Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | /** |
| 20 | * hub_pio_map - establish a HUB PIO mapping |
| 21 | * |
| 22 | * @hub: hub to perform PIO mapping on |
| 23 | * @widget: widget ID to perform PIO mapping for |
| 24 | * @xtalk_addr: xtalk_address that needs to be mapped |
| 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); |
| 32 | volatile hubreg_t junk; |
| 33 | unsigned i; |
| 34 | |
| 35 | /* use small-window mapping if possible */ |
| 36 | if ((xtalk_addr % SWIN_SIZE) + size <= SWIN_SIZE) |
| 37 | return NODE_SWIN_BASE(nasid, widget) + (xtalk_addr % SWIN_SIZE); |
| 38 | |
| 39 | if ((xtalk_addr % BWIN_SIZE) + size > BWIN_SIZE) { |
| 40 | printk(KERN_WARNING "PIO mapping at hub %d widget %d addr 0x%lx" |
| 41 | " too big (%ld)\n", |
| 42 | nasid, widget, xtalk_addr, size); |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | xtalk_addr &= ~(BWIN_SIZE-1); |
| 47 | for (i = 0; i < HUB_NUM_BIG_WINDOW; i++) { |
| 48 | if (test_and_set_bit(i, hub_data(cnode)->h_bigwin_used)) |
| 49 | continue; |
| 50 | |
| 51 | /* |
| 52 | * The code below does a PIO write to setup an ITTE entry. |
| 53 | * |
| 54 | * We need to prevent other CPUs from seeing our updated |
| 55 | * memory shadow of the ITTE (in the piomap) until the ITTE |
| 56 | * entry is actually set up; otherwise, another CPU might |
| 57 | * attempt a PIO prematurely. |
| 58 | * |
| 59 | * Also, the only way we can know that an entry has been |
| 60 | * received by the hub and can be used by future PIO reads/ |
| 61 | * writes is by reading back the ITTE entry after writing it. |
| 62 | * |
| 63 | * For these two reasons, we PIO read back the ITTE entry |
| 64 | * after we write it. |
| 65 | */ |
| 66 | IIO_ITTE_PUT(nasid, i, HUB_PIO_MAP_TO_MEM, widget, xtalk_addr); |
| 67 | junk = HUB_L(IIO_ITTE_GET(nasid, i)); |
| 68 | |
| 69 | return NODE_BWIN_BASE(nasid, widget) + (xtalk_addr % BWIN_SIZE); |
| 70 | } |
| 71 | |
| 72 | printk(KERN_WARNING "unable to establish PIO mapping for at" |
| 73 | " hub %d widget %d addr 0x%lx\n", |
| 74 | nasid, widget, xtalk_addr); |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | |
| 79 | /* |
| 80 | * hub_setup_prb(nasid, prbnum, credits, conveyor) |
| 81 | * |
| 82 | * Put a PRB into fire-and-forget mode if conveyor isn't set. Otherwise, |
| 83 | * put it into conveyor belt mode with the specified number of credits. |
| 84 | */ |
| 85 | static void hub_setup_prb(nasid_t nasid, int prbnum, int credits) |
| 86 | { |
| 87 | iprb_t prb; |
| 88 | int prb_offset; |
| 89 | |
| 90 | /* |
| 91 | * Get the current register value. |
| 92 | */ |
| 93 | prb_offset = IIO_IOPRB(prbnum); |
| 94 | prb.iprb_regval = REMOTE_HUB_L(nasid, prb_offset); |
| 95 | |
| 96 | /* |
| 97 | * Clear out some fields. |
| 98 | */ |
| 99 | prb.iprb_ovflow = 1; |
| 100 | prb.iprb_bnakctr = 0; |
| 101 | prb.iprb_anakctr = 0; |
| 102 | |
| 103 | /* |
| 104 | * Enable or disable fire-and-forget mode. |
| 105 | */ |
| 106 | prb.iprb_ff = force_fire_and_forget ? 1 : 0; |
