xref: /openbmc/linux/include/misc/ocxl.h (revision d731feea)
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 	u64 lpc_mem_offset;
36 	u64 lpc_mem_size;
37 	u64 special_purpose_mem_offset;
38 	u64 special_purpose_mem_size;
39 	u8 pasid_supported_log;
40 	u16 actag_supported;
41 };
42 
43 struct ocxl_fn_config {
44 	int dvsec_tl_pos;       /* offset of the Transaction Layer DVSEC */
45 	int dvsec_function_pos; /* offset of the Function DVSEC */
46 	int dvsec_afu_info_pos; /* offset of the AFU information DVSEC */
47 	s8 max_pasid_log;
48 	s8 max_afu_index;
49 };
50 
51 enum ocxl_endian {
52 	OCXL_BIG_ENDIAN = 0,    /**< AFU data is big-endian */
53 	OCXL_LITTLE_ENDIAN = 1, /**< AFU data is little-endian */
54 	OCXL_HOST_ENDIAN = 2,   /**< AFU data is the same endianness as the host */
55 };
56 
57 // These are opaque outside the ocxl driver
58 struct ocxl_afu;
59 struct ocxl_fn;
60 struct ocxl_context;
61 
62 // Device detection & initialisation
63 
64 /**
65  * ocxl_function_open() - Open an OpenCAPI function on an OpenCAPI device
66  * @dev: The PCI device that contains the function
67  *
68  * Returns an opaque pointer to the function, or an error pointer (check with IS_ERR)
69  */
70 struct ocxl_fn *ocxl_function_open(struct pci_dev *dev);
71 
72 /**
73  * ocxl_function_afu_list() - Get the list of AFUs associated with a PCI function device
74  * Returns a list of struct ocxl_afu *
75  *
76  * @fn: The OpenCAPI function containing the AFUs
77  */
78 struct list_head *ocxl_function_afu_list(struct ocxl_fn *fn);
79 
80 /**
81  * ocxl_function_fetch_afu() - Fetch an AFU instance from an OpenCAPI function
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  * ocxl_afu_get() - Take a reference to an AFU
93  * @afu: The AFU to increment the reference count on
94  */
95 void ocxl_afu_get(struct ocxl_afu *afu);
96 
97 /**
98  * ocxl_afu_put() - Release a reference to an AFU
99  * @afu: The AFU to decrement the reference count on
100  */
101 void ocxl_afu_put(struct ocxl_afu *afu);
102 
103 
104 /**
105  * ocxl_function_config() - Get the configuration information for an OpenCAPI function
106  * @fn: The OpenCAPI function to get the config for
107  *
108  * Returns the function config, or NULL on error
109  */
110 const struct ocxl_fn_config *ocxl_function_config(struct ocxl_fn *fn);
111 
112 /**
113  * ocxl_function_close() - Close an OpenCAPI function
114  * This will free any AFUs previously retrieved from the function, and
115  * detach and associated contexts. The contexts must by freed by the caller.
