1/*
2 * Cell MIC driver for ECC counting
3 *
4 * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
5 *                <benh@kernel.crashing.org>
6 *
7 * This file may be distributed under the terms of the
8 * GNU General Public License.
9 */
10#undef DEBUG
11
12#include <linux/edac.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/platform_device.h>
16#include <linux/stop_machine.h>
17#include <linux/io.h>
18#include <linux/of_address.h>
19#include <asm/machdep.h>
20#include <asm/cell-regs.h>
21
22#include "edac_core.h"
23
24struct cell_edac_priv
25{
26	struct cbe_mic_tm_regs __iomem	*regs;
27	int				node;
28	int				chanmask;
29#ifdef DEBUG
30	u64				prev_fir;
31#endif
32};
33
34static void cell_edac_count_ce(struct mem_ctl_info *mci, int chan, u64 ar)
35{
36	struct cell_edac_priv		*priv = mci->pvt_info;
37	struct csrow_info		*csrow = mci->csrows[0];
38	unsigned long			address, pfn, offset, syndrome;
39
40	dev_dbg(mci->pdev, "ECC CE err on node %d, channel %d, ar = 0x%016llx\n",
41		priv->node, chan, ar);
42
43	/* Address decoding is likely a bit bogus, to dbl check */
44	address = (ar & 0xffffffffe0000000ul) >> 29;
45	if (priv->chanmask == 0x3)
46		address = (address << 1) | chan;
47	pfn = address >> PAGE_SHIFT;
48	offset = address & ~PAGE_MASK;
49	syndrome = (ar & 0x000000001fe00000ul) >> 21;
50
51	/* TODO: Decoding of the error address */
52	edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
53			     csrow->first_page + pfn, offset, syndrome,
54			     0, chan, -1, "", "");
55}
56
57static void cell_edac_count_ue(struct mem_ctl_info *mci, int chan, u64 ar)
58{
59	struct cell_edac_priv		*priv = mci->pvt_info;
60	struct csrow_info		*csrow = mci->csrows[0];
61	unsigned long			address, pfn, offset;
62
63	dev_dbg(mci->pdev, "ECC UE err on node %d, channel %d, ar = 0x%016llx\n",
64		priv->node, chan, ar);
65
66	/* Address decoding is likely a bit bogus, to dbl check */
67	address = (ar & 0xffffffffe0000000ul) >> 29;
68	if (priv->chanmask == 0x3)
69		address = (address << 1) | chan;
70	pfn = address >> PAGE_SHIFT;
71	offset = address & ~PAGE_MASK;
72
73	/* TODO: Decoding of the error address */
74	edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
75			     csrow->first_page + pfn, offset, 0,
76			     0, chan, -1, "", "");
77}
78
79static void cell_edac_check(struct mem_ctl_info *mci)
80{
81	struct cell_edac_priv		*priv = mci->pvt_info;
82	u64				fir, addreg, clear = 0;
83
84	fir = in_be64(&priv->regs->mic_fir);
85#ifdef DEBUG
86	if (fir != priv->prev_fir) {
87		dev_dbg(mci->pdev, "fir change : 0x%016lx\n", fir);
88		priv->prev_fir = fir;
89	}
90#endif
91	if ((priv->chanmask & 0x1) && (fir & CBE_MIC_FIR_ECC_SINGLE_0_ERR)) {
92		addreg = in_be64(&priv->regs->mic_df_ecc_address_0);
93		clear |= CBE_MIC_FIR_ECC_SINGLE_0_RESET;
94		cell_edac_count_ce(mci, 0, addreg);
95	}
96	if ((priv->chanmask & 0x2) && (fir & CBE_MIC_FIR_ECC_SINGLE_1_ERR)) {
