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[linux/fpc-iii.git] / include / misc / cxl.h
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1 /*
2 * Copyright 2015 IBM Corp.
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 */
10 #ifndef _MISC_CXL_H
11 #define _MISC_CXL_H
13 #include <linux/pci.h>
14 #include <linux/poll.h>
15 #include <linux/interrupt.h>
16 #include <uapi/misc/cxl.h>
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.
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.
27 #define CXL_SLOT_FLAG_DMA 0x1
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.
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)
39 bool cxl_slot_is_supported(struct pci_dev *dev, int flags);
42 #define CXL_BIMODE_CXL 1
43 #define CXL_BIMODE_PCI 2
46 * Check the mode that the given bi-modal CXL adapter is currently in and
47 * change it if necessary. This does not apply to AFU drivers.
49 * If the mode matches the requested mode this function will return 0 - if the
50 * driver was expecting the generic CXL driver to have bound to the adapter and
51 * it gets this return value it should fail the probe function to give the CXL
52 * driver a chance to probe it.
54 * If the mode does not match it will start a background task to unplug the
55 * device from Linux and switch its mode, and will return -EBUSY. At this
56 * point the calling driver should make sure it has released the device and
57 * fail its probe function.
59 * The offset of the CXL VSEC can be provided to this function. If 0 is passed,
60 * this function will search for a CXL VSEC with ID 0x1280 and return -ENODEV
61 * if it is not found.
63 #ifdef CONFIG_CXL_BIMODAL
64 int cxl_check_and_switch_mode(struct pci_dev *dev, int mode, int vsec);
65 #endif
67 /* Get the AFU associated with a pci_dev */
68 struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev);
70 /* Get the AFU conf record number associated with a pci_dev */
71 unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev);
75 * Context lifetime overview:
77 * An AFU context may be inited and then started and stoppped multiple times
78 * before it's released. ie.
79 * - cxl_dev_context_init()
80 * - cxl_start_context()
81 * - cxl_stop_context()
82 * - cxl_start_context()
83 * - cxl_stop_context()
84 * ...repeat...
85 * - cxl_release_context()
86 * Once released, a context can't be started again.
88 * One context is inited by the cxl driver for every pci_dev. This is to be
89 * used as a default kernel context. cxl_get_context() will get this
90 * context. This context will be released by PCI hot unplug, so doesn't need to
91 * be released explicitly by drivers.
93 * Additional kernel contexts may be inited using cxl_dev_context_init().
94 * These must be released using cxl_context_detach().
96 * Once a context has been inited, IRQs may be configured. Firstly these IRQs
97 * must be allocated (cxl_allocate_afu_irqs()), then individually mapped to
98 * specific handlers (cxl_map_afu_irq()).
100 * These IRQs can be unmapped (cxl_unmap_afu_irq()) and finally released
101 * (cxl_free_afu_irqs()).
103 * The AFU can be reset (cxl_afu_reset()). This will cause the PSL/AFU
104 * hardware to lose track of all contexts. It's upto the caller of
105 * cxl_afu_reset() to restart these contexts.
109 * On pci_enabled_device(), the cxl driver will init a single cxl context for
110 * use by the driver. It doesn't start this context (as that will likely
111 * generate DMA traffic for most AFUs).
113 * This gets the default context associated with this pci_dev. This context
114 * doesn't need to be released as this will be done by the PCI subsystem on hot
115 * unplug.
117 struct cxl_context *cxl_get_context(struct pci_dev *dev);
119 * Allocate and initalise a context associated with a AFU PCI device. This
120 * doesn't start the context in the AFU.
122 struct cxl_context *cxl_dev_context_init(struct pci_dev *dev);
124 * Release and free a context. Context should be stopped before calling.
126 int cxl_release_context(struct cxl_context *ctx);
129 * Set and get private data associated with a context. Allows drivers to have a
130 * back pointer to some useful structure.
