// SPDX-License-Identifier: GPL-2.0
/*
* bioscalls.c - the lowlevel layer of the PnPBIOS driver
*/
#include <linux/types.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/pnp.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kmod.h>
#include <linux/completion.h>
#include <linux/spinlock.h>
#include <asm/page.h>
#include <asm/desc.h>
#include <asm/byteorder.h>
#include "pnpbios.h"
__visible struct {
u16 offset;
u16 segment;
} pnp_bios_callpoint;
/*
* These are some opcodes for a "static asmlinkage"
* As this code is *not* executed inside the linux kernel segment, but in a
* alias at offset 0, we need a far return that can not be compiled by
* default (please, prove me wrong! this is *really* ugly!)
* This is the only way to get the bios to return into the kernel code,
* because the bios code runs in 16 bit protected mode and therefore can only
* return to the caller if the call is within the first 64kB, and the linux
* kernel begins at offset 3GB...
*/
asmlinkage __visible void pnp_bios_callfunc(void);
__asm__(".text \n"
__ALIGN_STR "\n"
".globl pnp_bios_callfunc\n"
"pnp_bios_callfunc:\n"
" pushl %edx \n"
" pushl %ecx \n"
" pushl %ebx \n"
" pushl %eax \n"
" lcallw *pnp_bios_callpoint\n"
" addl $16, %esp \n"
" lret \n"
".previous \n");
#define Q2_SET_SEL(cpu, selname, address, size) \
do { \
struct desc_struct *gdt = get_cpu_gdt_rw((cpu)); \
set_desc_base(&gdt[(selname) >> 3], (u32)(address)); \
set_desc_limit(&gdt[(selname) >> 3], (size) - 1); \
} while(0)
static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(DESC_DATA32_BIOS,
(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
/*
* At some point we want to use this stack frame pointer to unwind
* after PnP BIOS oopses.
*/
__visible u32 pnp_bios_fault_esp;
__visible u32 pnp_bios_fault_eip;
__visible u32 pnp_bios_is_utter_crap = 0;
static DEFINE_SPINLOCK(pnp_bios_lock);
/*
* Support Functions
*/
static inline u16 call_pnp_bios(u16 func, u16 arg1, u16 arg2, u16 arg3,
u16 arg4, u16 arg5, u16 arg6, u16 arg7,
void *ts1_base, u32 ts1_size,
void *ts2_base, u32 ts2_size)
{
unsigned long flags;
u16 status;
struct desc_struct save_desc_40;
int cpu;
/*
* PnP BIOSes are generally not terribly re-entrant.
* Also, don't rely on them to save everything correctly.
*/
if (pnp_bios_is_utter_crap)
return PNP_FUNCTION_NOT_SUPPORTED;
cpu = get_cpu();
save_desc_40 = get_cpu_gdt_rw(cpu)[0x40 / 8];
get_cpu_gdt_rw(cpu)[0x40 / 8] = bad_bios_desc;
/* On some boxes IRQ's during PnP BIOS calls are deadly. */
spin_lock_irqsave(&pnp_bios_lock, flags);
/* The lock prevents us bouncing CPU here */
if (ts1_size)
Q2_SET_SEL(smp_processor_id(), PNP_TS1, ts1_base, ts1_size);
if (ts2_size)
Q2_SET_SEL(smp_processor_id(), PNP_TS2, ts2_base, ts2_size);
__asm__ __volatile__("pushl %%ebp\n\t"
"pushl %%edi\n\t"
"pushl %%esi\n\t"
"pushl %%ds\n\t"
"pushl %%es\n\t"
"pushl %%fs\n\t"
"pushl %%gs\n\t"
"pushfl\n\t"
"movl %%esp, pnp_bios_fault_esp\n\t"
"movl $1f, pnp_bios_fault_eip\n\t"
"lcall %5,%6\n\t"
"1:popfl\n\t"
"popl %%gs\n\t"
"popl %%fs\n\t"
"popl %%es\n\t"
"popl %%ds\n\t"
