1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright 2016-17 IBM Corp.
4  */
5 
6 #ifndef _VAS_H
7 #define _VAS_H
8 #include <linux/atomic.h>
9 #include <linux/idr.h>
10 #include <asm/vas.h>
11 #include <linux/io.h>
12 #include <linux/dcache.h>
13 #include <linux/mutex.h>
14 #include <linux/stringify.h>
15 
16 /*
17  * Overview of Virtual Accelerator Switchboard (VAS).
18  *
19  * VAS is a hardware "switchboard" that allows senders and receivers to
20  * exchange messages with _minimal_ kernel involvment. The receivers are
21  * typically NX coprocessor engines that perform compression or encryption
22  * in hardware, but receivers can also be other software threads.
23  *
24  * Senders are user/kernel threads that submit compression/encryption or
25  * other requests to the receivers. Senders must format their messages as
26  * Coprocessor Request Blocks (CRB)s and submit them using the "copy" and
27  * "paste" instructions which were introduced in Power9.
28  *
29  * A Power node can have (upto?) 8 Power chips. There is one instance of
30  * VAS in each Power9 chip. Each instance of VAS has 64K windows or ports,
31  * Senders and receivers must each connect to a separate window before they
32  * can exchange messages through the switchboard.
33  *
34  * Each window is described by two types of window contexts:
35  *
36  *	Hypervisor Window Context (HVWC) of size VAS_HVWC_SIZE bytes
37  *
38  *	OS/User Window Context (UWC) of size VAS_UWC_SIZE bytes.
39  *
40  * A window context can be viewed as a set of 64-bit registers. The settings
41  * in these registers configure/control/determine the behavior of the VAS
42  * hardware when messages are sent/received through the window. The registers
43  * in the HVWC are configured by the kernel while the registers in the UWC can
44  * be configured by the kernel or by the user space application that is using
45  * the window.
46  *
47  * The HVWCs for all windows on a specific instance of VAS are in a contiguous
48  * range of hardware addresses or Base address region (BAR) referred to as the
49  * HVWC BAR for the instance. Similarly the UWCs for all windows on an instance
50  * are referred to as the UWC BAR for the instance.
51  *
52  * The two BARs for each instance are defined Power9 MMIO Ranges spreadsheet
53  * and available to the kernel in the VAS node's "reg" property in the device
54  * tree:
55  *
56  *	/proc/device-tree/vasm@.../reg
57  *
58  * (see vas_probe() for details on the reg property).
59  *
60  * The kernel maps the HVWC and UWC BAR regions into the kernel address
61  * space (hvwc_map and uwc_map). The kernel can then access the window
62  * contexts of a specific window using:
63  *
64  *	 hvwc = hvwc_map + winid * VAS_HVWC_SIZE.
65  *	 uwc = uwc_map + winid * VAS_UWC_SIZE.
66  *
67  * where winid is the window index (0..64K).
68  *
69  * As mentioned, a window context is used to "configure" a window. Besides
70  * this configuration address, each _send_ window also has a unique hardware
71  * "paste" address that is used to submit requests/CRBs (see vas_paste_crb()).
72  *
73  * The hardware paste address for a window is computed using the "paste
74  * base address" and "paste win id shift" reg properties in the VAS device
75  * tree node using:
76  *
77  *	paste_addr = paste_base + ((winid << paste_win_id_shift))
78  *
79  * (again, see vas_probe() for ->paste_base_addr and ->paste_win_id_shift).
80  *
81  * The kernel maps this hardware address into the sender's address space
82  * after which they can use the 'paste' instruction (new in Power9) to
83  * send a message (submit a request aka CRB) to the coprocessor.
84  *
85  * NOTE: In the initial version, senders can only in-kernel drivers/threads.
86  *	 Support for user space threads will be added in follow-on patches.
87  *
88  * TODO: Do we need to map the UWC into user address space so they can return
89  *	 credits? Its NA for NX but may be needed for other receive windows.
90  *
91  */
92 
93 #define VAS_WINDOWS_PER_CHIP		(64 << 10)
94 
95 /*
96  * Hypervisor and OS/USer Window Context sizes
97  */
98 #define VAS_HVWC_SIZE			512
99 #define VAS_UWC_SIZE			PAGE_SIZE
100 
101 /*
102  * Initial per-process credits.
