xref: /openbmc/linux/arch/powerpc/include/asm/vas.h (revision 2cf1c348)
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  * Get/Set bit fields
34  */
35 #define GET_FIELD(m, v)                (((v) & (m)) >> MASK_LSH(m))
36 #define MASK_LSH(m)            (__builtin_ffsl(m) - 1)
37 #define SET_FIELD(m, v, val)   \
38 		(((v) & ~(m)) | ((((typeof(v))(val)) << MASK_LSH(m)) & (m)))
39 
40 /*
41  * Co-processor Engine type.
42  */
43 enum vas_cop_type {
44 	VAS_COP_TYPE_FAULT,
45 	VAS_COP_TYPE_842,
46 	VAS_COP_TYPE_842_HIPRI,
47 	VAS_COP_TYPE_GZIP,
48 	VAS_COP_TYPE_GZIP_HIPRI,
49 	VAS_COP_TYPE_FTW,
50 	VAS_COP_TYPE_MAX,
51 };
52 
53 /*
54  * User space VAS windows are opened by tasks and take references
55  * to pid and mm until windows are closed.
56  * Stores pid, mm, and tgid for each window.
57  */
58 struct vas_user_win_ref {
59 	struct pid *pid;	/* PID of owner */
60 	struct pid *tgid;	/* Thread group ID of owner */
61 	struct mm_struct *mm;	/* Linux process mm_struct */
62 };
63 
64 /*
65  * Common VAS window struct on PowerNV and PowerVM
66  */
67 struct vas_window {
68 	u32 winid;
69 	u32 wcreds_max;	/* Window credits */
70 	enum vas_cop_type cop;
71 	struct vas_user_win_ref task_ref;
72 	char *dbgname;
73 	struct dentry *dbgdir;
74 };
75 
76 /*
77  * User space window operations used for powernv and powerVM
78  */
79 struct vas_user_win_ops {
80 	struct vas_window * (*open_win)(int vas_id, u64 flags,
81 				enum vas_cop_type);
82 	u64 (*paste_addr)(struct vas_window *);
83 	int (*close_win)(struct vas_window *);
84 };
85 
86 static inline void put_vas_user_win_ref(struct vas_user_win_ref *ref)
87 {
88 	/* Drop references to pid, tgid, and mm */
89 	put_pid(ref->pid);
90 	put_pid(ref->tgid);
91 	if (ref->mm)
92 		mmdrop(ref->mm);
93 }
94 
95 static inline void vas_user_win_add_mm_context(struct vas_user_win_ref *ref)
96 {
97 	mm_context_add_vas_window(ref->mm);
98 	/*
99 	 * Even a process that has no foreign real address mapping can
100 	 * use an unpaired COPY instruction (to no real effect). Issue
101 	 * CP_ABORT to clear any pending COPY and prevent a covert
102 	 * channel.
103 	 *
104 	 * __switch_to() will issue CP_ABORT on future context switches
105 	 * if process / thread has any open VAS window (Use
106 	 * current->mm->context.vas_windows).
107 	 */
108 	asm volatile(PPC_CP_ABORT);
109 }
110 
111 /*
112  * Receive window attributes specified by the (in-kernel) owner of window.
113  */
114 struct vas_rx_win_attr {
115 	void *rx_fifo;
116 	int rx_fifo_size;
117 	int wcreds_max;
118 
119 	bool pin_win;
120 	bool rej_no_credit;
121 	bool tx_wcred_mode;
122 	bool rx_wcred_mode;
123 	bool tx_win_ord_mode;
124 	bool rx_win_ord_mode;
125 	bool data_stamp;
126 	bool nx_win;
127 	bool fault_win;
128 	bool user_win;
129 	bool notify_disable;
130 	bool intr_disable;
131 	bool notify_early;
132 
133 	int lnotify_lpid;
134 	int lnotify_pid;
135 	int lnotify_tid;
136 	u32 pswid;
137 
138 	int tc_mode;
139 };
140 
141 /*
142  * Window attributes specified by the in-kernel owner of a send window.
143  */
144 struct vas_tx_win_attr {
145 	enum vas_cop_type cop;
146 	int wcreds_max;
147 	int lpid;
148 	int pidr;		/* hardware PID (from SPRN_PID) */
149 	int pswid;
150 	int rsvd_txbuf_count;
151 	int tc_mode;
152 
153 	bool user_win;
154 	bool pin_win;
155 	bool rej_no_credit;
156 	bool rsvd_txbuf_enable;
157 	bool tx_wcred_mode;
158 	bool rx_wcred_mode;
159 	bool tx_win_ord_mode;
160 	bool rx_win_ord_mode;
161 };
162 
163 #ifdef CONFIG_PPC_POWERNV
164 /*
165  * Helper to map a chip id to VAS id.