"popl %%esi\n\t"
"popl %%edi\n\t"
"popl %%ebp\n\t":"=a"(status)
:"0"((func) | (((u32) arg1) << 16)),
"b"((arg2) | (((u32) arg3) << 16)),
"c"((arg4) | (((u32) arg5) << 16)),
"d"((arg6) | (((u32) arg7) << 16)),
"i"(PNP_CS32), "i"(0)
:"memory");
spin_unlock_irqrestore(&pnp_bios_lock, flags);
get_cpu_gdt_rw(cpu)[0x40 / 8] = save_desc_40;
put_cpu();
/* If we get here and this is set then the PnP BIOS faulted on us. */
if (pnp_bios_is_utter_crap) {
printk(KERN_ERR
"PnPBIOS: Warning! Your PnP BIOS caused a fatal error. Attempting to continue\n");
printk(KERN_ERR
"PnPBIOS: You may need to reboot with the \"pnpbios=off\" option to operate stably\n");
printk(KERN_ERR
"PnPBIOS: Check with your vendor for an updated BIOS\n");
}
return status;
}
void pnpbios_print_status(const char *module, u16 status)
{
switch (status) {
case PNP_SUCCESS:
printk(KERN_ERR "PnPBIOS: %s: function successful\n", module);
break;
case PNP_NOT_SET_STATICALLY:
printk(KERN_ERR "PnPBIOS: %s: unable to set static resources\n",
module);
break;
case PNP_UNKNOWN_FUNCTION:
printk(KERN_ERR "PnPBIOS: %s: invalid function number passed\n",
module);
break;
case PNP_FUNCTION_NOT_SUPPORTED:
printk(KERN_ERR
"PnPBIOS: %s: function not supported on this system\n",
module);
break;
case PNP_INVALID_HANDLE:
printk(KERN_ERR "PnPBIOS: %s: invalid handle\n", module);
break;
case PNP_BAD_PARAMETER:
printk(KERN_ERR "PnPBIOS: %s: invalid parameters were passed\n",
module);
break;
case PNP_SET_FAILED:
printk(KERN_ERR "PnPBIOS: %s: unable to set resources\n",
module);
break;
case PNP_EVENTS_NOT_PENDING:
printk(KERN_ERR "PnPBIOS: %s: no events are pending\n", module);
break;
case PNP_SYSTEM_NOT_DOCKED:
printk(KERN_ERR "PnPBIOS: %s: the system is not docked\n",
module);
break;
case PNP_NO_ISA_PNP_CARDS:
printk(KERN_ERR
"PnPBIOS: %s: no isapnp cards are installed on this system\n",
module);
break;
case PNP_UNABLE_TO_DETERMINE_DOCK_CAPABILITIES:
printk(KERN_ERR
"PnPBIOS: %s: cannot determine the capabilities of the docking station\n",
module);
break;
case PNP_CONFIG_CHANGE_FAILED_NO_BATTERY:
printk(KERN_ERR
"PnPBIOS: %s: unable to undock, the system does not have a battery\n",
module);
break;
case PNP_CONFIG_CHANGE_FAILED_RESOURCE_CONFLICT:
printk(KERN_ERR
"PnPBIOS: %s: could not dock due to resource conflicts\n",
module);
break;
case PNP_BUFFER_TOO_SMALL:
printk(KERN_ERR "PnPBIOS: %s: the buffer passed is too small\n",
module);
break;
case PNP_USE_ESCD_SUPPORT:
printk(KERN_ERR "PnPBIOS: %s: use ESCD instead\n", module);
break;
case PNP_MESSAGE_NOT_SUPPORTED:
printk(KERN_ERR "PnPBIOS: %s: the message is unsupported\n",
module);
break;
case PNP_HARDWARE_ERROR:
printk(KERN_ERR "PnPBIOS: %s: a hardware failure has occurred\n",
module);
break;
default:
printk(KERN_ERR "PnPBIOS: %s: unexpected status 0x%x\n", module,
status);
break;
}
}
/*
* PnP BIOS Low Level Calls
*/
#define PNP_GET_NUM_SYS_DEV_NODES 0x00
#define PNP_GET_SYS_DEV_NODE 0x01
#define PNP_SET_SYS_DEV_NODE 0x02
#define PNP_GET_EVENT 0x03
#define PNP_SEND_MESSAGE 0x04
#define PNP_GET_DOCKING_STATION_INFORMATION 0x05
