xref: /linux/drivers/sbus/char/oradax.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1 /*
2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
3  *
4  * This program is free software: you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation, either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 /*
19  * Oracle Data Analytics Accelerator (DAX)
20  *
21  * DAX is a coprocessor which resides on the SPARC M7 (DAX1) and M8
22  * (DAX2) processor chips, and has direct access to the CPU's L3
23  * caches as well as physical memory. It can perform several
24  * operations on data streams with various input and output formats.
25  * The driver provides a transport mechanism only and has limited
26  * knowledge of the various opcodes and data formats. A user space
27  * library provides high level services and translates these into low
28  * level commands which are then passed into the driver and
29  * subsequently the hypervisor and the coprocessor.  The library is
30  * the recommended way for applications to use the coprocessor, and
31  * the driver interface is not intended for general use.
32  *
33  * See Documentation/sparc/oradax/oracle-dax.txt for more details.
34  */
35 
36 #include <linux/uaccess.h>
37 #include <linux/module.h>
38 #include <linux/delay.h>
39 #include <linux/cdev.h>
40 #include <linux/slab.h>
41 #include <linux/mm.h>
42 
43 #include <asm/hypervisor.h>
44 #include <asm/mdesc.h>
45 #include <asm/oradax.h>
46 
47 MODULE_LICENSE("GPL");
48 MODULE_DESCRIPTION("Driver for Oracle Data Analytics Accelerator");
49 
50 #define	DAX_DBG_FLG_BASIC	0x01
51 #define	DAX_DBG_FLG_STAT	0x02
52 #define	DAX_DBG_FLG_INFO	0x04
53 #define	DAX_DBG_FLG_ALL		0xff
54 
55 #define	dax_err(fmt, ...)      pr_err("%s: " fmt "\n", __func__, ##__VA_ARGS__)
56 #define	dax_info(fmt, ...)     pr_info("%s: " fmt "\n", __func__, ##__VA_ARGS__)
57 
58 #define	dax_dbg(fmt, ...)	do {					\
59 					if (dax_debug & DAX_DBG_FLG_BASIC)\
60 						dax_info(fmt, ##__VA_ARGS__); \
61 				} while (0)
62 #define	dax_stat_dbg(fmt, ...)	do {					\
63 					if (dax_debug & DAX_DBG_FLG_STAT) \
64 						dax_info(fmt, ##__VA_ARGS__); \
65 				} while (0)
66 #define	dax_info_dbg(fmt, ...)	do { \
67 					if (dax_debug & DAX_DBG_FLG_INFO) \
68 						dax_info(fmt, ##__VA_ARGS__); \
69 				} while (0)
70 
71 #define	DAX1_MINOR		1
72 #define	DAX1_MAJOR		1
73 #define	DAX2_MINOR		0
74 #define	DAX2_MAJOR		2
75 
76 #define	DAX1_STR    "ORCL,sun4v-dax"
77 #define	DAX2_STR    "ORCL,sun4v-dax2"
78 
79 #define	DAX_CA_ELEMS		(DAX_MMAP_LEN / sizeof(struct dax_cca))
80 
81 #define	DAX_CCB_USEC		100
82 #define	DAX_CCB_RETRIES		10000
83 
84 /* stream types */
85 enum {
86 	OUT,
87 	PRI,
88 	SEC,
89 	TBL,
90 	NUM_STREAM_TYPES
91 };
92 
93 /* completion status */
94 #define	CCA_STAT_NOT_COMPLETED	0
95 #define	CCA_STAT_COMPLETED	1
96 #define	CCA_STAT_FAILED		2
97 #define	CCA_STAT_KILLED		3
98 #define	CCA_STAT_NOT_RUN	4
99 #define	CCA_STAT_PIPE_OUT	5
100 #define	CCA_STAT_PIPE_SRC	6
101 #define	CCA_STAT_PIPE_DST	7
102 
103 /* completion err */
104 #define	CCA_ERR_SUCCESS		0x0	/* no error */
105 #define	CCA_ERR_OVERFLOW	0x1	/* buffer overflow */
106 #define	CCA_ERR_DECODE		0x2	/* CCB decode error */
107 #define	CCA_ERR_PAGE_OVERFLOW	0x3	/* page overflow */
108 #define	CCA_ERR_KILLED		0x7	/* command was killed */
109 #define	CCA_ERR_TIMEOUT		0x8	/* Timeout */
110 #define	CCA_ERR_ADI		0x9	/* ADI error */
111 #define	CCA_ERR_DATA_FMT	0xA	/* data format error */
112 #define	CCA_ERR_OTHER_NO_RETRY	0xE	/* Other error, do not retry */
113 #define	CCA_ERR_OTHER_RETRY	0xF	/* Other error, retry */
114 #define	CCA_ERR_PARTIAL_SYMBOL	0x80	/* QP partial symbol warning */
115 
116 /* CCB address types */
117 #define	DAX_ADDR_TYPE_NONE	0
118 #define	DAX_ADDR_TYPE_VA_ALT	1	/* secondary context */
119 #define	DAX_ADDR_TYPE_RA	2	/* real address */
120 #define	DAX_ADDR_TYPE_VA	3	/* virtual address */
121 
