sun4/vm/vm_dep.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * UNIX machine dependent virtual memory support.
 */

#include <sys/vm.h>
#include <sys/exec.h>

#include <sys/exechdr.h>
#include <vm/seg_kmem.h>
#include <sys/atomic.h>
#include <sys/archsystm.h>
#include <sys/machsystm.h>
#include <sys/kdi.h>
#include <sys/cpu_module.h>

#include <vm/hat_sfmmu.h>

#include <sys/memnode.h>

#include <sys/mem_config.h>
#include <sys/mem_cage.h>
#include <vm/vm_dep.h>
#include <vm/page.h>
#include <sys/platform_module.h>

/*
 * These variables are set by module specific config routines.
 * They are only set by modules which will use physical cache page coloring.
 */
int do_pg_coloring = 0;

/*
 * These variables can be conveniently patched at kernel load time to
 * prevent do_pg_coloring from being enabled by
 * module specific config routines.
 */

int use_page_coloring = 1;

/*
 * initialized by page_coloring_init()
 */
extern uint_t page_colors;
extern uint_t page_colors_mask;
extern uint_t page_coloring_shift;
int cpu_page_colors;
uint_t vac_colors = 0;
uint_t vac_colors_mask = 0;

/* cpu specific coloring initialization */
extern void page_coloring_init_cpu();
#pragma weak page_coloring_init_cpu

/*
 * get the ecache setsize for the current cpu.
 */
#define	CPUSETSIZE()	(cpunodes[CPU->cpu_id].ecache_setsize)

plcnt_t		plcnt;		/* page list count */

/*
 * This variable is set by the cpu module to contain the lowest
 * address not affected by the SF_ERRATA_57 workaround.  It should
 * remain 0 if the workaround is not needed.
 */
#if defined(SF_ERRATA_57)
caddr_t errata57_limit;
#endif

static void page_flt_init(page_freelist_type_t *);

extern void page_relocate_hash(page_t *, page_t *);

/*
 * these must be defined in platform specific areas
 */
extern void map_addr_proc(caddr_t *, size_t, offset_t, int, caddr_t,
	struct proc *, uint_t);
extern page_t *page_get_freelist(struct vnode *, u_offset_t, struct seg *,
	caddr_t, size_t, uint_t, struct lgrp *);
/*
 * Convert page frame number to an OBMEM page frame number
 * (i.e. put in the type bits -- zero for this implementation)
 */
pfn_t
impl_obmem_pfnum(pfn_t pf)
{
	return (pf);
}

/*
 * Use physmax to determine the highest physical page of DRAM memory
 * It is assumed that any physical addresses above physmax is in IO space.
 * We don't bother checking the low end because we assume that memory space
 * begins at physical page frame 0.
 *
 * Return 1 if the page frame is onboard DRAM memory, else 0.
 * Returns 0 for nvram so it won't be cached.
 */
int
pf_is_memory(pfn_t pf)
{
	/* We must be IO space */
	if (pf > physmax)
		return (0);

	/* We must be memory space */
	return (1);
}

/*
 * Handle a pagefault.
 */
faultcode_t
pagefault(caddr_t addr, enum fault_type type, enum seg_rw rw, int iskernel)
{
	struct as *as;
	struct proc *p;
	faultcode_t res;
	caddr_t base;
	size_t len;
	int err;

	if (INVALID_VADDR(addr))
		return (FC_NOMAP);

	if (iskernel) {
		as = &kas;
	} else {
		p = curproc;
		as = p->p_as;
#if defined(SF_ERRATA_57)
		/*
		 * Prevent infinite loops due to a segment driver
		 * setting the execute permissions and the sfmmu hat
		 * silently ignoring them.
		 */
		if (rw == S_EXEC && AS_TYPE_64BIT(as) &&
		    addr < errata57_limit) {
			res = FC_NOMAP;
			goto out;
		}
#endif
	}

	/*
	 * Dispatch pagefault.
	 */
	res = as_fault(as->a_hat, as, addr, 1, type, rw);

