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freebsd-nq/sys/i386/include/pc/bios.h
Konstantin Belousov d86c1f0dc1 i386 4/4G split. 
The change makes the user and kernel address spaces on i386
independent, giving each almost the full 4G of usable virtual addresses
except for one PDE at top used for trampoline and per-CPU trampoline
stacks, and system structures that must be always mapped, namely IDT,
GDT, common TSS and LDT, and process-private TSS and LDT if allocated.

By using 1:1 mapping for the kernel text and data, it appeared
possible to eliminate assembler part of the locore.S which bootstraps
initial page table and KPTmap.  The code is rewritten in C and moved
into the pmap_cold(). The comment in vmparam.h explains the KVA
layout.

There is no PCID mechanism available in protected mode, so each
kernel/user switch forth and back completely flushes the TLB, except
for the trampoline PTD region. The TLB invalidations for userspace
becomes trivial, because IPI handlers switch page tables. On the other
hand, context switches no longer need to reload %cr3.

copyout(9) was rewritten to use vm_fault_quick_hold().  An issue for
new copyout(9) is compatibility with wiring user buffers around sysctl
handlers. This explains two kind of locks for copyout ptes and
accounting of the vslock() calls.  The vm_fault_quick_hold() AKA slow
path, is only tried after the 'fast path' failed, which temporary
changes mapping to the userspace and copies the data to/from small
per-cpu buffer in the trampoline.  If a page fault occurs during the
copy, it is short-circuit by exception.s to not even reach C code.

The change was motivated by the need to implement the Meltdown
mitigation, but instead of KPTI the full split is done.  The i386
architecture already shows the sizing problems, in particular, it is
impossible to link clang and lld with debugging.  I expect that the
issues due to the virtual address space limits would only exaggerate
and the split gives more liveness to the platform.

