Michal Simek | 4115ac8 | 2009-03-27 14:25:43 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Definitions used by low-level trap handlers |
| 3 | * |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 4 | * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> |
| 5 | * Copyright (C) 2007-2009 PetaLogix |
Michal Simek | 4115ac8 | 2009-03-27 14:25:43 +0100 | [diff] [blame] | 6 | * Copyright (C) 2007 John Williams <john.williams@petalogix.com> |
| 7 | * |
| 8 | * This file is subject to the terms and conditions of the GNU General |
| 9 | * Public License. See the file COPYING in the main directory of this |
| 10 | * archive for more details. |
| 11 | */ |
| 12 | |
| 13 | #ifndef _ASM_MICROBLAZE_ENTRY_H |
| 14 | #define _ASM_MICROBLAZE_ENTRY_H |
| 15 | |
| 16 | #include <asm/percpu.h> |
| 17 | #include <asm/ptrace.h> |
| 18 | |
| 19 | /* |
| 20 | * These are per-cpu variables required in entry.S, among other |
| 21 | * places |
| 22 | */ |
| 23 | |
| 24 | #define PER_CPU(var) per_cpu__##var |
| 25 | |
| 26 | # ifndef __ASSEMBLY__ |
| 27 | DECLARE_PER_CPU(unsigned int, KSP); /* Saved kernel stack pointer */ |
| 28 | DECLARE_PER_CPU(unsigned int, KM); /* Kernel/user mode */ |
| 29 | DECLARE_PER_CPU(unsigned int, ENTRY_SP); /* Saved SP on kernel entry */ |
| 30 | DECLARE_PER_CPU(unsigned int, R11_SAVE); /* Temp variable for entry */ |
| 31 | DECLARE_PER_CPU(unsigned int, CURRENT_SAVE); /* Saved current pointer */ |
Michal Simek | 4115ac8 | 2009-03-27 14:25:43 +0100 | [diff] [blame] | 32 | # endif /* __ASSEMBLY__ */ |
| 33 | |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 34 | #ifndef CONFIG_MMU |
| 35 | |
Michal Simek | 2921e2b | 2009-04-21 14:08:47 +0200 | [diff] [blame] | 36 | /* noMMU hasn't any space for args */ |
| 37 | # define STATE_SAVE_ARG_SPACE (0) |
| 38 | |
Michal Simek | ca54502 | 2009-05-26 16:30:21 +0200 | [diff] [blame] | 39 | #else /* CONFIG_MMU */ |
| 40 | |
| 41 | /* If true, system calls save and restore all registers (except result |
| 42 | * registers, of course). If false, then `call clobbered' registers |
| 43 | * will not be preserved, on the theory that system calls are basically |
| 44 | * function calls anyway, and the caller should be able to deal with it. |
| 45 | * This is a security risk, of course, as `internal' values may leak out |
| 46 | * after a system call, but that certainly doesn't matter very much for |
| 47 | * a processor with no MMU protection! For a protected-mode kernel, it |
| 48 | * would be faster to just zero those registers before returning. |
| 49 | * |
| 50 | * I can not rely on the glibc implementation. If you turn it off make |
| 51 | * sure that r11/r12 is saved in user-space. --KAA |
| 52 | * |
| 53 | * These are special variables using by the kernel trap/interrupt code |
| 54 | * to save registers in, at a time when there are no spare registers we |
| 55 | * can use to do so, and we can't depend on the value of the stack |
| 56 | * pointer. This means that they must be within a signed 16-bit |
| 57 | * displacement of 0x00000000. |
| 58 | */ |
| 59 | |
| 60 | /* A `state save frame' is a struct pt_regs preceded by some extra space |
| 61 | * suitable for a function call stack frame. */ |
| 62 | |
| 63 | /* Amount of room on the stack reserved for arguments and to satisfy the |
| 64 | * C calling conventions, in addition to the space used by the struct |
| 65 | * pt_regs that actually holds saved values. */ |
| 66 | #define STATE_SAVE_ARG_SPACE (6*4) /* Up to six arguments */ |
| 67 | |
| 68 | #endif /* CONFIG_MMU */ |
| 69 | |
Michal Simek | 4115ac8 | 2009-03-27 14:25:43 +0100 | [diff] [blame] | 70 | #endif /* _ASM_MICROBLAZE_ENTRY_H */ |