	/*
	 * If this isn't a potential unmapped hole in the user's
	 * UNIX data or stack segments, just return status info.
	 */
	if (!(res == FC_NOMAP && iskernel == 0))
		goto out;

	/*
	 * Check to see if we happened to faulted on a currently unmapped
	 * part of the UNIX data or stack segments.  If so, create a zfod
	 * mapping there and then try calling the fault routine again.
	 */
	base = p->p_brkbase;
	len = p->p_brksize;

	if (addr < base || addr >= base + len) {		/* data seg? */
		base = (caddr_t)(p->p_usrstack - p->p_stksize);
		len = p->p_stksize;
		if (addr < base || addr >= p->p_usrstack) {	/* stack seg? */
			/* not in either UNIX data or stack segments */
			res = FC_NOMAP;
			goto out;
		}
	}

	/* the rest of this function implements a 3.X 4.X 5.X compatibility */
	/* This code is probably not needed anymore */

	/* expand the gap to the page boundaries on each side */
	len = (((uintptr_t)base + len + PAGEOFFSET) & PAGEMASK) -
	    ((uintptr_t)base & PAGEMASK);
	base = (caddr_t)((uintptr_t)base & PAGEMASK);

	as_rangelock(as);
	as_purge(as);
	if (as_gap(as, PAGESIZE, &base, &len, AH_CONTAIN, addr) == 0) {
		err = as_map(as, base, len, segvn_create, zfod_argsp);
		as_rangeunlock(as);
		if (err) {
			res = FC_MAKE_ERR(err);
			goto out;
		}
	} else {
		/*
		 * This page is already mapped by another thread after we
		 * returned from as_fault() above.  We just fallthrough
		 * as_fault() below.
		 */
		as_rangeunlock(as);
	}

	res = as_fault(as->a_hat, as, addr, 1, F_INVAL, rw);

out:

	return (res);
}

/*
 * This is the routine which defines the address limit implied
 * by the flag '_MAP_LOW32'.  USERLIMIT32 matches the highest
 * mappable address in a 32-bit process on this platform (though
 * perhaps we should make it be UINT32_MAX here?)
 */
void
map_addr(caddr_t *addrp, size_t len, offset_t off, int vacalign, uint_t flags)
{
	struct proc *p = curproc;
	caddr_t userlimit = flags & _MAP_LOW32 ?
	    (caddr_t)USERLIMIT32 : p->p_as->a_userlimit;
	map_addr_proc(addrp, len, off, vacalign, userlimit, p, flags);
}

/*
 * Some V9 CPUs have holes in the middle of the 64-bit virtual address range.
 */
caddr_t	hole_start, hole_end;

/*
 * kpm mapping window
 */
caddr_t kpm_vbase;
size_t  kpm_size;
uchar_t kpm_size_shift;

int valid_va_range_aligned_wraparound;
/*
 * Determine whether [*basep, *basep + *lenp) contains a mappable range of
 * addresses at least "minlen" long, where the base of the range is at "off"
 * phase from an "align" boundary and there is space for a "redzone"-sized
 * redzone on either side of the range.  On success, 1 is returned and *basep
 * and *lenp are adjusted to describe the acceptable range (including
 * the redzone).  On failure, 0 is returned.
 */
int
valid_va_range_aligned(caddr_t *basep, size_t *lenp, size_t minlen, int dir,
    size_t align, size_t redzone, size_t off)
{
	caddr_t hi, lo;
	size_t tot_len;

	ASSERT(align == 0 ? off == 0 : off < align);
	ASSERT(ISP2(align));
	ASSERT(align == 0 || align >= PAGESIZE);

	lo = *basep;
	hi = lo + *lenp;
	tot_len = minlen + 2 * redzone;	/* need at least this much space */