103  * Max send window credits:    4K-1 (12-bits in VAS_TX_WCRED)
104  * Max receive window credits: 64K-1 (16 bits in VAS_LRX_WCRED)
105  *
106  * TODO: Needs tuning for per-process credits
107  */
108 #define VAS_RX_WCREDS_MAX		((64 << 10) - 1)
109 #define VAS_TX_WCREDS_MAX		((4 << 10) - 1)
110 #define VAS_WCREDS_DEFAULT		(1 << 10)
111 
112 /*
113  * VAS Window Context Register Offsets and bitmasks.
114  * See Section 3.1.4 of VAS Work book
115  */
116 #define VAS_LPID_OFFSET			0x010
117 #define VAS_LPID			PPC_BITMASK(0, 11)
118 
119 #define VAS_PID_OFFSET			0x018
120 #define VAS_PID_ID			PPC_BITMASK(0, 19)
121 
122 #define VAS_XLATE_MSR_OFFSET		0x020
123 #define VAS_XLATE_MSR_DR		PPC_BIT(0)
124 #define VAS_XLATE_MSR_TA		PPC_BIT(1)
125 #define VAS_XLATE_MSR_PR		PPC_BIT(2)
126 #define VAS_XLATE_MSR_US		PPC_BIT(3)
127 #define VAS_XLATE_MSR_HV		PPC_BIT(4)
128 #define VAS_XLATE_MSR_SF		PPC_BIT(5)
129 
130 #define VAS_XLATE_LPCR_OFFSET		0x028
131 #define VAS_XLATE_LPCR_PAGE_SIZE	PPC_BITMASK(0, 2)
132 #define VAS_XLATE_LPCR_ISL		PPC_BIT(3)
133 #define VAS_XLATE_LPCR_TC		PPC_BIT(4)
134 #define VAS_XLATE_LPCR_SC		PPC_BIT(5)
135 
136 #define VAS_XLATE_CTL_OFFSET		0x030
137 #define VAS_XLATE_MODE			PPC_BITMASK(0, 1)
138 
139 #define VAS_AMR_OFFSET			0x040
140 #define VAS_AMR				PPC_BITMASK(0, 63)
141 
142 #define VAS_SEIDR_OFFSET		0x048
143 #define VAS_SEIDR			PPC_BITMASK(0, 63)
144 
145 #define VAS_FAULT_TX_WIN_OFFSET		0x050
146 #define VAS_FAULT_TX_WIN		PPC_BITMASK(48, 63)
147 
148 #define VAS_OSU_INTR_SRC_RA_OFFSET	0x060
149 #define VAS_OSU_INTR_SRC_RA		PPC_BITMASK(8, 63)
150 
151 #define VAS_HV_INTR_SRC_RA_OFFSET	0x070
152 #define VAS_HV_INTR_SRC_RA		PPC_BITMASK(8, 63)
153 
154 #define VAS_PSWID_OFFSET		0x078
155 #define VAS_PSWID_EA_HANDLE		PPC_BITMASK(0, 31)
156 
157 #define VAS_SPARE1_OFFSET		0x080
158 #define VAS_SPARE2_OFFSET		0x088
159 #define VAS_SPARE3_OFFSET		0x090
160 #define VAS_SPARE4_OFFSET		0x130
161 #define VAS_SPARE5_OFFSET		0x160
162 #define VAS_SPARE6_OFFSET		0x188
163 
164 #define VAS_LFIFO_BAR_OFFSET		0x0A0
165 #define VAS_LFIFO_BAR			PPC_BITMASK(8, 53)
166 #define VAS_PAGE_MIGRATION_SELECT	PPC_BITMASK(54, 56)
167 
168 #define VAS_LDATA_STAMP_CTL_OFFSET	0x0A8
