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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright 2016-17 IBM Corp.
4 */
5
6#ifndef _ASM_POWERPC_VAS_H
7#define _ASM_POWERPC_VAS_H
8#include <linux/sched/mm.h>
9#include <linux/mmu_context.h>
10#include <asm/icswx.h>
11#include <uapi/asm/vas-api.h>
12
13/*
14 * Min and max FIFO sizes are based on Version 1.05 Section 3.1.4.25
15 * (Local FIFO Size Register) of the VAS workbook.
16 */
17#define VAS_RX_FIFO_SIZE_MIN (1 << 10) /* 1KB */
18#define VAS_RX_FIFO_SIZE_MAX (8 << 20) /* 8MB */
19
20/*
21 * Threshold Control Mode: Have paste operation fail if the number of
22 * requests in receive FIFO exceeds a threshold.
23 *
24 * NOTE: No special error code yet if paste is rejected because of these
25 * limits. So users can't distinguish between this and other errors.
26 */
27#define VAS_THRESH_DISABLED 0
28#define VAS_THRESH_FIFO_GT_HALF_FULL 1
29#define VAS_THRESH_FIFO_GT_QTR_FULL 2
30#define VAS_THRESH_FIFO_GT_EIGHTH_FULL 3
31
32/*
33 * VAS window Linux status bits
34 */
35#define VAS_WIN_ACTIVE 0x0 /* Used in platform independent */
36 /* vas mmap() */
37/* Window is closed in the hypervisor due to lost credit */
38#define VAS_WIN_NO_CRED_CLOSE 0x00000001
39/* Window is closed due to migration */
40#define VAS_WIN_MIGRATE_CLOSE 0x00000002
41
42/*
43 * Get/Set bit fields
44 */
45#define GET_FIELD(m, v) (((v) & (m)) >> MASK_LSH(m))
46#define MASK_LSH(m) (__builtin_ffsl(m) - 1)
47#define SET_FIELD(m, v, val) \
48 (((v) & ~(m)) | ((((typeof(v))(val)) << MASK_LSH(m)) & (m)))
49
50/*
51 * Co-processor Engine type.
52 */
53enum vas_cop_type {
54 VAS_COP_TYPE_FAULT,
55 VAS_COP_TYPE_842,
56 VAS_COP_TYPE_842_HIPRI,
57 VAS_COP_TYPE_GZIP,
58 VAS_COP_TYPE_GZIP_HIPRI,
59 VAS_COP_TYPE_FTW,
60 VAS_COP_TYPE_MAX,
61};
62
63/*
64 * User space VAS windows are opened by tasks and take references
65 * to pid and mm until windows are closed.
66 * Stores pid, mm, and tgid for each window.
67 */
68struct vas_user_win_ref {
69 struct pid *pid; /* PID of owner */
70 struct pid *tgid; /* Thread group ID of owner */
71 struct mm_struct *mm; /* Linux process mm_struct */
72 struct mutex mmap_mutex; /* protects paste address mmap() */
73 /* with DLPAR close/open windows */
74 struct vm_area_struct *vma; /* Save VMA and used in DLPAR ops */
75};
76
77/*
78 * Common VAS window struct on PowerNV and PowerVM
79 */
80struct vas_window {
81 u32 winid;
82 u32 wcreds_max; /* Window credits */
83 u32 status; /* Window status used in OS */
84 enum vas_cop_type cop;
85 struct vas_user_win_ref task_ref;
86 char *dbgname;
87 struct dentry *dbgdir;
88};
89
90/*
91 * User space window operations used for powernv and powerVM
92 */
93struct vas_user_win_ops {
94 struct vas_window * (*open_win)(int vas_id, u64 flags,
95 enum vas_cop_type);
96 u64 (*paste_addr)(struct vas_window *);
97 int (*close_win)(struct vas_window *);
98};
99
100static inline void put_vas_user_win_ref(struct vas_user_win_ref *ref)
101{
102 /* Drop references to pid, tgid, and mm */
103 put_pid(ref->pid);
104 put_pid(ref->tgid);
105 if (ref->mm)
106 mmdrop(ref->mm);
107}
108
109static inline void vas_user_win_add_mm_context(struct vas_user_win_ref *ref)
110{
111 mm_context_add_vas_window(ref->mm);
112 /*
113 * Even a process that has no foreign real address mapping can
114 * use an unpaired COPY instruction (to no real effect). Issue
115 * CP_ABORT to clear any pending COPY and prevent a covert
116 * channel.
117 *
118 * __switch_to() will issue CP_ABORT on future context switches
119 * if process / thread has any open VAS window (Use
120 * current->mm->context.vas_windows).
121 */
122 asm volatile(PPC_CP_ABORT);
123}
124
125/*
126 * Receive window attributes specified by the (in-kernel) owner of window.
127 */
128struct vas_rx_win_attr {
129 u64 rx_fifo;
130 int rx_fifo_size;
131 int wcreds_max;
132
133 bool pin_win;
134 bool rej_no_credit;
135 bool tx_wcred_mode;
136 bool rx_wcred_mode;
137 bool tx_win_ord_mode;
138 bool rx_win_ord_mode;
139 bool data_stamp;
140 bool nx_win;
141 bool fault_win;
142 bool user_win;
143 bool notify_disable;
144 bool intr_disable;
145 bool notify_early;
146
147 int lnotify_lpid;
148 int lnotify_pid;
149 int lnotify_tid;
150 u32 pswid;
151
152 int tc_mode;
153};
154
155/*
156 * Window attributes specified by the in-kernel owner of a send window.
