1 /*
2  * Copyright 2011 Tilera Corporation. All Rights Reserved.
3  *
4  *   This program is free software; you can redistribute it and/or
5  *   modify it under the terms of the GNU General Public License
6  *   as published by the Free Software Foundation, version 2.
7  *
8  *   This program is distributed in the hope that it will be useful, but
9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11  *   NON INFRINGEMENT.  See the GNU General Public License for
12  *   more details.
13  * Tilera-specific EDAC driver.
14  *
15  * This source code is derived from the following driver:
16  *
17  * Cell MIC driver for ECC counting
18  *
19  * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
20  *                <benh@kernel.crashing.org>
21  *
22  */
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/platform_device.h>
27 #include <linux/io.h>
28 #include <linux/uaccess.h>
29 #include <linux/edac.h>
30 #include <hv/hypervisor.h>
31 #include <hv/drv_mshim_intf.h>
32 
33 #include "edac_core.h"
34 
35 #define DRV_NAME	"tile-edac"
36 
37 /* Number of cs_rows needed per memory controller on TILEPro. */
38 #define TILE_EDAC_NR_CSROWS	1
39 
40 /* Number of channels per memory controller on TILEPro. */
41 #define TILE_EDAC_NR_CHANS	1
42 
43 /* Granularity of reported error in bytes on TILEPro. */
44 #define TILE_EDAC_ERROR_GRAIN	8
45 
46 /* TILE processor has multiple independent memory controllers. */
47 struct platform_device *mshim_pdev[TILE_MAX_MSHIMS];
48 
49 struct tile_edac_priv {
50 	int		hv_devhdl;	/* Hypervisor device handle. */
51 	int		node;		/* Memory controller instance #. */
52 	unsigned int	ce_count;	/*
53 					 * Correctable-error counter
54 					 * kept by the driver.
55 					 */
56 };
57 
tile_edac_check(struct mem_ctl_info * mci)58 static void tile_edac_check(struct mem_ctl_info *mci)
59 {
60 	struct tile_edac_priv	*priv = mci->pvt_info;
61 	struct mshim_mem_error	mem_error;
62 
63 	if (hv_dev_pread(priv->hv_devhdl, 0, (HV_VirtAddr)&mem_error,
64 		sizeof(struct mshim_mem_error), MSHIM_MEM_ERROR_OFF) !=
65 		sizeof(struct mshim_mem_error)) {
66 		pr_err(DRV_NAME ": MSHIM_MEM_ERROR_OFF pread failure.\n");
67 		return;
68 	}
69 
70 	/* Check if the current error count is different from the saved one. */
71 	if (mem_error.sbe_count != priv->ce_count) {
72 		dev_dbg(mci->dev, "ECC CE err on node %d\n", priv->node);
73 		priv->ce_count = mem_error.sbe_count;
74 		edac_mc_handle_ce(mci, 0, 0, 0, 0, 0, mci->ctl_name);
75 	}
76 }
77 
78 /*
79  * Initialize the 'csrows' table within the mci control structure with the
80  * addressing of memory.
81  */
tile_edac_init_csrows(struct mem_ctl_info * mci)82 static int __devinit tile_edac_init_csrows(struct mem_ctl_info *mci)
83 {
84 	struct csrow_info	*csrow = &mci->csrows[0];
85 	struct tile_edac_priv	*priv = mci->pvt_info;
86 	struct mshim_mem_info	mem_info;
87 
88 	if (hv_dev_pread(priv->hv_devhdl, 0, (HV_VirtAddr)&mem_info,
89 		sizeof(struct mshim_mem_info), MSHIM_MEM_INFO_OFF) !=
90 		sizeof(struct mshim_mem_info)) {
91 		pr_err(DRV_NAME ": MSHIM_MEM_INFO_OFF pread failure.\n");
92 		return -1;
93 	}
94 
95 	if (mem_info.mem_ecc)
96 		csrow->edac_mode = EDAC_SECDED;
97 	else
98 		csrow->edac_mode = EDAC_NONE;
99 	switch (mem_info.mem_type) {
100 	case DDR2:
101 		csrow->mtype = MEM_DDR2;
102 		break;
103 
104 	case DDR3:
105 		csrow->mtype = MEM_DDR3;
106 		break;
107 
108 	default:
109 		return -1;
110 	}
111 
112 	csrow->first_page = 0;
113 	csrow->nr_pages = mem_info.mem_size >> PAGE_SHIFT;
114 	csrow->last_page = csrow->first_page + csrow->nr_pages - 1;
115 	csrow->grain = TILE_EDAC_ERROR_GRAIN;
116 	csrow->dtype = DEV_UNKNOWN;
117 
118 	return 0;
119 }
120 
