aboutsummaryrefslogtreecommitdiff
path: root/drivers/misc/cxl/main.c
blob: 9fde75ed4facd50dcfacb9e455e82a5f3e42135b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
/*
 * Copyright 2014 IBM Corp.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/spinlock.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/pci.h>
#include <asm/cputable.h>
#include <misc/cxl-base.h>

#include "cxl.h"
#include "trace.h"

static DEFINE_SPINLOCK(adapter_idr_lock);
static DEFINE_IDR(cxl_adapter_idr);

uint cxl_verbose;
module_param_named(verbose, cxl_verbose, uint, 0600);
MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");

static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm)
{
	struct task_struct *task;
	unsigned long flags;
	if (!(task = get_pid_task(ctx->pid, PIDTYPE_PID))) {
		pr_devel("%s unable to get task %i\n",
			 __func__, pid_nr(ctx->pid));
		return;
	}

	if (task->mm != mm)
		goto out_put;

	pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__,
		 ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe);

	spin_lock_irqsave(&ctx->sste_lock, flags);
	trace_cxl_slbia(ctx);
	memset(ctx->sstp, 0, ctx->sst_size);
	spin_unlock_irqrestore(&ctx->sste_lock, flags);
	mb();
	cxl_afu_slbia(ctx->afu);
out_put:
	put_task_struct(task);
}

static inline void cxl_slbia_core(struct mm_struct *mm)
{
	struct cxl *adapter;
	struct cxl_afu *afu;
	struct cxl_context *ctx;
	int card, slice, id;

	pr_devel("%s called\n", __func__);

	spin_lock(&adapter_idr_lock);
	idr_for_each_entry(&cxl_adapter_idr, adapter, card) {
		/* XXX: Make this lookup faster with link from mm to ctx */
		spin_lock(&adapter->afu_list_lock);
		for (slice = 0; slice < adapter->slices; slice++) {
			afu = adapter->afu[slice];
			if (!afu || !afu->enabled)
				continue;
			rcu_read_lock();
			idr_for_each_entry(&afu->contexts_idr, ctx, id)
				_cxl_slbia(ctx, mm);
			rcu_read_unlock();
		}
		spin_unlock(&adapter->afu_list_lock);
	}
	spin_unlock(&adapter_idr_lock);
}

static struct cxl_calls cxl_calls = {
	.cxl_slbia = cxl_slbia_core,
	.owner = THIS_MODULE,
};

int cxl_alloc_sst(struct cxl_context *ctx)
{
	unsigned long vsid;
	u64 ea_mask, size, sstp0, sstp1;

	sstp0 = 0;
	sstp1 = 0;

	ctx->sst_size = PAGE_SIZE;
	ctx->sst_lru = 0;
	ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL);
	if (!ctx->sstp) {
		pr_err("cxl_alloc_sst: Unable to allocate segment table\n");
		return -ENOMEM;
	}
	pr_devel("SSTP allocated at 0x%p\n", ctx->sstp);

	vsid  = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12;

	sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT;
	sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50;

	size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT;
	if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) {
		WARN(1, "Impossible segment table size\n");
		return -EINVAL;
	}
	sstp0 |= size;

	if (mmu_kernel_ssize == MMU_SEGSIZE_256M)
		ea_mask = 0xfffff00ULL;
	else
		ea_mask = 0xffffffff00ULL;

	sstp0 |=  vsid >>     (50-14);  /*   Top 14 bits of VSID */
	sstp1 |= (vsid << (64-(50-14))) & ~ea_mask;
	sstp1 |= (u64)ctx->sstp & ea_mask;
	sstp1 |= CXL_SSTP1_An_V;

	pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n",
			(u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1);

	/* Store calculated sstp hardware points for use later */
	ctx->sstp0 = sstp0;
	ctx->sstp1 = sstp1;

	return 0;
}

/* Find a CXL adapter by it's number and increase it's refcount */
struct cxl *get_cxl_adapter(int num)
{
	struct cxl *adapter;

	spin_lock(&adapter_idr_lock);
	if ((adapter = idr_find(&cxl_adapter_idr, num)))
		get_device(&adapter->dev);
	spin_unlock(&adapter_idr_lock);

	return adapter;
}

int cxl_alloc_adapter_nr(struct cxl *adapter)
{
	int i;

	idr_preload(GFP_KERNEL);
	spin_lock(&adapter_idr_lock);
	i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
	spin_unlock(&adapter_idr_lock);
	idr_preload_end();
	if (i < 0)
		return i;

	adapter->adapter_num = i;

	return 0;
}

void cxl_remove_adapter_nr(struct cxl *adapter)
{
	idr_remove(&cxl_adapter_idr, adapter->adapter_num);
}

int cxl_afu_select_best_mode(struct cxl_afu *afu)
{
	if (afu->modes_supported & CXL_MODE_DIRECTED)
		return cxl_afu_activate_mode(afu, CXL_MODE_DIRECTED);

	if (afu->modes_supported & CXL_MODE_DEDICATED)
		return cxl_afu_activate_mode(afu, CXL_MODE_DEDICATED);

	dev_warn(&afu->dev, "No supported programming modes available\n");
	/* We don't fail this so the user can inspect sysfs */
	return 0;
}

static int __init init_cxl(void)
{
	int rc = 0;

	if (!cpu_has_feature(CPU_FTR_HVMODE))
		return -EPERM;

	if ((rc = cxl_file_init()))
		return rc;

	cxl_debugfs_init();

	if ((rc = register_cxl_calls(&cxl_calls)))
		goto err;

	if ((rc = pci_register_driver(&cxl_pci_driver)))
		goto err1;

	return 0;
err1:
	unregister_cxl_calls(&cxl_calls);
err:
	cxl_debugfs_exit();
	cxl_file_exit();

	return rc;
}

static void exit_cxl(void)
{
	pci_unregister_driver(&cxl_pci_driver);

	cxl_debugfs_exit();
	cxl_file_exit();
	unregister_cxl_calls(&cxl_calls);
	idr_destroy(&cxl_adapter_idr);
}

module_init(init_cxl);
module_exit(exit_cxl);

MODULE_DESCRIPTION("IBM Coherent Accelerator");
MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
MODULE_LICENSE("GPL");