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6f7f0b3d MN |
1 | /* |
2 | * Copyright 2015 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 | #ifndef _MISC_CXL_H | |
11 | #define _MISC_CXL_H | |
12 | ||
13 | #include <linux/pci.h> | |
14 | #include <linux/poll.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <uapi/misc/cxl.h> | |
17 | ||
18 | /* | |
19 | * This documents the in kernel API for driver to use CXL. It allows kernel | |
20 | * drivers to bind to AFUs using an AFU configuration record exposed as a PCI | |
21 | * configuration record. | |
22 | * | |
23 | * This API enables control over AFU and contexts which can't be part of the | |
24 | * generic PCI API. This API is agnostic to the actual AFU. | |
25 | */ | |
26 | ||
4e56f858 IM |
27 | #define CXL_SLOT_FLAG_DMA 0x1 |
28 | ||
29 | /* | |
30 | * Checks if the given card is in a cxl capable slot. Pass CXL_SLOT_FLAG_DMA if | |
31 | * the card requires CAPP DMA mode to also check if the system supports it. | |
32 | * This is intended to be used by bi-modal devices to determine if they can use | |
33 | * cxl mode or if they should continue running in PCI mode. | |
34 | * | |
35 | * Note that this only checks if the slot is cxl capable - it does not | |
36 | * currently check if the CAPP is currently available for chips where it can be | |
37 | * assigned to different PHBs on a first come first serve basis (i.e. P8) | |
38 | */ | |
39 | bool cxl_slot_is_supported(struct pci_dev *dev, int flags); | |
40 | ||
41 | ||
6f7f0b3d MN |
42 | /* Get the AFU associated with a pci_dev */ |
43 | struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev); | |
44 | ||
45 | /* Get the AFU conf record number associated with a pci_dev */ | |
46 | unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev); | |
47 | ||
6f7f0b3d MN |
48 | |
49 | /* | |
50 | * Context lifetime overview: | |
51 | * | |
52 | * An AFU context may be inited and then started and stoppped multiple times | |
53 | * before it's released. ie. | |
54 | * - cxl_dev_context_init() | |
55 | * - cxl_start_context() | |
56 | * - cxl_stop_context() | |
57 | * - cxl_start_context() | |
58 | * - cxl_stop_context() | |
59 | * ...repeat... | |
60 | * - cxl_release_context() | |
61 | * Once released, a context can't be started again. | |
62 | * | |
63 | * One context is inited by the cxl driver for every pci_dev. This is to be | |
64 | * used as a default kernel context. cxl_get_context() will get this | |
65 | * context. This context will be released by PCI hot unplug, so doesn't need to | |
66 | * be released explicitly by drivers. | |
67 | * | |
68 | * Additional kernel contexts may be inited using cxl_dev_context_init(). | |
69 | * These must be released using cxl_context_detach(). | |
70 | * | |
71 | * Once a context has been inited, IRQs may be configured. Firstly these IRQs | |
72 | * must be allocated (cxl_allocate_afu_irqs()), then individually mapped to | |
73 | * specific handlers (cxl_map_afu_irq()). | |
74 | * | |
75 | * These IRQs can be unmapped (cxl_unmap_afu_irq()) and finally released | |
76 | * (cxl_free_afu_irqs()). | |
77 | * | |
78 | * The AFU can be reset (cxl_afu_reset()). This will cause the PSL/AFU | |
79 | * hardware to lose track of all contexts. It's upto the caller of | |
80 | * cxl_afu_reset() to restart these contexts. | |
81 | */ | |
82 | ||
83 | /* | |
84 | * On pci_enabled_device(), the cxl driver will init a single cxl context for | |
85 | * use by the driver. It doesn't start this context (as that will likely | |
86 | * generate DMA traffic for most AFUs). | |
87 | * | |
88 | * This gets the default context associated with this pci_dev. This context | |
89 | * doesn't need to be released as this will be done by the PCI subsystem on hot | |
90 | * unplug. | |
91 | */ | |
92 | struct cxl_context *cxl_get_context(struct pci_dev *dev); | |
93 | /* | |
94 | * Allocate and initalise a context associated with a AFU PCI device. This | |
95 | * doesn't start the context in the AFU. | |
96 | */ | |
97 | struct cxl_context *cxl_dev_context_init(struct pci_dev *dev); | |
98 | /* | |
99 | * Release and free a context. Context should be stopped before calling. | |
100 | */ | |
101 | int cxl_release_context(struct cxl_context *ctx); | |
102 | ||
ad42de85 MN |
103 | /* |
104 | * Set and get private data associated with a context. Allows drivers to have a | |
105 | * back pointer to some useful structure. | |