	/* If hi rolled over the top try cutting back. */
	if (hi < lo) {
		*lenp = 0UL - (uintptr_t)lo - 1UL;
		/* Trying to see if this really happens, and then if so, why */
		valid_va_range_aligned_wraparound++;
		hi = lo + *lenp;
	}
	if (*lenp < tot_len) {
		return (0);
	}

	/*
	 * Deal with a possible hole in the address range between
	 * hole_start and hole_end that should never be mapped by the MMU.
	 */

	if (lo < hole_start) {
		if (hi > hole_start)
			if (hi < hole_end)
				hi = hole_start;
			else
				/* lo < hole_start && hi >= hole_end */
				if (dir == AH_LO) {
					/*
					 * prefer lowest range
					 */
					if (hole_start - lo >= tot_len)
						hi = hole_start;
					else if (hi - hole_end >= tot_len)
						lo = hole_end;
					else
						return (0);
				} else {
					/*
					 * prefer highest range
					 */
					if (hi - hole_end >= tot_len)
						lo = hole_end;
					else if (hole_start - lo >= tot_len)
						hi = hole_start;
					else
						return (0);
				}
	} else {
		/* lo >= hole_start */
		if (hi < hole_end)
			return (0);
		if (lo < hole_end)
			lo = hole_end;
	}

	/* Check if remaining length is too small */
	if (hi - lo < tot_len) {
		return (0);
	}
	if (align > 1) {
		caddr_t tlo = lo + redzone;
		caddr_t thi = hi - redzone;
		tlo = (caddr_t)P2PHASEUP((uintptr_t)tlo, align, off);
		if (tlo < lo + redzone) {
			return (0);
		}
		if (thi < tlo || thi - tlo < minlen) {
			return (0);
		}
	}
	*basep = lo;
	*lenp = hi - lo;
	return (1);
}

/*
 * Determine whether [*basep, *basep + *lenp) contains a mappable range of
 * addresses at least "minlen" long.  On success, 1 is returned and *basep
 * and *lenp are adjusted to describe the acceptable range.  On failure, 0
 * is returned.
 */
int
valid_va_range(caddr_t *basep, size_t *lenp, size_t minlen, int dir)
{
	return (valid_va_range_aligned(basep, lenp, minlen, dir, 0, 0, 0));
}

/*
 * Determine whether [addr, addr+len] with protections `prot' are valid
 * for a user address space.
 */
/*ARGSUSED*/
int
valid_usr_range(caddr_t addr, size_t len, uint_t prot, struct as *as,
    caddr_t userlimit)
{
	caddr_t eaddr = addr + len;

	if (eaddr <= addr || addr >= userlimit || eaddr > userlimit)
		return (RANGE_BADADDR);

	/*
	 * Determine if the address range falls within an illegal
	 * range of the MMU.
	 */
	if (eaddr > hole_start && addr < hole_end)
		return (RANGE_BADADDR);

#if defined(SF_ERRATA_57)
	/*
	 * Make sure USERLIMIT isn't raised too high
	 */
	ASSERT64(addr <= (caddr_t)0xffffffff80000000ul ||
	    errata57_limit == 0);

	if (AS_TYPE_64BIT(as) &&
	    (addr < errata57_limit) &&
	    (prot & PROT_EXEC))
		return (RANGE_BADPROT);
#endif /* SF_ERRATA57 */
	return (RANGE_OKAY);
}

/*
 * Routine used to check to see if an a.out can be executed
 * by the current machine/architecture.
 */
int
chkaout(struct exdata *exp)
{
	if (exp->ux_mach == M_SPARC)
		return (0);
	else
		return (ENOEXEC);
}

/*
 * The following functions return information about an a.out
 * which is used when a program is executed.
 */

/*
 * Return the load memory address for the data segment.
 */
caddr_t
getdmem(struct exec *exp)
{
	/*
	 * XXX - Sparc Reference Hack approaching
	 * Remember that we are loading
	 * 8k executables into a 4k machine
	 * DATA_ALIGN == 2 * PAGESIZE
	 */
	if (exp->a_text)
		return ((caddr_t)(roundup(USRTEXT + exp->a_text, DATA_ALIGN)));
	else
		return ((caddr_t)USRTEXT);
}