132 int cxl_set_priv(struct cxl_context *ctx, void *priv);
133 void *cxl_get_priv(struct cxl_context *ctx);
136 * Allocate AFU interrupts for this context. num=0 will allocate the default
137 * for this AFU as given in the AFU descriptor. This number doesn't include the
138 * interrupt 0 (CAIA defines AFU IRQ 0 for page faults). Each interrupt to be
139 * used must map a handler with cxl_map_afu_irq.
141 int cxl_allocate_afu_irqs(struct cxl_context *cxl, int num);
142 /* Free allocated interrupts */
143 void cxl_free_afu_irqs(struct cxl_context *cxl);
146 * Map a handler for an AFU interrupt associated with a particular context. AFU
147 * IRQS numbers start from 1 (CAIA defines AFU IRQ 0 for page faults). cookie
148 * is private data is that will be provided to the interrupt handler.
150 int cxl_map_afu_irq(struct cxl_context *cxl, int num,
151 irq_handler_t handler, void *cookie, char *name);
152 /* unmap mapped IRQ handlers */
153 void cxl_unmap_afu_irq(struct cxl_context *cxl, int num, void *cookie);
156 * Start work on the AFU. This starts an cxl context and associates it with a
157 * task. task == NULL will make it a kernel context.
159 int cxl_start_context(struct cxl_context *ctx, u64 wed,
160 struct task_struct *task);
162 * Stop a context and remove it from the PSL
164 int cxl_stop_context(struct cxl_context *ctx);
166 /* Reset the AFU */
167 int cxl_afu_reset(struct cxl_context *ctx);
170 * Set a context as a master context.
171 * This sets the default problem space area mapped as the full space, rather
172 * than just the per context area (for slaves).
174 void cxl_set_master(struct cxl_context *ctx);
177 * Sets the context to use real mode memory accesses to operate with
178 * translation disabled. Note that this only makes sense for kernel contexts
179 * under bare metal, and will not work with virtualisation. May only be
180 * performed on stopped contexts.
182 int cxl_set_translation_mode(struct cxl_context *ctx, bool real_mode);
185 * Map and unmap the AFU Problem Space area. The amount and location mapped
186 * depends on if this context is a master or slave.
188 void __iomem *cxl_psa_map(struct cxl_context *ctx);
189 void cxl_psa_unmap(void __iomem *addr);
191 /* Get the process element for this context */
192 int cxl_process_element(struct cxl_context *ctx);
195 * Limit the number of interrupts that a single context can allocate via
196 * cxl_start_work. If using the api with a real phb, this may be used to
197 * request that additional default contexts be created when allocating
198 * interrupts via pci_enable_msix_range. These will be set to the same running
199 * state as the default context, and if that is running it will reuse the
200 * parameters previously passed to cxl_start_context for the default context.
202 int cxl_set_max_irqs_per_process(struct pci_dev *dev, int irqs);
203 int cxl_get_max_irqs_per_process(struct pci_dev *dev);
206 * Use to simultaneously iterate over hardware interrupt numbers, contexts and
207 * afu interrupt numbers allocated for the device via pci_enable_msix_range and
208 * is a useful convenience function when working with hardware that has
209 * limitations on the number of interrupts per process. *ctx and *afu_irq
210 * should be NULL and 0 to start the iteration.
212 int cxl_next_msi_hwirq(struct pci_dev *pdev, struct cxl_context **ctx, int *afu_irq);
215 * These calls allow drivers to create their own file descriptors and make them
216 * identical to the cxl file descriptor user API. An example use case:
218 * struct file_operations cxl_my_fops = {};
219 * ......