122 /* dax_header_t opcode */
123 #define	DAX_OP_SYNC_NOP		0x0
124 #define	DAX_OP_EXTRACT		0x1
125 #define	DAX_OP_SCAN_VALUE	0x2
126 #define	DAX_OP_SCAN_RANGE	0x3
127 #define	DAX_OP_TRANSLATE	0x4
128 #define	DAX_OP_SELECT		0x5
129 #define	DAX_OP_INVERT		0x10	/* OR with translate, scan opcodes */
130 
131 struct dax_header {
132 	u32 ccb_version:4;	/* 31:28 CCB Version */
133 				/* 27:24 Sync Flags */
134 	u32 pipe:1;		/* Pipeline */
135 	u32 longccb:1;		/* Longccb. Set for scan with lu2, lu3, lu4. */
136 	u32 cond:1;		/* Conditional */
137 	u32 serial:1;		/* Serial */
138 	u32 opcode:8;		/* 23:16 Opcode */
139 				/* 15:0 Address Type. */
140 	u32 reserved:3;		/* 15:13 reserved */
141 	u32 table_addr_type:2;	/* 12:11 Huffman Table Address Type */
142 	u32 out_addr_type:3;	/* 10:8 Destination Address Type */
143 	u32 sec_addr_type:3;	/* 7:5 Secondary Source Address Type */
144 	u32 pri_addr_type:3;	/* 4:2 Primary Source Address Type */
145 	u32 cca_addr_type:2;	/* 1:0 Completion Address Type */
146 };
147 
148 struct dax_control {
149 	u32 pri_fmt:4;		/* 31:28 Primary Input Format */
150 	u32 pri_elem_size:5;	/* 27:23 Primary Input Element Size(less1) */
151 	u32 pri_offset:3;	/* 22:20 Primary Input Starting Offset */
152 	u32 sec_encoding:1;	/* 19    Secondary Input Encoding */
153 				/*	 (must be 0 for Select) */
154 	u32 sec_offset:3;	/* 18:16 Secondary Input Starting Offset */
155 	u32 sec_elem_size:2;	/* 15:14 Secondary Input Element Size */
156 				/*	 (must be 0 for Select) */
157 	u32 out_fmt:2;		/* 13:12 Output Format */
158 	u32 out_elem_size:2;	/* 11:10 Output Element Size */
159 	u32 misc:10;		/* 9:0 Opcode specific info */
160 };
161 
162 struct dax_data_access {
163 	u64 flow_ctrl:2;	/* 63:62 Flow Control Type */
164 	u64 pipe_target:2;	/* 61:60 Pipeline Target */
165 	u64 out_buf_size:20;	/* 59:40 Output Buffer Size */
166 				/*	 (cachelines less 1) */
167 	u64 unused1:8;		/* 39:32 Reserved, Set to 0 */
168 	u64 out_alloc:5;	/* 31:27 Output Allocation */
169 	u64 unused2:1;		/* 26	 Reserved */
170 	u64 pri_len_fmt:2;	/* 25:24 Input Length Format */
171 	u64 pri_len:24;		/* 23:0  Input Element/Byte/Bit Count */
172 				/*	 (less 1) */
173 };
174 
175 struct dax_ccb {
176 	struct dax_header hdr;	/* CCB Header */
177 	struct dax_control ctrl;/* Control Word */
178 	void *ca;		/* Completion Address */
179 	void *pri;		/* Primary Input Address */
180 	struct dax_data_access dac; /* Data Access Control */
181 	void *sec;		/* Secondary Input Address */
182 	u64 dword5;		/* depends on opcode */
183 	void *out;		/* Output Address */
184 	void *tbl;		/* Table Address or bitmap */
185 };
186 
187 struct dax_cca {
188 	u8	status;		/* user may mwait on this address */
189 	u8	err;		/* user visible error notification */
190 	u8	rsvd[2];	/* reserved */
191 	u32	n_remaining;	/* for QP partial symbol warning */
192 	u32	output_sz;	/* output in bytes */
193 	u32	rsvd2;		/* reserved */
194 	u64	run_cycles;	/* run time in OCND2 cycles */
195 	u64	run_stats;	/* nothing reported in version 1.0 */
196 	u32	n_processed;	/* number input elements */
197 	u32	rsvd3[5];	/* reserved */
198 	u64	retval;		/* command return value */
199 	u64	rsvd4[8];	/* reserved */
200 };
201 
202 /* per thread CCB context */
203 struct dax_ctx {
204 	struct dax_ccb		*ccb_buf;
205 	u64			ccb_buf_ra;	/* cached RA of ccb_buf  */
206 	struct dax_cca		*ca_buf;
207 	u64			ca_buf_ra;	/* cached RA of ca_buf   */
208 	struct page		*pages[DAX_CA_ELEMS][NUM_STREAM_TYPES];
209 						/* array of locked pages */
210 	struct task_struct	*owner;		/* thread that owns ctx  */
211 	struct task_struct	*client;	/* requesting thread     */
212 	union ccb_result	result;
213 	u32			ccb_count;
214 	u32			fail_count;
215 };
216 
217 /* driver public entry points */
218 static int dax_open(struct inode *inode, struct file *file);
219 static ssize_t dax_read(struct file *filp, char __user *buf,
