mips/sgi-ip27/ip27-hubio.c

1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 1992-1997, 2000-2003 Silicon Graphics, Inc.
6  * Support functions for the HUB ASIC - mostly PIO mapping related.
22  * hub_pio_map	-  establish a HUB PIO mapping
24  * @hub:	hub to perform PIO mapping on
25  * @widget:	widget ID to perform PIO mapping for
27  * @size:	size of the PIO mapping
35 	/* use small-window mapping if possible */  in hub_pio_map()
40 		printk(KERN_WARNING "PIO mapping at hub %d widget %d addr 0x%lx"  in hub_pio_map()
46 	xtalk_addr &= ~(BWIN_SIZE-1);  in hub_pio_map()
48 		if (test_and_set_bit(i, hub_data(nasid)->h_bigwin_used))  in hub_pio_map()
52 		 * The code below does a PIO write to setup an ITTE entry.  in hub_pio_map()
57 		 * attempt a PIO prematurely.  in hub_pio_map()
60 		 * received  by the hub and can be used by future PIO reads/  in hub_pio_map()
63 		 * For these two reasons, we PIO read back the ITTE entry  in hub_pio_map()
72 	printk(KERN_WARNING "unable to establish PIO mapping for at"  in hub_pio_map()
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.
104 	 * Enable or disable fire-and-forget mode.  in hub_setup_prb()
109 	 * Set the appropriate number of PIO credits for the widget.  in hub_setup_prb()
120  * hub_set_piomode  -  set pio mode for a given hub
124  * Put the hub into either "PIO conveyor belt" mode or "fire-and-forget" mode.
128  * XXX - This code should really check what kind of widget we're talking
132  * XXX - There is a bug in the crossbow that link reset PIOs do not
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.
161 	 * XXX - Here's where we should take the widget type into  in hub_set_piomode()
171  * hub_pio_init	 -  PIO-related hub initialization
180 	bitmap_zero(hub_data(nasid)->h_bigwin_used, HUB_NUM_BIG_WINDOW);  in hub_pio_init()