linux/arch/sh/include/asm/processor_32.h
Michael Trimarchi 01ab10393c sh: Fix up DSP context save/restore.
There were a number of issues with the DSP context save/restore code,
mostly left-over relics from when it was introduced on SH3-DSP with
little follow-up testing, resulting in things like task_pt_dspregs()
referencing incorrect state on the stack.

This follows the MIPS convention of tracking the DSP state in the
thread_struct and handling the state save/restore in switch_to() and
finish_arch_switch() respectively. The regset interface is also updated,
which allows us to finally be rid of task_pt_dspregs() and the special
cased task_pt_regs().

Signed-off-by: Michael Trimarchi <michael@evidence.eu.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-04-04 11:48:11 -04:00

221 lines
4.8 KiB
C

/*
* include/asm-sh/processor.h
*
* Copyright (C) 1999, 2000 Niibe Yutaka
* Copyright (C) 2002, 2003 Paul Mundt
*/
#ifndef __ASM_SH_PROCESSOR_32_H
#define __ASM_SH_PROCESSOR_32_H
#ifdef __KERNEL__
#include <linux/compiler.h>
#include <linux/linkage.h>
#include <asm/page.h>
#include <asm/types.h>
#include <asm/ptrace.h>
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() ({ void *pc; __asm__("mova 1f, %0\n.align 2\n1:":"=z" (pc)); pc; })
/* Core Processor Version Register */
#define CCN_PVR 0xff000030
#define CCN_CVR 0xff000040
#define CCN_PRR 0xff000044
asmlinkage void __init sh_cpu_init(void);
/*
* User space process size: 2GB.
*
* Since SH7709 and SH7750 have "area 7", we can't use 0x7c000000--0x7fffffff
*/
#define TASK_SIZE 0x7c000000UL
#define STACK_TOP TASK_SIZE
#define STACK_TOP_MAX STACK_TOP
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
/*
* Bit of SR register
*
* FD-bit:
* When it's set, it means the processor doesn't have right to use FPU,
* and it results exception when the floating operation is executed.
*
* IMASK-bit:
* Interrupt level mask
*/
#define SR_DSP 0x00001000
#define SR_IMASK 0x000000f0
#define SR_FD 0x00008000
/*
* DSP structure and data
*/
struct sh_dsp_struct {
unsigned long dsp_regs[14];
long status;
};
/*
* FPU structure and data
*/
struct sh_fpu_hard_struct {
unsigned long fp_regs[16];
unsigned long xfp_regs[16];
unsigned long fpscr;
unsigned long fpul;
long status; /* software status information */
};
/* Dummy fpu emulator */
struct sh_fpu_soft_struct {
unsigned long fp_regs[16];
unsigned long xfp_regs[16];
unsigned long fpscr;
unsigned long fpul;
unsigned char lookahead;
unsigned long entry_pc;
};
union sh_fpu_union {
struct sh_fpu_hard_struct hard;
struct sh_fpu_soft_struct soft;
};
struct thread_struct {
/* Saved registers when thread is descheduled */
unsigned long sp;
unsigned long pc;
/* Hardware debugging registers */
unsigned long ubc_pc;
/* floating point info */
union sh_fpu_union fpu;
#ifdef CONFIG_SH_DSP
/* Dsp status information */
struct sh_dsp_struct dsp_status;
#endif
};
/* Count of active tasks with UBC settings */
extern int ubc_usercnt;
#define INIT_THREAD { \
.sp = sizeof(init_stack) + (long) &init_stack, \
}
/*
* Do necessary setup to start up a newly executed thread.
*/
#define start_thread(_regs, new_pc, new_sp) \
set_fs(USER_DS); \
_regs->pr = 0; \
_regs->sr = SR_FD; /* User mode. */ \
_regs->pc = new_pc; \
_regs->regs[15] = new_sp
/* Forward declaration, a strange C thing */
struct task_struct;
struct mm_struct;
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
/* 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)
/*
* FPU lazy state save handling.
*/
static __inline__ void disable_fpu(void)
{
unsigned long __dummy;
/* Set FD flag in SR */
__asm__ __volatile__("stc sr, %0\n\t"
"or %1, %0\n\t"
"ldc %0, sr"
: "=&r" (__dummy)
: "r" (SR_FD));
}
static __inline__ void enable_fpu(void)
{
unsigned long __dummy;
/* Clear out FD flag in SR */
__asm__ __volatile__("stc sr, %0\n\t"
"and %1, %0\n\t"
"ldc %0, sr"
: "=&r" (__dummy)
: "r" (~SR_FD));
}
/* Double presision, NANS as NANS, rounding to nearest, no exceptions */
#define FPSCR_INIT 0x00080000
#define FPSCR_CAUSE_MASK 0x0001f000 /* Cause bits */
#define FPSCR_FLAG_MASK 0x0000007c /* Flag bits */
/*
* Return saved PC of a blocked thread.
*/
#define thread_saved_pc(tsk) (tsk->thread.pc)
void show_trace(struct task_struct *tsk, unsigned long *sp,
struct pt_regs *regs);
#ifdef CONFIG_DUMP_CODE
void show_code(struct pt_regs *regs);
#else
static inline void show_code(struct pt_regs *regs)
{
}
#endif
extern unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[15])
#define user_stack_pointer(_regs) ((_regs)->regs[15])
#if defined(CONFIG_CPU_SH2A) || defined(CONFIG_CPU_SH4)
#define PREFETCH_STRIDE L1_CACHE_BYTES
#define ARCH_HAS_PREFETCH
#define ARCH_HAS_PREFETCHW
static inline void prefetch(void *x)
{
__asm__ __volatile__ ("pref @%0\n\t" : : "r" (x) : "memory");
}
#define prefetchw(x) prefetch(x)
#endif
#endif /* __KERNEL__ */
#endif /* __ASM_SH_PROCESSOR_32_H */