linux_dsm_epyc7002/drivers/pnp/pnpbios/pnpbios.h
Gustavo A. R. Silva 9361797c76 PNPBIOS: Replace zero-length array with flexible-array
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-05-15 18:20:49 +02:00

170 lines
5.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* pnpbios.h - contains local definitions
*/
/*
* Include file for the interface to a PnP BIOS
*
* Original BIOS code (C) 1998 Christian Schmidt (chr.schmidt@tu-bs.de)
* PnP handler parts (c) 1998 Tom Lees <tom@lpsg.demon.co.uk>
* Minor reorganizations by David Hinds <dahinds@users.sourceforge.net>
*/
/*
* 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
#define ESCD_SUCCESS 0x00
#define ESCD_IO_ERROR_READING 0x55
#define ESCD_INVALID 0x56
#define ESCD_BUFFER_TOO_SMALL 0x59
#define ESCD_NVRAM_TOO_SMALL 0x5a
#define ESCD_FUNCTION_NOT_SUPPORTED 0x81
/*
* Events that can be received by "get event"
*/
#define PNPEV_ABOUT_TO_CHANGE_CONFIG 0x0001
#define PNPEV_DOCK_CHANGED 0x0002
#define PNPEV_SYSTEM_DEVICE_CHANGED 0x0003
#define PNPEV_CONFIG_CHANGED_FAILED 0x0004
#define PNPEV_UNKNOWN_SYSTEM_EVENT 0xffff
/* 0x8000 through 0xfffe are OEM defined */
/*
* Messages that should be sent through "send message"
*/
#define PNPMSG_OK 0x00
#define PNPMSG_ABORT 0x01
#define PNPMSG_UNDOCK_DEFAULT_ACTION 0x40
#define PNPMSG_POWER_OFF 0x41
#define PNPMSG_PNP_OS_ACTIVE 0x42
#define PNPMSG_PNP_OS_INACTIVE 0x43
/*
* Plug and Play BIOS flags
*/
#define PNPBIOS_NO_DISABLE 0x0001
#define PNPBIOS_NO_CONFIG 0x0002
#define PNPBIOS_OUTPUT 0x0004
#define PNPBIOS_INPUT 0x0008
#define PNPBIOS_BOOTABLE 0x0010
#define PNPBIOS_DOCK 0x0020
#define PNPBIOS_REMOVABLE 0x0040
#define pnpbios_is_static(x) (((x)->flags & 0x0100) == 0x0000)
#define pnpbios_is_dynamic(x) ((x)->flags & 0x0080)
/*
* Function Parameters
*/
#define PNPMODE_STATIC 1
#define PNPMODE_DYNAMIC 0
/* 0x8000 through 0xffff are OEM defined */
#pragma pack(1)
struct pnp_dev_node_info {
__u16 no_nodes;
__u16 max_node_size;
};
struct pnp_docking_station_info {
__u32 location_id;
__u32 serial;
__u16 capabilities;
};
struct pnp_isa_config_struc {
__u8 revision;
__u8 no_csns;
__u16 isa_rd_data_port;
__u16 reserved;
};
struct escd_info_struc {
__u16 min_escd_write_size;
__u16 escd_size;
__u32 nv_storage_base;
};
struct pnp_bios_node {
__u16 size;
__u8 handle;
__u32 eisa_id;
__u8 type_code[3];
__u16 flags;
__u8 data[];
};
#pragma pack()
/* non-exported */
extern struct pnp_dev_node_info node_info;
extern int pnp_bios_dev_node_info(struct pnp_dev_node_info *data);
extern int pnp_bios_get_dev_node(u8 *nodenum, char config,
struct pnp_bios_node *data);
extern int pnp_bios_set_dev_node(u8 nodenum, char config,
struct pnp_bios_node *data);
extern int pnp_bios_get_stat_res(char *info);
extern int pnp_bios_isapnp_config(struct pnp_isa_config_struc *data);
extern int pnp_bios_escd_info(struct escd_info_struc *data);
extern int pnp_bios_read_escd(char *data, u32 nvram_base);
extern int pnp_bios_dock_station_info(struct pnp_docking_station_info *data);
#pragma pack(1)
union pnp_bios_install_struct {
struct {
u32 signature; /* "$PnP" */
u8 version; /* in BCD */
u8 length; /* length in bytes, currently 21h */
u16 control; /* system capabilities */
u8 checksum; /* all bytes must add up to 0 */
u32 eventflag; /* phys. address of the event flag */
u16 rmoffset; /* real mode entry point */
u16 rmcseg;
u16 pm16offset; /* 16 bit protected mode entry */
u32 pm16cseg;
u32 deviceID; /* EISA encoded system ID or 0 */
u16 rmdseg; /* real mode data segment */
u32 pm16dseg; /* 16 bit pm data segment base */
} fields;
char chars[0x21]; /* To calculate the checksum */
};
#pragma pack()
extern int pnp_bios_present(void);
extern int pnpbios_dont_use_current_config;
extern int pnpbios_parse_data_stream(struct pnp_dev *dev, struct pnp_bios_node * node);
extern int pnpbios_read_resources_from_node(struct pnp_dev *dev, struct pnp_bios_node *node);
extern int pnpbios_write_resources_to_node(struct pnp_dev *dev, struct pnp_bios_node *node);
extern void pnpid32_to_pnpid(u32 id, char *str);
extern void pnpbios_print_status(const char * module, u16 status);
extern void pnpbios_calls_init(union pnp_bios_install_struct * header);
#ifdef CONFIG_PNPBIOS_PROC_FS
extern int pnpbios_interface_attach_device(struct pnp_bios_node * node);
extern int pnpbios_proc_init (void);
extern void pnpbios_proc_exit (void);
#else
static inline int pnpbios_interface_attach_device(struct pnp_bios_node * node) { return 0; }
static inline int pnpbios_proc_init (void) { return 0; }
static inline void pnpbios_proc_exit (void) { ; }
#endif /* CONFIG_PNPBIOS_PROC_FS */