97		addreg = in_be64(&priv->regs->mic_df_ecc_address_1);
98		clear |= CBE_MIC_FIR_ECC_SINGLE_1_RESET;
99		cell_edac_count_ce(mci, 1, addreg);
100	}
101	if ((priv->chanmask & 0x1) && (fir & CBE_MIC_FIR_ECC_MULTI_0_ERR)) {
102		addreg = in_be64(&priv->regs->mic_df_ecc_address_0);
103		clear |= CBE_MIC_FIR_ECC_MULTI_0_RESET;
104		cell_edac_count_ue(mci, 0, addreg);
105	}
106	if ((priv->chanmask & 0x2) && (fir & CBE_MIC_FIR_ECC_MULTI_1_ERR)) {
107		addreg = in_be64(&priv->regs->mic_df_ecc_address_1);
108		clear |= CBE_MIC_FIR_ECC_MULTI_1_RESET;
109		cell_edac_count_ue(mci, 1, addreg);
110	}
111
112	/* The procedure for clearing FIR bits is a bit ... weird */
113	if (clear) {
114		fir &= ~(CBE_MIC_FIR_ECC_ERR_MASK | CBE_MIC_FIR_ECC_SET_MASK);
115		fir |= CBE_MIC_FIR_ECC_RESET_MASK;
116		fir &= ~clear;
117		out_be64(&priv->regs->mic_fir, fir);
118		(void)in_be64(&priv->regs->mic_fir);
119
120		mb();	/* sync up */
121#ifdef DEBUG
122		fir = in_be64(&priv->regs->mic_fir);
123		dev_dbg(mci->pdev, "fir clear  : 0x%016lx\n", fir);
124#endif
125	}
126}
127
128static void cell_edac_init_csrows(struct mem_ctl_info *mci)
129{
130	struct csrow_info		*csrow = mci->csrows[0];
131	struct dimm_info		*dimm;
132	struct cell_edac_priv		*priv = mci->pvt_info;
133	struct device_node		*np;
134	int				j;
135	u32				nr_pages;
136
137	for_each_node_by_name(np, "memory") {
138		struct resource r;
139
140		/* We "know" that the Cell firmware only creates one entry
141		 * in the "memory" nodes. If that changes, this code will
142		 * need to be adapted.
143		 */
144		if (of_address_to_resource(np, 0, &r))
145			continue;
146		if (of_node_to_nid(np) != priv->node)
147			continue;
148		csrow->first_page = r.start >> PAGE_SHIFT;
149		nr_pages = resource_size(&r) >> PAGE_SHIFT;
150		csrow->last_page = csrow->first_page + nr_pages - 1;
151
152		for (j = 0; j < csrow->nr_channels; j++) {
153			dimm = csrow->channels[j]->dimm;
154			dimm->mtype = MEM_XDR;
155			dimm->edac_mode = EDAC_SECDED;
156			dimm->nr_pages = nr_pages / csrow->nr_channels;
157		}
158		dev_dbg(mci->pdev,
159			"Initialized on node %d, chanmask=0x%x,"
160			" first_page=0x%lx, nr_pages=0x%x\n",
161			priv->node, priv->chanmask,
162			csrow->first_page, nr_pages);
163		break;
164	}
165	of_node_put(np);
166}
167
168static int cell_edac_probe(struct platform_device *pdev)
169{
170	struct cbe_mic_tm_regs __iomem	*regs;
171	struct mem_ctl_info		*mci;
172	struct edac_mc_layer		layers[2];
173	struct cell_edac_priv		*priv;
174	u64				reg;
175	int				rc, chanmask, num_chans;
176
177	regs = cbe_get_cpu_mic_tm_regs(cbe_node_to_cpu(pdev->id));
178	if (regs == NULL)
179		return -ENODEV;
180
181	edac_op_state = EDAC_OPSTATE_POLL;
182
183	/* Get channel population */
184	reg = in_be64(&regs->mic_mnt_cfg);
185	dev_dbg(&pdev->dev, "MIC_MNT_CFG = 0x%016llx\n", reg);
