cregit-Linux how code gets into the kernel

Release 4.14 arch/mips/sgi-ip27/ip27-hubio.c

/*
 * Copyright (C) 1992-1997, 2000-2003 Silicon Graphics, Inc.
 * Copyright (C) 2004 Christoph Hellwig.
 *      Released under GPL v2.
 *
 * Support functions for the HUB ASIC - mostly PIO mapping related.
 */

#include <linux/bitops.h>
#include <linux/string.h>
#include <linux/mmzone.h>
#include <asm/sn/addrs.h>
#include <asm/sn/arch.h>
#include <asm/sn/hub.h>



static int force_fire_and_forget = 1;

/**
 * hub_pio_map  -  establish a HUB PIO mapping
 *
 * @hub:        hub to perform PIO mapping on
 * @widget:     widget ID to perform PIO mapping for
 * @xtalk_addr: xtalk_address that needs to be mapped
 * @size:       size of the PIO mapping
 *
 **/

unsigned long hub_pio_map(cnodeid_t cnode, xwidgetnum_t widget, unsigned long xtalk_addr, size_t size) { nasid_t nasid = COMPACT_TO_NASID_NODEID(cnode); unsigned i; /* use small-window mapping if possible */ if ((xtalk_addr % SWIN_SIZE) + size <= SWIN_SIZE) return NODE_SWIN_BASE(nasid, widget) + (xtalk_addr % SWIN_SIZE); if ((xtalk_addr % BWIN_SIZE) + size > BWIN_SIZE) { printk(KERN_WARNING "PIO mapping at hub %d widget %d addr 0x%lx" " too big (%ld)\n", nasid, widget, xtalk_addr, size); return 0; } xtalk_addr &= ~(BWIN_SIZE-1); for (i = 0; i < HUB_NUM_BIG_WINDOW; i++) { if (test_and_set_bit(i, hub_data(cnode)->h_bigwin_used)) continue; /* * The code below does a PIO write to setup an ITTE entry. * * We need to prevent other CPUs from seeing our updated * memory shadow of the ITTE (in the piomap) until the ITTE * entry is actually set up; otherwise, another CPU might * attempt a PIO prematurely. * * Also, the only way we can know that an entry has been * received by the hub and can be used by future PIO reads/ * writes is by reading back the ITTE entry after writing it. * * For these two reasons, we PIO read back the ITTE entry * after we write it. */ IIO_ITTE_PUT(nasid, i, HUB_PIO_MAP_TO_MEM, widget, xtalk_addr); (void) HUB_L(IIO_ITTE_GET(nasid, i)); return NODE_BWIN_BASE(nasid, widget) + (xtalk_addr % BWIN_SIZE); } printk(KERN_WARNING "unable to establish PIO mapping for at" " hub %d widget %d addr 0x%lx\n", nasid, widget, xtalk_addr); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton18197.84%133.33%
Ralf Bächle42.16%266.67%
Total185100.00%3100.00%

/* * hub_setup_prb(nasid, prbnum, credits, conveyor) * * Put a PRB into fire-and-forget mode if conveyor isn't set. Otherwise, * put it into conveyor belt mode with the specified number of credits. */
static void hub_setup_prb(nasid_t nasid, int prbnum, int credits) { iprb_t prb; int prb_offset; /* * Get the current register value. */ prb_offset = IIO_IOPRB(prbnum); prb.iprb_regval = REMOTE_HUB_L(nasid, prb_offset); /* * Clear out some fields. */ prb.iprb_ovflow = 1; prb.iprb_bnakctr = 0; prb.iprb_anakctr = 0; /* * Enable or disable fire-and-forget mode. */ prb.iprb_ff = force_fire_and_forget ? 1 : 0; /* * Set the appropriate number of PIO credits for the widget. */ prb.iprb_xtalkctr = credits; /* * Store the new value to the register. */ REMOTE_HUB_S(nasid, prb_offset, prb.iprb_regval); }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton8898.88%150.00%
Andrea Gelmini11.12%150.00%
Total89100.00%2100.00%

/** * hub_set_piomode - set pio mode for a given hub * * @nasid: physical node ID for the hub in question * * Put the hub into either "PIO conveyor belt" mode or "fire-and-forget" mode. * To do this, we have to make absolutely sure that no PIOs are in progress * so we turn off access to all widgets for the duration of the function. * * XXX - This code should really check what kind of widget we're talking * to. Bridges can only handle three requests, but XG will do more. * How many can crossbow handle to widget 0? We're assuming 1. * * XXX - There is a bug in the crossbow that link reset PIOs do not * return write responses. The easiest solution to this problem is to * leave widget 0 (xbow) in fire-and-forget mode at all times. This * only affects pio's to xbow registers, which should be rare. **/
static void hub_set_piomode(nasid_t nasid) { hubreg_t ii_iowa; hubii_wcr_t ii_wcr; unsigned i; ii_iowa = REMOTE_HUB_L(nasid, IIO_OUTWIDGET_ACCESS); REMOTE_HUB_S(nasid, IIO_OUTWIDGET_ACCESS, 0); ii_wcr.wcr_reg_value = REMOTE_HUB_L(nasid, IIO_WCR); if (ii_wcr.iwcr_dir_con) { /* * Assume a bridge here. */ hub_setup_prb(nasid, 0, 3); } else { /* * Assume a crossbow here. */ hub_setup_prb(nasid, 0, 1); } /* * XXX - Here's where we should take the widget type into * when account assigning credits. */ for (i = HUB_WIDGET_ID_MIN; i <= HUB_WIDGET_ID_MAX; i++) hub_setup_prb(nasid, i, 3); REMOTE_HUB_S(nasid, IIO_OUTWIDGET_ACCESS, ii_iowa); }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton110100.00%1100.00%
Total110100.00%1100.00%

/* * hub_pio_init - PIO-related hub initialization * * @hub: hubinfo structure for our hub */
void hub_pio_init(cnodeid_t cnode) { nasid_t nasid = COMPACT_TO_NASID_NODEID(cnode); unsigned i; /* initialize big window piomaps for this hub */ bitmap_zero(hub_data(cnode)->h_bigwin_used, HUB_NUM_BIG_WINDOW); for (i = 0; i < HUB_NUM_BIG_WINDOW; i++) IIO_ITTE_DISABLE(nasid, i); hub_set_piomode(nasid); }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton5698.25%266.67%
Ralf Bächle11.75%133.33%
Total57100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton45797.23%233.33%
Ralf Bächle122.55%350.00%
Andrea Gelmini10.21%116.67%
Total470100.00%6100.00%
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