166  * For POWER9, this is a 1:1 mapping. In the future this maybe a 1:N
167  * mapping in which case, we will need to update this helper.
168  *
169  * Return the VAS id or -1 if no matching vasid is found.
170  */
171 int chip_to_vas_id(int chipid);
172 
173 /*
174  * Helper to initialize receive window attributes to defaults for an
175  * NX window.
176  */
177 void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, enum vas_cop_type cop);
178 
179 /*
180  * Open a VAS receive window for the instance of VAS identified by @vasid
181  * Use @attr to initialize the attributes of the window.
182  *
183  * Return a handle to the window or ERR_PTR() on error.
184  */
185 struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop,
186 				   struct vas_rx_win_attr *attr);
187 
188 /*
189  * Helper to initialize send window attributes to defaults for an NX window.
190  */
191 extern void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr,
192 			enum vas_cop_type cop);
193 
194 /*
195  * Open a VAS send window for the instance of VAS identified by @vasid
196  * and the co-processor type @cop. Use @attr to initialize attributes
197  * of the window.
198  *
199  * Note: The instance of VAS must already have an open receive window for
200  * the coprocessor type @cop.
201  *
202  * Return a handle to the send window or ERR_PTR() on error.
203  */
204 struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
205 			struct vas_tx_win_attr *attr);
206 
207 /*
208  * Close the send or receive window identified by @win. For receive windows
209  * return -EAGAIN if there are active send windows attached to this receive
210  * window.
211  */
212 int vas_win_close(struct vas_window *win);
213 
214 /*
215  * Copy the co-processor request block (CRB) @crb into the local L2 cache.
216  */
217 int vas_copy_crb(void *crb, int offset);
218 
219 /*
220  * Paste a previously copied CRB (see vas_copy_crb()) from the L2 cache to
221  * the hardware address associated with the window @win. @re is expected/
222  * assumed to be true for NX windows.
223  */
224 int vas_paste_crb(struct vas_window *win, int offset, bool re);
225 
226 int vas_register_api_powernv(struct module *mod, enum vas_cop_type cop_type,
227 			     const char *name);
228 void vas_unregister_api_powernv(void);
229 #endif
230 
231 #ifdef CONFIG_PPC_PSERIES
232 
233 /* VAS Capabilities */
234 #define VAS_GZIP_QOS_FEAT	0x1
235 #define VAS_GZIP_DEF_FEAT	0x2
236 #define VAS_GZIP_QOS_FEAT_BIT	PPC_BIT(VAS_GZIP_QOS_FEAT) /* Bit 1 */
237 #define VAS_GZIP_DEF_FEAT_BIT	PPC_BIT(VAS_GZIP_DEF_FEAT) /* Bit 2 */
238 
239 /* NX Capabilities */
240 #define VAS_NX_GZIP_FEAT	0x1
241 #define VAS_NX_GZIP_FEAT_BIT	PPC_BIT(VAS_NX_GZIP_FEAT) /* Bit 1 */
242 
243 /*
244  * These structs are used to retrieve overall VAS capabilities that
245  * the hypervisor provides.
246  */
247 struct hv_vas_all_caps {
248 	__be64  descriptor;
249 	__be64  feat_type;
250 } __packed __aligned(0x1000);
251 
252 struct vas_all_caps {
253 	u64     descriptor;
254 	u64     feat_type;
255 };
256 
257 int h_query_vas_capabilities(const u64 hcall, u8 query_type, u64 result);
258 int vas_register_api_pseries(struct module *mod,
259 			     enum vas_cop_type cop_type, const char *name);
260 void vas_unregister_api_pseries(void);
261 #endif
262 
263 /*
264  * Register / unregister coprocessor type to VAS API which will be exported
265  * to user space. Applications can use this API to open / close window
266  * which can be used to send / receive requests directly to cooprcessor.
267  *
268  * Only NX GZIP coprocessor type is supported now, but this API can be
269  * used for others in future.
270  */
271 int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
272 			    const char *name,
273 			    const struct vas_user_win_ops *vops);
274 void vas_unregister_coproc_api(void);
275 
276 int get_vas_user_win_ref(struct vas_user_win_ref *task_ref);
277 void vas_update_csb(struct coprocessor_request_block *crb,
278 		    struct vas_user_win_ref *task_ref);
279 void vas_dump_crb(struct coprocessor_request_block *crb);
280 #endif /* __ASM_POWERPC_VAS_H */
281