220 			size_t count, loff_t *ppos);
221 static ssize_t dax_write(struct file *filp, const char __user *buf,
222 			 size_t count, loff_t *ppos);
223 static int dax_devmap(struct file *f, struct vm_area_struct *vma);
224 static int dax_close(struct inode *i, struct file *f);
225 
226 static const struct file_operations dax_fops = {
227 	.owner	=	THIS_MODULE,
228 	.open	=	dax_open,
229 	.read	=	dax_read,
230 	.write	=	dax_write,
231 	.mmap	=	dax_devmap,
232 	.release =	dax_close,
233 };
234 
235 static int dax_ccb_exec(struct dax_ctx *ctx, const char __user *buf,
236 			size_t count, loff_t *ppos);
237 static int dax_ccb_info(u64 ca, struct ccb_info_result *info);
238 static int dax_ccb_kill(u64 ca, u16 *kill_res);
239 
240 static struct cdev c_dev;
241 static struct class *cl;
242 static dev_t first;
243 
244 static int max_ccb_version;
245 static int dax_debug;
246 module_param(dax_debug, int, 0644);
247 MODULE_PARM_DESC(dax_debug, "Debug flags");
248 
249 static int __init dax_attach(void)
250 {
251 	unsigned long dummy, hv_rv, major, minor, minor_requested, max_ccbs;
252 	struct mdesc_handle *hp = mdesc_grab();
253 	char *prop, *dax_name;
254 	bool found = false;
255 	int len, ret = 0;
256 	u64 pn;
257 
258 	if (hp == NULL) {
259 		dax_err("Unable to grab mdesc");
260 		return -ENODEV;
261 	}
262 
263 	mdesc_for_each_node_by_name(hp, pn, "virtual-device") {
264 		prop = (char *)mdesc_get_property(hp, pn, "name", &len);
265 		if (prop == NULL)
266 			continue;
267 		if (strncmp(prop, "dax", strlen("dax")))
268 			continue;
269 		dax_dbg("Found node 0x%llx = %s", pn, prop);
270 
271 		prop = (char *)mdesc_get_property(hp, pn, "compatible", &len);
272 		if (prop == NULL)
273 			continue;
274 		dax_dbg("Found node 0x%llx = %s", pn, prop);
275 		found = true;
276 		break;
277 	}
278 
279 	if (!found) {
280 		dax_err("No DAX device found");
281 		ret = -ENODEV;
282 		goto done;
283 	}
284 
285 	if (strncmp(prop, DAX2_STR, strlen(DAX2_STR)) == 0) {
286 		dax_name = DAX_NAME "2";
287 		major = DAX2_MAJOR;
288 		minor_requested = DAX2_MINOR;
289 		max_ccb_version = 1;
290 		dax_dbg("MD indicates DAX2 coprocessor");
291 	} else if (strncmp(prop, DAX1_STR, strlen(DAX1_STR)) == 0) {
292 		dax_name = DAX_NAME "1";
293 		major = DAX1_MAJOR;
294 		minor_requested = DAX1_MINOR;
295 		max_ccb_version = 0;
296 		dax_dbg("MD indicates DAX1 coprocessor");
297 	} else {
298 		dax_err("Unknown dax type: %s", prop);
299 		ret = -ENODEV;
300 		goto done;
301 	}
302 
303 	minor = minor_requested;
304 	dax_dbg("Registering DAX HV api with major %ld minor %ld", major,
305 		minor);
306 	if (sun4v_hvapi_register(HV_GRP_DAX, major, &minor)) {
307 		dax_err("hvapi_register failed");
308 		ret = -ENODEV;
309 		goto done;
310 	} else {
311 		dax_dbg("Max minor supported by HV = %ld (major %ld)", minor,
312 			major);
313 		minor = min(minor, minor_requested);
314 		dax_dbg("registered DAX major %ld minor %ld", major, minor);
315 	}
316 
317 	/* submit a zero length ccb array to query coprocessor queue size */
318 	hv_rv = sun4v_ccb_submit(0, 0, HV_CCB_QUERY_CMD, 0, &max_ccbs, &dummy);
319 	if (hv_rv != 0) {
320 		dax_err("get_hwqueue_size failed with status=%ld and max_ccbs=%ld",
321 			hv_rv, max_ccbs);
322 		ret = -ENODEV;
323 		goto done;
324 	}
325 
326 	if (max_ccbs != DAX_MAX_CCBS) {
327 		dax_err("HV reports unsupported max_ccbs=%ld", max_ccbs);
328 		ret = -ENODEV;
329 		goto done;
330 	}
331 
332 	if (alloc_chrdev_region(&first, 0, 1, DAX_NAME) < 0) {
333 		dax_err("alloc_chrdev_region failed");
334 		ret = -ENXIO;
335 		goto done;
336 	}
337 
338 	cl = class_create(THIS_MODULE, DAX_NAME);
339 	if (IS_ERR(cl)) {
340 		dax_err("class_create failed");
341 		ret = PTR_ERR(cl);
342 		goto class_error;
343 	}
344 
345 	if (device_create(cl, NULL, first, NULL, dax_name) == NULL) {
346 		dax_err("device_create failed");
347 		ret = -ENXIO;
348 		goto device_error;
349 	}
350 
