25c8a78b1e
The recent merge of fpu.S broken the handling of fpscr for ARCH=powerpc and CONFIG_PPC64=y. FP registers could be corrupted, leading to strange random application crashes. The confusion arises, because the thread_struct has (and requires) a 64-bit area to save the fpscr, because we use load/store double instructions to get it in to/out of the FPU. However, only the low 32-bits are actually used, so we want to treat it as a 32-bit quantity when manipulating its bits to avoid extra load/stores on 32-bit. This patch replaces the current definition with a structure of two 32-bit quantities (pad and val), to clarify things as much as is possible. The 'val' field is used when manipulating bits, the structure itself is used when obtaining the address for loading/unloading the value from the FPU. While we're at it, consolidate the 4 (!) almost identical versions of cvt_fd() and cvt_df() (arch/ppc/kernel/misc.S, arch/ppc64/kernel/misc.S, arch/powerpc/kernel/misc_32.S, arch/powerpc/kernel/misc_64.S) into a single version in fpu.S. The new version takes a pointer to thread_struct and applies the correct offset itself, rather than a pointer to the fpscr field itself, again to avoid confusion as to which is the correct field to use. Finally, this patch makes ARCH=ppc64 also use the consolidated fpu.S code, which it previously did not. Built for G5 (ARCH=ppc64 and ARCH=powerpc), 32-bit powermac (ARCH=ppc and ARCH=powerpc) and Walnut (ARCH=ppc, CONFIG_MATH_EMULATION=y). Booted on G5 (ARCH=powerpc) and things which previously fell over no longer do. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
308 lines
8.7 KiB
C
308 lines
8.7 KiB
C
#ifndef __PPC64_SYSTEM_H
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#define __PPC64_SYSTEM_H
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/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/config.h>
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#include <linux/compiler.h>
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#include <asm/page.h>
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#include <asm/processor.h>
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#include <asm/hw_irq.h>
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#include <asm/synch.h>
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/*
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* Memory barrier.
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* The sync instruction guarantees that all memory accesses initiated
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* by this processor have been performed (with respect to all other
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* mechanisms that access memory). The eieio instruction is a barrier
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* providing an ordering (separately) for (a) cacheable stores and (b)
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* loads and stores to non-cacheable memory (e.g. I/O devices).
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*
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* mb() prevents loads and stores being reordered across this point.
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* rmb() prevents loads being reordered across this point.
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* wmb() prevents stores being reordered across this point.
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* read_barrier_depends() prevents data-dependent loads being reordered
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* across this point (nop on PPC).
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*
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* We have to use the sync instructions for mb(), since lwsync doesn't
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* order loads with respect to previous stores. Lwsync is fine for
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* rmb(), though.
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* For wmb(), we use sync since wmb is used in drivers to order
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* stores to system memory with respect to writes to the device.
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* However, smp_wmb() can be a lighter-weight eieio barrier on
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* SMP since it is only used to order updates to system memory.
