xref: /openbmc/linux/drivers/misc/cxl/api.c (revision 3e26a691)
1 /*
2  * Copyright 2014 IBM Corp.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  */
9 
10 #include <linux/pci.h>
11 #include <linux/slab.h>
12 #include <linux/anon_inodes.h>
13 #include <linux/file.h>
14 #include <misc/cxl.h>
15 #include <linux/fs.h>
16 
17 #include "cxl.h"
18 
19 struct cxl_context *cxl_dev_context_init(struct pci_dev *dev)
20 {
21 	struct address_space *mapping;
22 	struct cxl_afu *afu;
23 	struct cxl_context  *ctx;
24 	int rc;
25 
26 	afu = cxl_pci_to_afu(dev);
27 
28 	ctx = cxl_context_alloc();
29 	if (IS_ERR(ctx)) {
30 		rc = PTR_ERR(ctx);
31 		goto err_dev;
32 	}
33 
34 	ctx->kernelapi = true;
35 
36 	/*
37 	 * Make our own address space since we won't have one from the
38 	 * filesystem like the user api has, and even if we do associate a file
39 	 * with this context we don't want to use the global anonymous inode's
40 	 * address space as that can invalidate unrelated users:
41 	 */
42 	mapping = kmalloc(sizeof(struct address_space), GFP_KERNEL);
43 	if (!mapping) {
44 		rc = -ENOMEM;
45 		goto err_ctx;
46 	}
47 	address_space_init_once(mapping);
48 
49 	/* Make it a slave context.  We can promote it later? */
50 	rc = cxl_context_init(ctx, afu, false, mapping);
51 	if (rc)
52 		goto err_mapping;
53 
54 	return ctx;
55 
56 err_mapping:
57 	kfree(mapping);
58 err_ctx:
59 	kfree(ctx);
60 err_dev:
61 	return ERR_PTR(rc);
62 }
63 EXPORT_SYMBOL_GPL(cxl_dev_context_init);
64 
65 struct cxl_context *cxl_get_context(struct pci_dev *dev)
66 {
67 	return dev->dev.archdata.cxl_ctx;
68 }
69 EXPORT_SYMBOL_GPL(cxl_get_context);
70 
71 struct device *cxl_get_phys_dev(struct pci_dev *dev)
72 {
73 	struct cxl_afu *afu;
74 
75 	afu = cxl_pci_to_afu(dev);
76 
77 	return afu->adapter->dev.parent;
78 }
79 
80 int cxl_release_context(struct cxl_context *ctx)
81 {
82 	if (ctx->status >= STARTED)
83 		return -EBUSY;
84 
85 	cxl_context_free(ctx);
86 
87 	return 0;
88 }
89 EXPORT_SYMBOL_GPL(cxl_release_context);
90 
91 static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num)
92 {
93 	__u16 range;
94 	int r;
95 
96 	for (r = 0; r < CXL_IRQ_RANGES; r++) {
97 		range = ctx->irqs.range[r];
98 		if (num < range) {
99 			return ctx->irqs.offset[r] + num;
100 		}
101 		num -= range;
102 	}
103 	return 0;
104 }
105 
106 int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num)
107 {
108 	int res;
109 	irq_hw_number_t hwirq;
110 
111 	if (num == 0)
112 		num = ctx->afu->pp_irqs;
113 	res = afu_allocate_irqs(ctx, num);
114 	if (!res && !cpu_has_feature(CPU_FTR_HVMODE)) {
115 		/* In a guest, the PSL interrupt is not multiplexed. It was
116 		 * allocated above, and we need to set its handler
117 		 */
118 		hwirq = cxl_find_afu_irq(ctx, 0);
119 		if (hwirq)
120 			cxl_map_irq(ctx->afu->adapter, hwirq, cxl_ops->psl_interrupt, ctx, "psl");
121 	}
122 	return res;
123 }
124 EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs);
125 
126 void cxl_free_afu_irqs(struct cxl_context *ctx)
127 {
128 	irq_hw_number_t hwirq;
129 	unsigned int virq;
130 
131 	if (!cpu_has_feature(CPU_FTR_HVMODE)) {
132 		hwirq = cxl_find_afu_irq(ctx, 0);
133 		if (hwirq) {
134 			virq = irq_find_mapping(NULL, hwirq);
135 			if (virq)
136 				cxl_unmap_irq(virq, ctx);
137 		}
138 	}
139 	afu_irq_name_free(ctx);
140 	cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);
141 }
142 EXPORT_SYMBOL_GPL(cxl_free_afu_irqs);
143 
144 int cxl_map_afu_irq(struct cxl_context *ctx, int num,
145 		    irq_handler_t handler, void *cookie, char *name)
146 {
147 	irq_hw_number_t hwirq;
148 
149 	/*
150 	 * Find interrupt we are to register.
