/*
* Copyright (c) 2020 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/**
* This header file stores the types, and prototypes used strictly by the pmap
* itself. The public pmap API exported to the rest of the kernel should be
* located in osfmk/arm/pmap.h.
*
* This file will automatically include all of the other internal arm/pmap/
* headers so .c files will only need to include this one header.
*/
#ifndef _ARM_PMAP_PMAP_INTERNAL_H_
#define _ARM_PMAP_PMAP_INTERNAL_H_
#include <stdint.h>
#include <kern/debug.h>
#include <kern/locks.h>
#include <mach/vm_types.h>
#include <mach_assert.h>
#include <arm/cpu_data.h>
#include <arm64/proc_reg.h>
/**
* arm/pmap.h and the other /arm/pmap/ internal header files are safe to be
* included in this file since they shouldn't rely on any of the internal pmap
* header files (so no circular dependencies). Implementation files will only
* need to include this one header to get all of the relevant pmap types.
*/
#include <arm/pmap.h>
#include <arm/pmap/pmap_data.h>
#include <arm/pmap/pmap_pt_geometry.h>
#if XNU_MONITOR
/**
* Temporary macros and prototypes needed to implement the ppl_handler_table.
*
* Eventually all calls to these macros will be in pmap_ppl_interface.c and
* these macros can be moved into that .c file.
*
* The <function>_internal() externs in here are also only included to be used
* by the ppl_handler_table. Once the ppl_handler_table moves into
* pmap_ppl_interface.c, then these prototypes can be removed (the
* PMAP_SUPPORT_PROTOTYPES() macro creates these prototypes automatically).
*
* TODO: Move PMAP_SUPPORT_PROTOTYPES_*() macros into pmap_ppl_interface.c and
* remove these _internal() prototypes.
*/
extern pmap_paddr_t pmap_release_ppl_pages_to_kernel_internal(void);
extern kern_return_t mapping_free_prime_internal(void);
extern void pmap_ledger_verify_size_internal(size_t);
extern ledger_t pmap_ledger_alloc_internal(void);
extern void pmap_ledger_free_internal(ledger_t);
/**
* This macro generates prototypes for the *_internal functions, which represent
* the PPL interface. When the PPL is enabled, this will also generate
* prototypes for the PPL entrypoints (*_ppl), as well as generating the
* entrypoints themselves.
*
* Since these macros generate code, they should only be called from a single
* implementation file for each PPL entry point.
*/
#define GEN_ASM_NAME(__function_name) _##__function_name##_ppl
#define PMAP_SUPPORT_PROTOTYPES_WITH_ASM_INTERNAL(__return_type, __function_name, __function_args, __function_index, __assembly_function_name) \
extern __return_type __function_name##_internal __function_args; \
extern __return_type __function_name##_ppl __function_args; \
__asm__ (".text \n" \
".align 2 \n" \
".globl " #__assembly_function_name "\n" \
#__assembly_function_name ":\n" \
"mov x15, " #__function_index "\n" \
"b _aprr_ppl_enter\n")
#define PMAP_SUPPORT_PROTOTYPES_WITH_ASM(__return_type, __function_name, __function_args, __function_index, __assembly_function_name) \
PMAP_SUPPORT_PROTOTYPES_WITH_ASM_INTERNAL(__return_type, __function_name, __function_args, __function_index, __assembly_function_name)
#define PMAP_SUPPORT_PROTOTYPES(__return_type, __function_name, __function_args, __function_index) \
PMAP_SUPPORT_PROTOTYPES_WITH_ASM(__return_type, __function_name, __function_args, __function_index, GEN_ASM_NAME(__function_name))
#else /* XNU_MONITOR */
#define PMAP_SUPPORT_PROTOTYPES(__return_type, __function_name, __function_args, __function_index) \
extern __return_type __function_name##_internal __function_args
#endif /* XNU_MONITOR */
/**
* Global variables exported to the rest of the internal pmap implementation.