116  *
117  * @fn: The OpenCAPI function to close
118  *
119  */
120 void ocxl_function_close(struct ocxl_fn *fn);
121 
122 // Context allocation
123 
124 /**
125  * ocxl_context_alloc() - Allocate an OpenCAPI context
126  * @context: The OpenCAPI context to allocate, must be freed with ocxl_context_free
127  * @afu: The AFU the context belongs to
128  * @mapping: The mapping to unmap when the context is closed (may be NULL)
129  */
130 int ocxl_context_alloc(struct ocxl_context **context, struct ocxl_afu *afu,
131 			struct address_space *mapping);
132 
133 /**
134  * ocxl_context_free() - Free an OpenCAPI context
135  * @ctx: The OpenCAPI context to free
136  */
137 void ocxl_context_free(struct ocxl_context *ctx);
138 
139 /**
140  * ocxl_context_attach() - Grant access to an MM to an OpenCAPI context
141  * @ctx: The OpenCAPI context to attach
142  * @amr: The value of the AMR register to restrict access
143  * @mm: The mm to attach to the context
144  *
145  * Returns 0 on success, negative on failure
146  */
147 int ocxl_context_attach(struct ocxl_context *ctx, u64 amr,
148 				struct mm_struct *mm);
149 
150 /**
151  * ocxl_context_detach() - Detach an MM from an OpenCAPI context
152  * @ctx: The OpenCAPI context to attach
153  *
154  * Returns 0 on success, negative on failure
155  */
156 int ocxl_context_detach(struct ocxl_context *ctx);
157 
158 // AFU IRQs
159 
160 /**
161  * ocxl_afu_irq_alloc() - Allocate an IRQ associated with an AFU context
162  * @ctx: the AFU context
163  * @irq_id: out, the IRQ ID
164  *
165  * Returns 0 on success, negative on failure
166  */
167 int ocxl_afu_irq_alloc(struct ocxl_context *ctx, int *irq_id);
168 
169 /**
170  * ocxl_afu_irq_free() - Frees an IRQ associated with an AFU context
171  * @ctx: the AFU context
172  * @irq_id: the IRQ ID
173  *
174  * Returns 0 on success, negative on failure
175  */
176 int ocxl_afu_irq_free(struct ocxl_context *ctx, int irq_id);
177 
178 /**
179  * ocxl_afu_irq_get_addr() - Gets the address of the trigger page for an IRQ
180  * This can then be provided to an AFU which will write to that
181  * page to trigger the IRQ.
182  * @ctx: The AFU context that the IRQ is associated with
183  * @irq_id: The IRQ ID
184  *
185  * returns the trigger page address, or 0 if the IRQ is not valid
186  */
187 u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, int irq_id);
188 
189 /**
190  * ocxl_irq_set_handler() - Provide a callback to be called when an IRQ is triggered
191  * @ctx: The AFU context that the IRQ is associated with
192  * @irq_id: The IRQ ID
193  * @handler: the callback to be called when the IRQ is triggered
194  * @free_private: the callback to be called when the IRQ is freed (may be NULL)
195  * @private: Private data to be passed to the callbacks
196  *
197  * Returns 0 on success, negative on failure
198  */
199 int ocxl_irq_set_handler(struct ocxl_context *ctx, int irq_id,
200 		irqreturn_t (*handler)(void *private),
201 		void (*free_private)(void *private),
202 		void *private);
203 
204 // AFU Metadata
205 
206 /**
207  * ocxl_afu_config() - Get a pointer to the config for an AFU
208  * @afu: a pointer to the AFU to get the config for
209  *
210  * Returns a pointer to the AFU config
211  */
212 struct ocxl_afu_config *ocxl_afu_config(struct ocxl_afu *afu);
213 
214 /**
215  * ocxl_afu_set_private() - Assign opaque hardware specific information to an OpenCAPI AFU.
216  * @afu: The OpenCAPI AFU
217  * @private: the opaque hardware specific information to assign to the driver
218  */
219 void ocxl_afu_set_private(struct ocxl_afu *afu, void *private);
220 
221 /**
222  * ocxl_afu_get_private() - Fetch the hardware specific information associated with
223  * an external OpenCAPI AFU. This may be consumed by an external OpenCAPI driver.