351 	cdev_init(&c_dev, &dax_fops);
352 	if (cdev_add(&c_dev, first, 1) == -1) {
353 		dax_err("cdev_add failed");
354 		ret = -ENXIO;
355 		goto cdev_error;
356 	}
357 
358 	pr_info("Attached DAX module\n");
359 	goto done;
360 
361 cdev_error:
362 	device_destroy(cl, first);
363 device_error:
364 	class_destroy(cl);
365 class_error:
366 	unregister_chrdev_region(first, 1);
367 done:
368 	mdesc_release(hp);
369 	return ret;
370 }
371 module_init(dax_attach);
372 
373 static void __exit dax_detach(void)
374 {
375 	pr_info("Cleaning up DAX module\n");
376 	cdev_del(&c_dev);
377 	device_destroy(cl, first);
378 	class_destroy(cl);
379 	unregister_chrdev_region(first, 1);
380 }
381 module_exit(dax_detach);
382 
383 /* map completion area */
384 static int dax_devmap(struct file *f, struct vm_area_struct *vma)
385 {
386 	struct dax_ctx *ctx = (struct dax_ctx *)f->private_data;
387 	size_t len = vma->vm_end - vma->vm_start;
388 
389 	dax_dbg("len=0x%lx, flags=0x%lx", len, vma->vm_flags);
390 
391 	if (ctx->owner != current) {
392 		dax_dbg("devmap called from wrong thread");
393 		return -EINVAL;
394 	}
395 
396 	if (len != DAX_MMAP_LEN) {
397 		dax_dbg("len(%lu) != DAX_MMAP_LEN(%d)", len, DAX_MMAP_LEN);
398 		return -EINVAL;
399 	}
400 
401 	/* completion area is mapped read-only for user */
402 	if (vma->vm_flags & VM_WRITE)
403 		return -EPERM;
404 	vma->vm_flags &= ~VM_MAYWRITE;
405 
406 	if (remap_pfn_range(vma, vma->vm_start, ctx->ca_buf_ra >> PAGE_SHIFT,
407 			    len, vma->vm_page_prot))
408 		return -EAGAIN;
409 
410 	dax_dbg("mmapped completion area at uva 0x%lx", vma->vm_start);
411 	return 0;
412 }
413 
414 /* Unlock user pages. Called during dequeue or device close */
415 static void dax_unlock_pages(struct dax_ctx *ctx, int ccb_index, int nelem)
416 {
417 	int i, j;
418 
419 	for (i = ccb_index; i < ccb_index + nelem; i++) {
420 		for (j = 0; j < NUM_STREAM_TYPES; j++) {
421 			struct page *p = ctx->pages[i][j];
422 
423 			if (p) {
424 				dax_dbg("freeing page %p", p);
425 				if (j == OUT)
426 					set_page_dirty(p);
427 				put_page(p);
428 				ctx->pages[i][j] = NULL;
429 			}
430 		}
431 	}
432 }
433 
434 static int dax_lock_page(void *va, struct page **p)
435 {
436 	int ret;
437 
438 	dax_dbg("uva %p", va);
439 
440 	ret = get_user_pages_fast((unsigned long)va, 1, 1, p);
441 	if (ret == 1) {
442 		dax_dbg("locked page %p, for VA %p", *p, va);
443 		return 0;
444 	}
445 
446 	dax_dbg("get_user_pages failed, va=%p, ret=%d", va, ret);
447 	return -1;
448 }
449 
450 static int dax_lock_pages(struct dax_ctx *ctx, int idx,
451 			  int nelem, u64 *err_va)
452 {
453 	int i;
454 
455 	for (i = 0; i < nelem; i++) {
456 		struct dax_ccb *ccbp = &ctx->ccb_buf[i];
457 
458 		/*
459 		 * For each address in the CCB whose type is virtual,
460 		 * lock the page and change the type to virtual alternate
461 		 * context. On error, return the offending address in
462 		 * err_va.
463 		 */
464 		if (ccbp->hdr.out_addr_type == DAX_ADDR_TYPE_VA) {
465 			dax_dbg("output");
466 			if (dax_lock_page(ccbp->out,
467 					  &ctx->pages[i + idx][OUT]) != 0) {
468 				*err_va = (u64)ccbp->out;
469 				goto error;
470 			}
471 			ccbp->hdr.out_addr_type = DAX_ADDR_TYPE_VA_ALT;
472 		}
473 
474 		if (ccbp->hdr.pri_addr_type == DAX_ADDR_TYPE_VA) {
475 			dax_dbg("input");
476 			if (dax_lock_page(ccbp->pri,
477 					  &ctx->pages[i + idx][PRI]) != 0) {
478 				*err_va = (u64)ccbp->pri;
479 				goto error;
480 			}
481 			ccbp->hdr.pri_addr_type = DAX_ADDR_TYPE_VA_ALT;
482 		}
483 
484 		if (ccbp->hdr.sec_addr_type == DAX_ADDR_TYPE_VA) {
485 			dax_dbg("sec input");
486 			if (dax_lock_page(ccbp->sec,
487 					  &ctx->pages[i + idx][SEC]) != 0) {
488 				*err_va = (u64)ccbp->sec;
489 				goto error;
490 			}
491 			ccbp->hdr.sec_addr_type = DAX_ADDR_TYPE_VA_ALT;
492 		}
493 
494 		if (ccbp->hdr.table_addr_type == DAX_ADDR_TYPE_VA) {
495 			dax_dbg("tbl");
