/*
* Copyright (c) 2022 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,
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*/
#include <pexpert/arm64/board_config.h>
#if HAS_GUARDED_IO_FILTER && !CONFIG_SPTM
#include <vm/pmap.h>
#include <arm/pmap/pmap_data.h>
extern uint64_t io_filter_vtop(uint64_t addr);
int io_filter_main(uint64_t addr, uint64_t value, uint64_t width, unsigned int io_attr_index, unsigned int io_filter_entry_index);
MARK_AS_PMAP_TEXT
static int
io_filter_write(uint64_t addr, uint64_t value, uint64_t width, unsigned int io_attr_index, unsigned int io_filter_entry_index)
{
/* Convert the addr to a physical address. */
const pmap_paddr_t pa = (pmap_paddr_t) io_filter_vtop(addr);
/* Fail out if PA is zero, indicating translation went wrong. */
if (__improbable(pa == 0)) {
return 0;
}
extern pmap_io_range_t *io_attr_table;
extern unsigned int num_io_rgns;
/* Fail if io_attr_table arguments are bad. */
if (__improbable(io_attr_table == NULL || io_attr_index >= (uint64_t) num_io_rgns)) {
return 0;
}
extern pmap_io_filter_entry_t *io_filter_table;
extern unsigned int num_io_filter_entries;
/* Fail if io_fitler_table arguments are bad. */
if (__improbable(io_filter_table == NULL || io_filter_entry_index >= (uint64_t) num_io_filter_entries)) {
return 0;
}
const pmap_io_range_t *io_range = &io_attr_table[io_attr_index];
const pmap_io_filter_entry_t *io_filter_entry = &io_filter_table[io_filter_entry_index];
/* Fail if pa is not described by the io_attr_table entry. */
if (__improbable(pa < io_range->addr || (pa + width) > (io_range->addr + io_range->len))) {
return 0;
}
const uint32_t signature = io_range->signature;
/* Fail if the signature doesn't match. */
if (__improbable(signature != io_filter_entry->signature)) {
return 0;
}
const uint16_t pa_offset = (uint16_t) (pa & PAGE_MASK);
const uint16_t pa_length = (uint16_t) width;
/* Fail if pa is not described by the io_filter_entry. */
if (__improbable(pa_offset < io_filter_entry->offset || (pa_offset + pa_length) > (io_filter_entry->offset + io_filter_entry->length))) {
return 0;
}
switch (width) {
case 1:
*(volatile uint8_t *)addr = (uint8_t) value;
break;
case 2:
*(volatile uint16_t *)addr = (uint16_t) value;
break;
case 4:
*(volatile uint32_t *)addr = (uint32_t) value;
break;
case 8:
*(volatile uint64_t *)addr = (uint64_t) value;
break;
default:
return 0;
}
return 1;
}
MARK_AS_PMAP_TEXT
int
io_filter_main(uint64_t addr, uint64_t value, uint64_t width, unsigned int io_attr_index, unsigned int io_filter_entry_index)
{
// Check if width is supported.
if ((width != 1) && (width != 2) && (width != 4) && (width != 8)) {
return 0;
}
// Check if addr is width aligned.
if ((width != 1) && ((addr & (width - 1)) != 0)) {
return 0;
}
return io_filter_write(addr, value, width, io_attr_index, io_filter_entry_index);
}
#endif /* HAS_GUARDED_IO_FILTER && !CONFIG_SPTM*/