xref: /linux/include/misc/ocxl.h (revision f29f24b5568fd6169e0363c78f1a80db38d0e7e9)
1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2017 IBM Corp.
3 #ifndef _MISC_OCXL_H_
4 #define _MISC_OCXL_H_
5 
6 #include <linux/pci.h>
7 
8 /*
9  * Opencapi drivers all need some common facilities, like parsing the
10  * device configuration space, adding a Process Element to the Shared
11  * Process Area, etc...
12  *
13  * The ocxl module provides a kernel API, to allow other drivers to
14  * reuse common code. A bit like a in-kernel library.
15  */
16 
17 #define OCXL_AFU_NAME_SZ      (24+1)  /* add 1 for NULL termination */
18 
19 
20 struct ocxl_afu_config {
21 	u8 idx;
22 	int dvsec_afu_control_pos; /* offset of AFU control DVSEC */
23 	char name[OCXL_AFU_NAME_SZ];
24 	u8 version_major;
25 	u8 version_minor;
26 	u8 afuc_type;
27 	u8 afum_type;
28 	u8 profile;
29 	u8 global_mmio_bar;     /* global MMIO area */
30 	u64 global_mmio_offset;
31 	u32 global_mmio_size;
32 	u8 pp_mmio_bar;         /* per-process MMIO area */
33 	u64 pp_mmio_offset;
34 	u32 pp_mmio_stride;
35 	u8 log_mem_size;
36 	u8 pasid_supported_log;
37 	u16 actag_supported;
38 };
39 
40 struct ocxl_fn_config {
41 	int dvsec_tl_pos;       /* offset of the Transaction Layer DVSEC */
42 	int dvsec_function_pos; /* offset of the Function DVSEC */
43 	int dvsec_afu_info_pos; /* offset of the AFU information DVSEC */
44 	s8 max_pasid_log;
45 	s8 max_afu_index;
46 };
47 
48 enum ocxl_endian {
49 	OCXL_BIG_ENDIAN = 0,    /**< AFU data is big-endian */
50 	OCXL_LITTLE_ENDIAN = 1, /**< AFU data is little-endian */
51 	OCXL_HOST_ENDIAN = 2,   /**< AFU data is the same endianness as the host */
52 };
53 
54 // These are opaque outside the ocxl driver
55 struct ocxl_afu;
56 struct ocxl_fn;
57 struct ocxl_context;
58 
59 // Device detection & initialisation
60 
61 /**
62  * Open an OpenCAPI function on an OpenCAPI device
63  *
64  * @dev: The PCI device that contains the function
65  *
66  * Returns an opaque pointer to the function, or an error pointer (check with IS_ERR)
67  */
68 struct ocxl_fn *ocxl_function_open(struct pci_dev *dev);
69 
70 /**
71  * Get the list of AFUs associated with a PCI function device
72  *
73  * Returns a list of struct ocxl_afu *
74  *
75  * @fn: The OpenCAPI function containing the AFUs
76  */
77 struct list_head *ocxl_function_afu_list(struct ocxl_fn *fn);
78 
79 /**
80  * Fetch an AFU instance from an OpenCAPI function
81  *
82  * @fn: The OpenCAPI function to get the AFU from
83  * @afu_idx: The index of the AFU to get
84  *
85  * If successful, the AFU should be released with ocxl_afu_put()
86  *
87  * Returns a pointer to the AFU, or NULL on error
88  */
89 struct ocxl_afu *ocxl_function_fetch_afu(struct ocxl_fn *fn, u8 afu_idx);
90 
91 /**
92  * Take a reference to an AFU
93  *
94  * @afu: The AFU to increment the reference count on
95  */
96 void ocxl_afu_get(struct ocxl_afu *afu);
97 
98 /**
99  * Release a reference to an AFU
100  *
101  * @afu: The AFU to decrement the reference count on
102  */
103 void ocxl_afu_put(struct ocxl_afu *afu);
104 
105 
106 /**
107  * Get the configuration information for an OpenCAPI function
108  *
109  * @fn: The OpenCAPI function to get the config for
110  *
111  * Returns the function config, or NULL on error
112  */
113 const struct ocxl_fn_config *ocxl_function_config(struct ocxl_fn *fn);
114 
115 /**
116  * Close an OpenCAPI function
117  *
118  * This will free any AFUs previously retrieved from the function, and
119  * detach and associated contexts. The contexts must by freed by the caller.