/*
 * Return the starting disk address for the data segment.
 */
ulong_t
getdfile(struct exec *exp)
{
	if (exp->a_magic == ZMAGIC)
		return (exp->a_text);
	else
		return (sizeof (struct exec) + exp->a_text);
}

/*
 * Return the load memory address for the text segment.
 */

/*ARGSUSED*/
caddr_t
gettmem(struct exec *exp)
{
	return ((caddr_t)USRTEXT);
}

/*
 * Return the file byte offset for the text segment.
 */
uint_t
gettfile(struct exec *exp)
{
	if (exp->a_magic == ZMAGIC)
		return (0);
	else
		return (sizeof (struct exec));
}

void
getexinfo(
	struct exdata *edp_in,
	struct exdata *edp_out,
	int *pagetext,
	int *pagedata)
{
	*edp_out = *edp_in;	/* structure copy */

	if ((edp_in->ux_mag == ZMAGIC) &&
	    ((edp_in->vp->v_flag & VNOMAP) == 0)) {
		*pagetext = 1;
		*pagedata = 1;
	} else {
		*pagetext = 0;
		*pagedata = 0;
	}
}

/*
 * Return non 0 value if the address may cause a VAC alias with KPM mappings.
 * KPM selects an address such that it's equal offset modulo shm_alignment and
 * assumes it can't be in VAC conflict with any larger than PAGESIZE mapping.
 */
int
map_addr_vacalign_check(caddr_t addr, u_offset_t off)
{
	if (vac) {
		return (((uintptr_t)addr ^ off) & shm_alignment - 1);
	} else {
		return (0);
	}
}

/*
 * Sanity control. Don't use large pages regardless of user
 * settings if there's less than priv or shm_lpg_min_physmem memory installed.
 * The units for this variable is 8K pages.
 */
pgcnt_t shm_lpg_min_physmem = 131072;			/* 1GB */
pgcnt_t privm_lpg_min_physmem = 131072;			/* 1GB */

static size_t
map_pgszheap(struct proc *p, caddr_t addr, size_t len)
{
	size_t		pgsz = MMU_PAGESIZE;
	int		szc;

	/*
	 * If len is zero, retrieve from proc and don't demote the page size.
	 * Use atleast the default pagesize.
	 */
	if (len == 0) {
		len = p->p_brkbase + p->p_brksize - p->p_bssbase;
	}
	len = MAX(len, default_uheap_lpsize);

	for (szc = mmu_page_sizes - 1; szc >= 0; szc--) {
		pgsz = hw_page_array[szc].hp_size;
		if ((disable_auto_data_large_pages & (1 << szc)) ||
		    pgsz > max_uheap_lpsize)
			continue;
		if (len >= pgsz) {
			break;
		}
	}

	/*
	 * If addr == 0 we were called by memcntl() when the
	 * size code is 0.  Don't set pgsz less than current size.
	 */
	if (addr == 0 && (pgsz < hw_page_array[p->p_brkpageszc].hp_size)) {
		pgsz = hw_page_array[p->p_brkpageszc].hp_size;
	}

	return (pgsz);
}

static size_t
map_pgszstk(struct proc *p, caddr_t addr, size_t len)
{
	size_t		pgsz = MMU_PAGESIZE;
	int		szc;

	/*
	 * If len is zero, retrieve from proc and don't demote the page size.
	 * Use atleast the default pagesize.
	 */
	if (len == 0) {
		len = p->p_stksize;
	}
	len = MAX(len, default_ustack_lpsize);

	for (szc = mmu_page_sizes - 1; szc >= 0; szc--) {
		pgsz = hw_page_array[szc].hp_size;
		if ((disable_auto_data_large_pages & (1 << szc)) ||
		    pgsz > max_ustack_lpsize)
			continue;
		if (len >= pgsz) {
			break;
		}
	}