151 	 */
152 	hwirq = cxl_find_afu_irq(ctx, num);
153 	if (!hwirq)
154 		return -ENOENT;
155 
156 	return cxl_map_irq(ctx->afu->adapter, hwirq, handler, cookie, name);
157 }
158 EXPORT_SYMBOL_GPL(cxl_map_afu_irq);
159 
160 void cxl_unmap_afu_irq(struct cxl_context *ctx, int num, void *cookie)
161 {
162 	irq_hw_number_t hwirq;
163 	unsigned int virq;
164 
165 	hwirq = cxl_find_afu_irq(ctx, num);
166 	if (!hwirq)
167 		return;
168 
169 	virq = irq_find_mapping(NULL, hwirq);
170 	if (virq)
171 		cxl_unmap_irq(virq, cookie);
172 }
173 EXPORT_SYMBOL_GPL(cxl_unmap_afu_irq);
174 
175 /*
176  * Start a context
177  * Code here similar to afu_ioctl_start_work().
178  */
179 int cxl_start_context(struct cxl_context *ctx, u64 wed,
180 		      struct task_struct *task)
181 {
182 	int rc = 0;
183 	bool kernel = true;
184 
185 	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
186 
187 	mutex_lock(&ctx->status_mutex);
188 	if (ctx->status == STARTED)
189 		goto out; /* already started */
190 
191 	if (task) {
192 		ctx->pid = get_task_pid(task, PIDTYPE_PID);
193 		ctx->glpid = get_task_pid(task->group_leader, PIDTYPE_PID);
194 		kernel = false;
195 	}
196 
197 	cxl_ctx_get();
198 
199 	if ((rc = cxl_ops->attach_process(ctx, kernel, wed, 0))) {
200 		put_pid(ctx->pid);
201 		cxl_ctx_put();
202 		goto out;
203 	}
204 
205 	ctx->status = STARTED;
206 out:
207 	mutex_unlock(&ctx->status_mutex);
208 	return rc;
209 }
210 EXPORT_SYMBOL_GPL(cxl_start_context);
211 
212 int cxl_process_element(struct cxl_context *ctx)
213 {
214 	return ctx->external_pe;
215 }
216 EXPORT_SYMBOL_GPL(cxl_process_element);
217 
218 /* Stop a context.  Returns 0 on success, otherwise -Errno */
219 int cxl_stop_context(struct cxl_context *ctx)
220 {
221 	return __detach_context(ctx);
222 }
223 EXPORT_SYMBOL_GPL(cxl_stop_context);
224 
225 void cxl_set_master(struct cxl_context *ctx)
226 {
227 	ctx->master = true;
228 }
229 EXPORT_SYMBOL_GPL(cxl_set_master);
230 
231 /* wrappers around afu_* file ops which are EXPORTED */
232 int cxl_fd_open(struct inode *inode, struct file *file)
233 {
234 	return afu_open(inode, file);
235 }
236 EXPORT_SYMBOL_GPL(cxl_fd_open);
237 int cxl_fd_release(struct inode *inode, struct file *file)
238 {
239 	return afu_release(inode, file);
240 }
241 EXPORT_SYMBOL_GPL(cxl_fd_release);
242 long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
243 {
244 	return afu_ioctl(file, cmd, arg);
245 }
246 EXPORT_SYMBOL_GPL(cxl_fd_ioctl);
247 int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm)
248 {
249 	return afu_mmap(file, vm);
250 }
251 EXPORT_SYMBOL_GPL(cxl_fd_mmap);
252 unsigned int cxl_fd_poll(struct file *file, struct poll_table_struct *poll)
253 {
254 	return afu_poll(file, poll);
255 }
256 EXPORT_SYMBOL_GPL(cxl_fd_poll);
257 ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
258 			loff_t *off)
259 {
260 	return afu_read(file, buf, count, off);
261 }
262 EXPORT_SYMBOL_GPL(cxl_fd_read);
263 
264 #define PATCH_FOPS(NAME) if (!fops->NAME) fops->NAME = afu_fops.NAME
265 
266 /* Get a struct file and fd for a context and attach the ops */
267 struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
268 			int *fd)
269 {
270 	struct file *file;
271 	int rc, flags, fdtmp;
272 
273 	flags = O_RDWR | O_CLOEXEC;
274 
275 	/* This code is similar to anon_inode_getfd() */
276 	rc = get_unused_fd_flags(flags);
277 	if (rc < 0)
278 		return ERR_PTR(rc);
279 	fdtmp = rc;
280 
281 	/*
282 	 * Patch the file ops.  Needs to be careful that this is rentrant safe.
