diff options
Diffstat (limited to 'include/asm-xtensa/processor.h')
| -rw-r--r-- | include/asm-xtensa/processor.h | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/include/asm-xtensa/processor.h b/include/asm-xtensa/processor.h new file mode 100644 index 00000000000..9cab5e4298b --- /dev/null +++ b/include/asm-xtensa/processor.h @@ -0,0 +1,205 @@ +/* + * include/asm-xtensa/processor.h + * + * 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. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + */ + +#ifndef _XTENSA_PROCESSOR_H +#define _XTENSA_PROCESSOR_H + +#ifdef __ASSEMBLY__ +#define _ASMLANGUAGE +#endif + +#include <xtensa/config/core.h> +#include <xtensa/config/specreg.h> +#include <xtensa/config/tie.h> +#include <xtensa/config/system.h> + +#include <asm/ptrace.h> +#include <asm/types.h> +#include <asm/coprocessor.h> + +/* Assertions. */ + +#if (XCHAL_HAVE_WINDOWED != 1) +#error Linux requires the Xtensa Windowed Registers Option. +#endif + +/* + * User space process size: 1 GB. + * Windowed call ABI requires caller and callee to be located within the same + * 1 GB region. The C compiler places trampoline code on the stack for sources + * that take the address of a nested C function (a feature used by glibc), so + * the 1 GB requirement applies to the stack as well. + */ + +#define TASK_SIZE 0x40000000 + +/* + * General exception cause assigned to debug exceptions. Debug exceptions go + * to their own vector, rather than the general exception vectors (user, + * kernel, double); and their specific causes are reported via DEBUGCAUSE + * rather than EXCCAUSE. However it is sometimes convenient to redirect debug + * exceptions to the general exception mechanism. To do this, an otherwise + * unused EXCCAUSE value was assigned to debug exceptions for this purpose. + */ + +#define EXCCAUSE_MAPPED_DEBUG 63 + +/* + * We use DEPC also as a flag to distinguish between double and regular + * exceptions. For performance reasons, DEPC might contain the value of + * EXCCAUSE for regular exceptions, so we use this definition to mark a + * valid double exception address. + * (Note: We use it in bgeui, so it should be 64, 128, or 256) + */ + +#define VALID_DOUBLE_EXCEPTION_ADDRESS 64 + +/* LOCKLEVEL defines the interrupt level that masks all + * general-purpose interrupts. + */ +#define LOCKLEVEL 1 + +/* WSBITS and WBBITS are the width of the WINDOWSTART and WINDOWBASE + * registers + */ +#define WSBITS (XCHAL_NUM_AREGS / 4) /* width of WINDOWSTART in bits */ +#define WBBITS (XCHAL_NUM_AREGS_LOG2 - 2) /* width of WINDOWBASE in bits */ + +#ifndef __ASSEMBLY__ + +/* Build a valid return address for the specified call winsize. + * winsize must be 1 (call4), 2 (call8), or 3 (call12) + */ +#define MAKE_RA_FOR_CALL(ra,ws) (((ra) & 0x3fffffff) | (ws) << 30) + +/* Convert return address to a valid pc + * Note: We assume that the stack pointer is in the same 1GB ranges as the ra + */ +#define MAKE_PC_FROM_RA(ra,sp) (((ra) & 0x3fffffff) | ((sp) & 0xc0000000)) + +typedef struct { + unsigned long seg; +} mm_segment_t; + +struct thread_struct { + + /* kernel's return address and stack pointer for context switching */ + unsigned long ra; /* kernel's a0: return address and window call size */ + unsigned long sp; /* kernel's a1: stack pointer */ + + mm_segment_t current_ds; /* see uaccess.h for example uses */ + + /* struct xtensa_cpuinfo info; */ + + unsigned long bad_vaddr; /* last user fault */ + unsigned long bad_uaddr; /* last kernel fault accessing user space */ + unsigned long error_code; + + unsigned long ibreak[XCHAL_NUM_IBREAK]; + unsigned long dbreaka[XCHAL_NUM_DBREAK]; + unsigned long dbreakc[XCHAL_NUM_DBREAK]; + + /* Allocate storage for extra state and coprocessor state. */ + unsigned char cp_save[XTENSA_CP_EXTRA_SIZE] + __attribute__ ((aligned(XTENSA_CP_EXTRA_ALIGN))); + + /* Make structure 16 bytes aligned. */ + int align[0] __attribute__ ((aligned(16))); +}; + + +/* + * Default implementation of macro that returns current + * instruction pointer ("program counter"). + */ +#define current_text_addr() ({ __label__ _l; _l: &&_l;}) + + +/* This decides where the kernel will search for a free chunk of vm + * space during mmap's. + */ +#define TASK_UNMAPPED_BASE (TASK_SIZE / 2) + +#define INIT_THREAD \ +{ \ + ra: 0, \ + sp: sizeof(init_stack) + (long) &init_stack, \ + current_ds: {0}, \ + /*info: {0}, */ \ + bad_vaddr: 0, \ + bad_uaddr: 0, \ + error_code: 0, \ +} + + +/* + * Do necessary setup to start up a newly executed thread. + * Note: We set-up ps as if we did a call4 to the new pc. + * set_thread_state in signal.c depends on it. + */ +#define USER_PS_VALUE ( (1 << XCHAL_PS_WOE_SHIFT) + \ + (1 << XCHAL_PS_CALLINC_SHIFT) + \ + (USER_RING << XCHAL_PS_RING_SHIFT) + \ + (1 << XCHAL_PS_PROGSTACK_SHIFT) + \ + (1 << XCHAL_PS_EXCM_SHIFT) ) + +/* Clearing a0 terminates the backtrace. */ +#define start_thread(regs, new_pc, new_sp) \ + regs->pc = new_pc; \ + regs->ps = USER_PS_VALUE; \ + regs->areg[1] = new_sp; \ + regs->areg[0] = 0; \ + regs->wmask = 1; \ + regs->depc = 0; \ + regs->windowbase = 0; \ + regs->windowstart = 1; + +/* Forward declaration */ +struct task_struct; +struct mm_struct; + +// FIXME: do we need release_thread for CP?? +/* Free all resources held by a thread. */ +#define release_thread(thread) do { } while(0) + +// FIXME: do we need prepare_to_copy (lazy status) for CP?? +/* Prepare to copy thread state - unlazy all lazy status */ +#define prepare_to_copy(tsk) do { } while (0) + +/* + * create a kernel thread without removing it from tasklists + */ +extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags); + +/* Copy and release all segment info associated with a VM */ + +#define copy_segments(p, mm) do { } while(0) +#define release_segments(mm) do { } while(0) +#define forget_segments() do { } while (0) + +#define thread_saved_pc(tsk) (xtensa_pt_regs(tsk)->pc) + +extern unsigned long get_wchan(struct task_struct *p); + +#define KSTK_EIP(tsk) (xtensa_pt_regs(tsk)->pc) +#define KSTK_ESP(tsk) (xtensa_pt_regs(tsk)->areg[1]) + +#define cpu_relax() do { } while (0) + +/* Special register access. */ + +#define WSR(v,sr) __asm__ __volatile__ ("wsr %0,"__stringify(sr) :: "a"(v)); +#define RSR(v,sr) __asm__ __volatile__ ("rsr %0,"__stringify(sr) : "=a"(v)); + +#define set_sr(x,sr) ({unsigned int v=(unsigned int)x; WSR(v,sr);}) +#define get_sr(sr) ({unsigned int v; RSR(v,sr); v; }) + +#endif /* __ASSEMBLY__ */ +#endif /* _XTENSA_PROCESSOR_H */ |