106 | */ | |
107 | int cxl_set_priv(struct cxl_context *ctx, void *priv); | |
108 | void *cxl_get_priv(struct cxl_context *ctx); | |
109 | ||
6f7f0b3d MN |
110 | /* |
111 | * Allocate AFU interrupts for this context. num=0 will allocate the default | |
112 | * for this AFU as given in the AFU descriptor. This number doesn't include the | |
113 | * interrupt 0 (CAIA defines AFU IRQ 0 for page faults). Each interrupt to be | |
114 | * used must map a handler with cxl_map_afu_irq. | |
115 | */ | |
116 | int cxl_allocate_afu_irqs(struct cxl_context *cxl, int num); | |
117 | /* Free allocated interrupts */ | |
118 | void cxl_free_afu_irqs(struct cxl_context *cxl); | |
119 | ||
120 | /* | |
121 | * Map a handler for an AFU interrupt associated with a particular context. AFU | |
122 | * IRQS numbers start from 1 (CAIA defines AFU IRQ 0 for page faults). cookie | |
123 | * is private data is that will be provided to the interrupt handler. | |
124 | */ | |
125 | int cxl_map_afu_irq(struct cxl_context *cxl, int num, | |
126 | irq_handler_t handler, void *cookie, char *name); | |
127 | /* unmap mapped IRQ handlers */ | |
128 | void cxl_unmap_afu_irq(struct cxl_context *cxl, int num, void *cookie); | |
129 | ||
130 | /* | |
131 | * Start work on the AFU. This starts an cxl context and associates it with a | |
132 | * task. task == NULL will make it a kernel context. | |
133 | */ | |
134 | int cxl_start_context(struct cxl_context *ctx, u64 wed, | |
135 | struct task_struct *task); | |
136 | /* | |
137 | * Stop a context and remove it from the PSL | |
138 | */ | |
139 | int cxl_stop_context(struct cxl_context *ctx); | |
140 | ||
141 | /* Reset the AFU */ | |
142 | int cxl_afu_reset(struct cxl_context *ctx); | |
143 | ||
144 | /* | |
145 | * Set a context as a master context. | |
146 | * This sets the default problem space area mapped as the full space, rather | |
147 | * than just the per context area (for slaves). | |
148 | */ | |
149 | void cxl_set_master(struct cxl_context *ctx); | |
150 | ||
7a0d85d3 IM |
151 | /* |
152 | * Sets the context to use real mode memory accesses to operate with | |
153 | * translation disabled. Note that this only makes sense for kernel contexts | |
154 | * under bare metal, and will not work with virtualisation. May only be | |
155 | * performed on stopped contexts. | |
156 | */ | |
157 | int cxl_set_translation_mode(struct cxl_context *ctx, bool real_mode); | |
158 | ||
6f7f0b3d MN |
159 | /* |
160 | * Map and unmap the AFU Problem Space area. The amount and location mapped | |
161 | * depends on if this context is a master or slave. | |
162 | */ | |
163 | void __iomem *cxl_psa_map(struct cxl_context *ctx); | |
164 | void cxl_psa_unmap(void __iomem *addr); | |
165 | ||
166 | /* Get the process element for this context */ | |
167 | int cxl_process_element(struct cxl_context *ctx); | |
168 | ||
169 | ||
170 | /* | |
171 | * These calls allow drivers to create their own file descriptors and make them | |
172 | * identical to the cxl file descriptor user API. An example use case: | |
173 | * | |
174 | * struct file_operations cxl_my_fops = {}; | |
175 | * ...... | |
176 | * // Init the context | |
177 | * ctx = cxl_dev_context_init(dev); | |
178 | * if (IS_ERR(ctx)) | |
179 | * return PTR_ERR(ctx); | |
180 | * // Create and attach a new file descriptor to my file ops | |
181 | * file = cxl_get_fd(ctx, &cxl_my_fops, &fd); | |
182 | * // Start context | |
183 | * rc = cxl_start_work(ctx, &work.work); | |
184 | * if (rc) { | |
185 | * fput(file); | |
186 | * put_unused_fd(fd); | |
187 | * return -ENODEV; | |
188 | * } | |
189 | * // No error paths after installing the fd | |
190 | * fd_install(fd, file); | |
191 | * return fd; | |
192 | * | |
193 | * This inits a context, and gets a file descriptor and associates some file | |
194 | * ops to that file descriptor. If the file ops are blank, the cxl driver will | |
195 | * fill them in with the default ones that mimic the standard user API. Once | |
196 | * completed, the file descriptor can be installed. Once the file descriptor is | |
197 | * installed, it's visible to the user so no errors must occur past this point. | |
198 | * | |
199 | * If cxl_fd_release() file op call is installed, the context will be stopped | |
200 | * and released when the fd is released. Hence the driver won't need to manage | |
201 | * this itself. | |
202 | */ | |
203 | ||
204 | /* | |