#define PNP_SET_STATIC_ALLOCED_RES_INFO 0x09
#define PNP_GET_STATIC_ALLOCED_RES_INFO 0x0a
#define PNP_GET_APM_ID_TABLE 0x0b
#define PNP_GET_PNP_ISA_CONFIG_STRUC 0x40
#define PNP_GET_ESCD_INFO 0x41
#define PNP_READ_ESCD 0x42
#define PNP_WRITE_ESCD 0x43
/*
* Call PnP BIOS with function 0x00, "get number of system device nodes"
*/
static int __pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
{
u16 status;
if (!pnp_bios_present())
return PNP_FUNCTION_NOT_SUPPORTED;
status = call_pnp_bios(PNP_GET_NUM_SYS_DEV_NODES, 0, PNP_TS1, 2,
PNP_TS1, PNP_DS, 0, 0, data,
sizeof(struct pnp_dev_node_info), NULL, 0);
data->no_nodes &= 0xff;
return status;
}
int pnp_bios_dev_node_info(struct pnp_dev_node_info *data)
{
int status = __pnp_bios_dev_node_info(data);
if (status)
pnpbios_print_status("dev_node_info", status);
return status;
}
/*
* Note that some PnP BIOSes (e.g., on Sony Vaio laptops) die a horrible
* death if they are asked to access the "current" configuration.
* Therefore, if it's a matter of indifference, it's better to call
* get_dev_node() and set_dev_node() with boot=1 rather than with boot=0.
*/
/*
* Call PnP BIOS with function 0x01, "get system device node"
* Input: *nodenum = desired node,
* boot = whether to get nonvolatile boot (!=0)
* or volatile current (0) config
* Output: *nodenum=next node or 0xff if no more nodes
*/
static int __pnp_bios_get_dev_node(u8 *nodenum, char boot,
struct pnp_bios_node *data)
{
u16 status;
u16 tmp_nodenum;
if (!pnp_bios_present())
return PNP_FUNCTION_NOT_SUPPORTED;
if (!boot && pnpbios_dont_use_current_config)
return PNP_FUNCTION_NOT_SUPPORTED;
tmp_nodenum = *nodenum;
status = call_pnp_bios(PNP_GET_SYS_DEV_NODE, 0, PNP_TS1, 0, PNP_TS2,
boot ? 2 : 1, PNP_DS, 0, &tmp_nodenum,
sizeof(tmp_nodenum), data, 65536);
*nodenum = tmp_nodenum;
return status;
}
int pnp_bios_get_dev_node(u8 *nodenum, char boot, struct pnp_bios_node *data)
{
int status;
status = __pnp_bios_get_dev_node(nodenum, boot, data);
if (status)
pnpbios_print_status("get_dev_node", status);
return status;
}
/*
* Call PnP BIOS with function 0x02, "set system device node"
* Input: *nodenum = desired node,
* boot = whether to set nonvolatile boot (!=0)
* or volatile current (0) config
*/
static int __pnp_bios_set_dev_node(u8 nodenum, char boot,
struct pnp_bios_node *data)
{
u16 status;
if (!pnp_bios_present())
return PNP_FUNCTION_NOT_SUPPORTED;
if (!boot && pnpbios_dont_use_current_config)
return PNP_FUNCTION_NOT_SUPPORTED;
status = call_pnp_bios(PNP_SET_SYS_DEV_NODE, nodenum, 0, PNP_TS1,
boot ? 2 : 1, PNP_DS, 0, 0, data, 65536, NULL,
0);
return status;
}
int pnp_bios_set_dev_node(u8 nodenum, char boot, struct pnp_bios_node *data)
{
int status;
status = __pnp_bios_set_dev_node(nodenum, boot, data);
if (status) {
pnpbios_print_status("set_dev_node", status);
return status;
}
if (!boot) { /* Update devlist */
status = pnp_bios_get_dev_node(&nodenum, boot, data);
if (status)
return status;
}
return status;
}
/*
* Call PnP BIOS with function 0x05, "get docking station information"
*/
