nes-proj/cpu/x86/mm/paging-prot-domains.h

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/*
* Copyright (C) 2015, Intel Corporation. All rights reserved.
*
* 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 copyright holder 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 COPYRIGHT HOLDERS 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
* COPYRIGHT HOLDER 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 CPU_X86_MM_PAGING_PROT_DOMAINS_H_
#define CPU_X86_MM_PAGING_PROT_DOMAINS_H_
#include <stdint.h>
#include <stdlib.h>
#include <stdbool.h>
#include "dma.h"
#include "helpers.h"
#include "paging.h"
#include "syscalls-int.h"
struct dom_kern_data {
/** Base physical address of optional MMIO region */
uintptr_t mmio;
/** Number of (contiguous) pages in MMIO region */
size_t mmio_sz;
/** Base physical address of optional metadata region */
uintptr_t meta;
/** Number of (contiguous) pages in metadata region */
size_t meta_sz;
/** Flags are defined with the prefix PROT_DOMAINS_FLAG in prot-domains.h */
uint32_t flags;
/**
* Original return address from call stack when this protection domain
* invoked some other protection domain. This serves to control the return
* entrypoint. The callee is not permitted to modify this value (unless the
* callee is the kernel protection domain).
*/
uintptr_t orig_ret_addr;
/* align to next-larger power of 2 to enable usage of shifting instead of
* multiplication to index an array of these structures.
*/
} __attribute__((aligned(32)));
/** Linear base address at which to map the MMIO region. */
#define PROT_DOMAINS_MMIO_LINEAR_BASE (MIN_PAGE_SIZE + (uintptr_t)&_ebss_kern_addr)
/** Maximum supported size of MMIO region */
#define PROT_DOMAINS_MAX_MMIO_SZ 0x4000
/** Linear base address at which to map the metadata region */
#define PROT_DOMAINS_META_LINEAR_BASE \
(MIN_PAGE_SIZE + (PROT_DOMAINS_MMIO_LINEAR_BASE + PROT_DOMAINS_MAX_MMIO_SZ))
#define PROT_DOMAINS_META_OFF_TO_PHYS(off, meta_phys_base) \
((meta_phys_base) + ((off) - PROT_DOMAINS_META_LINEAR_BASE))
/** Any MMIO region mapping always starts at a particular linear address. */
#define PROT_DOMAINS_MMIO(dcd) PROT_DOMAINS_MMIO_LINEAR_BASE
/**
* Any metadata region mapping always starts at a particular linear address.
*/
#define PROT_DOMAINS_META(dcd) PROT_DOMAINS_META_LINEAR_BASE
#define PROT_DOMAINS_ENTER_ISR(exc) \
PROT_DOMAINS_ENTER_ISR_COMMON(exc)
#define PROT_DOMAINS_LEAVE_ISR(exc) PROT_DOMAINS_LEAVE_ISR_COMMON(exc)
/* Enable paging */
#define CR0_PG BIT(31)
/* Enable write protection in supervisor mode */
#define CR0_WP BIT(16)
/* Enable protected mode */
#define CR0_PE BIT(0)
/**
* \brief Enable or disable write protection enforcement in supervisor mode.
* When disabled, supervisory code (i.e. code running at ring levels
* 0-2) is permitted to write to pages that are marked read-only in
* page tables.
*
* \param en Set to true to enable write protection enforcement.
*/
static inline void prot_domains_set_wp(bool en)
{
uint32_t cr0_val = CR0_PG | CR0_PE;
if(en) {
cr0_val |= CR0_WP;
}
__asm__ __volatile__ ("mov %0, %%cr0" :: "r"(cr0_val));
}
#endif /* CPU_X86_MM_PAGING_PROT_DOMAINS_H_ */