c658eac628
The Xtensa architecture allows to define custom instructions and registers. Registers that are bound to a coprocessor are only accessible if the corresponding enable bit is set, which allows to implement a 'lazy' context switch mechanism. Other registers needs to be saved and restore at the time of the context switch or during interrupt handling. This patch adds support for these additional states: - save and restore registers that are used by the compiler upon interrupt entry and exit. - context switch additional registers unbound to any coprocessor - 'lazy' context switch of registers bound to a coprocessor - ptrace interface to provide access to additional registers - update configuration files in include/asm-xtensa/variant-fsf Signed-off-by: Chris Zankel <chris@zankel.net>
135 lines
3.9 KiB
C
135 lines
3.9 KiB
C
/*
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* include/asm-xtensa/ptrace.h
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001 - 2005 Tensilica Inc.
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*/
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#ifndef _XTENSA_PTRACE_H
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#define _XTENSA_PTRACE_H
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/*
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* Kernel stack
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*
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* +-----------------------+ -------- STACK_SIZE
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* | register file | |
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* +-----------------------+ |
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* | struct pt_regs | |
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* +-----------------------+ | ------ PT_REGS_OFFSET
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* double : 16 bytes spill area : | ^
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* excetion :- - - - - - - - - - - -: | |
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* frame : struct pt_regs : | |
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* :- - - - - - - - - - - -: | |
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* | | | |
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* | memory stack | | |
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* | | | |
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* ~ ~ ~ ~
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* ~ ~ ~ ~
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* | | | |
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* | | | |
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* +-----------------------+ | | --- STACK_BIAS
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* | struct task_struct | | | ^
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* current --> +-----------------------+ | | |
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* | struct thread_info | | | |
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* +-----------------------+ --------
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*/
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#define KERNEL_STACK_SIZE (2 * PAGE_SIZE)
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/* Offsets for exception_handlers[] (3 x 64-entries x 4-byte tables). */
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#define EXC_TABLE_KSTK 0x004 /* Kernel Stack */
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#define EXC_TABLE_DOUBLE_SAVE 0x008 /* Double exception save area for a0 */
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#define EXC_TABLE_FIXUP 0x00c /* Fixup handler */
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#define EXC_TABLE_PARAM 0x010 /* For passing a parameter to fixup */
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#define EXC_TABLE_SYSCALL_SAVE 0x014 /* For fast syscall handler */
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#define EXC_TABLE_FAST_USER 0x100 /* Fast user exception handler */
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#define EXC_TABLE_FAST_KERNEL 0x200 /* Fast kernel exception handler */
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#define EXC_TABLE_DEFAULT 0x300 /* Default C-Handler */
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#define EXC_TABLE_SIZE 0x400
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/* Registers used by strace */
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#define REG_A_BASE 0x0000
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#define REG_AR_BASE 0x0100
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#define REG_PC 0x0020
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#define REG_PS 0x02e6
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#define REG_WB 0x0248
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#define REG_WS 0x0249
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#define REG_LBEG 0x0200
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#define REG_LEND 0x0201
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#define REG_LCOUNT 0x0202
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#define REG_SAR 0x0203
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#define SYSCALL_NR 0x00ff
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/* Other PTRACE_ values defined in <linux/ptrace.h> using values 0-9,16,17,24 */
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#define PTRACE_GETREGS 12
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#define PTRACE_SETREGS 13
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#define PTRACE_GETXTREGS 18
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#define PTRACE_SETXTREGS 19
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#ifndef __ASSEMBLY__
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#ifdef __KERNEL__
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/*
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* This struct defines the way the registers are stored on the
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* kernel stack during a system call or other kernel entry.
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*/
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struct pt_regs {
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unsigned long pc; /* 4 */
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unsigned long ps; /* 8 */
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unsigned long depc; /* 12 */
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unsigned long exccause; /* 16 */
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unsigned long excvaddr; /* 20 */
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unsigned long debugcause; /* 24 */
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unsigned long wmask; /* 28 */
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unsigned long lbeg; /* 32 */
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unsigned long lend; /* 36 */
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unsigned long lcount; /* 40 */
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unsigned long sar; /* 44 */
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unsigned long windowbase; /* 48 */
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unsigned long windowstart; /* 52 */
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unsigned long syscall; /* 56 */
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unsigned long icountlevel; /* 60 */
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int reserved[1]; /* 64 */
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/* Additional configurable registers that are used by the compiler. */
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xtregs_opt_t xtregs_opt;
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/* Make sure the areg field is 16 bytes aligned. */
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int align[0] __attribute__ ((aligned(16)));
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/* current register frame.
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* Note: The ESF for kernel exceptions ends after 16 registers!
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*/
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unsigned long areg[16]; /* 128 (64) */
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};
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#include <asm/variant/core.h>
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# define task_pt_regs(tsk) ((struct pt_regs*) \
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(task_stack_page(tsk) + KERNEL_STACK_SIZE - (XCHAL_NUM_AREGS-16)*4) - 1)
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# define user_mode(regs) (((regs)->ps & 0x00000020)!=0)
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# define instruction_pointer(regs) ((regs)->pc)
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extern void show_regs(struct pt_regs *);
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# ifndef CONFIG_SMP
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# define profile_pc(regs) instruction_pointer(regs)
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# endif
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#endif /* __KERNEL__ */
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#else /* __ASSEMBLY__ */
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#ifdef __KERNEL__
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# include <asm/asm-offsets.h>
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#define PT_REGS_OFFSET (KERNEL_STACK_SIZE - PT_USER_SIZE)
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#endif
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#endif /* !__ASSEMBLY__ */
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#endif /* _XTENSA_PTRACE_H */
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