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*/
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#define mb() __asm__ __volatile__ ("sync" : : : "memory")
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#define rmb() __asm__ __volatile__ ("lwsync" : : : "memory")
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#define wmb() __asm__ __volatile__ ("sync" : : : "memory")
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#define read_barrier_depends() do { } while(0)
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#define set_mb(var, value) do { var = value; smp_mb(); } while (0)
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#define set_wmb(var, value) do { var = value; smp_wmb(); } while (0)
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#ifdef CONFIG_SMP
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#define smp_mb() mb()
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#define smp_rmb() rmb()
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#define smp_wmb() eieio()
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#define smp_read_barrier_depends() read_barrier_depends()
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#else
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#define smp_mb() __asm__ __volatile__("": : :"memory")
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#define smp_rmb() __asm__ __volatile__("": : :"memory")
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#define smp_wmb() __asm__ __volatile__("": : :"memory")
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#define smp_read_barrier_depends() do { } while(0)
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#endif /* CONFIG_SMP */
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#ifdef __KERNEL__
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struct task_struct;
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struct pt_regs;
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#ifdef CONFIG_DEBUGGER
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extern int (*__debugger)(struct pt_regs *regs);
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extern int (*__debugger_ipi)(struct pt_regs *regs);
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extern int (*__debugger_bpt)(struct pt_regs *regs);
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extern int (*__debugger_sstep)(struct pt_regs *regs);
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extern int (*__debugger_iabr_match)(struct pt_regs *regs);
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extern int (*__debugger_dabr_match)(struct pt_regs *regs);
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extern int (*__debugger_fault_handler)(struct pt_regs *regs);
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#define DEBUGGER_BOILERPLATE(__NAME) \
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static inline int __NAME(struct pt_regs *regs) \
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{ \
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if (unlikely(__ ## __NAME)) \
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return __ ## __NAME(regs); \
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return 0; \
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}
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DEBUGGER_BOILERPLATE(debugger)
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DEBUGGER_BOILERPLATE(debugger_ipi)
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DEBUGGER_BOILERPLATE(debugger_bpt)
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DEBUGGER_BOILERPLATE(debugger_sstep)
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DEBUGGER_BOILERPLATE(debugger_iabr_match)
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DEBUGGER_BOILERPLATE(debugger_dabr_match)
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DEBUGGER_BOILERPLATE(debugger_fault_handler)
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#ifdef CONFIG_XMON
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extern void xmon_init(int enable);
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#endif
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#else
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static inline int debugger(struct pt_regs *regs) { return 0; }
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static inline int debugger_ipi(struct pt_regs *regs) { return 0; }
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static inline int debugger_bpt(struct pt_regs *regs) { return 0; }
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static inline int debugger_sstep(struct pt_regs *regs) { return 0; }
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static inline int debugger_iabr_match(struct pt_regs *regs) { return 0; }
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static inline int debugger_dabr_match(struct pt_regs *regs) { return 0; }
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static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; }
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#endif
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extern int set_dabr(unsigned long dabr);
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extern void _exception(int signr, struct pt_regs *regs, int code,
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unsigned long addr);
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extern int fix_alignment(struct pt_regs *regs);
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extern void bad_page_fault(struct pt_regs *regs, unsigned long address,
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int sig);
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extern void show_regs(struct pt_regs * regs);
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extern void low_hash_fault(struct pt_regs *regs, unsigned long address);
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extern int die(const char *str, struct pt_regs *regs, long err);
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extern int _get_PVR(void);
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extern void giveup_fpu(struct task_struct *);
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extern void disable_kernel_fp(void);
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extern void flush_fp_to_thread(struct task_struct *);
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extern void enable_kernel_fp(void);
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extern void giveup_altivec(struct task_struct *);
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extern void disable_kernel_altivec(void);
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extern void enable_kernel_altivec(void);
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extern int emulate_altivec(struct pt_regs *);
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extern void cvt_fd(float *from, double *to, struct thread_struct *thread);
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extern void cvt_df(double *from, float *to, struct thread_struct *thread);
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#ifdef CONFIG_ALTIVEC
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extern void flush_altivec_to_thread(struct task_struct *);
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#else
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static inline void flush_altivec_to_thread(struct task_struct *t)
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{
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}
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#endif
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static inline void flush_spe_to_thread(struct task_struct *t)
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{
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}
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extern int mem_init_done; /* set on boot once kmalloc can be called */
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/* EBCDIC -> ASCII conversion for [0-9A-Z] on iSeries */
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extern unsigned char e2a(unsigned char);
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extern struct task_struct *__switch_to(struct task_struct *,
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struct task_struct *);
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#define switch_to(prev, next, last) ((last) = __switch_to((prev), (next)))
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struct thread_struct;
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extern struct task_struct * _switch(struct thread_struct *prev,
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struct thread_struct *next);
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extern int powersave_nap; /* set if nap mode can be used in idle loop */
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/*
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* Atomic exchange
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*
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* Changes the memory location '*ptr' to be val and returns
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* the previous value stored there.
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*
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* Inline asm pulled from arch/ppc/kernel/misc.S so ppc64
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* is more like most of the other architectures.
