Files
netbsd/sys/arch/riscv/include/pte.h
2015-10-15 10:25:28 +02:00

287 lines
6.7 KiB
C

/* $NetBSD: pte.h,v 1.1 2014/09/19 17:36:26 matt Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifndef _RISCV_PTE_H_
#define _RISCV_PTE_H_
//
// RV32 page table entry (4 GB VA space)
// [31..22] = PPN[1]
// [21..12] = PPN[0]
// [11.. 9] = software
//
// RV64 page table entry (4 TB VA space)
// [64..43] = 0
// [42..33] = PPN[2]
// [32..23] = PPN[1]
// [22..13] = PPN[0]
// [12.. 9] = software
//
// Common to both:
// [8] = SX
// [7] = SW
// [6] = SR
// [5] = UX
// [4] = UW
// [3] = UR
// [2] = G
// [1] = T
// [0] = V
//
#define NPTEPG (1 + __BITS(9, 0)) // PTEs per Page
#define NSEGPG NPTEPG
#define NPDEPG NPTEPG
#ifdef _LP64
#define PTE_PPN __BITS(63, 13) // Physical Page Number
#define PTE_PPN0 __BITS(42, 33) // 1K 8-byte SDEs / PAGE
#define PTE_PPN1 __BITS(32, 23) // 1K 8-byte PDEs / PAGE
#define PTE_PPN2 __BITS(22, 13) // 1K 8-byte PTEs / PAGE
typedef __uint64_t pt_entry_t;
typedef __uint64_t pd_entry_t;
#define atomic_cas_pte atomic_cas_64
#define atomic_cas_pde atomic_cas_64
#else
#define PTE_PPN __BITS(31, 12) // Physical Page Number
#define PTE_PPN0 __BITS(31, 22) // 1K 4-byte PDEs / PAGE
#define PTE_PPN1 __BITS(21, 12) // 1K 4-byte PTEs / PAGE
typedef __uint32_t pt_entry_t;
typedef __uint32_t pd_entry_t;
#define atomic_cas_pte atomic_cas_32
#define atomic_cas_pde atomic_cas_32
#endif
// These only mean something to NetBSD
#define PTE_NX __BIT(11) // Unexecuted
#define PTE_NW __BIT(10) // Unmodified
#define PTE_WIRED __BIT(9) // Do Not Delete
// These are hardware defined bits
#define PTE_SX __BIT(8) // Supervisor eXecute
#define PTE_SW __BIT(7) // Supervisor Write
#define PTE_SR __BIT(6) // Supervisor Read
#define PTE_UX __BIT(5) // User eXecute
#define PTE_UW __BIT(4) // User Write
#define PTE_UR __BIT(3) // User Read
#define PTE_G __BIT(2) // Global
#define PTE_T __BIT(1) // "Transit" (non-leaf)
#define PTE_V __BIT(0) // Valid
static inline bool
pte_valid_p(pt_entry_t pte)
{
return (pte & PTE_V) != 0;
}
static inline bool
pte_wired_p(pt_entry_t pte)
{
return (pte & PTE_WIRED) != 0;
}
static inline bool
pte_modified_p(pt_entry_t pte)
{
return (pte & PTE_NW) == 0 && (pte & (PTE_UW|PTE_SW)) != 0;
}
static inline bool
pte_cached_p(pt_entry_t pte)
{
return true;
}
static inline bool
pte_deferred_exec_p(pt_entry_t pte)
{
return (pte & PTE_NX) != 0;
}
static inline pt_entry_t
pte_wire_entry(pt_entry_t pte)
{
return pte | PTE_WIRED;
}
static inline pt_entry_t
pte_unwire_entry(pt_entry_t pte)
{
return pte & ~PTE_WIRED;
}
static inline paddr_t
pte_to_paddr(pt_entry_t pte)
{
return pte & ~PAGE_MASK;
}
static inline pt_entry_t
