arch/parisc/include/asm/unistd.h

Source file repositories/reference/linux-study-clean/arch/parisc/include/asm/unistd.h

File Facts

System
Linux kernel
Corpus path
arch/parisc/include/asm/unistd.h
Extension
.h
Size
4895 bytes
Lines
152
Domain
Architecture Layer
Bucket
arch/parisc
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _ASM_PARISC_UNISTD_H_
#define _ASM_PARISC_UNISTD_H_

#include <uapi/asm/unistd.h>

#define __NR_Linux_syscalls	__NR_syscalls

#ifndef __ASSEMBLER__

#define SYS_ify(syscall_name)   __NR_##syscall_name

#define __IGNORE_fadvise64		/* fadvise64_64 */

#ifndef ASM_LINE_SEP
# define ASM_LINE_SEP ;
#endif

/* Definition taken from glibc 2.3.3
 * sysdeps/unix/sysv/linux/hppa/sysdep.h
 */

#ifndef DONT_USE_PIC
/* WARNING: CANNOT BE USED IN A NOP! */
# define K_STW_ASM_PIC	"       copy %%r19, %%r4\n"
# define K_LDW_ASM_PIC	"       copy %%r4, %%r19\n"
# define K_USING_GR4	"%r4",
#else
# define K_STW_ASM_PIC	" \n"
# define K_LDW_ASM_PIC	" \n"
# define K_USING_GR4
#endif

/* GCC has to be warned that a syscall may clobber all the ABI
   registers listed as "caller-saves", see page 8, Table 2
   in section 2.2.6 of the PA-RISC RUN-TIME architecture
   document. However! r28 is the result and will conflict with
   the clobber list so it is left out. Also the input arguments
   registers r20 -> r26 will conflict with the list so they
   are treated specially. Although r19 is clobbered by the syscall
   we cannot say this because it would violate ABI, thus we say
   r4 is clobbered and use that register to save/restore r19
   across the syscall. */

#define K_CALL_CLOB_REGS "%r1", "%r2", K_USING_GR4 \
			 "%r20", "%r29", "%r31"

#undef K_INLINE_SYSCALL
#define K_INLINE_SYSCALL(name, nr, args...)	({			\
	long __sys_res;							\
	{								\
		register unsigned long __res __asm__("r28");		\
		K_LOAD_ARGS_##nr(args)					\
		/* FIXME: HACK stw/ldw r19 around syscall */		\
		__asm__ volatile(					\
			K_STW_ASM_PIC					\
			"	ble  0x100(%%sr2, %%r0)\n"		\
			"	ldi %1, %%r20\n"			\
			K_LDW_ASM_PIC					\
			: "=r" (__res)					\
			: "i" (name) K_ASM_ARGS_##nr			\
			: "memory", K_CALL_CLOB_REGS K_CLOB_ARGS_##nr	\
		);							\
		__sys_res = (long)__res;				\
	}								\
	__sys_res;							\
})

#define K_LOAD_ARGS_0()
#define K_LOAD_ARGS_1(r26)					\
	register unsigned long __r26 __asm__("r26") = (unsigned long)(r26);   \
	K_LOAD_ARGS_0()
#define K_LOAD_ARGS_2(r26,r25)					\
	register unsigned long __r25 __asm__("r25") = (unsigned long)(r25);   \
	K_LOAD_ARGS_1(r26)
#define K_LOAD_ARGS_3(r26,r25,r24)				\
	register unsigned long __r24 __asm__("r24") = (unsigned long)(r24);   \
	K_LOAD_ARGS_2(r26,r25)
#define K_LOAD_ARGS_4(r26,r25,r24,r23)				\
	register unsigned long __r23 __asm__("r23") = (unsigned long)(r23);   \
	K_LOAD_ARGS_3(r26,r25,r24)
#define K_LOAD_ARGS_5(r26,r25,r24,r23,r22)			\
	register unsigned long __r22 __asm__("r22") = (unsigned long)(r22);   \
	K_LOAD_ARGS_4(r26,r25,r24,r23)
#define K_LOAD_ARGS_6(r26,r25,r24,r23,r22,r21)			\
	register unsigned long __r21 __asm__("r21") = (unsigned long)(r21);   \
	K_LOAD_ARGS_5(r26,r25,r24,r23,r22)

/* Even with zero args we use r20 for the syscall number */
#define K_ASM_ARGS_0
#define K_ASM_ARGS_1 K_ASM_ARGS_0, "r" (__r26)

Annotation

Implementation Notes