;
924 	case HV_EWOULDBLOCK:
925 		/*
926 		 * This is a transient HV API error. The user library
927 		 * can retry.
928 		 */
929 		dax_dbg("hcall returned HV_EWOULDBLOCK");
930 		ctx->result.exec.status = DAX_SUBMIT_ERR_WOULDBLOCK;
931 		break;
932 	case HV_ENOMAP:
933 		/*
934 		 * HV was unable to translate a VA. The VA it could
935 		 * not translate is returned in the status_data param.
936 		 */
937 		dax_dbg("hcall returned HV_ENOMAP");
938 		ctx->result.exec.status = DAX_SUBMIT_ERR_NOMAP;
939 		break;
940 	case HV_EINVAL:
941 		/*
942 		 * This is the result of an invalid user CCB as HV is
943 		 * validating some of the user CCB fields.  Pass this
944 		 * error back to the user. There is no supporting info
945 		 * to isolate the invalid field.
946 		 */
947 		dax_dbg("hcall returned HV_EINVAL");
948 		ctx->result.exec.status = DAX_SUBMIT_ERR_CCB_INVAL;
949 		break;
950 	case HV_ENOACCESS:
951 		/*
952 		 * HV found a VA that did not have the appropriate
953 		 * permissions (such as the w bit). The VA in question
954 		 * is returned in status_data param.
955 		 */
956 		dax_dbg("hcall returned HV_ENOACCESS");
957 		ctx->result.exec.status = DAX_SUBMIT_ERR_NOACCESS;
958 		break;
959 	case HV_EUNAVAILABLE:
960 		/*
961 		 * The requested CCB operation could not be performed
962 		 * at this time. Return the specific unavailable code
963 		 * in the status_data field.
964 		 */
965 		dax_dbg("hcall returned HV_EUNAVAILABLE");
966 		ctx->result.exec.status = DAX_SUBMIT_ERR_UNAVAIL;
967 		break;
968 	default:
969 		ctx->result.exec.status = DAX_SUBMIT_ERR_INTERNAL;
970 		dax_dbg("unknown hcall return value (%ld)", hv_rv);
971 		break;
972 	}
973 
974 	/* unlock pages associated with the unaccepted CCBs */
975 	naccepted = accepted_len / sizeof(struct dax_ccb);
976 	dax_unlock_pages(ctx, idx + naccepted, nccbs - naccepted);
977 
978 	/* mark unaccepted CCBs as not completed */
979 	for (i = idx + naccepted; i < idx + nccbs; i++)
980 		ctx->ca_buf[i].status = CCA_STAT_COMPLETED;
981 
982 	ctx->ccb_count += naccepted;
983 	ctx->fail_count += nccbs - naccepted;
984 
985 	dax_dbg("hcall rv=%ld, accepted_len=%ld, status_data=0x%llx, ret status=%d",
986 		hv_rv, accepted_len, ctx->result.exec.status_data,
987 		ctx->result.exec.status);
988 
989 	if (count == accepted_len)
990 		ctx->client = NULL; /* no read needed to complete protocol */
991 	return accepted_len;
992 }
993