xref: /openbmc/linux/arch/powerpc/include/asm/vas.h (revision fbb6b31a)
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  */
53 enum 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  */
68 struct 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  */
80 struct 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  */
93 struct 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 
100 static 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 
109 static 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  */
128 struct vas_rx_win_attr {
129 	void *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  */
158 struct 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  */
185 int chip_to_vas_id(int chipid);
186 
187 /*
188  * Helper to initialize receive window attributes to defaults for an
189  * NX window.
190  */
191 void 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  */
199 struct 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  */
205 extern 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  */
218 struct 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  */
226 int vas_win_close(struct vas_window *win);
227 
228 /*
229  * Copy the co-processor request block (CRB) @crb into the local L2 cache.
230  */
231 int 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  */
238 int vas_paste_crb(struct vas_window *win, int offset, bool re);
239 
240 int vas_register_api_powernv(struct module *mod, enum vas_cop_type cop_type,
241 			     const char *name);
242 void 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  */
261 struct hv_vas_all_caps {
262 	__be64  descriptor;
263 	__be64  feat_type;
264 } __packed __aligned(0x1000);
265 
266 struct vas_all_caps {
267 	u64     descriptor;
268 	u64     feat_type;
269 };
270 
271 int h_query_vas_capabilities(const u64 hcall, u8 query_type, u64 result);
272 int vas_register_api_pseries(struct module *mod,
273 			     enum vas_cop_type cop_type, const char *name);
274 void 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  */
285 int 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);
288 void vas_unregister_coproc_api(void);
289 
290 int get_vas_user_win_ref(struct vas_user_win_ref *task_ref);
291 void vas_update_csb(struct coprocessor_request_block *crb,
292 		    struct vas_user_win_ref *task_ref);
293 void vas_dump_crb(struct coprocessor_request_block *crb);
294 #endif /* __ASM_POWERPC_VAS_H */
295