224  * @afu: The OpenCAPI AFU
225  *
226  * Returns the opaque pointer associated with the device, or NULL if not set
227  */
228 void *ocxl_afu_get_private(struct ocxl_afu *afu);
229 
230 // Global MMIO
231 /**
232  * ocxl_global_mmio_read32() - Read a 32 bit value from global MMIO
233  * @afu: The AFU
234  * @offset: The Offset from the start of MMIO
235  * @endian: the endianness that the MMIO data is in
236  * @val: returns the value
237  *
238  * Returns 0 for success, negative on error
239  */
240 int ocxl_global_mmio_read32(struct ocxl_afu *afu, size_t offset,
241 			    enum ocxl_endian endian, u32 *val);
242 
243 /**
244  * ocxl_global_mmio_read64() - Read a 64 bit value from global MMIO
245  * @afu: The AFU
246  * @offset: The Offset from the start of MMIO
247  * @endian: the endianness that the MMIO data is in
248  * @val: returns the value
249  *
250  * Returns 0 for success, negative on error
251  */
252 int ocxl_global_mmio_read64(struct ocxl_afu *afu, size_t offset,
253 			    enum ocxl_endian endian, u64 *val);
254 
255 /**
256  * ocxl_global_mmio_write32() - Write a 32 bit value to global MMIO
257  * @afu: The AFU
258  * @offset: The Offset from the start of MMIO
259  * @endian: the endianness that the MMIO data is in
260  * @val: The value to write
261  *
262  * Returns 0 for success, negative on error
263  */
264 int ocxl_global_mmio_write32(struct ocxl_afu *afu, size_t offset,
265 			     enum ocxl_endian endian, u32 val);
266 
267 /**
268  * ocxl_global_mmio_write64() - Write a 64 bit value to global MMIO
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_write64(struct ocxl_afu *afu, size_t offset,
277 			     enum ocxl_endian endian, u64 val);
278 
279 /**
280  * ocxl_global_mmio_set32() - Set bits in a 32 bit global MMIO register
281  * @afu: The AFU
282  * @offset: The Offset from the start of MMIO
283  * @endian: the endianness that the MMIO data is in
284  * @mask: a mask of the bits to set
285  *
286  * Returns 0 for success, negative on error
287  */
288 int ocxl_global_mmio_set32(struct ocxl_afu *afu, size_t offset,
289 			   enum ocxl_endian endian, u32 mask);
290 
291 /**
292  * ocxl_global_mmio_set64() - Set bits in a 64 bit global MMIO register
293  * @afu: The AFU
294  * @offset: The Offset from the start of MMIO
295  * @endian: the endianness that the MMIO data is in
296  * @mask: a mask of the bits to set
297  *
298  * Returns 0 for success, negative on error
299  */
300 int ocxl_global_mmio_set64(struct ocxl_afu *afu, size_t offset,
301 			   enum ocxl_endian endian, u64 mask);
302 
303 /**
304  * ocxl_global_mmio_clear32() - Set bits in a 32 bit global MMIO register
305  * @afu: The AFU
306  * @offset: The Offset from the start of MMIO
307  * @endian: the endianness that the MMIO data is in
308  * @mask: a mask of the bits to set
309  *
310  * Returns 0 for success, negative on error
311  */
312 int ocxl_global_mmio_clear32(struct ocxl_afu *afu, size_t offset,
313 			     enum ocxl_endian endian, u32 mask);
314 
315 /**
316  * ocxl_global_mmio_clear64() - Set bits in a 64 bit global MMIO register
317  * @afu: The AFU
318  * @offset: The Offset from the start of MMIO
319  * @endian: the endianness that the MMIO data is in
320  * @mask: a mask of the bits to set
321  *
322  * Returns 0 for success, negative on error
323  */
324 int ocxl_global_mmio_clear64(struct ocxl_afu *afu, size_t offset,
325 			     enum ocxl_endian endian, u64 mask);
326 
327 // Functions left here are for compatibility with the cxlflash driver
328 
329 /*
330  * Read the configuration space of a function for the AFU specified by
331  * the index 'afu_idx'. Fills in a ocxl_afu_config structure
332  */
333 int ocxl_config_read_afu(struct pci_dev *dev,
334 				struct ocxl_fn_config *fn,
335 				struct ocxl_afu_config *afu,
336 				u8 afu_idx);
337 
338 /*
339  * Tell an AFU, by writing in the configuration space, the PASIDs that
340  * it can use. Range starts at 'pasid_base' and its size is a multiple
341  * of 2
342  *
343  * 'afu_control_offset' is the offset of the AFU control DVSEC which
344  * can be found in the function configuration
345  */
346 void ocxl_config_set_afu_pasid(struct pci_dev *dev,
347 				int afu_control_offset,
348 				int pasid_base, u32 pasid_count_log);
349 
350 /*
351  * Get the actag configuration for the function:
352  * 'base' is the first actag value that can be used.
353  * 'enabled' it the number of actags available, starting from base.