283 	 */
284 	if (fops) {
285 		PATCH_FOPS(open);
286 		PATCH_FOPS(poll);
287 		PATCH_FOPS(read);
288 		PATCH_FOPS(release);
289 		PATCH_FOPS(unlocked_ioctl);
290 		PATCH_FOPS(compat_ioctl);
291 		PATCH_FOPS(mmap);
292 	} else /* use default ops */
293 		fops = (struct file_operations *)&afu_fops;
294 
295 	file = anon_inode_getfile("cxl", fops, ctx, flags);
296 	if (IS_ERR(file))
297 		goto err_fd;
298 
299 	file->f_mapping = ctx->mapping;
300 
301 	*fd = fdtmp;
302 	return file;
303 
304 err_fd:
305 	put_unused_fd(fdtmp);
306 	return NULL;
307 }
308 EXPORT_SYMBOL_GPL(cxl_get_fd);
309 
310 struct cxl_context *cxl_fops_get_context(struct file *file)
311 {
312 	return file->private_data;
313 }
314 EXPORT_SYMBOL_GPL(cxl_fops_get_context);
315 
316 int cxl_start_work(struct cxl_context *ctx,
317 		   struct cxl_ioctl_start_work *work)
318 {
319 	int rc;
320 
321 	/* code taken from afu_ioctl_start_work */
322 	if (!(work->flags & CXL_START_WORK_NUM_IRQS))
323 		work->num_interrupts = ctx->afu->pp_irqs;
324 	else if ((work->num_interrupts < ctx->afu->pp_irqs) ||
325 		 (work->num_interrupts > ctx->afu->irqs_max)) {
326 		return -EINVAL;
327 	}
328 
329 	rc = afu_register_irqs(ctx, work->num_interrupts);
330 	if (rc)
331 		return rc;
332 
333 	rc = cxl_start_context(ctx, work->work_element_descriptor, current);
334 	if (rc < 0) {
335 		afu_release_irqs(ctx, ctx);
336 		return rc;
337 	}
338 
339 	return 0;
340 }
341 EXPORT_SYMBOL_GPL(cxl_start_work);
342 
343 void __iomem *cxl_psa_map(struct cxl_context *ctx)
344 {
345 	if (ctx->status != STARTED)
346 		return NULL;
347 
348 	pr_devel("%s: psn_phys%llx size:%llx\n",
349 		__func__, ctx->psn_phys, ctx->psn_size);
350 	return ioremap(ctx->psn_phys, ctx->psn_size);
351 }
352 EXPORT_SYMBOL_GPL(cxl_psa_map);
353 
354 void cxl_psa_unmap(void __iomem *addr)
355 {
356 	iounmap(addr);
357 }
358 EXPORT_SYMBOL_GPL(cxl_psa_unmap);
359 
360 int cxl_afu_reset(struct cxl_context *ctx)
361 {
362 	struct cxl_afu *afu = ctx->afu;
363 	int rc;
364 
365 	rc = cxl_ops->afu_reset(afu);
366 	if (rc)
367 		return rc;
368 
369 	return cxl_ops->afu_check_and_enable(afu);
370 }
371 EXPORT_SYMBOL_GPL(cxl_afu_reset);
372 
373 void cxl_perst_reloads_same_image(struct cxl_afu *afu,
374 				  bool perst_reloads_same_image)
375 {
376 	afu->adapter->perst_same_image = perst_reloads_same_image;
377 }
378 EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image);
379 
380 ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count)
381 {
382 	struct cxl_afu *afu = cxl_pci_to_afu(dev);
383 
384 	return cxl_ops->read_adapter_vpd(afu->adapter, buf, count);
385 }
386 EXPORT_SYMBOL_GPL(cxl_read_adapter_vpd);
387