120  *
121  * @fn: The OpenCAPI function to close
122  *
123  */
124 void ocxl_function_close(struct ocxl_fn *fn);
125 
126 // Context allocation
127 
128 /**
129  * Allocate an OpenCAPI context
130  *
131  * @context: The OpenCAPI context to allocate, must be freed with ocxl_context_free
132  * @afu: The AFU the context belongs to
133  * @mapping: The mapping to unmap when the context is closed (may be NULL)
134  */
135 int ocxl_context_alloc(struct ocxl_context **context, struct ocxl_afu *afu,
136 			struct address_space *mapping);
137 
138 /**
139  * Free an OpenCAPI context
140  *
141  * @ctx: The OpenCAPI context to free
142  */
143 void ocxl_context_free(struct ocxl_context *ctx);
144 
145 /**
146  * Grant access to an MM to an OpenCAPI context
147  * @ctx: The OpenCAPI context to attach
148  * @amr: The value of the AMR register to restrict access
149  * @mm: The mm to attach to the context
150  *
151  * Returns 0 on success, negative on failure
152  */
153 int ocxl_context_attach(struct ocxl_context *ctx, u64 amr,
154 				struct mm_struct *mm);
155 
156 /**
157  * Detach an MM from an OpenCAPI context
158  * @ctx: The OpenCAPI context to attach
159  *
160  * Returns 0 on success, negative on failure
161  */
162 int ocxl_context_detach(struct ocxl_context *ctx);
163 
164 // AFU IRQs
165 
166 /**
167  * Allocate an IRQ associated with an AFU context
168  * @ctx: the AFU context
169  * @irq_id: out, the IRQ ID
170  *
171  * Returns 0 on success, negative on failure
172  */
173 extern int ocxl_afu_irq_alloc(struct ocxl_context *ctx, int *irq_id);
174 
175 /**
176  * Frees an IRQ associated with an AFU context
177  * @ctx: the AFU context
178  * @irq_id: the IRQ ID
179  *
180  * Returns 0 on success, negative on failure
181  */
182 extern int ocxl_afu_irq_free(struct ocxl_context *ctx, int irq_id);
183 
184 /**
185  * Gets the address of the trigger page for an IRQ
186  * This can then be provided to an AFU which will write to that
187  * page to trigger the IRQ.
188  * @ctx: The AFU context that the IRQ is associated with
189  * @irq_id: The IRQ ID
190  *
191  * returns the trigger page address, or 0 if the IRQ is not valid
192  */
193 extern u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, int irq_id);
194 
195 /**
196  * Provide a callback to be called when an IRQ is triggered
197  * @ctx: The AFU context that the IRQ is associated with
198  * @irq_id: The IRQ ID
199  * @handler: the callback to be called when the IRQ is triggered
200  * @free_private: the callback to be called when the IRQ is freed (may be NULL)
201  * @private: Private data to be passed to the callbacks
202  *
203  * Returns 0 on success, negative on failure
204  */
205 int ocxl_irq_set_handler(struct ocxl_context *ctx, int irq_id,
206 		irqreturn_t (*handler)(void *private),
207 		void (*free_private)(void *private),
208 		void *private);
209 
210 // AFU Metadata
211 
212 /**
213  * Get a pointer to the config for an AFU
214  *
215  * @afu: a pointer to the AFU to get the config for
216  *
217  * Returns a pointer to the AFU config
218  */
219 struct ocxl_afu_config *ocxl_afu_config(struct ocxl_afu *afu);
220 
221 /**
222  * Assign opaque hardware specific information to an OpenCAPI AFU.
223  *
224  * @dev: The PCI device associated with the OpenCAPI device
225  * @private: the opaque hardware specific information to assign to the driver
226  */
227 void ocxl_afu_set_private(struct ocxl_afu *afu, void *private);
228 
229 /**
230  * Fetch the hardware specific information associated with an external OpenCAPI
231  * AFU. This may be consumed by an external OpenCAPI driver.