*/
extern lck_grp_t pmap_lck_grp;
extern bool hib_entry_pmap_lockdown;
extern pmap_paddr_t avail_start;
extern pmap_paddr_t avail_end;
extern uint32_t pmap_max_asids;
/**
* Functions exported to the rest of the internal pmap implementation.
*/
#if XNU_MONITOR
extern void pmap_set_xprr_perm(unsigned int, unsigned int, unsigned int);
extern void pa_set_range_xprr_perm(pmap_paddr_t, pmap_paddr_t, unsigned int, unsigned int);
#endif /* XNU_MONITOR */
extern int pmap_remove_range_options(
pmap_t, vm_map_address_t, pt_entry_t *, pt_entry_t *, vm_map_address_t *, bool *, int);
extern void pmap_tte_deallocate(
pmap_t, vm_offset_t, vm_offset_t, bool, tt_entry_t *, unsigned int);
#if defined(PVH_FLAG_EXEC)
extern void pmap_set_ptov_ap(unsigned int, unsigned int, boolean_t);
#endif /* defined(PVH_FLAG_EXEC) */
extern pmap_t current_pmap(void);
extern void pmap_tt_ledger_credit(pmap_t, vm_size_t);
extern void pmap_tt_ledger_debit(pmap_t, vm_size_t);
extern void write_pte(pt_entry_t *, pt_entry_t);
/**
* The qsort function is used by various parts of the pmap but doesn't contain
* its own header file with prototype so it must be manually extern'd.
*
* The `cmpfunc_t` type is a pointer to a function that should return the
* following:
*
* return < 0 for a < b
* 0 for a == b
* > 0 for a > b
*/
typedef int (*cmpfunc_t)(const void *a, const void *b);
extern void qsort(void *a, size_t n, size_t es, cmpfunc_t cmp);
/**
* Inline and macro functions exported for usage by other pmap modules.
*
* In an effort to not cause any performance regressions while breaking up the
* pmap, I'm keeping all functions originally marked as "static inline", as
* inline and moving them into header files to be shared across the pmap
* modules. In reality, many of these functions probably don't need to be inline
* and can be moved back into a .c file.
*
* TODO: rdar://70538514 (PMAP Cleanup: re-evaluate whether inline functions should actually be inline)
*/
/**
* Macro used to ensure that pmap data structures aren't modified during
* hibernation image copying.
*/
#if HIBERNATION
#define ASSERT_NOT_HIBERNATING() (assertf(!hib_entry_pmap_lockdown, \
"Attempted to modify PMAP data structures after hibernation image copying has begun."))
#else
#define ASSERT_NOT_HIBERNATING()
#endif /* HIBERNATION */
/* Helper macro for rounding an address up to a correctly aligned value. */
#define PMAP_ALIGN(addr, align) ((addr) + ((align) - 1) & ~((align) - 1))
/**
* pmap_data.h must be included before this point so that pmap_lock_mode_t is
* defined before the rest of the locking code.
*/
/**
* Initialize a pmap object's reader/writer lock.
*
* @param pmap The pmap whose lock to initialize.
*/
static inline void
pmap_lock_init(pmap_t pmap)
{
lck_rw_init(&pmap->rwlock, &pmap_lck_grp, 0);
pmap->rwlock.lck_rw_can_sleep = FALSE;
}
/**
* Destroy a pmap object's reader/writer lock.
*
* @param pmap The pmap whose lock to destroy.
*/
static inline void
pmap_lock_destroy(pmap_t pmap)
{
lck_rw_destroy(&pmap->rwlock, &pmap_lck_grp);
}
/**
* Assert that the pmap lock is held in the given mode.
*
* @param pmap The pmap whose lock to assert is being held.
* @param mode The mode the lock should be held in.