157 */
158struct vas_tx_win_attr {
159 enum vas_cop_type cop;
160 int wcreds_max;
161 int lpid;
162 int pidr; /* hardware PID (from SPRN_PID) */
163 int pswid;
164 int rsvd_txbuf_count;
165 int tc_mode;
166
167 bool user_win;
168 bool pin_win;
169 bool rej_no_credit;
170 bool rsvd_txbuf_enable;
171 bool tx_wcred_mode;
172 bool rx_wcred_mode;
173 bool tx_win_ord_mode;
174 bool rx_win_ord_mode;
175};
176
177#ifdef CONFIG_PPC_POWERNV
178/*
179 * Helper to map a chip id to VAS id.
180 * For POWER9, this is a 1:1 mapping. In the future this maybe a 1:N
181 * mapping in which case, we will need to update this helper.
182 *
183 * Return the VAS id or -1 if no matching vasid is found.
184 */
185int chip_to_vas_id(int chipid);
186
187/*
188 * Helper to initialize receive window attributes to defaults for an
189 * NX window.
190 */
191void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, enum vas_cop_type cop);
192
193/*
194 * Open a VAS receive window for the instance of VAS identified by @vasid
195 * Use @attr to initialize the attributes of the window.
196 *
197 * Return a handle to the window or ERR_PTR() on error.
198 */
199struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop,
200 struct vas_rx_win_attr *attr);
201
202/*
203 * Helper to initialize send window attributes to defaults for an NX window.
204 */
205extern void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr,
206 enum vas_cop_type cop);
207
208/*
209 * Open a VAS send window for the instance of VAS identified by @vasid
210 * and the co-processor type @cop. Use @attr to initialize attributes
211 * of the window.
212 *
213 * Note: The instance of VAS must already have an open receive window for
214 * the coprocessor type @cop.
215 *
216 * Return a handle to the send window or ERR_PTR() on error.
217 */
218struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
219 struct vas_tx_win_attr *attr);
220
221/*
222 * Close the send or receive window identified by @win. For receive windows
223 * return -EAGAIN if there are active send windows attached to this receive
224 * window.
225 */
226int vas_win_close(struct vas_window *win);
227
228/*
229 * Copy the co-processor request block (CRB) @crb into the local L2 cache.
230 */
231int vas_copy_crb(void *crb, int offset);
232
233/*
234 * Paste a previously copied CRB (see vas_copy_crb()) from the L2 cache to
235 * the hardware address associated with the window @win. @re is expected/
236 * assumed to be true for NX windows.
237 */
238int vas_paste_crb(struct vas_window *win, int offset, bool re);
239
240int vas_register_api_powernv(struct module *mod, enum vas_cop_type cop_type,
241 const char *name);
242void vas_unregister_api_powernv(void);
243#endif
244
245#ifdef CONFIG_PPC_PSERIES
246
247/* VAS Capabilities */
248#define VAS_GZIP_QOS_FEAT 0x1
249#define VAS_GZIP_DEF_FEAT 0x2
250#define VAS_GZIP_QOS_FEAT_BIT PPC_BIT(VAS_GZIP_QOS_FEAT) /* Bit 1 */
251#define VAS_GZIP_DEF_FEAT_BIT PPC_BIT(VAS_GZIP_DEF_FEAT) /* Bit 2 */
252
253/* NX Capabilities */
254#define VAS_NX_GZIP_FEAT 0x1
255#define VAS_NX_GZIP_FEAT_BIT PPC_BIT(VAS_NX_GZIP_FEAT) /* Bit 1 */
256
257/*
258 * These structs are used to retrieve overall VAS capabilities that
259 * the hypervisor provides.
260 */
261struct hv_vas_all_caps {
262 __be64 descriptor;
263 __be64 feat_type;
264} __packed __aligned(0x1000);
265
266struct vas_all_caps {
267 u64 descriptor;
268 u64 feat_type;
269};
270
271int h_query_vas_capabilities(const u64 hcall, u8 query_type, u64 result);
272int vas_register_api_pseries(struct module *mod,
273 enum vas_cop_type cop_type, const char *name);
274void vas_unregister_api_pseries(void);
275#endif
276
277/*
278 * Register / unregister coprocessor type to VAS API which will be exported
279 * to user space. Applications can use this API to open / close window
280 * which can be used to send / receive requests directly to cooprcessor.
281 *
282 * Only NX GZIP coprocessor type is supported now, but this API can be
283 * used for others in future.
284 */
285int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
286 const char *name,
287 const struct vas_user_win_ops *vops);
288void vas_unregister_coproc_api(void);
289
290int get_vas_user_win_ref(struct vas_user_win_ref *task_ref);
291void vas_update_csb(struct coprocessor_request_block *crb,
292 struct vas_user_win_ref *task_ref);
293void vas_dump_crb(struct coprocessor_request_block *crb);
294#endif /* __ASM_POWERPC_VAS_H */