| // 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(0x4092, | 
 | 			(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 spinlock_t 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; | 
 |  | 
 | 	spin_lock_init(&pnp_bios_lock); | 
 | 	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)); | 
 | 	} | 
 | } |