1/*
2 * Serial Attached SCSI (SAS) Expander discovery and configuration
3 *
4 * Copyright (C) 2007 James E.J. Bottomley
5 *		<James.Bottomley@HansenPartnership.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; version 2 only.
10 */
11#include <linux/scatterlist.h>
12#include <linux/blkdev.h>
13#include <linux/slab.h>
14#include <linux/export.h>
15
16#include "sas_internal.h"
17
18#include <scsi/scsi_transport.h>
19#include <scsi/scsi_transport_sas.h>
20#include "../scsi_sas_internal.h"
21
22static void sas_host_smp_discover(struct sas_ha_struct *sas_ha, u8 *resp_data,
23				  u8 phy_id)
24{
25	struct sas_phy *phy;
26	struct sas_rphy *rphy;
27
28	if (phy_id >= sas_ha->num_phys) {
29		resp_data[2] = SMP_RESP_NO_PHY;
30		return;
31	}
32	resp_data[2] = SMP_RESP_FUNC_ACC;
33
34	phy = sas_ha->sas_phy[phy_id]->phy;
35	resp_data[9] = phy_id;
36	resp_data[13] = phy->negotiated_linkrate;
37	memcpy(resp_data + 16, sas_ha->sas_addr, SAS_ADDR_SIZE);
38	memcpy(resp_data + 24, sas_ha->sas_phy[phy_id]->attached_sas_addr,
39	       SAS_ADDR_SIZE);
40	resp_data[40] = (phy->minimum_linkrate << 4) |
41		phy->minimum_linkrate_hw;
42	resp_data[41] = (phy->maximum_linkrate << 4) |
43		phy->maximum_linkrate_hw;
44
45	if (!sas_ha->sas_phy[phy_id]->port ||
46	    !sas_ha->sas_phy[phy_id]->port->port_dev)
47		return;
48
49	rphy = sas_ha->sas_phy[phy_id]->port->port_dev->rphy;
50	resp_data[12] = rphy->identify.device_type << 4;
51	resp_data[14] = rphy->identify.initiator_port_protocols;
52	resp_data[15] = rphy->identify.target_port_protocols;
53}
54
55/**
56 * to_sas_gpio_gp_bit - given the gpio frame data find the byte/bit position of 'od'
57 * @od: od bit to find
58 * @data: incoming bitstream (from frame)
59 * @index: requested data register index (from frame)
60 * @count: total number of registers in the bitstream (from frame)
61 * @bit: bit position of 'od' in the returned byte
62 *
63 * returns NULL if 'od' is not in 'data'
64 *
65 * From SFF-8485 v0.7:
66 * "In GPIO_TX[1], bit 0 of byte 3 contains the first bit (i.e., OD0.0)
67 *  and bit 7 of byte 0 contains the 32nd bit (i.e., OD10.1).
68 *
69 *  In GPIO_TX[2], bit 0 of byte 3 contains the 33rd bit (i.e., OD10.2)
70 *  and bit 7 of byte 0 contains the 64th bit (i.e., OD21.0)."
71 *
72 * The general-purpose (raw-bitstream) RX registers have the same layout
73 * although 'od' is renamed 'id' for 'input data'.
74 *
75 * SFF-8489 defines the behavior of the LEDs in response to the 'od' values.
76 */
77static u8 *to_sas_gpio_gp_bit(unsigned int od, u8 *data, u8 index, u8 count, u8 *bit)
78{
79	unsigned int reg;
80	u8 byte;
81
82	/* gp registers start at index 1 */
83	if (index == 0)
84		return NULL;
85
86	index--; /* make index 0-based */
87	if (od < index * 32)
88		return NULL;
89
90	od -= index * 32;
91	reg = od >> 5;
92
93	if (reg >= count)
94		return NULL;
95
96	od &= (1 << 5) - 1;
97	byte = 3 - (od >> 3);
98	*bit = od & ((1 << 3) - 1);
99
100	return &data[reg * 4 + byte];
101}
102
103int try_test_sas_gpio_gp_bit(unsigned int od, u8 *data, u8 index, u8 count)
104{
105	u8 *byte;
106	u8 bit;
107
108	byte = to_sas_gpio_gp_bit(od, data, index, count, &bit);
109	if (!byte)
110		return -1;
111
112	return (*byte >> bit) & 1;
113}
114EXPORT_SYMBOL(try_test_sas_gpio_gp_bit);
115
116static int sas_host_smp_write_gpio(struct sas_ha_struct *sas_ha, u8 *resp_data,
117				   u8 reg_type, u8 reg_index, u8 reg_count,
118				   u8 *req_data)
119{
120	struct sas_internal *i = to_sas_internal(sas_ha->core.shost->transportt);
121	int written;
122