496 			if (dax_lock_page(ccbp->tbl,
497 					  &ctx->pages[i + idx][TBL]) != 0) {
498 				*err_va = (u64)ccbp->tbl;
499 				goto error;
500 			}
501 			ccbp->hdr.table_addr_type = DAX_ADDR_TYPE_VA_ALT;
502 		}
503 
504 		/* skip over 2nd 64 bytes of long CCB */
505 		if (ccbp->hdr.longccb)
506 			i++;
507 	}
508 	return DAX_SUBMIT_OK;
509 
510 error:
511 	dax_unlock_pages(ctx, idx, nelem);
512 	return DAX_SUBMIT_ERR_NOACCESS;
513 }
514 
515 static void dax_ccb_wait(struct dax_ctx *ctx, int idx)
516 {
517 	int ret, nretries;
518 	u16 kill_res;
519 
520 	dax_dbg("idx=%d", idx);
521 
522 	for (nretries = 0; nretries < DAX_CCB_RETRIES; nretries++) {
523 		if (ctx->ca_buf[idx].status == CCA_STAT_NOT_COMPLETED)
524 			udelay(DAX_CCB_USEC);
525 		else
526 			return;
527 	}
528 	dax_dbg("ctx (%p): CCB[%d] timed out, wait usec=%d, retries=%d. Killing ccb",
529 		(void *)ctx, idx, DAX_CCB_USEC, DAX_CCB_RETRIES);
530 
531 	ret = dax_ccb_kill(ctx->ca_buf_ra + idx * sizeof(struct dax_cca),
532 			   &kill_res);
533 	dax_dbg("Kill CCB[%d] %s", idx, ret ? "failed" : "succeeded");
534 }
535 
536 static int dax_close(struct inode *ino, struct file *f)
537 {
538 	struct dax_ctx *ctx = (struct dax_ctx *)f->private_data;
539 	int i;
540 
541 	f->private_data = NULL;
542 
543 	for (i = 0; i < DAX_CA_ELEMS; i++) {
544 		if (ctx->ca_buf[i].status == CCA_STAT_NOT_COMPLETED) {
545 			dax_dbg("CCB[%d] not completed", i);
546 			dax_ccb_wait(ctx, i);
547 		}
548 		dax_unlock_pages(ctx, i, 1);
549 	}
550 
551 	kfree(ctx->ccb_buf);
552 	kfree(ctx->ca_buf);
553 	dax_stat_dbg("CCBs: %d good, %d bad", ctx->ccb_count, ctx->fail_count);
554 	kfree(ctx);
555 
556 	return 0;
557 }
558 
559 static ssize_t dax_read(struct file *f, char __user *buf,
560 			size_t count, loff_t *ppos)
561 {
562 	struct dax_ctx *ctx = f->private_data;
563 
564 	if (ctx->client != current)
565 		return -EUSERS;
566 
567 	ctx->client = NULL;
568 
569 	if (count != sizeof(union ccb_result))
570 		return -EINVAL;
571 	if (copy_to_user(buf, &ctx->result, sizeof(union ccb_result)))
572 		return -EFAULT;
573 	return count;
574 }
575 
576 static ssize_t dax_write(struct file *f, const char __user *buf,
577 			 size_t count, loff_t *ppos)
578 {
579 	struct dax_ctx *ctx = f->private_data;
580 	struct dax_command hdr;
581 	unsigned long ca;
582 	int i, idx, ret;
583 
584 	if (ctx->client != NULL)
585 		return -EINVAL;
586 
587 	if (count == 0 || count > DAX_MAX_CCBS * sizeof(struct dax_ccb))
588 		return -EINVAL;
589 
590 	if (count % sizeof(struct dax_ccb) == 0)
591 		return dax_ccb_exec(ctx, buf, count, ppos); /* CCB EXEC */
592 
593 	if (count != sizeof(struct dax_command))
594 		return -EINVAL;
595 
596 	/* immediate command */
597 	if (ctx->owner != current)
598 		return -EUSERS;
599 
600 	if (copy_from_user(&hdr, buf, sizeof(hdr)))
601 		return -EFAULT;
602 
603 	ca = ctx->ca_buf_ra + hdr.ca_offset;
604 
605 	switch (hdr.command) {
606 	case CCB_KILL:
607 		if (hdr.ca_offset >= DAX_MMAP_LEN) {
608 			dax_dbg("invalid ca_offset (%d) >= ca_buflen (%d)",
609 				hdr.ca_offset, DAX_MMAP_LEN);
610 			return -EINVAL;
611 		}
612 
613 		ret = dax_ccb_kill(ca, &ctx->result.kill.action);
614 		if (ret != 0) {
615 			dax_dbg("dax_ccb_kill failed (ret=%d)", ret);
616 			return ret;
617 		}
618 
619 		dax_info_dbg("killed (ca_offset %d)", hdr.ca_offset);
620 		idx = hdr.ca_offset / sizeof(struct dax_cca);
621 		ctx->ca_buf[idx].status = CCA_STAT_KILLED;
622 		ctx->ca_buf[idx].err = CCA_ERR_KILLED;
623 		ctx->client = current;
624 		return count;
625 
626 	case CCB_INFO:
627 		if (hdr.ca_offset >= DAX_MMAP_LEN) {
628 			dax_dbg("invalid ca_offset (%d) >= ca_buflen (%d)",
629 				hdr.ca_offset, DAX_MMAP_LEN);
630 			return -EINVAL;
631 		}
632 
633 		ret = dax_ccb_info(ca, &ctx->result.info);
634 		if (ret != 0) {
635 			dax_dbg("dax_ccb_info failed (ret=%d)", ret);
636 			return ret;
637 		}
638 