tile_edac_mc_probe(struct platform_device * pdev)121 static int __devinit tile_edac_mc_probe(struct platform_device *pdev)
122 {
123 	char			hv_file[32];
124 	int			hv_devhdl;
125 	struct mem_ctl_info	*mci;
126 	struct tile_edac_priv	*priv;
127 	int			rc;
128 
129 	sprintf(hv_file, "mshim/%d", pdev->id);
130 	hv_devhdl = hv_dev_open((HV_VirtAddr)hv_file, 0);
131 	if (hv_devhdl < 0)
132 		return -EINVAL;
133 
134 	/* A TILE MC has a single channel and one chip-select row. */
135 	mci = edac_mc_alloc(sizeof(struct tile_edac_priv),
136 		TILE_EDAC_NR_CSROWS, TILE_EDAC_NR_CHANS, pdev->id);
137 	if (mci == NULL)
138 		return -ENOMEM;
139 	priv = mci->pvt_info;
140 	priv->node = pdev->id;
141 	priv->hv_devhdl = hv_devhdl;
142 
143 	mci->dev = &pdev->dev;
144 	mci->mtype_cap = MEM_FLAG_DDR2;
145 	mci->edac_ctl_cap = EDAC_FLAG_SECDED;
146 
147 	mci->mod_name = DRV_NAME;
148 #ifdef __tilegx__
149 	mci->ctl_name = "TILEGx_Memory_Controller";
150 #else
151 	mci->ctl_name = "TILEPro_Memory_Controller";
152 #endif
153 	mci->dev_name = dev_name(&pdev->dev);
154 	mci->edac_check = tile_edac_check;
155 
156 	/*
157 	 * Initialize the MC control structure 'csrows' table
158 	 * with the mapping and control information.
159 	 */
160 	if (tile_edac_init_csrows(mci)) {
161 		/* No csrows found. */
162 		mci->edac_cap = EDAC_FLAG_NONE;
163 	} else {
164 		mci->edac_cap = EDAC_FLAG_SECDED;
165 	}
166 
167 	platform_set_drvdata(pdev, mci);
168 
169 	/* Register with EDAC core */
170 	rc = edac_mc_add_mc(mci);
171 	if (rc) {
172 		dev_err(&pdev->dev, "failed to register with EDAC core\n");
173 		edac_mc_free(mci);
174 		return rc;
175 	}
176 
177 	return 0;
178 }
179 
tile_edac_mc_remove(struct platform_device * pdev)180 static int __devexit tile_edac_mc_remove(struct platform_device *pdev)
181 {
182 	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
183 
184 	edac_mc_del_mc(&pdev->dev);
185 	if (mci)
186 		edac_mc_free(mci);
187 	return 0;
188 }
189 
190 static struct platform_driver tile_edac_mc_driver = {
191 	.driver		= {
192 		.name	= DRV_NAME,
193 		.owner	= THIS_MODULE,
194 	},
195 	.probe		= tile_edac_mc_probe,
196 	.remove		= __devexit_p(tile_edac_mc_remove),
197 };
198 
199 /*
200  * Driver init routine.
201  */
tile_edac_init(void)202 static int __init tile_edac_init(void)
203 {
204 	char	hv_file[32];
205 	struct platform_device *pdev;
206 	int i, err, num = 0;
207 
208 	/* Only support POLL mode. */
209 	edac_op_state = EDAC_OPSTATE_POLL;
210 
211 	err = platform_driver_register(&tile_edac_mc_driver);
212 	if (err)
213 		return err;
214 
215 	for (i = 0; i < TILE_MAX_MSHIMS; i++) {
216 		/*
217 		 * Not all memory controllers are configured such as in the
218 		 * case of a simulator. So we register only those mshims
219 		 * that are configured by the hypervisor.
220 		 */
221 		sprintf(hv_file, "mshim/%d", i);
222 		if (hv_dev_open((HV_VirtAddr)hv_file, 0) < 0)
223 			continue;
224 
225 		pdev = platform_device_register_simple(DRV_NAME, i, NULL, 0);
226 		if (IS_ERR(pdev))
227 			continue;
228 		mshim_pdev[i] = pdev;
229 		num++;
230 	}
231 
232 	if (num == 0) {
233 		platform_driver_unregister(&tile_edac_mc_driver);
234 		return -ENODEV;
235 	}
236 	return 0;
237 }
238 
239 /*
240  * Driver cleanup routine.
241  */
tile_edac_exit(void)242 static void __exit tile_edac_exit(void)
243 {
244 	int i;
245 
246 	for (i = 0; i < TILE_MAX_MSHIMS; i++) {
247 		struct platform_device *pdev = mshim_pdev[i];
248 		if (!pdev)
249 			continue;
250 
251 		platform_set_drvdata(pdev, NULL);
252 		platform_device_unregister(pdev);
253 	}
254 	platform_driver_unregister(&tile_edac_mc_driver);
255 }
256 
257 module_init(tile_edac_init);
258 module_exit(tile_edac_exit);
259