| 107 | |
| 108 | /* |
| 109 | * Set the appropriate number of PIO cresits for the widget. |
| 110 | */ |
| 111 | prb.iprb_xtalkctr = credits; |
| 112 | |
| 113 | /* |
| 114 | * Store the new value to the register. |
| 115 | */ |
| 116 | REMOTE_HUB_S(nasid, prb_offset, prb.iprb_regval); |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * hub_set_piomode - set pio mode for a given hub |
| 121 | * |
| 122 | * @nasid: physical node ID for the hub in question |
| 123 | * |
| 124 | * Put the hub into either "PIO conveyor belt" mode or "fire-and-forget" mode. |
| 125 | * To do this, we have to make absolutely sure that no PIOs are in progress |
| 126 | * so we turn off access to all widgets for the duration of the function. |
| 127 | * |
| 128 | * XXX - This code should really check what kind of widget we're talking |
| 129 | * to. Bridges can only handle three requests, but XG will do more. |
| 130 | * How many can crossbow handle to widget 0? We're assuming 1. |
| 131 | * |
| 132 | * XXX - There is a bug in the crossbow that link reset PIOs do not |
| 133 | * return write responses. The easiest solution to this problem is to |
| 134 | * leave widget 0 (xbow) in fire-and-forget mode at all times. This |
| 135 | * only affects pio's to xbow registers, which should be rare. |
| 136 | **/ |
| 137 | static void hub_set_piomode(nasid_t nasid) |
| 138 | { |
| 139 | hubreg_t ii_iowa; |
| 140 | hubii_wcr_t ii_wcr; |
| 141 | unsigned i; |
| 142 | |
| 143 | ii_iowa = REMOTE_HUB_L(nasid, IIO_OUTWIDGET_ACCESS); |
| 144 | REMOTE_HUB_S(nasid, IIO_OUTWIDGET_ACCESS, 0); |
| 145 | |
| 146 | ii_wcr.wcr_reg_value = REMOTE_HUB_L(nasid, IIO_WCR); |
| 147 | |
| 148 | if (ii_wcr.iwcr_dir_con) { |
| 149 | /* |
| 150 | * Assume a bridge here. |
| 151 | */ |
| 152 | hub_setup_prb(nasid, 0, 3); |
| 153 | } else { |
| 154 | /* |
| 155 | * Assume a crossbow here. |
| 156 | */ |
| 157 | hub_setup_prb(nasid, 0, 1); |
| 158 | } |
| 159 | |
| 160 | /* |
| 161 | * XXX - Here's where we should take the widget type into |
| 162 | * when account assigning credits. |
| 163 | */ |
| 164 | for (i = HUB_WIDGET_ID_MIN; i <= HUB_WIDGET_ID_MAX; i++) |
| 165 | hub_setup_prb(nasid, i, 3); |
| 166 | |
| 167 | REMOTE_HUB_S(nasid, IIO_OUTWIDGET_ACCESS, ii_iowa); |
| 168 | } |
| 169 | |
| 170 | /* |
Joe Perches | 603e82e | 2008-02-03 16:54:53 +0200 | [diff] [blame^] | 171 | * hub_pio_init - PIO-related hub initialization |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | * |
| 173 | * @hub: hubinfo structure for our hub |
| 174 | */ |
| 175 | void hub_pio_init(cnodeid_t cnode) |
| 176 | { |
| 177 | nasid_t nasid = COMPACT_TO_NASID_NODEID(cnode); |
| 178 | unsigned i; |
| 179 | |
| 180 | /* initialize big window piomaps for this hub */ |
| 181 | bitmap_zero(hub_data(cnode)->h_bigwin_used, HUB_NUM_BIG_WINDOW); |
| 182 | for (i = 0; i < HUB_NUM_BIG_WINDOW; i++) |
| 183 | IIO_ITTE_DISABLE(nasid, i); |
| 184 | |
| 185 | hub_set_piomode(nasid); |
| 186 | } |