354  * 'supported' is the total number of actags desired by all the AFUs
355  *             of the function.
356  */
357 int ocxl_config_get_actag_info(struct pci_dev *dev,
358 				u16 *base, u16 *enabled, u16 *supported);
359 
360 /*
361  * Tell a function, by writing in the configuration space, the actags
362  * it can use.
363  *
364  * 'func_offset' is the offset of the Function DVSEC that can found in
365  * the function configuration
366  */
367 void ocxl_config_set_actag(struct pci_dev *dev, int func_offset,
368 				u32 actag_base, u32 actag_count);
369 
370 /*
371  * Tell an AFU, by writing in the configuration space, the actags it
372  * can use.
373  *
374  * 'afu_control_offset' is the offset of the AFU control DVSEC for the
375  * desired AFU. It can be found in the AFU configuration
376  */
377 void ocxl_config_set_afu_actag(struct pci_dev *dev,
378 				int afu_control_offset,
379 				int actag_base, int actag_count);
380 
381 /*
382  * Enable/disable an AFU, by writing in the configuration space.
383  *
384  * 'afu_control_offset' is the offset of the AFU control DVSEC for the
385  * desired AFU. It can be found in the AFU configuration
386  */
387 void ocxl_config_set_afu_state(struct pci_dev *dev,
388 				int afu_control_offset, int enable);
389 
390 /*
391  * Set the Transaction Layer configuration in the configuration space.
392  * Only needed for function 0.
393  *
394  * It queries the host TL capabilities, find some common ground
395  * between the host and device, and set the Transaction Layer on both
396  * accordingly.
397  */
398 int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec);
399 
400 /*
401  * Request an AFU to terminate a PASID.
402  * Will return once the AFU has acked the request, or an error in case
403  * of timeout.
404  *
405  * The hardware can only terminate one PASID at a time, so caller must
406  * guarantee some kind of serialization.
407  *
408  * 'afu_control_offset' is the offset of the AFU control DVSEC for the
409  * desired AFU. It can be found in the AFU configuration
410  */
411 int ocxl_config_terminate_pasid(struct pci_dev *dev,
412 				int afu_control_offset, int pasid);
413 
414 /*
415  * Read the configuration space of a function and fill in a
416  * ocxl_fn_config structure with all the function details
417  */
418 int ocxl_config_read_function(struct pci_dev *dev,
419 				struct ocxl_fn_config *fn);
420 
421 /*
422  * Set up the opencapi link for the function.
423  *
424  * When called for the first time for a link, it sets up the Shared
425  * Process Area for the link and the interrupt handler to process
426  * translation faults.
427  *
428  * Returns a 'link handle' that should be used for further calls for
429  * the link
430  */
431 int ocxl_link_setup(struct pci_dev *dev, int PE_mask,
432 			void **link_handle);
433 
434 /*
435  * Remove the association between the function and its link.
436  */
437 void ocxl_link_release(struct pci_dev *dev, void *link_handle);
438 
439 /*
440  * Add a Process Element to the Shared Process Area for a link.
441  * The process is defined by its PASID, pid, tid and its mm_struct.
442  *
443  * 'xsl_err_cb' is an optional callback if the driver wants to be
444  * notified when the translation fault interrupt handler detects an
445  * address error.
446  * 'xsl_err_data' is an argument passed to the above callback, if
447  * defined
448  */
449 int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,
450 		u64 amr, u16 bdf, struct mm_struct *mm,
451 		void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),
452 		void *xsl_err_data);
453 
454 /*
455  * Remove a Process Element from the Shared Process Area for a link
456  */
457 int ocxl_link_remove_pe(void *link_handle, int pasid);
458 
459 /*
460  * Allocate an AFU interrupt associated to the link.
461  *
462  * 'hw_irq' is the hardware interrupt number
463  */
464 int ocxl_link_irq_alloc(void *link_handle, int *hw_irq);
465 
466 /*
467  * Free a previously allocated AFU interrupt
468  */
469 void ocxl_link_free_irq(void *link_handle, int hw_irq);
470 
471 #endif /* _MISC_OCXL_H_ */
472