tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * GRU KERNEL MCS INSTRUCTIONS
4 *
5 * Copyright (c) 2008 Silicon Graphics, Inc. All Rights Reserved.
6 */
7
8#include <linux/kernel.h>
9#include "gru.h"
10#include "grulib.h"
11#include "grutables.h"
12
13/* 10 sec */
14#ifdef CONFIG_IA64
15#include <asm/processor.h>
16#define GRU_OPERATION_TIMEOUT (((cycles_t) local_cpu_data->itc_freq)*10)
17#define CLKS2NSEC(c) ((c) *1000000000 / local_cpu_data->itc_freq)
18#else
19#include <linux/sync_core.h>
20#include <asm/tsc.h>
21#define GRU_OPERATION_TIMEOUT ((cycles_t) tsc_khz*10*1000)
22#define CLKS2NSEC(c) ((c) * 1000000 / tsc_khz)
23#endif
24
25/* Extract the status field from a kernel handle */
26#define GET_MSEG_HANDLE_STATUS(h) (((*(unsigned long *)(h)) >> 16) & 3)
27
28struct mcs_op_statistic mcs_op_statistics[mcsop_last];
29
30static void update_mcs_stats(enum mcs_op op, unsigned long clks)
31{
32 unsigned long nsec;
33
34 nsec = CLKS2NSEC(clks);
35 atomic_long_inc(&mcs_op_statistics[op].count);
36 atomic_long_add(nsec, &mcs_op_statistics[op].total);
37 if (mcs_op_statistics[op].max < nsec)
38 mcs_op_statistics[op].max = nsec;
39}
40
41static void start_instruction(void *h)
42{
43 unsigned long *w0 = h;
44
45 wmb(); /* setting CMD/STATUS bits must be last */
46 *w0 = *w0 | 0x20001;
47 gru_flush_cache(h);
48}
49
50static void report_instruction_timeout(void *h)
51{
52 unsigned long goff = GSEGPOFF((unsigned long)h);
53 char *id = "???";
54
55 if (TYPE_IS(CCH, goff))
56 id = "CCH";
57 else if (TYPE_IS(TGH, goff))
58 id = "TGH";
59 else if (TYPE_IS(TFH, goff))
60 id = "TFH";
61
62 panic(KERN_ALERT "GRU %p (%s) is malfunctioning\n", h, id);
63}
64
65static int wait_instruction_complete(void *h, enum mcs_op opc)
66{
67 int status;
68 unsigned long start_time = get_cycles();
69
70 while (1) {
71 cpu_relax();
72 status = GET_MSEG_HANDLE_STATUS(h);
73 if (status != CCHSTATUS_ACTIVE)
74 break;
75 if (GRU_OPERATION_TIMEOUT < (get_cycles() - start_time)) {
76 report_instruction_timeout(h);
77 start_time = get_cycles();
78 }
79 }
80 if (gru_options & OPT_STATS)
81 update_mcs_stats(opc, get_cycles() - start_time);
82 return status;
83}
84
85int cch_allocate(struct gru_context_configuration_handle *cch)
86{
87 int ret;
88
89 cch->opc = CCHOP_ALLOCATE;
90 start_instruction(cch);
91 ret = wait_instruction_complete(cch, cchop_allocate);
92
93 /*
94 * Stop speculation into the GSEG being mapped by the previous ALLOCATE.
95 * The GSEG memory does not exist until the ALLOCATE completes.
96 */
97 sync_core();
98 return ret;
99}
100
101int cch_start(struct gru_context_configuration_handle *cch)
102{
103 cch->opc = CCHOP_START;
104 start_instruction(cch);
105 return wait_instruction_complete(cch, cchop_start);
106}
107
108int cch_interrupt(struct gru_context_configuration_handle *cch)
109{
110 cch->opc = CCHOP_INTERRUPT;
111 start_instruction(cch);
112 return wait_instruction_complete(cch, cchop_interrupt);
113}
114
115int cch_deallocate(struct gru_context_configuration_handle *cch)
116{
117 int ret;
118
119 cch->opc = CCHOP_DEALLOCATE;
120 start_instruction(cch);
121 ret = wait_instruction_complete(cch, cchop_deallocate);
122
123 /*
124 * Stop speculation into the GSEG being unmapped by the previous
125 * DEALLOCATE.
126 */
127 sync_core();
128 return ret;
129}
130
131int cch_interrupt_sync(struct gru_context_configuration_handle
132 *cch)
133{
134 cch->opc = CCHOP_INTERRUPT_SYNC;
135 start_instruction(cch);
136 return wait_instruction_complete(cch, cchop_interrupt_sync);
137}
138
139int tgh_invalidate(struct gru_tlb_global_handle *tgh,
140 unsigned long vaddr, unsigned long vaddrmask,
141 int asid, int pagesize, int global, int n,
142 unsigned short ctxbitmap)
143{
144 tgh->vaddr = vaddr;
145 tgh->asid = asid;
146 tgh->pagesize = pagesize;
147 tgh->n = n;
148 tgh->global = global;
149 tgh->vaddrmask = vaddrmask;
150 tgh->ctxbitmap = ctxbitmap;
151 tgh->opc = TGHOP_TLBINV;
152 start_instruction(tgh);
153 return wait_instruction_complete(tgh, tghop_invalidate);
154}
155
156int tfh_write_only(struct gru_tlb_fault_handle *tfh,
157 unsigned long paddr, int gaa,
158 unsigned long vaddr, int asid, int dirty,
159 int pagesize)
160{
161 tfh->fillasid = asid;
162 tfh->fillvaddr = vaddr;
163 tfh->pfn = paddr >> GRU_PADDR_SHIFT;
164 tfh->gaa = gaa;
165 tfh->dirty = dirty;
166 tfh->pagesize = pagesize;
167 tfh->opc = TFHOP_WRITE_ONLY;
168 start_instruction(tfh);
169 return wait_instruction_complete(tfh, tfhop_write_only);
170}
171
172void tfh_write_restart(struct gru_tlb_fault_handle *tfh,
173 unsigned long paddr, int gaa,
174 unsigned long vaddr, int asid, int dirty,
175 int pagesize)
176{
177 tfh->fillasid = asid;
178 tfh->fillvaddr = vaddr;
179 tfh->pfn = paddr >> GRU_PADDR_SHIFT;
180 tfh->gaa = gaa;
181 tfh->dirty = dirty;
182 tfh->pagesize = pagesize;
183 tfh->opc = TFHOP_WRITE_RESTART;
184 start_instruction(tfh);
185}
186
187void tfh_user_polling_mode(struct gru_tlb_fault_handle *tfh)
188{
189 tfh->opc = TFHOP_USER_POLLING_MODE;
190 start_instruction(tfh);
191}
192
193void tfh_exception(struct gru_tlb_fault_handle *tfh)
194{
195 tfh->opc = TFHOP_EXCEPTION;
196 start_instruction(tfh);
197}
198