pte_nv_entry(bool kernel_p)
{
return kernel_p ? PTE_G : 0;
}
static inline pt_entry_t
pte_prot_nowrite(pt_entry_t pte)
{
return pte & ~(PTE_NW|PTE_SW|PTE_UW);
}
static inline pt_entry_t
pte_prot_downgrade(pt_entry_t pte, vm_prot_t newprot)
{
pte &= ~(PTE_NW|PTE_SW|PTE_UW);
if ((newprot & VM_PROT_EXECUTE) == 0)
pte &= ~(PTE_NX|PTE_SX|PTE_UX);
return pte;
}
static inline pt_entry_t
pte_prot_bits(struct vm_page_md *mdpg, vm_prot_t prot, bool kernel_p)
{
KASSERT(prot & VM_PROT_READ);
pt_entry_t pt_entry = PTE_SR | (kernel_p ? 0 : PTE_UR);
if (prot & VM_PROT_EXECUTE) {
if (mdpg != NULL && !VM_PAGEMD_EXECPAGE_P(mdpg))
pt_entry |= PTE_NX;
else
pt_entry |= kernel_p ? PTE_SX : PTE_UX;
}
if (prot & VM_PROT_WRITE) {
if (mdpg != NULL && !VM_PAGEMD_MODIFIED_P(mdpg))
pt_entry |= PTE_NW;
else
pt_entry |= PTE_SW | (kernel_p ? 0 : PTE_UW);
}
return pt_entry;
}
static inline pt_entry_t
pte_flag_bits(struct vm_page_md *mdpg, int flags, bool kernel_p)
{
#if 0
if (__predict_false(flags & PMAP_NOCACHE)) {
if (__predict_true(mdpg != NULL)) {
return pte_nocached_bits();
} else {
return pte_ionocached_bits();
}
} else {
if (__predict_false(mdpg != NULL)) {
return pte_cached_bits();
} else {
return pte_iocached_bits();
}
}
#else
return 0;
#endif
}
static inline pt_entry_t
pte_make_enter(paddr_t pa, struct vm_page_md *mdpg, vm_prot_t prot,
int flags, bool kernel_p)
{
pt_entry_t pte = (pt_entry_t) pa & ~PAGE_MASK;
pte |= pte_flag_bits(mdpg, flags, kernel_p);
pte |= pte_prot_bits(mdpg, prot, kernel_p);
if (mdpg == NULL && VM_PAGEMD_REFERENCED_P(mdpg))
pte |= PTE_V;
return pte;
}
static inline pt_entry_t
pte_make_kenter_pa(paddr_t pa, struct vm_page_md *mdpg, vm_prot_t prot,
int flags)
{
pt_entry_t pte = (pt_entry_t) pa & ~PAGE_MASK;
pte |= PTE_WIRED | PTE_V;
pte |= pte_flag_bits(NULL, flags, true);
pte |= pte_prot_bits(NULL, prot, true); /* pretend unmanaged */
return pte;
}
static inline void
pte_set(pt_entry_t *ptep, pt_entry_t pte)
{
*ptep = pte;
}
static inline pd_entry_t
pte_invalid_pde(void)
{
return 0;
}
static inline pd_entry_t
pte_pde_pdetab(paddr_t pa)
{
return PTE_V | PTE_G | PTE_T | pa;
}
static inline pd_entry_t
pte_pde_ptpage(paddr_t pa)
{
return PTE_V | PTE_G | PTE_T | pa;
}
static inline bool
pte_pde_valid_p(pd_entry_t pde)
{
return (pde & (PTE_V|PTE_T)) == (PTE_V|PTE_T);
}
static inline paddr_t
pte_pde_to_paddr(pd_entry_t pde)
{
return pde & ~PAGE_MASK;
}
static inline pd_entry_t
pte_pde_cas(pd_entry_t *pdep, pd_entry_t opde, pt_entry_t npde)
{
#ifdef MULTIPROCESSOR
#ifdef _LP64
return atomic_cas_64(pdep, opde, npde);
#else
return atomic_cas_32(pdep, opde, npde);
#endif
#else
*pdep = npde;
return 0;
#endif
}
#endif /* _RISCV_PTE_H_ */