169 #define VAS_LDATA_STAMP			PPC_BITMASK(0, 1)
170 #define VAS_XTRA_WRITE			PPC_BIT(2)
171 
172 #define VAS_LDMA_CACHE_CTL_OFFSET	0x0B0
173 #define VAS_LDMA_TYPE			PPC_BITMASK(0, 1)
174 #define VAS_LDMA_FIFO_DISABLE		PPC_BIT(2)
175 
176 #define VAS_LRFIFO_PUSH_OFFSET		0x0B8
177 #define VAS_LRFIFO_PUSH			PPC_BITMASK(0, 15)
178 
179 #define VAS_CURR_MSG_COUNT_OFFSET	0x0C0
180 #define VAS_CURR_MSG_COUNT		PPC_BITMASK(0, 7)
181 
182 #define VAS_LNOTIFY_AFTER_COUNT_OFFSET	0x0C8
183 #define VAS_LNOTIFY_AFTER_COUNT		PPC_BITMASK(0, 7)
184 
185 #define VAS_LRX_WCRED_OFFSET		0x0E0
186 #define VAS_LRX_WCRED			PPC_BITMASK(0, 15)
187 
188 #define VAS_LRX_WCRED_ADDER_OFFSET	0x190
189 #define VAS_LRX_WCRED_ADDER		PPC_BITMASK(0, 15)
190 
191 #define VAS_TX_WCRED_OFFSET		0x0F0
192 #define VAS_TX_WCRED			PPC_BITMASK(4, 15)
193 
194 #define VAS_TX_WCRED_ADDER_OFFSET	0x1A0
195 #define VAS_TX_WCRED_ADDER		PPC_BITMASK(4, 15)
196 
197 #define VAS_LFIFO_SIZE_OFFSET		0x100
198 #define VAS_LFIFO_SIZE			PPC_BITMASK(0, 3)
199 
200 #define VAS_WINCTL_OFFSET		0x108
201 #define VAS_WINCTL_OPEN			PPC_BIT(0)
202 #define VAS_WINCTL_REJ_NO_CREDIT	PPC_BIT(1)
203 #define VAS_WINCTL_PIN			PPC_BIT(2)
204 #define VAS_WINCTL_TX_WCRED_MODE	PPC_BIT(3)
205 #define VAS_WINCTL_RX_WCRED_MODE	PPC_BIT(4)
206 #define VAS_WINCTL_TX_WORD_MODE		PPC_BIT(5)
207 #define VAS_WINCTL_RX_WORD_MODE		PPC_BIT(6)
208 #define VAS_WINCTL_RSVD_TXBUF		PPC_BIT(7)
209 #define VAS_WINCTL_THRESH_CTL		PPC_BITMASK(8, 9)
210 #define VAS_WINCTL_FAULT_WIN		PPC_BIT(10)
211 #define VAS_WINCTL_NX_WIN		PPC_BIT(11)
212 
213 #define VAS_WIN_STATUS_OFFSET		0x110
214 #define VAS_WIN_BUSY			PPC_BIT(1)
215 
216 #define VAS_WIN_CTX_CACHING_CTL_OFFSET	0x118
217 #define VAS_CASTOUT_REQ			PPC_BIT(0)
218 #define VAS_PUSH_TO_MEM			PPC_BIT(1)
219 #define VAS_WIN_CACHE_STATUS		PPC_BIT(4)
220 
221 #define VAS_TX_RSVD_BUF_COUNT_OFFSET	0x120
222 #define VAS_RXVD_BUF_COUNT		PPC_BITMASK(58, 63)
223 
224 #define VAS_LRFIFO_WIN_PTR_OFFSET	0x128
225 #define VAS_LRX_WIN_ID			PPC_BITMASK(0, 15)
226 
227 /*
228  * Local Notification Control Register controls what happens in _response_
229  * to a paste command and hence applies only to receive windows.