Tested by: pho
Discussed with:	bde
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Differential revision:	https://reviews.freebsd.org/D14633
2018-04-13 20:30:49 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1997 Michael Smith
* Copyright (c) 1998 Jonathan Lemon
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#ifndef _MACHINE_PC_BIOS_H_
#define _MACHINE_PC_BIOS_H_
/*
* Signature structure for the BIOS32 Service Directory header
*/
struct bios32_SDheader
{
u_int8_t sig[4];
u_int32_t entry;
u_int8_t revision;
u_int8_t len;
u_int8_t cksum;
u_int8_t pad[5];
};
/*
* PnP BIOS presence structure
*/
struct PnPBIOS_table
{
u_int8_t sig[4]; /* "$PnP */
u_int8_t version; /* should be 0x10 */
u_int8_t len; /* total structure length */
u_int16_t control; /* BIOS feature flags */
u_int8_t cksum; /* checksum */
u_int32_t evflagaddr; /* address of event notificaton flag */
u_int16_t rmentryoffset; /* real-mode entry offset */
u_int16_t rmentryseg; /* segment */
u_int16_t pmentryoffset; /* protected-mode entry offset */
u_int32_t pmentrybase; /* segment base */
u_int32_t oemdevid; /* motherboard EISA ID */
u_int16_t rmbiosseg; /* real-mode BIOS segment */
u_int32_t pmdataseg; /* protected-mode data segment */
} __packed;
/*
* PnP BIOS return codes
*/
#define PNP_SUCCESS 0x00
#define PNP_NOT_SET_STATICALLY 0x7f
#define PNP_UNKNOWN_FUNCTION 0x81
#define PNP_FUNCTION_NOT_SUPPORTED 0x82
#define PNP_INVALID_HANDLE 0x83
#define PNP_BAD_PARAMETER 0x84
#define PNP_SET_FAILED 0x85
#define PNP_EVENTS_NOT_PENDING 0x86
#define PNP_SYSTEM_NOT_DOCKED 0x87
#define PNP_NO_ISA_PNP_CARDS 0x88
#define PNP_UNABLE_TO_DETERMINE_DOCK_CAPABILITIES 0x89
#define PNP_CONFIG_CHANGE_FAILED_NO_BATTERY 0x8a
#define PNP_CONFIG_CHANGE_FAILED_RESOURCE_CONFLICT 0x8b
#define PNP_BUFFER_TOO_SMALL 0x8c
#define PNP_USE_ESCD_SUPPORT 0x8d
#define PNP_MESSAGE_NOT_SUPPORTED 0x8e
#define PNP_HARDWARE_ERROR 0x8f
/*
* DMI return codes
*/
#define DMI_SUCCESS 0x00
#define DMI_UNKNOWN_FUNCTION 0x81
#define DMI_FUNCTION_NOT_SUPPORTED 0x82
#define DMI_INVALID_HANDLE 0x83
#define DMI_BAD_PARAMETER 0x84
#define DMI_INVALID_SUBFUNCTION 0x85
#define DMI_NO_CHANGE 0x86
#define DMI_ADD_STRUCTURE_FAILED 0x87
#define DMI_READ_ONLY 0x8d
#define DMI_LOCK_NOT_SUPPORTED 0x90
#define DMI_CURRENTLY_LOCKED 0x91
#define DMI_INVALID_LOCK 0x92
/*
* format specifiers and defines for bios16()
* s = short (16 bits)
* i = int (32 bits)
* p = pointer (converted to seg:offset)
* C,D,U = selector (corresponding to code/data/utility segment)
*/
#define PNP_COUNT_DEVNODES "sppD", 0x00
#define PNP_GET_DEVNODE "sppsD", 0x01
#define PNP_SET_DEVNODE "sspsD", 0x02
#define PNP_GET_EVENT "spD", 0x03
#define PNP_SEND_MSG "ssD", 0x04
#define PNP_GET_DOCK_INFO "spD", 0x05
#define PNP_SEL_PRIBOOT "ssiiisspD", 0x07
#define PNP_GET_PRIBOOT "sspppppD", 0x08
#define PNP_SET_RESINFO "spD", 0x09
#define PNP_GET_RESINFO "spD", 0x0A
#define PNP_GET_APM_ID "sppD", 0x0B
#define PNP_GET_ISA_INFO "spD", 0x40
#define PNP_GET_ECSD_INFO "spppD", 0x41
#define PNP_READ_ESCD "spUD", 0x42
#define PNP_WRITE_ESCD "spUD", 0x43
#define PNP_GET_DMI_INFO "spppppD", 0x50
#define PNP_GET_DMI_STRUCTURE "sppUD", 0x51
#define PNP_SET_DMI_STRUCTURE "sppsUD" 0x52
#define PNP_GET_DMI_CHANGE "spUD" 0x53
#define PNP_DMI_CONTROL "sspsUD" 0x54
#define PNP_GET_GPNV_INFO "sppppD" 0x55
#define PNP_READ_GPNV_DATA "ssppUD" 0x56
#define PNP_WRITE_GPNV_DATA "sspsUD" 0x57
#define PNP_BOOT_CHECK "sp", 0x60
#define PNP_COUNT_IPL "sppp", 0x61
#define PNP_GET_BOOTPRI "spp", 0x62
#define PNP_SET_BOOTPRI "sp", 0x63
#define PNP_GET_LASTBOOT "sp", 0x64
#define PNP_GET_BOOTFIRST "sp", 0x65
#define PNP_SET_BOOTFIRST "sp", 0x66
/*
* PCI BIOS functions
*/
#define PCIBIOS_BIOS_PRESENT 0xb101
#define PCIBIOS_READ_CONFIG_BYTE 0xb108
#define PCIBIOS_READ_CONFIG_WORD 0xb109
#define PCIBIOS_READ_CONFIG_DWORD 0xb10a
#define PCIBIOS_WRITE_CONFIG_BYTE 0xb10b
#define PCIBIOS_WRITE_CONFIG_WORD 0xb10c
#define PCIBIOS_WRITE_CONFIG_DWORD 0xb10d
#define PCIBIOS_GET_IRQ_ROUTING 0xb10e
#define PCIBIOS_ROUTE_INTERRUPT 0xb10f
/*
* PCI interrupt routing table.
*
* $PIR in the BIOS segment contains a PIR_table
* int 1a:b106 returns PIR_table in buffer at es:(e)di
* int 1a:b18e returns PIR_table in buffer at es:(e)di