232  *
233  * @afu: The AFU
234  *
235  * Returns the opaque pointer associated with the device, or NULL if not set
236  */
237 void *ocxl_afu_get_private(struct ocxl_afu *dev);
238 
239 // Global MMIO
240 /**
241  * Read a 32 bit value from global MMIO
242  *
243  * @afu: The AFU
244  * @offset: The Offset from the start of MMIO
245  * @endian: the endianness that the MMIO data is in
246  * @val: returns the value
247  *
248  * Returns 0 for success, negative on error
249  */
250 int ocxl_global_mmio_read32(struct ocxl_afu *afu, size_t offset,
251 				enum ocxl_endian endian, u32 *val);
252 
253 /**
254  * Read a 64 bit value from global MMIO
255  *
256  * @afu: The AFU
257  * @offset: The Offset from the start of MMIO
258  * @endian: the endianness that the MMIO data is in
259  * @val: returns the value
260  *
261  * Returns 0 for success, negative on error
262  */
263 int ocxl_global_mmio_read64(struct ocxl_afu *afu, size_t offset,
264 				enum ocxl_endian endian, u64 *val);
265 
266 /**
267  * Write a 32 bit value to global MMIO
268  *
269  * @afu: The AFU
270  * @offset: The Offset from the start of MMIO
271  * @endian: the endianness that the MMIO data is in
272  * @val: The value to write
273  *
274  * Returns 0 for success, negative on error
275  */
276 int ocxl_global_mmio_write32(struct ocxl_afu *afu, size_t offset,
277 				enum ocxl_endian endian, u32 val);
278 
279 /**
280  * Write a 64 bit value to global MMIO
281  *
282  * @afu: The AFU
283  * @offset: The Offset from the start of MMIO
284  * @endian: the endianness that the MMIO data is in
285  * @val: The value to write
286  *
287  * Returns 0 for success, negative on error
288  */
289 int ocxl_global_mmio_write64(struct ocxl_afu *afu, size_t offset,
290 				enum ocxl_endian endian, u64 val);
291 
292 /**
293  * Set bits in a 32 bit global MMIO register
294  *
295  * @afu: The AFU
296  * @offset: The Offset from the start of MMIO
297  * @endian: the endianness that the MMIO data is in
298  * @mask: a mask of the bits to set
299  *
300  * Returns 0 for success, negative on error
301  */
302 int ocxl_global_mmio_set32(struct ocxl_afu *afu, size_t offset,
303 				enum ocxl_endian endian, u32 mask);
304 
305 /**
306  * Set bits in a 64 bit global MMIO register
307  *
308  * @afu: The AFU
309  * @offset: The Offset from the start of MMIO
310  * @endian: the endianness that the MMIO data is in
311  * @mask: a mask of the bits to set
312  *
313  * Returns 0 for success, negative on error
314  */
315 int ocxl_global_mmio_set64(struct ocxl_afu *afu, size_t offset,
316 				enum ocxl_endian endian, u64 mask);
317 
318 /**
319  * Set bits in a 32 bit global MMIO register
320  *
321  * @afu: The AFU
322  * @offset: The Offset from the start of MMIO
323  * @endian: the endianness that the MMIO data is in
324  * @mask: a mask of the bits to set
325  *
326  * Returns 0 for success, negative on error
327  */
328 int ocxl_global_mmio_clear32(struct ocxl_afu *afu, size_t offset,
329 				enum ocxl_endian endian, u32 mask);
330 
331 /**
332  * Set bits in a 64 bit global MMIO register
333  *
334  * @afu: The AFU
335  * @offset: The Offset from the start of MMIO
336  * @endian: the endianness that the MMIO data is in
337  * @mask: a mask of the bits to set
338  *
339  * Returns 0 for success, negative on error
340  */
341 int ocxl_global_mmio_clear64(struct ocxl_afu *afu, size_t offset,
342 				enum ocxl_endian endian, u64 mask);
343 
344 // Functions left here are for compatibility with the cxlflash driver
345 
346 /*
347  * Read the configuration space of a function for the AFU specified by
348  * the index 'afu_idx'. Fills in a ocxl_afu_config structure
349  */
350 int ocxl_config_read_afu(struct pci_dev *dev,
351 				struct ocxl_fn_config *fn,
352 				struct ocxl_afu_config *afu,
353 				u8 afu_idx);
354 
355 /*
356  * Tell an AFU, by writing in the configuration space, the PASIDs that
357  * it can use. Range starts at 'pasid_base' and its size is a multiple
358  * of 2
359  *
360  * 'afu_control_offset' is the offset of the AFU control DVSEC which
361  * can be found in the function configuration
362  */
363 void ocxl_config_set_afu_pasid(struct pci_dev *dev,
364 				int afu_control_offset,
365 				int pasid_base, u32 pasid_count_log);
366 
367 /*
368  * Get the actag configuration for the function:
369  * 'base' is the first actag value that can be used.