123	if (i->dft->lldd_write_gpio == NULL) {
124		resp_data[2] = SMP_RESP_FUNC_UNK;
125		return 0;
126	}
127
128	written = i->dft->lldd_write_gpio(sas_ha, reg_type, reg_index,
129					  reg_count, req_data);
130
131	if (written < 0) {
132		resp_data[2] = SMP_RESP_FUNC_FAILED;
133		written = 0;
134	} else
135		resp_data[2] = SMP_RESP_FUNC_ACC;
136
137	return written;
138}
139
140static void sas_report_phy_sata(struct sas_ha_struct *sas_ha, u8 *resp_data,
141				u8 phy_id)
142{
143	struct sas_rphy *rphy;
144	struct dev_to_host_fis *fis;
145	int i;
146
147	if (phy_id >= sas_ha->num_phys) {
148		resp_data[2] = SMP_RESP_NO_PHY;
149		return;
150	}
151
152	resp_data[2] = SMP_RESP_PHY_NO_SATA;
153
154	if (!sas_ha->sas_phy[phy_id]->port)
155		return;
156
157	rphy = sas_ha->sas_phy[phy_id]->port->port_dev->rphy;
158	fis = (struct dev_to_host_fis *)
159		sas_ha->sas_phy[phy_id]->port->port_dev->frame_rcvd;
160	if (rphy->identify.target_port_protocols != SAS_PROTOCOL_SATA)
161		return;
162
163	resp_data[2] = SMP_RESP_FUNC_ACC;
164	resp_data[9] = phy_id;
165	memcpy(resp_data + 16, sas_ha->sas_phy[phy_id]->attached_sas_addr,
166	       SAS_ADDR_SIZE);
167
168	/* check to see if we have a valid d2h fis */
169	if (fis->fis_type != 0x34)
170		return;
171
172	/* the d2h fis is required by the standard to be in LE format */
173	for (i = 0; i < 20; i += 4) {
174		u8 *dst = resp_data + 24 + i, *src =
175			&sas_ha->sas_phy[phy_id]->port->port_dev->frame_rcvd[i];
176		dst[0] = src[3];
177		dst[1] = src[2];
178		dst[2] = src[1];
179		dst[3] = src[0];
180	}
181}
182
183static void sas_phy_control(struct sas_ha_struct *sas_ha, u8 phy_id,
184			    u8 phy_op, enum sas_linkrate min,
185			    enum sas_linkrate max, u8 *resp_data)
186{
187	struct sas_internal *i =
188		to_sas_internal(sas_ha->core.shost->transportt);
189	struct sas_phy_linkrates rates;
190	struct asd_sas_phy *asd_phy;
191
192	if (phy_id >= sas_ha->num_phys) {
193		resp_data[2] = SMP_RESP_NO_PHY;
194		return;
195	}
196
197	asd_phy = sas_ha->sas_phy[phy_id];
198	switch (phy_op) {
199	case PHY_FUNC_NOP:
200	case PHY_FUNC_LINK_RESET:
201	case PHY_FUNC_HARD_RESET:
202	case PHY_FUNC_DISABLE:
203	case PHY_FUNC_CLEAR_ERROR_LOG:
204	case PHY_FUNC_CLEAR_AFFIL:
205	case PHY_FUNC_TX_SATA_PS_SIGNAL:
206		break;
207
208	default:
209		resp_data[2] = SMP_RESP_PHY_UNK_OP;
210		return;
211	}
212
213	rates.minimum_linkrate = min;
214	rates.maximum_linkrate = max;
215
216	/* filter reset requests through libata eh */
217	if (phy_op == PHY_FUNC_LINK_RESET && sas_try_ata_reset(asd_phy) == 0) {
218		resp_data[2] = SMP_RESP_FUNC_ACC;
219		return;
220	}
221
222	if (i->dft->lldd_control_phy(asd_phy, phy_op, &rates))
223		resp_data[2] = SMP_RESP_FUNC_FAILED;
224	else
225		resp_data[2] = SMP_RESP_FUNC_ACC;
226}
227
228int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
229			 struct request *rsp)
230{
231	u8 *req_data = NULL, *resp_data = NULL, *buf;
232	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
233	int error = -EINVAL;
234
235	/* eight is the minimum size for request and response frames */
236	if (blk_rq_bytes(req) < 8 || blk_rq_bytes(rsp) < 8)
237		goto out;
238
239	if (bio_offset(req->bio) + blk_rq_bytes(req) > PAGE_SIZE ||
240	    bio_offset(rsp->bio) + blk_rq_bytes(rsp) > PAGE_SIZE) {
241		shost_printk(KERN_ERR, shost,
242			"SMP request/response frame crosses page boundary");
243		goto out;
244	}
245
246	req_data = kzalloc(blk_rq_bytes(req), GFP_KERNEL);
247
248	/* make sure frame can always be built ... we copy
249	 * back only the requested length */
