cxl.h (4ba24fef3eb3b142197135223b90ced2f319cd53) cxl.h (6f7f0b3df6d49316c6f27390bb5ec250255be548)
1/*
1/*
2 * Copyright 2014 IBM Corp.
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
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#ifdef CONFIG_CXL_BASE
13#include <linux/pci.h>
14#include <linux/poll.h>
15#include <linux/interrupt.h>
16#include <uapi/misc/cxl.h>
14
17
15#define CXL_IRQ_RANGES 4
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 */
16
26
17struct cxl_irq_ranges {
18 irq_hw_number_t offset[CXL_IRQ_RANGES];
19 irq_hw_number_t range[CXL_IRQ_RANGES];
20};
27/* Get the AFU associated with a pci_dev */
28struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev);
21
29
22extern atomic_t cxl_use_count;
30/* Get the AFU conf record number associated with a pci_dev */
31unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev);
23
32
24static inline bool cxl_ctx_in_use(void)
25{
26 return (atomic_read(&cxl_use_count) != 0);
27}
33/* Get the physical device (ie. the PCIe card) which the AFU is attached */
34struct device *cxl_get_phys_dev(struct pci_dev *dev);
28
35
29static inline void cxl_ctx_get(void)
30{
31 atomic_inc(&cxl_use_count);
32}
33
36
34static inline void cxl_ctx_put(void)
35{
36 atomic_dec(&cxl_use_count);
37}
37/*
38 * Context lifetime overview:
39 *
40 * An AFU context may be inited and then started and stoppped multiple times
41 * before it's released. ie.
42 * - cxl_dev_context_init()
43 * - cxl_start_context()
44 * - cxl_stop_context()
45 * - cxl_start_context()
46 * - cxl_stop_context()
47 * ...repeat...
48 * - cxl_release_context()
49 * Once released, a context can't be started again.
50 *
51 * One context is inited by the cxl driver for every pci_dev. This is to be
52 * used as a default kernel context. cxl_get_context() will get this
53 * context. This context will be released by PCI hot unplug, so doesn't need to
54 * be released explicitly by drivers.
55 *
56 * Additional kernel contexts may be inited using cxl_dev_context_init().
57 * These must be released using cxl_context_detach().
58 *
59 * Once a context has been inited, IRQs may be configured. Firstly these IRQs
60 * must be allocated (cxl_allocate_afu_irqs()), then individually mapped to
61 * specific handlers (cxl_map_afu_irq()).
62 *
63 * These IRQs can be unmapped (cxl_unmap_afu_irq()) and finally released
64 * (cxl_free_afu_irqs()).
65 *
66 * The AFU can be reset (cxl_afu_reset()). This will cause the PSL/AFU
67 * hardware to lose track of all contexts. It's upto the caller of
68 * cxl_afu_reset() to restart these contexts.
69 */
38
70
39void cxl_slbia(struct mm_struct *mm);
71/*
72 * On pci_enabled_device(), the cxl driver will init a single cxl context for
73 * use by the driver. It doesn't start this context (as that will likely
74 * generate DMA traffic for most AFUs).
75 *
76 * This gets the default context associated with this pci_dev. This context
77 * doesn't need to be released as this will be done by the PCI subsystem on hot
78 * unplug.
79 */
80struct cxl_context *cxl_get_context(struct pci_dev *dev);
81/*
82 * Allocate and initalise a context associated with a AFU PCI device. This
83 * doesn't start the context in the AFU.
84 */
85struct cxl_context *cxl_dev_context_init(struct pci_dev *dev);
86/*
87 * Release and free a context. Context should be stopped before calling.
88 */
89int cxl_release_context(struct cxl_context *ctx);
40
90
41#else /* CONFIG_CXL_BASE */
91/*
92 * Allocate AFU interrupts for this context. num=0 will allocate the default
93 * for this AFU as given in the AFU descriptor. This number doesn't include the
94 * interrupt 0 (CAIA defines AFU IRQ 0 for page faults). Each interrupt to be
95 * used must map a handler with cxl_map_afu_irq.