205 | * Take a context and associate it with my file ops. Returns the associated | |
206 | * file and file descriptor. Any file ops which are blank are filled in by the | |
207 | * cxl driver with the default ops to mimic the standard API. | |
208 | */ | |
209 | struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops, | |
210 | int *fd); | |
211 | /* Get the context associated with this file */ | |
212 | struct cxl_context *cxl_fops_get_context(struct file *file); | |
213 | /* | |
214 | * Start a context associated a struct cxl_ioctl_start_work used by the | |
215 | * standard cxl user API. | |
216 | */ | |
217 | int cxl_start_work(struct cxl_context *ctx, | |
218 | struct cxl_ioctl_start_work *work); | |
219 | /* | |
220 | * Export all the existing fops so drivers can use them | |
221 | */ | |
222 | int cxl_fd_open(struct inode *inode, struct file *file); | |
223 | int cxl_fd_release(struct inode *inode, struct file *file); | |
224 | long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg); | |
225 | int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm); | |
226 | unsigned int cxl_fd_poll(struct file *file, struct poll_table_struct *poll); | |
227 | ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count, | |
228 | loff_t *off); | |
229 | ||
13e68d8b DA |
230 | /* |
231 | * For EEH, a driver may want to assert a PERST will reload the same image | |
232 | * from flash into the FPGA. | |
233 | * | |
234 | * This is a property of the entire adapter, not a single AFU, so drivers | |
235 | * should set this property with care! | |
236 | */ | |
237 | void cxl_perst_reloads_same_image(struct cxl_afu *afu, | |
238 | bool perst_reloads_same_image); | |
239 | ||
d601ea91 FB |
240 | /* |
241 | * Read the VPD for the card where the AFU resides | |
242 | */ | |
243 | ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count); | |
244 | ||
b810253b PB |
245 | /* |
246 | * AFU driver ops allow an AFU driver to create their own events to pass to | |
247 | * userspace through the file descriptor as a simpler alternative to overriding | |
248 | * the read() and poll() calls that works with the generic cxl events. These | |
249 | * events are given priority over the generic cxl events, so they will be | |
250 | * delivered first if multiple types of events are pending. | |
251 | * | |
252 | * The AFU driver must call cxl_context_events_pending() to notify the cxl | |
253 | * driver that new events are ready to be delivered for a specific context. | |
254 | * cxl_context_events_pending() will adjust the current count of AFU driver | |
255 | * events for this context, and wake up anyone waiting on the context wait | |
256 | * queue. | |
257 | * | |
258 | * The cxl driver will then call fetch_event() to get a structure defining | |
259 | * the size and address of the driver specific event data. The cxl driver | |
260 | * will build a cxl header with type and process_element fields filled in, | |
261 | * and header.size set to sizeof(struct cxl_event_header) + data_size. | |
262 | * The total size of the event is limited to CXL_READ_MIN_SIZE (4K). | |
263 | * | |
264 | * fetch_event() is called with a spin lock held, so it must not sleep. | |
265 | * | |
266 | * The cxl driver will then deliver the event to userspace, and finally | |
267 | * call event_delivered() to return the status of the operation, identified | |
268 | * by cxl context and AFU driver event data pointers. | |
269 | * 0 Success | |
270 | * -EFAULT copy_to_user() has failed | |
271 | * -EINVAL Event data pointer is NULL, or event size is greater than | |
272 | * CXL_READ_MIN_SIZE. | |
273 | */ | |
274 | struct cxl_afu_driver_ops { | |
275 | struct cxl_event_afu_driver_reserved *(*fetch_event) ( | |
276 | struct cxl_context *ctx); | |
277 | void (*event_delivered) (struct cxl_context *ctx, | |
278 | struct cxl_event_afu_driver_reserved *event, | |
279 | int rc); | |
280 | }; | |
281 | ||
282 | /* | |
283 | * Associate the above driver ops with a specific context. | |
284 | * Reset the current count of AFU driver events. | |
285 | */ | |
286 | void cxl_set_driver_ops(struct cxl_context *ctx, | |
287 | struct cxl_afu_driver_ops *ops); | |
288 | ||
289 | /* Notify cxl driver that new events are ready to be delivered for context */ | |
290 | void cxl_context_events_pending(struct cxl_context *ctx, | |
291 | unsigned int new_events); | |
292 | ||
6f7f0b3d | 293 | #endif /* _MISC_CXL_H */ |