	/*
	 * If addr == 0 we were called by memcntl() or exec_args() when the
	 * size code is 0.  Don't set pgsz less than current size.
	 */
	if (addr == 0 && (pgsz < hw_page_array[p->p_stkpageszc].hp_size)) {
		pgsz = hw_page_array[p->p_stkpageszc].hp_size;
	}

	return (pgsz);
}

static size_t
map_pgszism(caddr_t addr, size_t len)
{
	uint_t szc;
	size_t pgsz;

	for (szc = mmu_page_sizes - 1; szc >= TTE4M; szc--) {
		if (disable_ism_large_pages & (1 << szc))
			continue;

		pgsz = hw_page_array[szc].hp_size;
		if ((len >= pgsz) && IS_P2ALIGNED(addr, pgsz))
			return (pgsz);
	}

	return (DEFAULT_ISM_PAGESIZE);
}

/*
 * Suggest a page size to be used to map a segment of type maptype and length
 * len.  Returns a page size (not a size code).
 */
/* ARGSUSED */
size_t
map_pgsz(int maptype, struct proc *p, caddr_t addr, size_t len, int memcntl)
{
	size_t	pgsz = MMU_PAGESIZE;

	ASSERT(maptype != MAPPGSZ_VA);

	if (maptype != MAPPGSZ_ISM && physmem < privm_lpg_min_physmem) {
		return (MMU_PAGESIZE);
	}

	switch (maptype) {
	case MAPPGSZ_ISM:
		pgsz = map_pgszism(addr, len);
		break;

	case MAPPGSZ_STK:
		if (max_ustack_lpsize > MMU_PAGESIZE) {
			pgsz = map_pgszstk(p, addr, len);
		}
		break;

	case MAPPGSZ_HEAP:
		if (max_uheap_lpsize > MMU_PAGESIZE) {
			pgsz = map_pgszheap(p, addr, len);
		}
		break;
	}
	return (pgsz);
}


/* assumes TTE8K...TTE4M == szc */

static uint_t
map_szcvec(caddr_t addr, size_t size, uintptr_t off, int disable_lpgs,
    size_t max_lpsize, size_t min_physmem)
{
	caddr_t eaddr = addr + size;
	uint_t szcvec = 0;
	caddr_t raddr;
	caddr_t readdr;
	size_t pgsz;
	int i;

	if (physmem < min_physmem || max_lpsize <= MMU_PAGESIZE) {
		return (0);
	}
	for (i = mmu_page_sizes - 1; i > 0; i--) {
		if (disable_lpgs & (1 << i)) {
			continue;
		}
		pgsz = page_get_pagesize(i);
		if (pgsz > max_lpsize) {
			continue;
		}
		raddr = (caddr_t)P2ROUNDUP((uintptr_t)addr, pgsz);
		readdr = (caddr_t)P2ALIGN((uintptr_t)eaddr, pgsz);
		if (raddr < addr || raddr >= readdr) {
			continue;
		}
		if (P2PHASE((uintptr_t)addr ^ off, pgsz)) {
			continue;
		}
		szcvec |= (1 << i);
		/*
		 * And or in the remaining enabled page sizes.
		 */
		szcvec |= P2PHASE(~disable_lpgs, (1 << i));
		szcvec &= ~1; /* no need to return 8K pagesize */
		break;
	}
	return (szcvec);
}

/*
 * Return a bit vector of large page size codes that
 * can be used to map [addr, addr + len) region.
 */
/* ARGSUSED */
uint_t
map_pgszcvec(caddr_t addr, size_t size, uintptr_t off, int flags, int type,
    int memcntl)
{
	if (flags & MAP_TEXT) {
		return (map_szcvec(addr, size, off,
		    disable_auto_text_large_pages,
		    max_utext_lpsize, shm_lpg_min_physmem));

	} else if (flags & MAP_INITDATA) {
		return (map_szcvec(addr, size, off,
		    disable_auto_data_large_pages,
		    max_uidata_lpsize, privm_lpg_min_physmem));

