| /* | |
| * Definitions used by low-level trap handlers | |
| * | |
| * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> | |
| * Copyright (C) 2007-2009 PetaLogix | |
| * Copyright (C) 2007 John Williams <john.williams@petalogix.com> | |
| * | |
| * This file is subject to the terms and conditions of the GNU General | |
| * Public License. See the file COPYING in the main directory of this | |
| * archive for more details. | |
| */ | |
| #ifndef _ASM_MICROBLAZE_ENTRY_H | |
| #define _ASM_MICROBLAZE_ENTRY_H | |
| #include <asm/percpu.h> | |
| #include <asm/ptrace.h> | |
| /* | |
| * These are per-cpu variables required in entry.S, among other | |
| * places | |
| */ | |
| #define PER_CPU(var) var | |
| # ifndef __ASSEMBLY__ | |
| DECLARE_PER_CPU(unsigned int, KSP); /* Saved kernel stack pointer */ | |
| DECLARE_PER_CPU(unsigned int, KM); /* Kernel/user mode */ | |
| DECLARE_PER_CPU(unsigned int, ENTRY_SP); /* Saved SP on kernel entry */ | |
| DECLARE_PER_CPU(unsigned int, R11_SAVE); /* Temp variable for entry */ | |
| DECLARE_PER_CPU(unsigned int, CURRENT_SAVE); /* Saved current pointer */ | |
| # endif /* __ASSEMBLY__ */ | |
| #ifndef CONFIG_MMU | |
| /* noMMU hasn't any space for args */ | |
| # define STATE_SAVE_ARG_SPACE (0) | |
| #else /* CONFIG_MMU */ | |
| /* If true, system calls save and restore all registers (except result | |
| * registers, of course). If false, then `call clobbered' registers | |
| * will not be preserved, on the theory that system calls are basically | |
| * function calls anyway, and the caller should be able to deal with it. | |
| * This is a security risk, of course, as `internal' values may leak out | |
| * after a system call, but that certainly doesn't matter very much for | |
| * a processor with no MMU protection! For a protected-mode kernel, it | |
| * would be faster to just zero those registers before returning. | |
| * | |
| * I can not rely on the glibc implementation. If you turn it off make | |
| * sure that r11/r12 is saved in user-space. --KAA | |
| * | |
| * These are special variables using by the kernel trap/interrupt code | |
| * to save registers in, at a time when there are no spare registers we | |
| * can use to do so, and we can't depend on the value of the stack | |
| * pointer. This means that they must be within a signed 16-bit | |
| * displacement of 0x00000000. | |
| */ | |
| /* A `state save frame' is a struct pt_regs preceded by some extra space | |
| * suitable for a function call stack frame. */ | |
| /* Amount of room on the stack reserved for arguments and to satisfy the | |
| * C calling conventions, in addition to the space used by the struct | |
| * pt_regs that actually holds saved values. */ | |
| #define STATE_SAVE_ARG_SPACE (6*4) /* Up to six arguments */ | |
| #endif /* CONFIG_MMU */ | |
| #endif /* _ASM_MICROBLAZE_ENTRY_H */ |