639 		dax_info_dbg("info succeeded on ca_offset %d", hdr.ca_offset);
640 		ctx->client = current;
641 		return count;
642 
643 	case CCB_DEQUEUE:
644 		for (i = 0; i < DAX_CA_ELEMS; i++) {
645 			if (ctx->ca_buf[i].status !=
646 			    CCA_STAT_NOT_COMPLETED)
647 				dax_unlock_pages(ctx, i, 1);
648 		}
649 		return count;
650 
651 	default:
652 		return -EINVAL;
653 	}
654 }
655 
656 static int dax_open(struct inode *inode, struct file *f)
657 {
658 	struct dax_ctx *ctx = NULL;
659 	int i;
660 
661 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
662 	if (ctx == NULL)
663 		goto done;
664 
665 	ctx->ccb_buf = kcalloc(DAX_MAX_CCBS, sizeof(struct dax_ccb),
666 			       GFP_KERNEL);
667 	if (ctx->ccb_buf == NULL)
668 		goto done;
669 
670 	ctx->ccb_buf_ra = virt_to_phys(ctx->ccb_buf);
671 	dax_dbg("ctx->ccb_buf=0x%p, ccb_buf_ra=0x%llx",
672 		(void *)ctx->ccb_buf, ctx->ccb_buf_ra);
673 
674 	/* allocate CCB completion area buffer */
675 	ctx->ca_buf = kzalloc(DAX_MMAP_LEN, GFP_KERNEL);
676 	if (ctx->ca_buf == NULL)
677 		goto alloc_error;
678 	for (i = 0; i < DAX_CA_ELEMS; i++)
679 		ctx->ca_buf[i].status = CCA_STAT_COMPLETED;
680 
681 	ctx->ca_buf_ra = virt_to_phys(ctx->ca_buf);
682 	dax_dbg("ctx=0x%p, ctx->ca_buf=0x%p, ca_buf_ra=0x%llx",
683 		(void *)ctx, (void *)ctx->ca_buf, ctx->ca_buf_ra);
684 
685 	ctx->owner = current;
686 	f->private_data = ctx;
687 	return 0;
688 
689 alloc_error:
690 	kfree(ctx->ccb_buf);
691 done:
692 	if (ctx != NULL)
693 		kfree(ctx);
694 	return -ENOMEM;
695 }
696 
697 static char *dax_hv_errno(unsigned long hv_ret, int *ret)
698 {
699 	switch (hv_ret) {
700 	case HV_EBADALIGN:
701 		*ret = -EFAULT;
702 		return "HV_EBADALIGN";
703 	case HV_ENORADDR:
704 		*ret = -EFAULT;
705 		return "HV_ENORADDR";
706 	case HV_EINVAL:
707 		*ret = -EINVAL;
708 		return "HV_EINVAL";
709 	case HV_EWOULDBLOCK:
710 		*ret = -EAGAIN;
711 		return "HV_EWOULDBLOCK";
712 	case HV_ENOACCESS:
713 		*ret = -EPERM;
714 		return "HV_ENOACCESS";
715 	default:
716 		break;
717 	}
718 
719 	*ret = -EIO;
720 	return "UNKNOWN";
721 }
722 
723 static int dax_ccb_kill(u64 ca, u16 *kill_res)
724 {
725 	unsigned long hv_ret;
726 	int count, ret = 0;
727 	char *err_str;
728 
729 	for (count = 0; count < DAX_CCB_RETRIES; count++) {
730 		dax_dbg("attempting kill on ca_ra 0x%llx", ca);
731 		hv_ret = sun4v_ccb_kill(ca, kill_res);
732 
733 		if (hv_ret == HV_EOK) {
734 			dax_info_dbg("HV_EOK (ca_ra 0x%llx): %d", ca,
735 				     *kill_res);
736 		} else {
737 			err_str = dax_hv_errno(hv_ret, &ret);
738 			dax_dbg("%s (ca_ra 0x%llx)", err_str, ca);
739 		}
740 
741 		if (ret != -EAGAIN)
742 			return ret;
743 		dax_info_dbg("ccb_kill count = %d", count);
744 		udelay(DAX_CCB_USEC);
745 	}
746 
747 	return -EAGAIN;
748 }
749 
750 static int dax_ccb_info(u64 ca, struct ccb_info_result *info)
751 {
752 	unsigned long hv_ret;
753 	char *err_str;
754 	int ret = 0;
755 
756 	dax_dbg("attempting info on ca_ra 0x%llx", ca);
757 	hv_ret = sun4v_ccb_info(ca, info);
758 
759 	if (hv_ret == HV_EOK) {
760 		dax_info_dbg("HV_EOK (ca_ra 0x%llx): %d", ca, info->state);
761 		if (info->state == DAX_CCB_ENQUEUED) {
762 			dax_info_dbg("dax_unit %d, queue_num %d, queue_pos %d",
763 				     info->inst_num, info->q_num, info->q_pos);
764 		}
765 	} else {
766 		err_str = dax_hv_errno(hv_ret, &ret);
767 		dax_dbg("%s (ca_ra 0x%llx)", err_str, ca);
768 	}
769 
770 	return ret;
771 }
772 
773 static void dax_prt_ccbs(struct dax_ccb *ccb, int nelem)
774 {
775 	int i, j;
776 	u64 *ccbp;
777 
778 	dax_dbg("ccb buffer:");
779 	for (i = 0; i < nelem; i++) {
780 		ccbp = (u64 *)&ccb[i];
781 		dax_dbg(" %sccb[%d]", ccb[i].hdr.longccb ? "long " : "",  i);
782 		for (j = 0; j < 8; j++)
783 			dax_dbg("\tccb[%d].dwords[%d]=0x%llx",
784 				i, j, *(ccbp + j));
785 	}
786 }
787 
788 /*
789  * Validates user CCB content.  Also sets completion address and address types
790  * for all addresses contained in CCB.