	} else if (type == MAPPGSZC_SHM) {
		return (map_szcvec(addr, size, off,
		    disable_auto_data_large_pages,
		    max_shm_lpsize, shm_lpg_min_physmem));

	} else if (type == MAPPGSZC_HEAP) {
		return (map_szcvec(addr, size, off,
		    disable_auto_data_large_pages,
		    max_uheap_lpsize, privm_lpg_min_physmem));

	} else if (type == MAPPGSZC_STACK) {
		return (map_szcvec(addr, size, off,
		    disable_auto_data_large_pages,
		    max_ustack_lpsize, privm_lpg_min_physmem));

	} else {
		return (map_szcvec(addr, size, off,
		    disable_auto_data_large_pages,
		    max_privmap_lpsize, privm_lpg_min_physmem));
	}
}

/*
 * For now there is only a single size cache list.
 * Allocated dynamically.
 */
page_t ***page_cachelists[MAX_MEM_TYPES];

kmutex_t *fpc_mutex[NPC_MUTEX];
kmutex_t *cpc_mutex[NPC_MUTEX];

/*
 * Calculate space needed for page freelists and counters
 */
size_t
calc_free_pagelist_sz(void)
{
	int szc;
	size_t alloc_sz, cache_sz, free_sz;

	/*
	 * one cachelist per color, node, and type
	 */
	cache_sz = (page_get_pagecolors(0) * sizeof (page_t *)) +
	    sizeof (page_t **);
	cache_sz *= max_mem_nodes * MAX_MEM_TYPES;

	/*
	 * one freelist per size, color, node, and type
	 */
	free_sz = sizeof (page_t **);
	for (szc = 0; szc < mmu_page_sizes; szc++)
		free_sz += sizeof (page_t *) * page_get_pagecolors(szc);
	free_sz *= max_mem_nodes * MAX_MEM_TYPES;

	alloc_sz = cache_sz + free_sz + page_ctrs_sz();
	return (alloc_sz);
}

caddr_t
alloc_page_freelists(caddr_t alloc_base)
{
	int	mnode, mtype;
	int	szc, clrs;

	/*
	 * We only support small pages in the cachelist.
	 */
	for (mtype = 0; mtype < MAX_MEM_TYPES; mtype++) {
		page_cachelists[mtype] = (page_t ***)alloc_base;
		alloc_base += (max_mem_nodes * sizeof (page_t **));
		for (mnode = 0; mnode < max_mem_nodes; mnode++) {
			page_cachelists[mtype][mnode] = (page_t **)alloc_base;
			alloc_base +=
			    (page_get_pagecolors(0) * sizeof (page_t *));
		}
	}

	/*
	 * Allocate freelists bins for all
	 * supported page sizes.
	 */
	for (szc = 0; szc < mmu_page_sizes; szc++) {
		clrs = page_get_pagecolors(szc);
		for (mtype = 0; mtype < MAX_MEM_TYPES; mtype++) {
			ufltp->pflt_freelists[szc][mtype] =
			    (page_t ***)alloc_base;
			alloc_base += (max_mem_nodes * sizeof (page_t **));
			for (mnode = 0; mnode < max_mem_nodes; mnode++) {
				ufltp->pflt_freelists[szc][mtype][mnode] =
				    (page_t **)alloc_base;
				alloc_base += (clrs * (sizeof (page_t *)));
			}
		}
	}

	alloc_base = page_ctrs_alloc(alloc_base);

	page_flt_init(ufltp);
	return (alloc_base);
}

/*
 * Allocate page_freelists locks for a memnode from the nucleus data
 * area. This is the first time that mmu_page_sizes is used during
 * bootup, so check mmu_page_sizes initialization.
 */
int
ndata_alloc_page_mutexs(struct memlist *ndata)
{
	size_t alloc_sz;
	caddr_t alloc_base;
	int	i;
	void	page_coloring_init();

	page_coloring_init();
	if (&mmu_init_mmu_page_sizes) {
		if (!mmu_init_mmu_page_sizes(0)) {
			cmn_err(CE_PANIC, "mmu_page_sizes %d not initialized",
			    mmu_page_sizes);
		}
	}
	ASSERT(mmu_page_sizes >= DEFAULT_MMU_PAGE_SIZES);