* int 1a:b406 returns es:di pointing to the BIOS PIR_table
*/
struct PIR_header
{
int8_t ph_signature[4];
u_int16_t ph_version;
u_int16_t ph_length;
u_int8_t ph_router_bus;
u_int8_t ph_router_dev_fn;
u_int16_t ph_pci_irqs;
u_int16_t ph_router_vendor;
u_int16_t ph_router_device;
u_int32_t ph_miniport;
u_int8_t ph_res[11];
u_int8_t ph_checksum;
} __packed;
struct PIR_intpin
{
u_int8_t link;
u_int16_t irqs;
} __packed;
struct PIR_entry
{
u_int8_t pe_bus;
u_int8_t pe_res1:3;
u_int8_t pe_device:5;
struct PIR_intpin pe_intpin[4];
u_int8_t pe_slot;
u_int8_t pe_res3;
} __packed;
struct PIR_table
{
struct PIR_header pt_header;
struct PIR_entry pt_entry[0];
} __packed;
/*
* Int 15:E820 'SMAP' structure
*/
#define SMAP_SIG 0x534D4150 /* 'SMAP' */
#define SMAP_TYPE_MEMORY 1
#define SMAP_TYPE_RESERVED 2
#define SMAP_TYPE_ACPI_RECLAIM 3
#define SMAP_TYPE_ACPI_NVS 4
#define SMAP_TYPE_ACPI_ERROR 5
#define SMAP_TYPE_DISABLED 6
#define SMAP_TYPE_PMEM 7
#define SMAP_TYPE_PRAM 12
#define SMAP_XATTR_ENABLED 0x00000001
#define SMAP_XATTR_NON_VOLATILE 0x00000002
#define SMAP_XATTR_MASK (SMAP_XATTR_ENABLED | SMAP_XATTR_NON_VOLATILE)
struct bios_smap {
u_int64_t base;
u_int64_t length;
u_int32_t type;
} __packed;
/* Structure extended to include extended attribute field in ACPI 3.0. */
struct bios_smap_xattr {
u_int64_t base;
u_int64_t length;
u_int32_t type;
u_int32_t xattr;
} __packed;
/*
* System Management BIOS
*/
#define SMBIOS_START 0xf0000
#define SMBIOS_STEP 0x10
#define SMBIOS_OFF 0
#define SMBIOS_LEN 4
#define SMBIOS_SIG "_SM_"
struct smbios_eps {
uint8_t anchor_string[4]; /* '_SM_' */
uint8_t checksum;
uint8_t length;
uint8_t major_version;
uint8_t minor_version;
uint16_t maximum_structure_size;
uint8_t entry_point_revision;
uint8_t formatted_area[5];
uint8_t intermediate_anchor_string[5]; /* '_DMI_' */
uint8_t intermediate_checksum;
uint16_t structure_table_length;
uint32_t structure_table_address;
uint16_t number_structures;
uint8_t BCD_revision;
};
struct smbios_structure_header {
uint8_t type;
uint8_t length;
uint16_t handle;
};
#ifdef _KERNEL
#define BIOS_PADDRTOVADDR(x) ((x) + PMAP_MAP_LOW)
#define BIOS_VADDRTOPADDR(x) ((x) - PMAP_MAP_LOW)
struct bios_oem_signature {
char * anchor; /* search anchor string in BIOS memory */
size_t offset; /* offset from anchor (may be negative) */
size_t totlen; /* total length of BIOS string to copy */
} __packed;
struct bios_oem_range {
u_int from; /* shouldn't be below 0xe0000 */
u_int to; /* shouldn't be above 0xfffff */
} __packed;
struct bios_oem {
struct bios_oem_range range;
struct bios_oem_signature signature[];
} __packed;
struct segment_info {
u_int base;
u_int limit;
};
#define BIOSCODE_FLAG 0x01
#define BIOSDATA_FLAG 0x02
#define BIOSUTIL_FLAG 0x04
#define BIOSARGS_FLAG 0x08
struct bios_segments {
struct segment_info code32; /* 32-bit code (mandatory) */
struct segment_info code16; /* 16-bit code */
struct segment_info data; /* 16-bit data */
struct segment_info util; /* 16-bit utility */
struct segment_info args; /* 16-bit args */
};
struct bios_regs {
u_int eax;
u_int ebx;
u_int ecx;
u_int edx;
u_int esi;
u_int edi;
};
struct bios_args {
u_int entry; /* entry point of routine */
struct bios_regs r;
struct bios_segments seg;
};
/*
* BIOS32 Service Directory entry. Caller supplies name, bios32_SDlookup
* fills in the rest of the details.
*/
struct bios32_SDentry
{
union
{
u_int8_t name[4]; /* service identifier */
u_int32_t id; /* as a 32-bit value */
} ident;
u_int32_t base; /* base of service */
u_int32_t len; /* service length */
u_int32_t entry; /* entrypoint offset from base */
vm_offset_t ventry; /* entrypoint in kernel virtual segment */
};
/*
* Exported lookup results
*/
extern struct bios32_SDentry PCIbios;
int bios_oem_strings(struct bios_oem *oem, u_char *buffer, size_t maxlen);
uint32_t bios_sigsearch(uint32_t start, u_char *sig, int siglen, int paralen,
int sigofs);
int bios16(struct bios_args *, char *, ...);
int bios16_call(struct bios_regs *, char *);
int bios32(struct bios_regs *, u_int, u_short);
int bios32_SDlookup(struct bios32_SDentry *ent);
void set_bios_selectors(struct bios_segments *, int);
#endif
#endif /* _MACHINE_PC_BIOS_H_ */
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