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*/
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static __inline__ unsigned long
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__xchg_u32(volatile unsigned int *m, unsigned long val)
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{
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unsigned long dummy;
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__asm__ __volatile__(
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EIEIO_ON_SMP
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"1: lwarx %0,0,%3 # __xchg_u32\n\
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stwcx. %2,0,%3\n\
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2: bne- 1b"
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ISYNC_ON_SMP
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: "=&r" (dummy), "=m" (*m)
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: "r" (val), "r" (m)
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: "cc", "memory");
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return (dummy);
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}
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static __inline__ unsigned long
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__xchg_u64(volatile long *m, unsigned long val)
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{
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unsigned long dummy;
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__asm__ __volatile__(
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EIEIO_ON_SMP
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"1: ldarx %0,0,%3 # __xchg_u64\n\
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stdcx. %2,0,%3\n\
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2: bne- 1b"
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ISYNC_ON_SMP
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: "=&r" (dummy), "=m" (*m)
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: "r" (val), "r" (m)
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: "cc", "memory");
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return (dummy);
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}
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/*
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* This function doesn't exist, so you'll get a linker error
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* if something tries to do an invalid xchg().
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*/
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extern void __xchg_called_with_bad_pointer(void);
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static __inline__ unsigned long
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__xchg(volatile void *ptr, unsigned long x, unsigned int size)
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{
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switch (size) {
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case 4:
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return __xchg_u32(ptr, x);
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case 8:
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return __xchg_u64(ptr, x);
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}
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__xchg_called_with_bad_pointer();
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return x;
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}
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#define xchg(ptr,x) \
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({ \
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__typeof__(*(ptr)) _x_ = (x); \
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(__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \
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})
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#define tas(ptr) (xchg((ptr),1))
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#define __HAVE_ARCH_CMPXCHG 1
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static __inline__ unsigned long
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__cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
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{
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unsigned int prev;
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__asm__ __volatile__ (
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EIEIO_ON_SMP
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"1: lwarx %0,0,%2 # __cmpxchg_u32\n\
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cmpw 0,%0,%3\n\
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bne- 2f\n\
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stwcx. %4,0,%2\n\
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bne- 1b"
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ISYNC_ON_SMP
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"\n\
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2:"
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: "=&r" (prev), "=m" (*p)
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: "r" (p), "r" (old), "r" (new), "m" (*p)
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: "cc", "memory");
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return prev;
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}
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static __inline__ unsigned long
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__cmpxchg_u64(volatile long *p, unsigned long old, unsigned long new)
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{
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unsigned long prev;
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__asm__ __volatile__ (
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EIEIO_ON_SMP
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"1: ldarx %0,0,%2 # __cmpxchg_u64\n\
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cmpd 0,%0,%3\n\
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bne- 2f\n\
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stdcx. %4,0,%2\n\
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bne- 1b"
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ISYNC_ON_SMP
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"\n\
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2:"
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: "=&r" (prev), "=m" (*p)
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: "r" (p), "r" (old), "r" (new), "m" (*p)
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: "cc", "memory");
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return prev;
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}
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/* This function doesn't exist, so you'll get a linker error
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if something tries to do an invalid cmpxchg(). */
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extern void __cmpxchg_called_with_bad_pointer(void);
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static __inline__ unsigned long
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__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
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unsigned int size)
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{
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switch (size) {
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case 4:
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return __cmpxchg_u32(ptr, old, new);
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case 8:
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return __cmpxchg_u64(ptr, old, new);
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}
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__cmpxchg_called_with_bad_pointer();
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return old;
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}
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#define cmpxchg(ptr,o,n)\
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((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
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(unsigned long)(n),sizeof(*(ptr))))
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/*
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* We handle most unaligned accesses in hardware. On the other hand
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* unaligned DMA can be very expensive on some ppc64 IO chips (it does
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* powers of 2 writes until it reaches sufficient alignment).
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*
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* Based on this we disable the IP header alignment in network drivers.
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*/
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#define NET_IP_ALIGN 0
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#define arch_align_stack(x) (x)
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extern unsigned long reloc_offset(void);
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#endif /* __KERNEL__ */
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#endif
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