96 */
97int cxl_allocate_afu_irqs(struct cxl_context *cxl, int num);
98/* Free allocated interrupts */
99void cxl_free_afu_irqs(struct cxl_context *cxl);
42
100
43static inline bool cxl_ctx_in_use(void) { return false; }
44static inline void cxl_slbia(struct mm_struct *mm) {}
101/*
102 * Map a handler for an AFU interrupt associated with a particular context. AFU
103 * IRQS numbers start from 1 (CAIA defines AFU IRQ 0 for page faults). cookie
104 * is private data is that will be provided to the interrupt handler.
105 */
106int cxl_map_afu_irq(struct cxl_context *cxl, int num,
107 irq_handler_t handler, void *cookie, char *name);
108/* unmap mapped IRQ handlers */
109void cxl_unmap_afu_irq(struct cxl_context *cxl, int num, void *cookie);
45
110
46#endif /* CONFIG_CXL_BASE */
111/*
112 * Start work on the AFU. This starts an cxl context and associates it with a
113 * task. task == NULL will make it a kernel context.
114 */
115int cxl_start_context(struct cxl_context *ctx, u64 wed,
116 struct task_struct *task);
117/*
118 * Stop a context and remove it from the PSL
119 */
120int cxl_stop_context(struct cxl_context *ctx);
47
121
48#endif
122/* Reset the AFU */
123int cxl_afu_reset(struct cxl_context *ctx);
124
125/*
126 * Set a context as a master context.
127 * This sets the default problem space area mapped as the full space, rather
128 * than just the per context area (for slaves).
129 */
130void cxl_set_master(struct cxl_context *ctx);
131
132/*
133 * Map and unmap the AFU Problem Space area. The amount and location mapped
134 * depends on if this context is a master or slave.
135 */
136void __iomem *cxl_psa_map(struct cxl_context *ctx);
137void cxl_psa_unmap(void __iomem *addr);
138
139/* Get the process element for this context */
140int cxl_process_element(struct cxl_context *ctx);
141
142
143/*
144 * These calls allow drivers to create their own file descriptors and make them
145 * identical to the cxl file descriptor user API. An example use case:
146 *
147 * struct file_operations cxl_my_fops = {};
148 * ......
149 * // Init the context
150 * ctx = cxl_dev_context_init(dev);
151 * if (IS_ERR(ctx))
152 * return PTR_ERR(ctx);
153 * // Create and attach a new file descriptor to my file ops
154 * file = cxl_get_fd(ctx, &cxl_my_fops, &fd);
155 * // Start context
156 * rc = cxl_start_work(ctx, &work.work);
157 * if (rc) {
158 * fput(file);
159 * put_unused_fd(fd);
160 * return -ENODEV;
161 * }
162 * // No error paths after installing the fd
163 * fd_install(fd, file);
164 * return fd;
165 *
166 * This inits a context, and gets a file descriptor and associates some file
167 * ops to that file descriptor. If the file ops are blank, the cxl driver will
168 * fill them in with the default ones that mimic the standard user API. Once
169 * completed, the file descriptor can be installed. Once the file descriptor is
170 * installed, it's visible to the user so no errors must occur past this point.
171 *
172 * If cxl_fd_release() file op call is installed, the context will be stopped
173 * and released when the fd is released. Hence the driver won't need to manage
174 * this itself.
175 */
176
177/*
178 * Take a context and associate it with my file ops. Returns the associated
179 * file and file descriptor. Any file ops which are blank are filled in by the
180 * cxl driver with the default ops to mimic the standard API.
181 */
182struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
183 int *fd);
184/* Get the context associated with this file */
185struct cxl_context *cxl_fops_get_context(struct file *file);
186/*
187 * Start a context associated a struct cxl_ioctl_start_work used by the
188 * standard cxl user API.
189 */
190int cxl_start_work(struct cxl_context *ctx,
191 struct cxl_ioctl_start_work *work);
192/*
193 * Export all the existing fops so drivers can use them
194 */
195int cxl_fd_open(struct inode *inode, struct file *file);
196int cxl_fd_release(struct inode *inode, struct file *file);
197long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
198int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm);
199unsigned int cxl_fd_poll(struct file *file, struct poll_table_struct *poll);
200ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
201 loff_t *off);
202
203#endif /* _MISC_CXL_H */