230  */
231 #define VAS_LNOTIFY_CTL_OFFSET		0x138
232 #define VAS_NOTIFY_DISABLE		PPC_BIT(0)
233 #define VAS_INTR_DISABLE		PPC_BIT(1)
234 #define VAS_NOTIFY_EARLY		PPC_BIT(2)
235 #define VAS_NOTIFY_OSU_INTR		PPC_BIT(3)
236 
237 #define VAS_LNOTIFY_PID_OFFSET		0x140
238 #define VAS_LNOTIFY_PID			PPC_BITMASK(0, 19)
239 
240 #define VAS_LNOTIFY_LPID_OFFSET		0x148
241 #define VAS_LNOTIFY_LPID		PPC_BITMASK(0, 11)
242 
243 #define VAS_LNOTIFY_TID_OFFSET		0x150
244 #define VAS_LNOTIFY_TID			PPC_BITMASK(0, 15)
245 
246 #define VAS_LNOTIFY_SCOPE_OFFSET	0x158
247 #define VAS_LNOTIFY_MIN_SCOPE		PPC_BITMASK(0, 1)
248 #define VAS_LNOTIFY_MAX_SCOPE		PPC_BITMASK(2, 3)
249 
250 #define VAS_NX_UTIL_OFFSET		0x1B0
251 #define VAS_NX_UTIL			PPC_BITMASK(0, 63)
252 
253 /* SE: Side effects */
254 #define VAS_NX_UTIL_SE_OFFSET		0x1B8
255 #define VAS_NX_UTIL_SE			PPC_BITMASK(0, 63)
256 
257 #define VAS_NX_UTIL_ADDER_OFFSET	0x180
258 #define VAS_NX_UTIL_ADDER		PPC_BITMASK(32, 63)
259 
260 /*
261  * VREG(x):
262  * Expand a register's short name (eg: LPID) into two parameters:
263  *	- the register's short name in string form ("LPID"), and
264  *	- the name of the macro (eg: VAS_LPID_OFFSET), defining the
265  *	  register's offset in the window context
266  */
267 #define VREG_SFX(n, s)	__stringify(n), VAS_##n##s
268 #define VREG(r)		VREG_SFX(r, _OFFSET)
269 
270 /*
271  * Local Notify Scope Control Register. (Receive windows only).
272  */
273 enum vas_notify_scope {
274 	VAS_SCOPE_LOCAL,
275 	VAS_SCOPE_GROUP,
276 	VAS_SCOPE_VECTORED_GROUP,
277 	VAS_SCOPE_UNUSED,
278 };
279 
280 /*
281  * Local DMA Cache Control Register (Receive windows only).
282  */
283 enum vas_dma_type {
284 	VAS_DMA_TYPE_INJECT,
285 	VAS_DMA_TYPE_WRITE,
286 };
287 
288 /*
289  * Local Notify Scope Control Register. (Receive windows only).
290  * Not applicable to NX receive windows.
291  */
292 enum vas_notify_after_count {
293 	VAS_NOTIFY_AFTER_256 = 0,
294 	VAS_NOTIFY_NONE,
295 	VAS_NOTIFY_AFTER_2
296 };
297 
298 /*
299  * One per instance of VAS. Each instance will have a separate set of
300  * receive windows, one per coprocessor type.
301  *
302  * See also function header of set_vinst_win() for details on ->windows[]
303  * and ->rxwin[] tables.
304  */
305 struct vas_instance {
306 	int vas_id;
307 	struct ida ida;
308 	struct list_head node;
309 	struct platform_device *pdev;
310 
311 	u64 hvwc_bar_start;
312 	u64 uwc_bar_start;
313 	u64 paste_base_addr;
314 	u64 paste_win_id_shift;
315 
316 	struct mutex mutex;
317 	struct vas_window *rxwin[VAS_COP_TYPE_MAX];
318 	struct vas_window *windows[VAS_WINDOWS_PER_CHIP];
319 
320 	char *dbgname;
321 	struct dentry *dbgdir;
322 };
323 
324 /*
325  * In-kernel state a VAS window. One per window.
326  */
327 struct vas_window {
328 	/* Fields common to send and receive windows */
329 	struct vas_instance *vinst;
330 	int winid;
331 	bool tx_win;		/* True if send window */
332 	bool nx_win;		/* True if NX window */
333 	bool user_win;		/* True if user space window */
334 	void *hvwc_map;		/* HV window context */
335 	void *uwc_map;		/* OS/User window context */
336 	pid_t pid;		/* Linux process id of owner */
337 	int wcreds_max;		/* Window credits */
338 
339 	char *dbgname;
340 	struct dentry *dbgdir;
341 
342 	/* Fields applicable only to send windows */
343 	void *paste_kaddr;
344 	char *paste_addr_name;
345 	struct vas_window *rxwin;
346 
347 	/* Feilds applicable only to receive windows */
348 	enum vas_cop_type cop;
349 	atomic_t num_txwins;
350 };
351 
352 /*
353  * Container for the hardware state of a window. One per-window.
