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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 1992-1997, 2000-2003 Silicon Graphics, Inc. | |
3 | * Copyright (C) 2004 Christoph Hellwig. | |
4 | * Released under GPL v2. | |
5 | * | |
6 | * Support functions for the HUB ASIC - mostly PIO mapping related. | |
7 | */ | |
8 | ||
9 | #include <linux/bitops.h> | |
10 | #include <linux/string.h> | |
11 | #include <linux/mmzone.h> | |
12 | #include <asm/sn/addrs.h> | |
13 | #include <asm/sn/arch.h> | |
14 | #include <asm/sn/hub.h> | |
15 | ||
16 | ||
17 | static int force_fire_and_forget = 1; | |
18 | ||
19 | /** | |
70342287 | 20 | * hub_pio_map - establish a HUB PIO mapping |
1da177e4 LT |
21 | * |
22 | * @hub: hub to perform PIO mapping on | |
23 | * @widget: widget ID to perform PIO mapping for | |
70342287 | 24 | * @xtalk_addr: xtalk_address that needs to be mapped |
1da177e4 LT |
25 | * @size: size of the PIO mapping |
26 | * | |
27 | **/ | |
28 | unsigned long hub_pio_map(cnodeid_t cnode, xwidgetnum_t widget, | |
29 | unsigned long xtalk_addr, size_t size) | |
30 | { | |
31 | nasid_t nasid = COMPACT_TO_NASID_NODEID(cnode); | |
1da177e4 LT |
32 | unsigned i; |
33 | ||
34 | /* use small-window mapping if possible */ | |
35 | if ((xtalk_addr % SWIN_SIZE) + size <= SWIN_SIZE) | |
36 | return NODE_SWIN_BASE(nasid, widget) + (xtalk_addr % SWIN_SIZE); | |
37 | ||
38 | if ((xtalk_addr % BWIN_SIZE) + size > BWIN_SIZE) { | |
39 | printk(KERN_WARNING "PIO mapping at hub %d widget %d addr 0x%lx" | |
40 | " too big (%ld)\n", | |
41 | nasid, widget, xtalk_addr, size); | |
42 | return 0; | |
43 | } | |
44 | ||
45 | xtalk_addr &= ~(BWIN_SIZE-1); | |
46 | for (i = 0; i < HUB_NUM_BIG_WINDOW; i++) { | |
47 | if (test_and_set_bit(i, hub_data(cnode)->h_bigwin_used)) | |
48 | continue; | |
49 | ||
50 | /* | |
51 | * The code below does a PIO write to setup an ITTE entry. | |
52 | * | |
53 | * We need to prevent other CPUs from seeing our updated | |
54 | * memory shadow of the ITTE (in the piomap) until the ITTE | |
55 | * entry is actually set up; otherwise, another CPU might | |
56 | * attempt a PIO prematurely. | |
57 | * | |
58 | * Also, the only way we can know that an entry has been | |
59 | * received by the hub and can be used by future PIO reads/ | |
60 | * writes is by reading back the ITTE entry after writing it. | |
61 | * | |
62 | * For these two reasons, we PIO read back the ITTE entry | |
63 | * after we write it. | |
64 | */ | |
65 | IIO_ITTE_PUT(nasid, i, HUB_PIO_MAP_TO_MEM, widget, xtalk_addr); | |
e12f47ef | 66 | (void) HUB_L(IIO_ITTE_GET(nasid, i)); |
1da177e4 LT |
67 | |
68 | return NODE_BWIN_BASE(nasid, widget) + (xtalk_addr % BWIN_SIZE); | |
69 | } | |
70 | ||
71 | printk(KERN_WARNING "unable to establish PIO mapping for at" | |
72 | " hub %d widget %d addr 0x%lx\n", | |
73 | nasid, widget, xtalk_addr); | |
74 | return 0; | |
75 | } | |
76 | ||
77 | ||
78 | /* | |
79 | * hub_setup_prb(nasid, prbnum, credits, conveyor) | |
80 | * | |
70342287 RB |
81 | * Put a PRB into fire-and-forget mode if conveyor isn't set. Otherwise, |
82 | * put it into conveyor belt mode with the specified number of credits. | |
1da177e4 LT |
83 | */ |
84 | static void hub_setup_prb(nasid_t nasid, int prbnum, int credits) | |
85 | { | |
86 | iprb_t prb; | |
87 | int prb_offset; | |
88 | ||
89 | /* | |
