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 17static 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 **/ 28unsigned 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 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); 66 (void) HUB_L(IIO_ITTE_GET(nasid, i)); 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 * 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. 83 */ 84static 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 /* 108 * Set the appropriate number of PIO cresits for the widget. 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 118static void hub_set_piomode(nasid_t nasid) 119{ 120 hubreg_t ii_iowa; 121 hubii_wcr_t ii_wcr; 122 unsigned i; 123 124 ii_iowa = REMOTE_HUB_L(nasid, IIO_OUTWIDGET_ACCESS); 125 REMOTE_HUB_S(nasid, IIO_OUTWIDGET_ACCESS, 0); 126 127 ii_wcr.wcr_reg_value = REMOTE_HUB_L(nasid, IIO_WCR); 128 129 if (ii_wcr.iwcr_dir_con) { 130 /* 131 * Assume a bridge here. 132 */ 133 hub_setup_prb(nasid, 0, 3); 134 } else { 135 /* 136 * Assume a crossbow here. 137 */ 138 hub_setup_prb(nasid, 0, 1); 139 } 140 141 for (i = HUB_WIDGET_ID_MIN; i <= HUB_WIDGET_ID_MAX; i++) 142 hub_setup_prb(nasid, i, 3); 143 144 REMOTE_HUB_S(nasid, IIO_OUTWIDGET_ACCESS, ii_iowa); 145} 146 147/* 148 * hub_pio_init - PIO-related hub initialization 149 * 150 * @hub: hubinfo structure for our hub 151 */ 152void hub_pio_init(cnodeid_t cnode) 153{ 154 nasid_t nasid = COMPACT_TO_NASID_NODEID(cnode); 155 unsigned i; 156 157 /* initialize big window piomaps for this hub */ 158 bitmap_zero(hub_data(cnode)->h_bigwin_used, HUB_NUM_BIG_WINDOW); 159 for (i = 0; i < HUB_NUM_BIG_WINDOW; i++) 160 IIO_ITTE_DISABLE(nasid, i); 161 162 hub_set_piomode(nasid); 163} 164