791  */
792 static int dax_preprocess_usr_ccbs(struct dax_ctx *ctx, int idx, int nelem)
793 {
794 	int i;
795 
796 	/*
797 	 * The user is not allowed to specify real address types in
798 	 * the CCB header.  This must be enforced by the kernel before
799 	 * submitting the CCBs to HV.  The only allowed values for all
800 	 * address fields are VA or IMM
801 	 */
802 	for (i = 0; i < nelem; i++) {
803 		struct dax_ccb *ccbp = &ctx->ccb_buf[i];
804 		unsigned long ca_offset;
805 
806 		if (ccbp->hdr.ccb_version > max_ccb_version)
807 			return DAX_SUBMIT_ERR_CCB_INVAL;
808 
809 		switch (ccbp->hdr.opcode) {
810 		case DAX_OP_SYNC_NOP:
811 		case DAX_OP_EXTRACT:
812 		case DAX_OP_SCAN_VALUE:
813 		case DAX_OP_SCAN_RANGE:
814 		case DAX_OP_TRANSLATE:
815 		case DAX_OP_SCAN_VALUE | DAX_OP_INVERT:
816 		case DAX_OP_SCAN_RANGE | DAX_OP_INVERT:
817 		case DAX_OP_TRANSLATE | DAX_OP_INVERT:
818 		case DAX_OP_SELECT:
819 			break;
820 		default:
821 			return DAX_SUBMIT_ERR_CCB_INVAL;
822 		}
823 
824 		if (ccbp->hdr.out_addr_type != DAX_ADDR_TYPE_VA &&
825 		    ccbp->hdr.out_addr_type != DAX_ADDR_TYPE_NONE) {
826 			dax_dbg("invalid out_addr_type in user CCB[%d]", i);
827 			return DAX_SUBMIT_ERR_CCB_INVAL;
828 		}
829 
830 		if (ccbp->hdr.pri_addr_type != DAX_ADDR_TYPE_VA &&
831 		    ccbp->hdr.pri_addr_type != DAX_ADDR_TYPE_NONE) {
832 			dax_dbg("invalid pri_addr_type in user CCB[%d]", i);
833 			return DAX_SUBMIT_ERR_CCB_INVAL;
834 		}
835 
836 		if (ccbp->hdr.sec_addr_type != DAX_ADDR_TYPE_VA &&
837 		    ccbp->hdr.sec_addr_type != DAX_ADDR_TYPE_NONE) {
838 			dax_dbg("invalid sec_addr_type in user CCB[%d]", i);
839 			return DAX_SUBMIT_ERR_CCB_INVAL;
840 		}
841 
842 		if (ccbp->hdr.table_addr_type != DAX_ADDR_TYPE_VA &&
843 		    ccbp->hdr.table_addr_type != DAX_ADDR_TYPE_NONE) {
844 			dax_dbg("invalid table_addr_type in user CCB[%d]", i);
845 			return DAX_SUBMIT_ERR_CCB_INVAL;
846 		}
847 
848 		/* set completion (real) address and address type */
849 		ccbp->hdr.cca_addr_type = DAX_ADDR_TYPE_RA;
850 		ca_offset = (idx + i) * sizeof(struct dax_cca);
851 		ccbp->ca = (void *)ctx->ca_buf_ra + ca_offset;
852 		memset(&ctx->ca_buf[idx + i], 0, sizeof(struct dax_cca));
853 
854 		dax_dbg("ccb[%d]=%p, ca_offset=0x%lx, compl RA=0x%llx",
855 			i, ccbp, ca_offset, ctx->ca_buf_ra + ca_offset);
856 
857 		/* skip over 2nd 64 bytes of long CCB */
858 		if (ccbp->hdr.longccb)
859 			i++;
860 	}
861 
862 	return DAX_SUBMIT_OK;
863 }
864 
865 static int dax_ccb_exec(struct dax_ctx *ctx, const char __user *buf,
866 			size_t count, loff_t *ppos)
867 {
868 	unsigned long accepted_len, hv_rv;
869 	int i, idx, nccbs, naccepted;
870 
871 	ctx->client = current;
872 	idx = *ppos;
873 	nccbs = count / sizeof(struct dax_ccb);
874 
875 	if (ctx->owner != current) {
876 		dax_dbg("wrong thread");
877 		ctx->result.exec.status = DAX_SUBMIT_ERR_THR_INIT;
878 		return 0;
879 	}
880 	dax_dbg("args: ccb_buf_len=%ld, idx=%d", count, idx);
881 
882 	/* for given index and length, verify ca_buf range exists */
883 	if (idx < 0 || idx > (DAX_CA_ELEMS - nccbs)) {
884 		ctx->result.exec.status = DAX_SUBMIT_ERR_NO_CA_AVAIL;
885 		return 0;
886 	}
887 
888 	/*
889 	 * Copy CCBs into kernel buffer to prevent modification by the
890 	 * user in between validation and submission.