220 * // Init the context
221 * ctx = cxl_dev_context_init(dev);
222 * if (IS_ERR(ctx))
223 * return PTR_ERR(ctx);
224 * // Create and attach a new file descriptor to my file ops
225 * file = cxl_get_fd(ctx, &cxl_my_fops, &fd);
226 * // Start context
227 * rc = cxl_start_work(ctx, &work.work);
228 * if (rc) {
229 * fput(file);
230 * put_unused_fd(fd);
231 * return -ENODEV;
233 * // No error paths after installing the fd
234 * fd_install(fd, file);
235 * return fd;
237 * This inits a context, and gets a file descriptor and associates some file
238 * ops to that file descriptor. If the file ops are blank, the cxl driver will
239 * fill them in with the default ones that mimic the standard user API. Once
240 * completed, the file descriptor can be installed. Once the file descriptor is
241 * installed, it's visible to the user so no errors must occur past this point.
243 * If cxl_fd_release() file op call is installed, the context will be stopped
244 * and released when the fd is released. Hence the driver won't need to manage
245 * this itself.
249 * Take a context and associate it with my file ops. Returns the associated
250 * file and file descriptor. Any file ops which are blank are filled in by the
251 * cxl driver with the default ops to mimic the standard API.
253 struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
254 int *fd);
255 /* Get the context associated with this file */
256 struct cxl_context *cxl_fops_get_context(struct file *file);
258 * Start a context associated a struct cxl_ioctl_start_work used by the
259 * standard cxl user API.
261 int cxl_start_work(struct cxl_context *ctx,
262 struct cxl_ioctl_start_work *work);
264 * Export all the existing fops so drivers can use them
266 int cxl_fd_open(struct inode *inode, struct file *file);
267 int cxl_fd_release(struct inode *inode, struct file *file);
268 long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
269 int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm);
270 unsigned int cxl_fd_poll(struct file *file, struct poll_table_struct *poll);
271 ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
272 loff_t *off);
275 * For EEH, a driver may want to assert a PERST will reload the same image
276 * from flash into the FPGA.
278 * This is a property of the entire adapter, not a single AFU, so drivers
279 * should set this property with care!
281 void cxl_perst_reloads_same_image(struct cxl_afu *afu,
282 bool perst_reloads_same_image);
285 * Read the VPD for the card where the AFU resides
287 ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count);
290 * AFU driver ops allow an AFU driver to create their own events to pass to
291 * userspace through the file descriptor as a simpler alternative to overriding
292 * the read() and poll() calls that works with the generic cxl events. These
293 * events are given priority over the generic cxl events, so they will be
294 * delivered first if multiple types of events are pending.
296 * The AFU driver must call cxl_context_events_pending() to notify the cxl
297 * driver that new events are ready to be delivered for a specific context.
298 * cxl_context_events_pending() will adjust the current count of AFU driver
299 * events for this context, and wake up anyone waiting on the context wait
300 * queue.
302 * The cxl driver will then call fetch_event() to get a structure defining
303 * the size and address of the driver specific event data. The cxl driver
304 * will build a cxl header with type and process_element fields filled in,
305 * and header.size set to sizeof(struct cxl_event_header) + data_size.
306 * The total size of the event is limited to CXL_READ_MIN_SIZE (4K).
308 * fetch_event() is called with a spin lock held, so it must not sleep.
310 * The cxl driver will then deliver the event to userspace, and finally
311 * call event_delivered() to return the status of the operation, identified
312 * by cxl context and AFU driver event data pointers.
313 * 0 Success
314 * -EFAULT copy_to_user() has failed
315 * -EINVAL Event data pointer is NULL, or event size is greater than
316 * CXL_READ_MIN_SIZE.
318 struct cxl_afu_driver_ops {
319 struct cxl_event_afu_driver_reserved *(*fetch_event) (
320 struct cxl_context *ctx);
321 void (*event_delivered) (struct cxl_context *ctx,
322 struct cxl_event_afu_driver_reserved *event,
323 int rc);
327 * Associate the above driver ops with a specific context.
328 * Reset the current count of AFU driver events.
330 void cxl_set_driver_ops(struct cxl_context *ctx,
331 struct cxl_afu_driver_ops *ops);
333 /* Notify cxl driver that new events are ready to be delivered for context */
334 void cxl_context_events_pending(struct cxl_context *ctx,
335 unsigned int new_events);
337 #endif /* _MISC_CXL_H */