	/* fpc_mutex and cpc_mutex */
	alloc_sz = 2 * NPC_MUTEX * max_mem_nodes * sizeof (kmutex_t);

	alloc_base = ndata_alloc(ndata, alloc_sz, ecache_alignsize);
	if (alloc_base == NULL)
		return (-1);

	ASSERT(((uintptr_t)alloc_base & (ecache_alignsize - 1)) == 0);

	for (i = 0; i < NPC_MUTEX; i++) {
		fpc_mutex[i] = (kmutex_t *)alloc_base;
		alloc_base += (sizeof (kmutex_t) * max_mem_nodes);
		cpc_mutex[i] = (kmutex_t *)alloc_base;
		alloc_base += (sizeof (kmutex_t) * max_mem_nodes);
	}
	return (0);
}

/*
 * To select our starting bin, we stride through the bins with a stride
 * of 337.  Why 337?  It's prime, it's largeish, and it performs well both
 * in simulation and practice for different workloads on varying cache sizes.
 */
uint32_t color_start_current = 0;
uint32_t color_start_stride = 337;
int color_start_random = 0;

/* ARGSUSED */
uint_t
get_color_start(struct as *as)
{
	uint32_t old, new;

	if (consistent_coloring == 2 || color_start_random) {
		return ((uint_t)(((gettick()) << (vac_shift - MMU_PAGESHIFT)) &
		    (hw_page_array[0].hp_colors - 1)));
	}

	do {
		old = color_start_current;
		new = old + (color_start_stride << (vac_shift - MMU_PAGESHIFT));
	} while (cas32(&color_start_current, old, new) != old);

	return ((uint_t)(new));
}

/*
 * Called once at startup from kphysm_init() -- before memialloc()
 * is invoked to do the 1st page_free()/page_freelist_add().
 *
 * initializes page_colors and page_colors_mask based on ecache_setsize.
 *
 * Also initializes the counter locks.
 */
void
page_coloring_init()
{
	int	a, i;
	uint_t colors;

	if (do_pg_coloring == 0) {
		page_colors = 1;
		for (i = 0; i < mmu_page_sizes; i++) {
			colorequivszc[i] = 0;
			hw_page_array[i].hp_colors = 1;
		}
		return;
	}

	/*
	 * Calculate page_colors from ecache_setsize. ecache_setsize contains
	 * the max ecache setsize of all cpus configured in the system or, for
	 * cheetah+ systems, the max possible ecache setsize for all possible
	 * cheetah+ cpus.
	 */
	page_colors = ecache_setsize / MMU_PAGESIZE;
	page_colors_mask = page_colors - 1;

	vac_colors = vac_size / MMU_PAGESIZE;
	vac_colors_mask = vac_colors -1;

	page_coloring_shift = 0;
	a = ecache_setsize;
	while (a >>= 1) {
		page_coloring_shift++;
	}

	/* initialize number of colors per page size */
	for (i = 0; i < mmu_page_sizes; i++) {
		hw_page_array[i].hp_colors = (page_colors_mask >>
		    (hw_page_array[i].hp_shift - hw_page_array[0].hp_shift))
		    + 1;
		colorequivszc[i] = 0;
	}

	/*
	 * initialize cpu_page_colors if ecache setsizes are homogenous.
	 * cpu_page_colors set to -1 during DR operation or during startup
	 * if setsizes are heterogenous.
	 *
	 * The value of cpu_page_colors determines if additional color bins
	 * need to be checked for a particular color in the page_get routines.
	 */
	if (cpu_setsize > 0 && cpu_page_colors == 0 &&
	    cpu_setsize < ecache_setsize) {
		cpu_page_colors = cpu_setsize / MMU_PAGESIZE;
		a = lowbit(page_colors) - lowbit(cpu_page_colors);
		ASSERT(a > 0);
		ASSERT(a < 16);

		for (i = 0; i < mmu_page_sizes; i++) {
			if ((colors = hw_page_array[i].hp_colors) <= 1) {
				continue;
			}
			while ((colors >> a) == 0)
				a--;
			ASSERT(a >= 0);