891 	 */
892 	if (copy_from_user(ctx->ccb_buf, buf, count)) {
893 		dax_dbg("copyin of user CCB buffer failed");
894 		ctx->result.exec.status = DAX_SUBMIT_ERR_CCB_ARR_MMU_MISS;
895 		return 0;
896 	}
897 
898 	/* check to see if ca_buf[idx] .. ca_buf[idx + nccbs] are available */
899 	for (i = idx; i < idx + nccbs; i++) {
900 		if (ctx->ca_buf[i].status == CCA_STAT_NOT_COMPLETED) {
901 			dax_dbg("CA range not available, dequeue needed");
902 			ctx->result.exec.status = DAX_SUBMIT_ERR_NO_CA_AVAIL;
903 			return 0;
904 		}
905 	}
906 	dax_unlock_pages(ctx, idx, nccbs);
907 
908 	ctx->result.exec.status = dax_preprocess_usr_ccbs(ctx, idx, nccbs);
909 	if (ctx->result.exec.status != DAX_SUBMIT_OK)
910 		return 0;
911 
912 	ctx->result.exec.status = dax_lock_pages(ctx, idx, nccbs,
913 						 &ctx->result.exec.status_data);
914 	if (ctx->result.exec.status != DAX_SUBMIT_OK)
915 		return 0;
916 
917 	if (dax_debug & DAX_DBG_FLG_BASIC)
918 		dax_prt_ccbs(ctx->ccb_buf, nccbs);
919 
920 	hv_rv = sun4v_ccb_submit(ctx->ccb_buf_ra, count,
921 				 HV_CCB_QUERY_CMD | HV_CCB_VA_SECONDARY, 0,
922 				 &accepted_len, &ctx->result.exec.status_data);
923 
924 	switch (hv_rv) {
925 	case HV_EOK:
926 		/*
927 		 * Hcall succeeded with no errors but the accepted
928 		 * length may be less than the requested length.  The
929 		 * only way the driver can resubmit the remainder is
930 		 * to wait for completion of the submitted CCBs since
931 		 * there is no way to guarantee the ordering semantics
932 		 * required by the client applications.  Therefore we
933 		 * let the user library deal with resubmissions.
934 		 */
935 		ctx->result.exec.status = DAX_SUBMIT_OK;
936 		break;
937 	case HV_EWOULDBLOCK:
938 		/*
939 		 * This is a transient HV API error. The user library
940 		 * can retry.
941 		 */
942 		dax_dbg("hcall returned HV_EWOULDBLOCK");
943 		ctx->result.exec.status = DAX_SUBMIT_ERR_WOULDBLOCK;
944 		break;
945 	case HV_ENOMAP:
946 		/*
947 		 * HV was unable to translate a VA. The VA it could
948 		 * not translate is returned in the status_data param.
949 		 */
950 		dax_dbg("hcall returned HV_ENOMAP");
951 		ctx->result.exec.status = DAX_SUBMIT_ERR_NOMAP;
952 		break;
953 	case HV_EINVAL:
954 		/*
955 		 * This is the result of an invalid user CCB as HV is
956 		 * validating some of the user CCB fields.  Pass this
957 		 * error back to the user. There is no supporting info
958 		 * to isolate the invalid field.
959 		 */
960 		dax_dbg("hcall returned HV_EINVAL");
961 		ctx->result.exec.status = DAX_SUBMIT_ERR_CCB_INVAL;
962 		break;
963 	case HV_ENOACCESS:
964 		/*
965 		 * HV found a VA that did not have the appropriate
966 		 * permissions (such as the w bit). The VA in question
967 		 * is returned in status_data param.
968 		 */
969 		dax_dbg("hcall returned HV_ENOACCESS");
970 		ctx->result.exec.status = DAX_SUBMIT_ERR_NOACCESS;
971 		break;
972 	case HV_EUNAVAILABLE:
973 		/*
974 		 * The requested CCB operation could not be performed
975 		 * at this time. Return the specific unavailable code
976 		 * in the status_data field.
977 		 */
978 		dax_dbg("hcall returned HV_EUNAVAILABLE");
979 		ctx->result.exec.status = DAX_SUBMIT_ERR_UNAVAIL;
980 		break;
981 	default:
982 		ctx->result.exec.status = DAX_SUBMIT_ERR_INTERNAL;
983 		dax_dbg("unknown hcall return value (%ld)", hv_rv);
984 		break;
985 	}
986 
987 	/* unlock pages associated with the unaccepted CCBs */
988 	naccepted = accepted_len / sizeof(struct dax_ccb);
989 	dax_unlock_pages(ctx, idx + naccepted, nccbs - naccepted);
990 
991 	/* mark unaccepted CCBs as not completed */
992 	for (i = idx + naccepted; i < idx + nccbs; i++)
993 		ctx->ca_buf[i].status = CCA_STAT_COMPLETED;
994 
995 	ctx->ccb_count += naccepted;
996 	ctx->fail_count += nccbs - naccepted;
997 
998 	dax_dbg("hcall rv=%ld, accepted_len=%ld, status_data=0x%llx, ret status=%d",
999 		hv_rv, accepted_len, ctx->result.exec.status_data,
1000 		ctx->result.exec.status);
1001 
1002 	if (count == accepted_len)
1003 		ctx->client = NULL; /* no read needed to complete protocol */
1004 	return accepted_len;
1005 }
1006