root/sys/riscv/include/vmparam.h
/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 * Copyright (c) 1994 John S. Dyson
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *      from: FreeBSD: src/sys/i386/include/vmparam.h,v 1.33 2000/03/30
 */

#ifndef _MACHINE_VMPARAM_H_
#define _MACHINE_VMPARAM_H_

/*
 * Virtual memory related constants, all in bytes
 */
#ifndef MAXTSIZ
#define MAXTSIZ         (1*1024*1024*1024)      /* max text size */
#endif
#ifndef DFLDSIZ
#define DFLDSIZ         (128*1024*1024)         /* initial data size limit */
#endif
#ifndef MAXDSIZ
#define MAXDSIZ         (1*1024*1024*1024)      /* max data size */
#endif
#ifndef DFLSSIZ
#define DFLSSIZ         (128*1024*1024)         /* initial stack size limit */
#endif
#ifndef MAXSSIZ
#define MAXSSIZ         (1*1024*1024*1024)      /* max stack size */
#endif
#ifndef SGROWSIZ
#define SGROWSIZ        (128*1024)              /* amount to grow stack */
#endif

/*
 * The physical address space is sparsely populated.
 */
#define VM_PHYSSEG_SPARSE

/*
 * The number of PHYSSEG entries.
 */
#define VM_PHYSSEG_MAX          64

/*
 * Create two free page pools: VM_FREEPOOL_DEFAULT is the default pool
 * from which physical pages are allocated and VM_FREEPOOL_DIRECT is
 * the pool from which physical pages for small UMA objects are
 * allocated.
 */
#define VM_NFREEPOOL            2
#define VM_FREEPOOL_DEFAULT     0
#define VM_FREEPOOL_DIRECT      1

/*
 * Create one free page list: VM_FREELIST_DEFAULT is for all physical
 * pages.
 */
#define VM_NFREELIST            1
#define VM_FREELIST_DEFAULT     0

/*
 * An allocation size of 16MB is supported in order to optimize the
 * use of the direct map by UMA.  Specifically, a cache line contains
 * at most four TTEs, collectively mapping 16MB of physical memory.
 * By reducing the number of distinct 16MB "pages" that are used by UMA,
 * the physical memory allocator reduces the likelihood of both 4MB
 * page TLB misses and cache misses caused by 4MB page TLB misses.
 */
#define VM_NFREEORDER           12

/*
 * Enable superpage reservations: 1 level.
 */
#ifndef VM_NRESERVLEVEL
#define VM_NRESERVLEVEL         1
#endif

/*
 * Level 0 reservations consist of 512 pages.
 */
#ifndef VM_LEVEL_0_ORDER
#define VM_LEVEL_0_ORDER        9
#endif

/**
 * Address space layout.
 *
 * RISC-V implements multiple paging modes with different virtual address space
 * sizes: SV32, SV39, SV48 and SV57.  Only SV39 and SV48 are supported by
 * FreeBSD.  SV39 provides a 512GB virtual address space and uses three-level
 * page tables, while SV48 provides a 256TB virtual address space and uses
 * four-level page tables.  64-bit RISC-V implementations are required to provide
 * at least SV39 mode; locore initially enables SV39 mode while bootstrapping
 * page tables, and pmap_bootstrap() optionally switches to SV48 mode.
 *
 * The address space is split into two regions at each end of the 64-bit address
 * space; the lower region is for use by user mode software, while the upper
 * region is used for various kernel maps.  The kernel map layout in SV48 mode
 * is currently identical to that used in SV39 mode.
 *
 * SV39 memory map:
 * 0x0000000000000000 - 0x0000003fffffffff    256GB user map
 * 0x0000004000000000 - 0xffffffbfffffffff    unmappable
 * 0xffffffc000000000 - 0xffffffc7ffffffff    32GB kernel map
 * 0xffffffc800000000 - 0xffffffcfffffffff    32GB unused
 * 0xffffffd000000000 - 0xffffffefffffffff    128GB direct map
 * 0xfffffff000000000 - 0xffffffffffffffff    64GB unused
 *
 * SV48 memory map:
 * 0x0000000000000000 - 0x00007fffffffffff    128TB user map
 * 0x0000800000000000 - 0xffff7fffffffffff    unmappable
 * 0xffff800000000000 - 0xffffffc7ffffffff    127.75TB hole
 * 0xffffffc000000000 - 0xffffffc7ffffffff    32GB kernel map
 * 0xffffffc800000000 - 0xffffffcfffffffff    32GB unused
 * 0xffffffd000000000 - 0xffffffefffffffff    128GB direct map
 * 0xfffffff000000000 - 0xffffffffffffffff    64GB unused
 *
 * The kernel is loaded at the beginning of the kernel map.
 *
 * We define some interesting address constants:
 *
 * VM_MIN_ADDRESS and VM_MAX_ADDRESS define the start and end of the entire
 * 64 bit address space, mostly just for convenience.
 *
 * VM_MIN_KERNEL_ADDRESS and VM_MAX_KERNEL_ADDRESS define the start and end of
 * mappable kernel virtual address space.
 *
 * VM_MIN_USER_ADDRESS and VM_MAX_USER_ADDRESS define the start and end of the
 * user address space.
 */
#define VM_MIN_ADDRESS          (0x0000000000000000UL)
#define VM_MAX_ADDRESS          (0xffffffffffffffffUL)