354  *
355  * A VAS Window context is a 512-byte area in the hardware that contains
356  * a set of 64-bit registers. Individual bit-fields in these registers
357  * determine the configuration/operation of the hardware. struct vas_winctx
358  * is a container for the register fields in the window context.
359  */
360 struct vas_winctx {
361 	void *rx_fifo;
362 	int rx_fifo_size;
363 	int wcreds_max;
364 	int rsvd_txbuf_count;
365 
366 	bool user_win;
367 	bool nx_win;
368 	bool fault_win;
369 	bool rsvd_txbuf_enable;
370 	bool pin_win;
371 	bool rej_no_credit;
372 	bool tx_wcred_mode;
373 	bool rx_wcred_mode;
374 	bool tx_word_mode;
375 	bool rx_word_mode;
376 	bool data_stamp;
377 	bool xtra_write;
378 	bool notify_disable;
379 	bool intr_disable;
380 	bool fifo_disable;
381 	bool notify_early;
382 	bool notify_os_intr_reg;
383 
384 	int lpid;
385 	int pidr;		/* value from SPRN_PID, not linux pid */
386 	int lnotify_lpid;
387 	int lnotify_pid;
388 	int lnotify_tid;
389 	u32 pswid;
390 	int rx_win_id;
391 	int fault_win_id;
392 	int tc_mode;
393 
394 	u64 irq_port;
395 
396 	enum vas_dma_type dma_type;
397 	enum vas_notify_scope min_scope;
398 	enum vas_notify_scope max_scope;
399 	enum vas_notify_after_count notify_after_count;
400 };
401 
402 extern struct mutex vas_mutex;
403 
404 extern struct vas_instance *find_vas_instance(int vasid);
405 extern void vas_init_dbgdir(void);
406 extern void vas_instance_init_dbgdir(struct vas_instance *vinst);
407 extern void vas_window_init_dbgdir(struct vas_window *win);
408 extern void vas_window_free_dbgdir(struct vas_window *win);
409 
410 static inline void vas_log_write(struct vas_window *win, char *name,
411 			void *regptr, u64 val)
412 {
413 	if (val)
414 		pr_debug("%swin #%d: %s reg %p, val 0x%016llx\n",
415 				win->tx_win ? "Tx" : "Rx", win->winid, name,
416 				regptr, val);
417 }
418 
419 static inline void write_uwc_reg(struct vas_window *win, char *name,
420 			s32 reg, u64 val)
421 {
422 	void *regptr;
423 
424 	regptr = win->uwc_map + reg;
425 	vas_log_write(win, name, regptr, val);
426 
427 	out_be64(regptr, val);
428 }
429 
430 static inline void write_hvwc_reg(struct vas_window *win, char *name,
431 			s32 reg, u64 val)
432 {
433 	void *regptr;
434 
435 	regptr = win->hvwc_map + reg;
436 	vas_log_write(win, name, regptr, val);
437 
438 	out_be64(regptr, val);
439 }
440 
441 static inline u64 read_hvwc_reg(struct vas_window *win,
442 			char *name __maybe_unused, s32 reg)
443 {
444 	return in_be64(win->hvwc_map+reg);
445 }
446 
447 /*
448  * Encode/decode the Partition Send Window ID (PSWID) for a window in
449  * a way that we can uniquely identify any window in the system. i.e.
450  * we should be able to locate the 'struct vas_window' given the PSWID.
451  *
452  *	Bits	Usage
453  *	0:7	VAS id (8 bits)
454  *	8:15	Unused, 0 (3 bits)
455  *	16:31	Window id (16 bits)
456  */
457 static inline u32 encode_pswid(int vasid, int winid)
458 {
459 	u32 pswid = 0;
460 
461 	pswid |= vasid << (31 - 7);
462 	pswid |= winid;
463 
464 	return pswid;
465 }
466 
467 static inline void decode_pswid(u32 pswid, int *vasid, int *winid)
468 {
469 	if (vasid)
470 		*vasid = pswid >> (31 - 7) & 0xFF;
471 
472 	if (winid)
473 		*winid = pswid & 0xFFFF;
474 }
475 #endif /* _VAS_H */
476