The following reply was made to PR port-mips/31915; it has been noted by GNATS.

From: Izumi Tsutsui <tsutsui@ceres.dti.ne.jp>
To: garrett_damore@tadpole.com
Cc: gnats-bugs@NetBSD.org, port-mips@NetBSD.org,
	tsutsui@ceres.dti.ne.jp
Subject: Re: port-mips/31915: provide centralized wired_map logic
Date: Thu, 27 Oct 2005 01:19:56 +0900

 In article <20051025205402.7B93A63B8C2@narn.netbsd.org>
 garrett_damore@tadpole.com wrote:
 
 >  Here are the diffs.  Again, I've not conditionalized the inclusion of 
 >  mips3_wired_map.c, but if folks feel strongly enough about it I can 
 >  certainly do so.
 
 IMO, currently only arc port uses wired map, so it might be better to
 have some proper option (like options MIPS3_WIRED_MAP etc.).
 
 >  Also, the ARC port could probably make use of my logic in 
 >  mips3_wired_map.c, but I wanted to minimize change (and I don't have an 
 >  ARC system to test against, anyway, so all I can do is verify the compile.)
 
 I think the MI wired map function should also handle independent
 (non-contiguous) PA ranges for TLB_LO0 and TLB_LO1.
 arc port requires it to map PCI memory and I/O space at the early
 bootstrap stage, and it could save wired TLB entries in other case.
 
 I also have some more quick comments:
 
 - VA region for wired map should be defined in machine dependent
   <machine/vmparam.h> and it should be managed by extent(9) etc.
 - pagemask for wired maps should be defined in machine dependent headers,
   or maybe it should be passed from callers.
 
 Currently I use the attached wired_map.[ch] for ews4800mips ports,
 though it lacks some sanity checks and unmap (or remap) functions.
 
 Maybe we should discuss more about APIs for these wired map functions.
 ---
 Izumi Tsutsui
 
 
 ---
 /*	$NetBSD$	*/
 
 /*-
  * Copyright (C) 2005 Izumi Tsutsui.
  * Copyright (C) 2000 Shuichiro URATA.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
 __KERNEL_RCSID(0, "$NetBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/malloc.h>
 #include <sys/extent.h>
 
 #include <uvm/uvm_extern.h>
 
 #include <mips/pte.h>
 
 #include <machine/locore.h>
 #include <machine/vmparam.h>
 
 #include <ews4800mips/ews4800mips/wired_map.h>
 
 #define EWS4800MIPS_TLB_WIRED_ENTRIES	8	/* upper limit */
 
 static int ews4800mips_enter_wired(vaddr_t va, paddr_t pa0, paddr_t pa1,
     uint32_t pg_size);
 
 static struct wired_map_entry {
 	paddr_t	pa0;
 	paddr_t	pa1;
 	vsize_t	size;
 	vaddr_t	va;
 } wired_map[EWS4800MIPS_TLB_WIRED_ENTRIES];
 
 static int nwired;
 static struct extent *wired_map_ex;
 static long wired_map_ex_storage[EXTENT_FIXED_STORAGE_SIZE(8) / sizeof(long)];
 
 void
 ews4800mips_init_wired_map(void)
 {
 
 	nwired = 0;
 	wired_map_ex = extent_create("wired_map",
 	    VM_MIN_WIRED_MAP_ADDRESS, VM_MAX_WIRED_MAP_ADDRESS, M_DEVBUF,
 	    (void *)wired_map_ex_storage, sizeof(wired_map_ex_storage),
 	    EX_NOWAIT);
 	if (wired_map_ex == NULL)
 		panic("ews4800mips_init_wired_map: can't create extent");
 }
 
 static int
 ews4800mips_enter_wired(vaddr_t va, paddr_t pa0, paddr_t pa1, uint32_t pg_size)
 {
 	struct tlb tlb;
 	psize_t size;
 
 	if (nwired >= EWS4800MIPS_TLB_WIRED_ENTRIES) {
 #ifdef DIAGNOSTIC
 		printf("ews4800mips_enter_wired: wired entry exausted.\n");
 #endif
 		return ENOMEM;
 	}
 
 	size = MIPS3_PG_SIZE_MASK_TO_SIZE(pg_size);
 	va = (va + (size - 1)) & ~(size - 1);
 
 	wired_map[nwired].va = va;
 	wired_map[nwired].pa0 = pa0;
 	wired_map[nwired].pa1 = pa1;
 	wired_map[nwired].size = size;
 
 	/* Allocate new wired entry */
 	mips3_cp0_wired_write(MIPS3_TLB_WIRED_UPAGES + nwired + 1);
 