90 | * Get the current register value. | |
91 | */ | |
92 | prb_offset = IIO_IOPRB(prbnum); | |
93 | prb.iprb_regval = REMOTE_HUB_L(nasid, prb_offset); | |
94 | ||
95 | /* | |
96 | * Clear out some fields. | |
97 | */ | |
98 | prb.iprb_ovflow = 1; | |
99 | prb.iprb_bnakctr = 0; | |
100 | prb.iprb_anakctr = 0; | |
101 | ||
102 | /* | |
103 | * Enable or disable fire-and-forget mode. | |
104 | */ | |
105 | prb.iprb_ff = force_fire_and_forget ? 1 : 0; | |
106 | ||
107 | /* | |
87fd4e26 | 108 | * Set the appropriate number of PIO credits for the widget. |
1da177e4 LT |
109 | */ |
110 | prb.iprb_xtalkctr = credits; | |
111 | ||
112 | /* | |
113 | * Store the new value to the register. | |
114 | */ | |
115 | REMOTE_HUB_S(nasid, prb_offset, prb.iprb_regval); | |
116 | } | |
117 | ||
118 | /** | |
119 | * hub_set_piomode - set pio mode for a given hub | |
120 | * | |
121 | * @nasid: physical node ID for the hub in question | |
122 | * | |
123 | * Put the hub into either "PIO conveyor belt" mode or "fire-and-forget" mode. | |
124 | * To do this, we have to make absolutely sure that no PIOs are in progress | |
125 | * so we turn off access to all widgets for the duration of the function. | |
126 | * | |
127 | * XXX - This code should really check what kind of widget we're talking | |
70342287 | 128 | * to. Bridges can only handle three requests, but XG will do more. |
1da177e4 LT |
129 | * How many can crossbow handle to widget 0? We're assuming 1. |
130 | * | |
131 | * XXX - There is a bug in the crossbow that link reset PIOs do not | |
132 | * return write responses. The easiest solution to this problem is to | |
70342287 | 133 | * leave widget 0 (xbow) in fire-and-forget mode at all times. This |
1da177e4 LT |
134 | * only affects pio's to xbow registers, which should be rare. |
135 | **/ | |
136 | static void hub_set_piomode(nasid_t nasid) | |
137 | { | |
138 | hubreg_t ii_iowa; | |
139 | hubii_wcr_t ii_wcr; | |
140 | unsigned i; | |
141 | ||
142 | ii_iowa = REMOTE_HUB_L(nasid, IIO_OUTWIDGET_ACCESS); | |
143 | REMOTE_HUB_S(nasid, IIO_OUTWIDGET_ACCESS, 0); | |
144 | ||
145 | ii_wcr.wcr_reg_value = REMOTE_HUB_L(nasid, IIO_WCR); | |
146 | ||
147 | if (ii_wcr.iwcr_dir_con) { | |
148 | /* | |
149 | * Assume a bridge here. | |
150 | */ | |
151 | hub_setup_prb(nasid, 0, 3); | |
152 | } else { | |
153 | /* | |
154 | * Assume a crossbow here. | |
155 | */ | |
156 | hub_setup_prb(nasid, 0, 1); | |
157 | } | |
158 | ||
159 | /* | |
160 | * XXX - Here's where we should take the widget type into | |
161 | * when account assigning credits. | |
162 | */ | |
163 | for (i = HUB_WIDGET_ID_MIN; i <= HUB_WIDGET_ID_MAX; i++) | |
164 | hub_setup_prb(nasid, i, 3); | |
165 | ||
166 | REMOTE_HUB_S(nasid, IIO_OUTWIDGET_ACCESS, ii_iowa); | |
167 | } | |
168 | ||
169 | /* | |
70342287 | 170 | * hub_pio_init - PIO-related hub initialization |
1da177e4 LT |
171 | * |
172 | * @hub: hubinfo structure for our hub | |
173 | */ | |
174 | void hub_pio_init(cnodeid_t cnode) | |
175 | { | |
176 | nasid_t nasid = COMPACT_TO_NASID_NODEID(cnode); | |
177 | unsigned i; | |
178 | ||
179 | /* initialize big window piomaps for this hub */ | |
180 | bitmap_zero(hub_data(cnode)->h_bigwin_used, HUB_NUM_BIG_WINDOW); | |
181 | for (i = 0; i < HUB_NUM_BIG_WINDOW; i++) | |
182 | IIO_ITTE_DISABLE(nasid, i); | |
183 | ||
184 | hub_set_piomode(nasid); | |
185 | } |