cregit-Linux how code gets into the kernel

Release 4.11 drivers/pnp/pnpbios/bioscalls.c

/*
 * 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_table((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_table(cpu)[0x40 / 8]; get_cpu_gdt_table(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_table(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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay18194.27%120.00%
Shai Fultheim63.12%120.00%
Zachary Amsden31.56%120.00%
Andy Whitcroft10.52%120.00%
Björn Helgaas10.52%120.00%
Total192100.00%5100.00%


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; } }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay23499.57%150.00%
Lucas De Marchi10.43%150.00%
Total235100.00%2100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay6498.46%150.00%
Al Viro11.54%150.00%
Total65100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay32100.00%1100.00%
Total32100.00%1100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay7782.80%150.00%
Zachary Amsden1617.20%150.00%
Total93100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay45100.00%1100.00%
Total45100.00%1100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay7498.67%150.00%
Al Viro11.33%150.00%
Total75100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay76100.00%1100.00%
Total76100.00%1100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay5798.28%150.00%
Al Viro11.72%150.00%
Total58100.00%2100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay5398.15%150.00%
Al Viro11.85%150.00%
Total54100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay33100.00%1100.00%
Total33100.00%1100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay5898.31%150.00%
Al Viro11.69%150.00%
Total59100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay34100.00%1100.00%
Total34100.00%1100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay5898.31%150.00%
Al Viro11.69%150.00%
Total59100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay34100.00%1100.00%
Total34100.00%1100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay60100.00%2100.00%
Total60100.00%2100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay38100.00%1100.00%
Total38100.00%1100.00%


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_table(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)); } }

Contributors

PersonTokensPropCommitsCommitProp
Adam Belay6152.14%233.33%
Zachary Amsden3429.06%233.33%
Akinobu Mita1815.38%116.67%
Rusty Russell43.42%116.67%
Total117100.00%6100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Adam Belay142691.94%315.79%
Zachary Amsden533.42%315.79%
Akinobu Mita392.51%315.79%
Andrew Morton70.45%15.26%
Andi Kleen60.39%210.53%
Al Viro60.39%210.53%
Shai Fultheim60.39%15.26%
Rusty Russell40.26%15.26%
Björn Helgaas20.13%15.26%
Andy Whitcroft10.06%15.26%
Lucas De Marchi10.06%15.26%
Total1551100.00%19100.00%
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