int pnp_bios_dock_station_info(struct pnp_docking_station_info *data)
{
u16 status;
if (!pnp_bios_present())
return PNP_FUNCTION_NOT_SUPPORTED;
status = call_pnp_bios(PNP_GET_DOCKING_STATION_INFORMATION, 0, PNP_TS1,
PNP_DS, 0, 0, 0, 0, data,
sizeof(struct pnp_docking_station_info), NULL,
0);
return status;
}
/*
* Call PnP BIOS with function 0x0a, "get statically allocated resource
* information"
*/
static int __pnp_bios_get_stat_res(char *info)
{
u16 status;
if (!pnp_bios_present())
return PNP_FUNCTION_NOT_SUPPORTED;
status = call_pnp_bios(PNP_GET_STATIC_ALLOCED_RES_INFO, 0, PNP_TS1,
PNP_DS, 0, 0, 0, 0, info, 65536, NULL, 0);
return status;
}
int pnp_bios_get_stat_res(char *info)
{
int status;
status = __pnp_bios_get_stat_res(info);
if (status)
pnpbios_print_status("get_stat_res", status);
return status;
}
/*
* Call PnP BIOS with function 0x40, "get isa pnp configuration structure"
*/
static int __pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
{
u16 status;
if (!pnp_bios_present())
return PNP_FUNCTION_NOT_SUPPORTED;
status = call_pnp_bios(PNP_GET_PNP_ISA_CONFIG_STRUC, 0, PNP_TS1, PNP_DS,
0, 0, 0, 0, data,
sizeof(struct pnp_isa_config_struc), NULL, 0);
return status;
}
int pnp_bios_isapnp_config(struct pnp_isa_config_struc *data)
{
int status;
status = __pnp_bios_isapnp_config(data);
if (status)
pnpbios_print_status("isapnp_config", status);
return status;
}
/*
* Call PnP BIOS with function 0x41, "get ESCD info"
*/
static int __pnp_bios_escd_info(struct escd_info_struc *data)
{
u16 status;
if (!pnp_bios_present())
return ESCD_FUNCTION_NOT_SUPPORTED;
status = call_pnp_bios(PNP_GET_ESCD_INFO, 0, PNP_TS1, 2, PNP_TS1, 4,
PNP_TS1, PNP_DS, data,
sizeof(struct escd_info_struc), NULL, 0);
return status;
}
int pnp_bios_escd_info(struct escd_info_struc *data)
{
int status;
status = __pnp_bios_escd_info(data);
if (status)
pnpbios_print_status("escd_info", status);
return status;
}
/*
* Call PnP BIOS function 0x42, "read ESCD"
* nvram_base is determined by calling escd_info
*/
static int __pnp_bios_read_escd(char *data, u32 nvram_base)
{
u16 status;
if (!pnp_bios_present())
return ESCD_FUNCTION_NOT_SUPPORTED;
status = call_pnp_bios(PNP_READ_ESCD, 0, PNP_TS1, PNP_TS2, PNP_DS, 0, 0,
0, data, 65536, __va(nvram_base), 65536);
return status;
}
int pnp_bios_read_escd(char *data, u32 nvram_base)
{
int status;
status = __pnp_bios_read_escd(data, nvram_base);
if (status)
pnpbios_print_status("read_escd", status);
return status;
}
void pnpbios_calls_init(union pnp_bios_install_struct *header)
{
int i;
pnp_bios_callpoint.offset = header->fields.pm16offset;
pnp_bios_callpoint.segment = PNP_CS16;
for_each_possible_cpu(i) {
struct desc_struct *gdt = get_cpu_gdt_rw(i);
if (!gdt)
continue;
set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS32],
(unsigned long)&pnp_bios_callfunc);
set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_CS16],
(unsigned long)__va(header->fields.pm16cseg));
set_desc_base(&gdt[GDT_ENTRY_PNPBIOS_DS],
(unsigned long)__va(header->fields.pm16dseg));
}
}
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