*/
static inline void
pmap_assert_locked(__unused pmap_t pmap, __unused pmap_lock_mode_t mode)
{
#if MACH_ASSERT
switch (mode) {
case PMAP_LOCK_SHARED:
LCK_RW_ASSERT(&pmap->rwlock, LCK_RW_ASSERT_SHARED);
break;
case PMAP_LOCK_EXCLUSIVE:
LCK_RW_ASSERT(&pmap->rwlock, LCK_RW_ASSERT_EXCLUSIVE);
break;
default:
panic("%s: Unknown pmap_lock_mode. pmap=%p, mode=%d", __FUNCTION__, pmap, mode);
}
#endif
}
/**
* Assert that the pmap lock is held in any mode.
*
* @param pmap The pmap whose lock should be held.
*/
__unused static inline void
pmap_assert_locked_any(__unused pmap_t pmap)
{
LCK_RW_ASSERT(&pmap->rwlock, LCK_RW_ASSERT_HELD);
}
/**
* Acquire a pmap object's reader/writer lock as either shared (read-only) or
* exclusive (read/write).
*
* @note Failed attempts to grab the lock will NOT go to sleep, they'll spin
* until the lock can be acquired.
*
* @param pmap The pmap whose lock to acquire.
* @param mode Whether to grab the lock as shared (read-only) or exclusive (read/write).
*/
static inline void
pmap_lock(pmap_t pmap, pmap_lock_mode_t mode)
{
#if !XNU_MONITOR
mp_disable_preemption();
#endif
switch (mode) {
case PMAP_LOCK_SHARED:
lck_rw_lock_shared(&pmap->rwlock);
break;
case PMAP_LOCK_EXCLUSIVE:
lck_rw_lock_exclusive(&pmap->rwlock);
break;
default:
panic("%s: Unknown pmap_lock_mode. pmap=%p, mode=%d", __func__, pmap, mode);
}
}
/**
* Attempt to acquire the pmap lock in the specified mode. If the lock couldn't
* be acquired, then spin until it can be or a preemption is pending.
*
* @param pmap The pmap whose lock to attempt to acquire.
* @param mode Whether to grab the lock as shared (read-only) or exclusive (read/write).
*
* @return true if the lock was acquired, false if it was not and the caller should
* abort to some preemptible state to allow the preemption.
*/
static inline bool
pmap_lock_preempt(pmap_t pmap, pmap_lock_mode_t mode)
{
bool ret = false;
/**
* When the lock cannot be acquired, we check if we are preemptible.
*
* If we are already preemptible, there's no point of exiting this function and aborting.
*
* Also, if we are very early in boot, we should just spin. This is similar to how
* pmap_verify_preemptible() is used in pmap.
*/
do {
#if !XNU_MONITOR
mp_disable_preemption();
#endif
bool (^check_preemption)(void) = ^{
return pmap_pending_preemption();
};
switch (mode) {
case PMAP_LOCK_SHARED:
ret = lck_rw_lock_shared_b(&pmap->rwlock, check_preemption);
break;
case PMAP_LOCK_EXCLUSIVE:
ret = lck_rw_lock_exclusive_b(&pmap->rwlock, check_preemption);
break;
default:
panic("%s: Unknown pmap_lock_mode. pmap=%p, mode=%d", __func__, pmap, mode);
}
if (!ret) {
#if !XNU_MONITOR
mp_enable_preemption();
#endif
}
} while (!ret && (preemption_enabled() || (startup_phase < STARTUP_SUB_EARLY_BOOT)));
return ret;
}
/**
* Attempt to acquire the pmap lock in the specified mode. If the lock couldn't
* be acquired, then return immediately instead of spinning.
*
* @param pmap The pmap whose lock to attempt to acquire.
* @param mode Whether to grab the lock as shared (read-only) or exclusive (read/write).
*
* @return True if the lock was acquired, false otherwise.