370  * 'enabled' it the number of actags available, starting from base.
371  * 'supported' is the total number of actags desired by all the AFUs
372  *             of the function.
373  */
374 int ocxl_config_get_actag_info(struct pci_dev *dev,
375 				u16 *base, u16 *enabled, u16 *supported);
376 
377 /*
378  * Tell a function, by writing in the configuration space, the actags
379  * it can use.
380  *
381  * 'func_offset' is the offset of the Function DVSEC that can found in
382  * the function configuration
383  */
384 void ocxl_config_set_actag(struct pci_dev *dev, int func_offset,
385 				u32 actag_base, u32 actag_count);
386 
387 /*
388  * Tell an AFU, by writing in the configuration space, the actags it
389  * can use.
390  *
391  * 'afu_control_offset' is the offset of the AFU control DVSEC for the
392  * desired AFU. It can be found in the AFU configuration
393  */
394 void ocxl_config_set_afu_actag(struct pci_dev *dev,
395 				int afu_control_offset,
396 				int actag_base, int actag_count);
397 
398 /*
399  * Enable/disable an AFU, by writing in the configuration space.
400  *
401  * 'afu_control_offset' is the offset of the AFU control DVSEC for the
402  * desired AFU. It can be found in the AFU configuration
403  */
404 void ocxl_config_set_afu_state(struct pci_dev *dev,
405 				int afu_control_offset, int enable);
406 
407 /*
408  * Set the Transaction Layer configuration in the configuration space.
409  * Only needed for function 0.
410  *
411  * It queries the host TL capabilities, find some common ground
412  * between the host and device, and set the Transaction Layer on both
413  * accordingly.
414  */
415 int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec);
416 
417 /*
418  * Request an AFU to terminate a PASID.
419  * Will return once the AFU has acked the request, or an error in case
420  * of timeout.
421  *
422  * The hardware can only terminate one PASID at a time, so caller must
423  * guarantee some kind of serialization.
424  *
425  * 'afu_control_offset' is the offset of the AFU control DVSEC for the
426  * desired AFU. It can be found in the AFU configuration
427  */
428 int ocxl_config_terminate_pasid(struct pci_dev *dev,
429 				int afu_control_offset, int pasid);
430 
431 /*
432  * Read the configuration space of a function and fill in a
433  * ocxl_fn_config structure with all the function details
434  */
435 int ocxl_config_read_function(struct pci_dev *dev,
436 				struct ocxl_fn_config *fn);
437 
438 /*
439  * Set up the opencapi link for the function.
440  *
441  * When called for the first time for a link, it sets up the Shared
442  * Process Area for the link and the interrupt handler to process
443  * translation faults.
444  *
445  * Returns a 'link handle' that should be used for further calls for
446  * the link
447  */
448 int ocxl_link_setup(struct pci_dev *dev, int PE_mask,
449 			void **link_handle);
450 
451 /*
452  * Remove the association between the function and its link.
453  */
454 void ocxl_link_release(struct pci_dev *dev, void *link_handle);
455 
456 /*
457  * Add a Process Element to the Shared Process Area for a link.
458  * The process is defined by its PASID, pid, tid and its mm_struct.
459  *
460  * 'xsl_err_cb' is an optional callback if the driver wants to be
461  * notified when the translation fault interrupt handler detects an
462  * address error.
463  * 'xsl_err_data' is an argument passed to the above callback, if
464  * defined
465  */
466 int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,
467 		u64 amr, struct mm_struct *mm,
468 		void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),
469 		void *xsl_err_data);
470 
471 /*
472  * Remove a Process Element from the Shared Process Area for a link
473  */
474 int ocxl_link_remove_pe(void *link_handle, int pasid);
475 
476 /*
477  * Allocate an AFU interrupt associated to the link.
478  *
479  * 'hw_irq' is the hardware interrupt number
480  * 'obj_handle' is the 64-bit object handle to be passed to the AFU to
481  * trigger the interrupt.
482  * On P9, 'obj_handle' is an address, which, if written, triggers the
483  * interrupt. It is an MMIO address which needs to be remapped (one
484  * page).
485  */
486 int ocxl_link_irq_alloc(void *link_handle, int *hw_irq,
487 			u64 *obj_handle);
488 
489 /*
490  * Free a previously allocated AFU interrupt
491  */
492 void ocxl_link_free_irq(void *link_handle, int hw_irq);
493 
494 #endif /* _MISC_OCXL_H_ */
495