			/* higher 4 bits encodes color equiv mask */
			colorequivszc[i] = (a << 4);
		}
	}

	/* do cpu specific color initialization */
	if (&page_coloring_init_cpu) {
		page_coloring_init_cpu();
	}
}

int
bp_color(struct buf *bp)
{
	int color = -1;

	if (vac) {
		if ((bp->b_flags & B_PAGEIO) != 0) {
			color = sfmmu_get_ppvcolor(bp->b_pages);
		} else if (bp->b_un.b_addr != NULL) {
			color = sfmmu_get_addrvcolor(bp->b_un.b_addr);
		}
	}
	return (color < 0 ? 0 : ptob(color));
}

/*
 * Function for flushing D-cache when performing module relocations
 * to an alternate mapping.  Stubbed out on all platforms except sun4u,
 * at least for now.
 */
void
dcache_flushall()
{
	sfmmu_cache_flushall();
}

static int
kdi_range_overlap(uintptr_t va1, size_t sz1, uintptr_t va2, size_t sz2)
{
	if (va1 < va2 && va1 + sz1 <= va2)
		return (0);

	if (va2 < va1 && va2 + sz2 <= va1)
		return (0);

	return (1);
}

/*
 * Return the number of bytes, relative to the beginning of a given range, that
 * are non-toxic (can be read from and written to with relative impunity).
 */
size_t
kdi_range_is_nontoxic(uintptr_t va, size_t sz, int write)
{
	/* OBP reads are harmless, but we don't want people writing there */
	if (write && kdi_range_overlap(va, sz, OFW_START_ADDR, OFW_END_ADDR -
	    OFW_START_ADDR + 1))
		return (va < OFW_START_ADDR ? OFW_START_ADDR - va : 0);

	if (kdi_range_overlap(va, sz, PIOMAPBASE, PIOMAPSIZE))
		return (va < PIOMAPBASE ? PIOMAPBASE - va : 0);

	return (sz); /* no overlap */
}

/*
 * Minimum physmem required for enabling large pages for kernel heap
 * Currently we do not enable lp for kmem on systems with less
 * than 1GB of memory. This value can be changed via /etc/system
 */
size_t segkmem_lpminphysmem = 0x40000000;	/* 1GB */

/*
 * this function chooses large page size for kernel heap
 */
size_t
get_segkmem_lpsize(size_t lpsize)
{
	size_t memtotal = physmem * PAGESIZE;
	size_t mmusz;
	uint_t szc;

	if (memtotal < segkmem_lpminphysmem)
		return (PAGESIZE);

	if (plat_lpkmem_is_supported != NULL &&
	    plat_lpkmem_is_supported() == 0)
		return (PAGESIZE);

	mmusz = mmu_get_kernel_lpsize(lpsize);
	szc = page_szc(mmusz);

	while (szc) {
		if (!(disable_large_pages & (1 << szc)))
			return (page_get_pagesize(szc));
		szc--;
	}
	return (PAGESIZE);
}
/*
 * Initializes the user page freelist type structures.
 */
static void
page_flt_init(page_freelist_type_t *ufp)
{
	ufp->pflt_type = PFLT_USER;
	ufp->pflt_get_free = &page_get_uflt;
	ufp->pflt_walk_init = page_list_walk_init;
	ufp->pflt_walk_next = page_list_walk_next_bin;
	ufp->pflt_num_policies = 2;
	ufp->pflt_policy[0] = page_get_mnode_freelist;
	ufp->pflt_policy[1] = page_get_contig_pages;
}