1 /*
2  *              GRU KERNEL MCS INSTRUCTIONS
3  *
4  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  */
20 
21 #include <linux/kernel.h>
22 #include "gru.h"
23 #include "grulib.h"
24 #include "grutables.h"
25 
26 /* 10 sec */
27 #ifdef CONFIG_IA64
28 #include <asm/processor.h>
29 #define GRU_OPERATION_TIMEOUT	(((cycles_t) local_cpu_data->itc_freq)*10)
30 #define CLKS2NSEC(c)		((c) *1000000000 / local_cpu_data->itc_freq)
31 #else
32 #include <asm/tsc.h>
33 #define GRU_OPERATION_TIMEOUT	((cycles_t) tsc_khz*10*1000)
34 #define CLKS2NSEC(c)		((c) * 1000000 / tsc_khz)
35 #endif
36 
37 /* Extract the status field from a kernel handle */
38 #define GET_MSEG_HANDLE_STATUS(h)	(((*(unsigned long *)(h)) >> 16) & 3)
39 
40 struct mcs_op_statistic mcs_op_statistics[mcsop_last];
41 
42 static void update_mcs_stats(enum mcs_op op, unsigned long clks)
43 {
44 	unsigned long nsec;
45 
46 	nsec = CLKS2NSEC(clks);
47 	atomic_long_inc(&mcs_op_statistics[op].count);
48 	atomic_long_add(nsec, &mcs_op_statistics[op].total);
49 	if (mcs_op_statistics[op].max < nsec)
50 		mcs_op_statistics[op].max = nsec;
51 }
52 
53 static void start_instruction(void *h)
54 {
55 	unsigned long *w0 = h;
56 
57 	wmb();		/* setting CMD/STATUS bits must be last */
58 	*w0 = *w0 | 0x20001;
59 	gru_flush_cache(h);
60 }
61 
62 static void report_instruction_timeout(void *h)
63 {
64 	unsigned long goff = GSEGPOFF((unsigned long)h);
65 	char *id = "???";
66 
67 	if (TYPE_IS(CCH, goff))
68 		id = "CCH";
69 	else if (TYPE_IS(TGH, goff))
70 		id = "TGH";
71 	else if (TYPE_IS(TFH, goff))
72 		id = "TFH";
73 
74 	panic(KERN_ALERT "GRU %p (%s) is malfunctioning\n", h, id);
75 }
76 
77 static int wait_instruction_complete(void *h, enum mcs_op opc)
78 {
79 	int status;
80 	unsigned long start_time = get_cycles();
81 
82 	while (1) {
83 		cpu_relax();
84 		status = GET_MSEG_HANDLE_STATUS(h);
85 		if (status != CCHSTATUS_ACTIVE)
86 			break;
87 		if (GRU_OPERATION_TIMEOUT < (get_cycles() - start_time)) {
88 			report_instruction_timeout(h);
89 			start_time = get_cycles();
90 		}
91 	}
92 	if (gru_options & OPT_STATS)
93 		update_mcs_stats(opc, get_cycles() - start_time);
94 	return status;
95 }
96 
97 int cch_allocate(struct gru_context_configuration_handle *cch)
98 {
99 	int ret;
100 
101 	cch->opc = CCHOP_ALLOCATE;
102 	start_instruction(cch);
103 	ret = wait_instruction_complete(cch, cchop_allocate);
104 
105 	/*
106 	 * Stop speculation into the GSEG being mapped by the previous ALLOCATE.
107 	 * The GSEG memory does not exist until the ALLOCATE completes.
108 	 */
109 	sync_core();
110 	return ret;
111 }
112 
113 int cch_start(struct gru_context_configuration_handle *cch)
114 {
115 	cch->opc = CCHOP_START;
116 	start_instruction(cch);
117 	return wait_instruction_complete(cch, cchop_start);
118 }
119 
120 int cch_interrupt(struct gru_context_configuration_handle *cch)
121 {
122 	cch->opc = CCHOP_INTERRUPT;
123 	start_instruction(cch);
124 	return wait_instruction_complete(cch, cchop_interrupt);
125 }
126 
127 int cch_deallocate(struct gru_context_configuration_handle *cch)
128 {
129 	int ret;
130 
131 	cch->opc = CCHOP_DEALLOCATE;
132 	start_instruction(cch);
133 	ret = wait_instruction_complete(cch, cchop_deallocate);
134 
135 	/*
136 	 * Stop speculation into the GSEG being unmapped by the previous
137 	 * DEALLOCATE.
138 	 */
139 	sync_core();
140 	return ret;
141 }
142 
143 int cch_interrupt_sync(struct gru_context_configuration_handle
144 				     *cch)
145 {
146 	cch->opc = CCHOP_INTERRUPT_SYNC;
147 	start_instruction(cch);
148 	return wait_instruction_complete(cch, cchop_interrupt_sync);
149 }
150 
151 int tgh_invalidate(struct gru_tlb_global_handle *tgh,
152 				 unsigned long vaddr, unsigned long vaddrmask,
153 				 int asid, int pagesize, int global, int n,
154 				 unsigned short ctxbitmap)
155 {
156 	tgh->vaddr = vaddr;
157 	tgh->asid = asid;
158 	tgh->pagesize = pagesize;
159 	tgh->n = n;
160 	tgh->global = global;
161 	tgh->vaddrmask = vaddrmask;
162 	tgh->ctxbitmap = ctxbitmap;
163 	tgh->opc = TGHOP_TLBINV;
164 	start_instruction(tgh);
165 	return wait_instruction_complete(tgh, tghop_invalidate);
166 }
167 
168 int tfh_write_only(struct gru_tlb_fault_handle *tfh,
169 				  unsigned long paddr, int gaa,
170 				  unsigned long vaddr, int asid, int dirty,
171 				  int pagesize)
172 {
173 	tfh->fillasid = asid;
174 	tfh->fillvaddr = vaddr;
175 	tfh->pfn = paddr >> GRU_PADDR_SHIFT;
176 	tfh->gaa = gaa;
177 	tfh->dirty = dirty;
178 	tfh->pagesize = pagesize;
179 	tfh->opc = TFHOP_WRITE_ONLY;
180 	start_instruction(tfh);
181 	return wait_instruction_complete(tfh, tfhop_write_only);
182 }
183 
184 void tfh_write_restart(struct gru_tlb_fault_handle *tfh,
185 				     unsigned long paddr, int gaa,
186 				     unsigned long vaddr, int asid, int dirty,
187 				     int pagesize)
188 {
189 	tfh->fillasid = asid;
190 	tfh->fillvaddr = vaddr;
191 	tfh->pfn = paddr >> GRU_PADDR_SHIFT;
192 	tfh->gaa = gaa;
193 	tfh->dirty = dirty;
194 	tfh->pagesize = pagesize;
195 	tfh->opc = TFHOP_WRITE_RESTART;
196 	start_instruction(tfh);
197 }
198 
199 void tfh_restart(struct gru_tlb_fault_handle *tfh)
200 {
201 	tfh->opc = TFHOP_RESTART;
202 	start_instruction(tfh);
203 }
204 
205 void tfh_user_polling_mode(struct gru_tlb_fault_handle *tfh)
206 {
207 	tfh->opc = TFHOP_USER_POLLING_MODE;
208 	start_instruction(tfh);
209 }
210 
211 void tfh_exception(struct gru_tlb_fault_handle *tfh)
212 {
213 	tfh->opc = TFHOP_EXCEPTION;
214 	start_instruction(tfh);
215 }
216 
217