 	/* Map to it */
 	tlb.tlb_mask = pg_size;
 	tlb.tlb_hi = mips3_vad_to_vpn(va);
 	if (pa0 == 0)
 		tlb.tlb_lo0 = MIPS3_PG_G;
 	else
 		tlb.tlb_lo0 = mips3_paddr_to_tlbpfn(pa0) | \
 		    MIPS3_PG_IOPAGE(PMAP_CCA_FOR_PA(pa0));
 	if (pa1 == 0)
 		tlb.tlb_lo1 = MIPS3_PG_G;
 	else
 		tlb.tlb_lo1 = mips3_paddr_to_tlbpfn(pa1) | \
 		    MIPS3_PG_IOPAGE(PMAP_CCA_FOR_PA(pa1));
 	mips3_TLBWriteIndexedVPS(MIPS3_TLB_WIRED_UPAGES + nwired, &tlb);
 
 	nwired++;
 
 	return 0;
 }
 
 /* Allocate new wired entries */
 int
 ews4800mips_map_wired(vaddr_t va, paddr_t pa0, paddr_t pa1, uint32_t pg_size)
 {
 	psize_t size;
 	int error;
 
 	size = MIPS3_PG_SIZE_MASK_TO_SIZE(pg_size);
 	va = (va + (size - 1)) & ~(size - 1);
 
 	if (va < VM_MIN_WIRED_MAP_ADDRESS ||
 	    va + size > VM_MAX_WIRED_MAP_ADDRESS) {
 #ifdef DIAGNOSTIC
 		printf("ews4800mips_enter_wired: invalid va range.\n");
 #endif
 		return EINVAL;
 	}
 
 	error = extent_alloc_region(wired_map_ex, va, size, EX_NOWAIT);
 	if (error) {
 #ifdef DIAGNOSTIC
 		printf("ews4800mips_enter_wired: cannot allocate region.\n");
 #endif
 		return error;
 	}
 
 	error = ews4800mips_enter_wired(va, pa0, pa1, pg_size);
 
 	return error;
 }
 
 vaddr_t
 ews4800mips_map_wired_region(paddr_t pa, int size, uint32_t pg_mask)
 {
 	vaddr_t va, rva;
 	vsize_t off;
 	psize_t pg_size;
 	int error;
 
 	pg_size = MIPS3_PG_SIZE_MASK_TO_SIZE(pg_mask);
 	off = pa & WIRED_ENTRY_OFFMASK(pg_size);
 	pa &= ~(paddr_t)WIRED_ENTRY_OFFMASK(pg_size);
 	size += off;
 
 	if ((size + WIRED_ENTRY_SIZE(pg_size) - 1) / WIRED_ENTRY_SIZE(pg_size) >
 	    EWS4800MIPS_TLB_WIRED_ENTRIES - nwired) {
 
 #ifdef DIAGNOSTIC
 		printf("ews4800mips_map_wired_region(0x%lx, 0x%lx)"
 		    ": %d is not enough\n", pa + off, size - off,
 		    EWS4800MIPS_TLB_WIRED_ENTRIES - nwired);
 #endif
 		return 0; /* free wired TLB is not enough */
 	}
 
 	error = extent_alloc(wired_map_ex, size, WIRED_ENTRY_SIZE(pg_size), 0,
 	    EX_NOWAIT, &va);
 	if (error) {
 #ifdef DIAGNOSTIC
 		printf("ews4800mips_map_wired_region: can't allocate region\n");
 #endif
 		return 0;
 	}
 	rva = va;
 
 	while (size > 0) {
 		ews4800mips_enter_wired(va, pa, pa + pg_size, pg_mask);
 		pa += WIRED_ENTRY_SIZE(pg_size);
 		va += WIRED_ENTRY_SIZE(pg_size);
 		size -= WIRED_ENTRY_SIZE(pg_size);
 	}
 
 	return rva + off;
 }
 ---
 
 ---
 /*	$NetBSD$	*/
 
 /*-
  * Copyright (C) 2005 Izumi Tsutsui.
  * Copyright (C) 2000 Shuichiro URATA.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #define WIRED_ENTRY_SIZE(pg_size)	((pg_size) * 2) 
 #define WIRED_ENTRY_OFFMASK(pg_size)	(WIRED_ENTRY_SIZE(pg_size) - 1)
 
 void	ews4800mips_init_wired_map(void);
 int	ews4800mips_map_wired(vaddr_t va, paddr_t pa0, paddr_t pa1,
     uint32_t pg_size);
 vaddr_t	ews4800mips_map_wired_region(paddr_t pa, int size, uint32_t pg_size);
 ---