186	chanmask = 0;
187	if (reg & CBE_MIC_MNT_CFG_CHAN_0_POP)
188		chanmask |= 0x1;
189	if (reg & CBE_MIC_MNT_CFG_CHAN_1_POP)
190		chanmask |= 0x2;
191	if (chanmask == 0) {
192		dev_warn(&pdev->dev,
193			 "Yuck ! No channel populated ? Aborting !\n");
194		return -ENODEV;
195	}
196	dev_dbg(&pdev->dev, "Initial FIR = 0x%016llx\n",
197		in_be64(&regs->mic_fir));
198
199	/* Allocate & init EDAC MC data structure */
200	num_chans = chanmask == 3 ? 2 : 1;
201
202	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
203	layers[0].size = 1;
204	layers[0].is_virt_csrow = true;
205	layers[1].type = EDAC_MC_LAYER_CHANNEL;
206	layers[1].size = num_chans;
207	layers[1].is_virt_csrow = false;
208	mci = edac_mc_alloc(pdev->id, ARRAY_SIZE(layers), layers,
209			    sizeof(struct cell_edac_priv));
210	if (mci == NULL)
211		return -ENOMEM;
212	priv = mci->pvt_info;
213	priv->regs = regs;
214	priv->node = pdev->id;
215	priv->chanmask = chanmask;
216	mci->pdev = &pdev->dev;
217	mci->mtype_cap = MEM_FLAG_XDR;
218	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
219	mci->edac_cap = EDAC_FLAG_EC | EDAC_FLAG_SECDED;
220	mci->mod_name = "cell_edac";
221	mci->ctl_name = "MIC";
222	mci->dev_name = dev_name(&pdev->dev);
223	mci->edac_check = cell_edac_check;
224	cell_edac_init_csrows(mci);
225
226	/* Register with EDAC core */
227	rc = edac_mc_add_mc(mci);
228	if (rc) {
229		dev_err(&pdev->dev, "failed to register with EDAC core\n");
230		edac_mc_free(mci);
231		return rc;
232	}
233
234	return 0;
235}
236
237static int cell_edac_remove(struct platform_device *pdev)
238{
239	struct mem_ctl_info *mci = edac_mc_del_mc(&pdev->dev);
240	if (mci)
241		edac_mc_free(mci);
242	return 0;
243}
244
245static struct platform_driver cell_edac_driver = {
246	.driver		= {
247		.name	= "cbe-mic",
248	},
249	.probe		= cell_edac_probe,
250	.remove		= cell_edac_remove,
251};
252
253static int __init cell_edac_init(void)
254{
255	/* Sanity check registers data structure */
256	BUILD_BUG_ON(offsetof(struct cbe_mic_tm_regs,
257			      mic_df_ecc_address_0) != 0xf8);
258	BUILD_BUG_ON(offsetof(struct cbe_mic_tm_regs,
259			      mic_df_ecc_address_1) != 0x1b8);
260	BUILD_BUG_ON(offsetof(struct cbe_mic_tm_regs,
261			      mic_df_config) != 0x218);
262	BUILD_BUG_ON(offsetof(struct cbe_mic_tm_regs,
263			      mic_fir) != 0x230);
264	BUILD_BUG_ON(offsetof(struct cbe_mic_tm_regs,
265			      mic_mnt_cfg) != 0x210);
266	BUILD_BUG_ON(offsetof(struct cbe_mic_tm_regs,
267			      mic_exc) != 0x208);
268
269	return platform_driver_register(&cell_edac_driver);
270}
271
272static void __exit cell_edac_exit(void)
273{
274	platform_driver_unregister(&cell_edac_driver);
275}
276
277module_init(cell_edac_init);
278module_exit(cell_edac_exit);
279
280MODULE_LICENSE("GPL");
281MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
282MODULE_DESCRIPTION("ECC counting for Cell MIC");
283