#define VM_MIN_KERNEL_ADDRESS   (0xffffffc000000000UL)
#define VM_MAX_KERNEL_ADDRESS   (0xffffffc800000000UL)

#define DMAP_MIN_ADDRESS        (0xffffffd000000000UL)
#define DMAP_MAX_ADDRESS        (0xfffffff000000000UL)

#define DMAP_MIN_PHYSADDR       (dmap_phys_base)
#define DMAP_MAX_PHYSADDR       (dmap_phys_max)

/* True if pa is in the dmap range */
#define PHYS_IN_DMAP(pa)        ((pa) >= DMAP_MIN_PHYSADDR && \
    (pa) < DMAP_MAX_PHYSADDR)
/* True if va is in the dmap range */
#define VIRT_IN_DMAP(va)        ((va) >= DMAP_MIN_ADDRESS && \
    (va) < (dmap_max_addr))

#define PMAP_HAS_DMAP   1
#define PHYS_TO_DMAP(pa)                                                \
({                                                                      \
        KASSERT(PHYS_IN_DMAP(pa),                                       \
            ("%s: PA out of range, PA: 0x%lx", __func__,                \
            (vm_paddr_t)(pa)));                                         \
        ((pa) - dmap_phys_base) + DMAP_MIN_ADDRESS;                     \
})

#define DMAP_TO_PHYS(va)                                                \
({                                                                      \
        KASSERT(VIRT_IN_DMAP(va),                                       \
            ("%s: VA out of range, VA: 0x%lx", __func__,                \
            (vm_offset_t)(va)));                                        \
        ((va) - DMAP_MIN_ADDRESS) + dmap_phys_base;                     \
})

#define VM_MIN_USER_ADDRESS             (0x0000000000000000UL)
#define VM_MAX_USER_ADDRESS_SV39        (0x0000004000000000UL)
#define VM_MAX_USER_ADDRESS_SV48        (0x0000800000000000UL)
#define VM_MAX_USER_ADDRESS             VM_MAX_USER_ADDRESS_SV48

#define VM_MINUSER_ADDRESS      (VM_MIN_USER_ADDRESS)
#define VM_MAXUSER_ADDRESS      (VM_MAX_USER_ADDRESS)

#define KERNBASE                (VM_MIN_KERNEL_ADDRESS)
#define SHAREDPAGE_SV39         (VM_MAX_USER_ADDRESS_SV39 - PAGE_SIZE)
#define SHAREDPAGE_SV48         (VM_MAX_USER_ADDRESS_SV48 - PAGE_SIZE)
#define SHAREDPAGE              SHAREDPAGE_SV48
#define USRSTACK_SV39           SHAREDPAGE_SV39
#define USRSTACK_SV48           SHAREDPAGE_SV48
#define USRSTACK                USRSTACK_SV48
#define PS_STRINGS_SV39         (USRSTACK_SV39 - sizeof(struct ps_strings))
#define PS_STRINGS_SV48         (USRSTACK_SV48 - sizeof(struct ps_strings))

/*
 * How many physical pages per kmem arena virtual page.
 */
#ifndef VM_KMEM_SIZE_SCALE
#define VM_KMEM_SIZE_SCALE      (1)
#endif

/*
 * Optional ceiling (in bytes) on the size of the kmem arena: 60% of the
 * kernel map.
 */
#ifndef VM_KMEM_SIZE_MAX
#define VM_KMEM_SIZE_MAX        ((VM_MAX_KERNEL_ADDRESS - \
    VM_MIN_KERNEL_ADDRESS + 1) * 3 / 5)
#endif

/*
 * Initial pagein size of beginning of executable file.
 */
#ifndef VM_INITIAL_PAGEIN
#define VM_INITIAL_PAGEIN       16
#endif

#define UMA_USE_DMAP

#ifndef LOCORE
extern vm_paddr_t dmap_phys_base;
extern vm_paddr_t dmap_phys_max;
extern vm_offset_t dmap_max_addr;
#endif

#define ZERO_REGION_SIZE        (64 * 1024)     /* 64KB */

/*
 * The top of KVA is reserved for early device mappings.
 */
#define DEVMAP_MAX_VADDR        VM_MAX_KERNEL_ADDRESS
#define DEVMAP_MIN_VADDR        (DEVMAP_MAX_VADDR - PMAP_MAPDEV_EARLY_SIZE)
#define PMAP_MAPDEV_EARLY_SIZE  (4 * L2_SIZE)

/*
 * No non-transparent large page support in the pmap.
 */
#define PMAP_HAS_LARGEPAGES     0

/*
 * Need a page dump array for minidump.
 */
#define MINIDUMP_PAGE_TRACKING  1
#define MINIDUMP_STARTUP_PAGE_TRACKING 1

#endif /* !_MACHINE_VMPARAM_H_ */