250	resp_data = kzalloc(max(blk_rq_bytes(rsp), 128U), GFP_KERNEL);
251
252	if (!req_data || !resp_data) {
253		error = -ENOMEM;
254		goto out;
255	}
256
257	local_irq_disable();
258	buf = kmap_atomic(bio_page(req->bio));
259	memcpy(req_data, buf, blk_rq_bytes(req));
260	kunmap_atomic(buf - bio_offset(req->bio));
261	local_irq_enable();
262
263	if (req_data[0] != SMP_REQUEST)
264		goto out;
265
266	/* always succeeds ... even if we can't process the request
267	 * the result is in the response frame */
268	error = 0;
269
270	/* set up default don't know response */
271	resp_data[0] = SMP_RESPONSE;
272	resp_data[1] = req_data[1];
273	resp_data[2] = SMP_RESP_FUNC_UNK;
274
275	switch (req_data[1]) {
276	case SMP_REPORT_GENERAL:
277		req->resid_len -= 8;
278		rsp->resid_len -= 32;
279		resp_data[2] = SMP_RESP_FUNC_ACC;
280		resp_data[9] = sas_ha->num_phys;
281		break;
282
283	case SMP_REPORT_MANUF_INFO:
284		req->resid_len -= 8;
285		rsp->resid_len -= 64;
286		resp_data[2] = SMP_RESP_FUNC_ACC;
287		memcpy(resp_data + 12, shost->hostt->name,
288		       SAS_EXPANDER_VENDOR_ID_LEN);
289		memcpy(resp_data + 20, "libsas virt phy",
290		       SAS_EXPANDER_PRODUCT_ID_LEN);
291		break;
292
293	case SMP_READ_GPIO_REG:
294		/* FIXME: need GPIO support in the transport class */
295		break;
296
297	case SMP_DISCOVER:
298		req->resid_len -= 16;
299		if ((int)req->resid_len < 0) {
300			req->resid_len = 0;
301			error = -EINVAL;
302			goto out;
303		}
304		rsp->resid_len -= 56;
305		sas_host_smp_discover(sas_ha, resp_data, req_data[9]);
306		break;
307
308	case SMP_REPORT_PHY_ERR_LOG:
309		/* FIXME: could implement this with additional
310		 * libsas callbacks providing the HW supports it */
311		break;
312
313	case SMP_REPORT_PHY_SATA:
314		req->resid_len -= 16;
315		if ((int)req->resid_len < 0) {
316			req->resid_len = 0;
317			error = -EINVAL;
318			goto out;
319		}
320		rsp->resid_len -= 60;
321		sas_report_phy_sata(sas_ha, resp_data, req_data[9]);
322		break;
323
324	case SMP_REPORT_ROUTE_INFO:
325		/* Can't implement; hosts have no routes */
326		break;
327
328	case SMP_WRITE_GPIO_REG: {
329		/* SFF-8485 v0.7 */
330		const int base_frame_size = 11;
331		int to_write = req_data[4];
332
333		if (blk_rq_bytes(req) < base_frame_size + to_write * 4 ||
334		    req->resid_len < base_frame_size + to_write * 4) {
335			resp_data[2] = SMP_RESP_INV_FRM_LEN;
336			break;
337		}
338
339		to_write = sas_host_smp_write_gpio(sas_ha, resp_data, req_data[2],
340						   req_data[3], to_write, &req_data[8]);
341		req->resid_len -= base_frame_size + to_write * 4;
342		rsp->resid_len -= 8;
343		break;
344	}
345
346	case SMP_CONF_ROUTE_INFO:
347		/* Can't implement; hosts have no routes */
348		break;
349
350	case SMP_PHY_CONTROL:
351		req->resid_len -= 44;
352		if ((int)req->resid_len < 0) {
353			req->resid_len = 0;
354			error = -EINVAL;
355			goto out;
356		}
357		rsp->resid_len -= 8;
358		sas_phy_control(sas_ha, req_data[9], req_data[10],
359				req_data[32] >> 4, req_data[33] >> 4,
360				resp_data);
361		break;
362
363	case SMP_PHY_TEST_FUNCTION:
364		/* FIXME: should this be implemented? */
365		break;
366
367	default:
368		/* probably a 2.0 function */
369		break;
370	}
371
372	local_irq_disable();
373	buf = kmap_atomic(bio_page(rsp->bio));
374	memcpy(buf, resp_data, blk_rq_bytes(rsp));
375	flush_kernel_dcache_page(bio_page(rsp->bio));
376	kunmap_atomic(buf - bio_offset(rsp->bio));
377	local_irq_enable();
378
379 out:
380	kfree(req_data);
381	kfree(resp_data);
382	return error;
383}
384