*/
static inline bool
pmap_try_lock(pmap_t pmap, pmap_lock_mode_t mode)
{
bool ret = false;
#if !XNU_MONITOR
mp_disable_preemption();
#endif
switch (mode) {
case PMAP_LOCK_SHARED:
ret = lck_rw_try_lock_shared(&pmap->rwlock);
break;
case PMAP_LOCK_EXCLUSIVE:
ret = lck_rw_try_lock_exclusive(&pmap->rwlock);
break;
default:
panic("%s: Unknown pmap_lock_mode. pmap=%p, mode=%d", __func__, pmap, mode);
}
if (!ret) {
#if !XNU_MONITOR
mp_enable_preemption();
#endif
}
return ret;
}
/**
* Attempts to promote an already acquired pmap lock from shared to exclusive.
*
* @param pmap The pmap whose lock should be promoted from shared to exclusive.
*
* @return True if successfully promoted, otherwise false upon failure in
* which case the shared lock is dropped.
*/
static inline bool
pmap_lock_shared_to_exclusive(pmap_t pmap)
{
pmap_assert_locked(pmap, PMAP_LOCK_SHARED);
bool locked = lck_rw_lock_shared_to_exclusive(&pmap->rwlock);
#if !XNU_MONITOR
if (!locked) {
mp_enable_preemption();
}
#endif
return locked;
}
/**
* Release a pmap object's reader/writer lock.
*
* @param pmap The pmap whose lock to release.
* @param mode Which mode the lock should be in at time of release.
*/
static inline void
pmap_unlock(pmap_t pmap, pmap_lock_mode_t mode)
{
switch (mode) {
case PMAP_LOCK_SHARED:
lck_rw_unlock_shared(&pmap->rwlock);
break;
case PMAP_LOCK_EXCLUSIVE:
lck_rw_unlock_exclusive(&pmap->rwlock);
break;
default:
panic("%s: Unknown pmap_lock_mode. pmap=%p, mode=%d", __func__, pmap, mode);
}
#if !XNU_MONITOR
mp_enable_preemption();
#endif
}
#if __arm64__
/*
* Disable interrupts and return previous state.
*
* The PPL has its own interrupt state facility separately from
* ml_set_interrupts_enable(), since that function is not part of the
* PPL, and so doing things like manipulating untrusted data and
* taking ASTs.
*
* @return The previous interrupt state, to be restored with
* pmap_interrupts_restore().
*/
static inline uint64_t __attribute__((warn_unused_result)) __used
pmap_interrupts_disable(void)
{
uint64_t state = __builtin_arm_rsr64("DAIF");
/* Ensure that debug exceptions are masked. */
assert((state & DAIF_DEBUGF) == DAIF_DEBUGF);
if ((state & DAIF_ALL) != DAIF_ALL) {
__builtin_arm_wsr64("DAIFSet", DAIFSC_ALL);
}
return state;
}
/*
* Restore previous interrupt state.
*
* @param state The previous interrupt state to restore.
*/
static inline void __used
pmap_interrupts_restore(uint64_t state)
{
// no unknown bits?
assert((state & ~DAIF_ALL) == 0);
/* Assert that previous state had debug exceptions masked. */
assert((state & DAIF_DEBUGF) == DAIF_DEBUGF);
if (state != DAIF_ALL) {
__builtin_arm_wsr64("DAIF", state);
}
}
/*
* Query interrupt state.
*
* ml_get_interrupts_enabled() is safe enough at the time of writing
* this comment, but because it is not considered part of the PPL, so
* could change without notice, and because it presently only checks
* DAIF_IRQ, we have our own version.
*
* @return true if interrupts are enable (not fully disabled).
*/
static inline bool __attribute__((warn_unused_result)) __used
pmap_interrupts_enabled(void)
{
return (__builtin_arm_rsr64("DAIF") & DAIF_ALL) != DAIF_ALL;
}
#endif /* __arm64__ */
#endif /* _ARM_PMAP_PMAP_INTERNAL_H_ */