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/*
* 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 - 2008 Tensilica Inc.
* Copyright (C) 2015 Cadence Design Systems Inc.
*/
#ifndef _XTENSA_PROCESSOR_H
#define _XTENSA_PROCESSOR_H
#include <asm/core.h>
#include <linux/compiler.h>
#include <linux/stringify.h>
#include <asm/ptrace.h>
#include <asm/types.h>
#include <asm/regs.h>
#define ARCH_SLAB_MINALIGN XTENSA_STACK_ALIGNMENT
/*
* 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.
*/
#ifdef CONFIG_MMU
#define TASK_SIZE __XTENSA_UL_CONST(0x40000000)
#else
#define TASK_SIZE __XTENSA_UL_CONST(0xffffffff)
#endif
#define STACK_TOP TASK_SIZE
#define STACK_TOP_MAX STACK_TOP
/*
* General exception cause assigned to fake NMI. Fake NMI needs to be handled
* differently from other interrupts, but it uses common kernel entry/exit
* code.
*/
#define EXCCAUSE_MAPPED_NMI 62
/*
* 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
#define XTENSA_INT_LEVEL(intno) _XTENSA_INT_LEVEL(intno)
#define _XTENSA_INT_LEVEL(intno) XCHAL_INT##intno##_LEVEL
#define XTENSA_INTLEVEL_MASK(level) _XTENSA_INTLEVEL_MASK(level)
#define _XTENSA_INTLEVEL_MASK(level) (XCHAL_INTLEVEL##level##_MASK)
#define XTENSA_INTLEVEL_ANDBELOW_MASK(l) _XTENSA_INTLEVEL_ANDBELOW_MASK(l)
#define _XTENSA_INTLEVEL_ANDBELOW_MASK(l) (XCHAL_INTLEVEL##l##_ANDBELOW_MASK)
#define PROFILING_INTLEVEL XTENSA_INT_LEVEL(XCHAL_PROFILING_INTERRUPT)
/* LOCKLEVEL defines the interrupt level that masks all
* general-purpose interrupts.
*/
#if defined(CONFIG_XTENSA_FAKE_NMI) && defined(XCHAL_PROFILING_INTERRUPT)
#define LOCKLEVEL (PROFILING_INTLEVEL - 1)
#else
#define LOCKLEVEL XCHAL_EXCM_LEVEL
#endif
#define TOPLEVEL XCHAL_EXCM_LEVEL
#define XTENSA_FAKE_NMI (LOCKLEVEL < TOPLEVEL)
/* 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 */
#if defined(__XTENSA_WINDOWED_ABI__)
#define KERNEL_PS_WOE_MASK PS_WOE_MASK
#elif defined(__XTENSA_CALL0_ABI__)
#define KERNEL_PS_WOE_MASK 0
#else
#error Unsupported xtensa ABI
#endif
#ifndef __ASSEMBLY__
#if defined(__XTENSA_WINDOWED_ABI__)
/* 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))
#elif defined(__XTENSA_CALL0_ABI__)
/* 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)
/* 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)
#else
#error Unsupported Xtensa ABI
#endif
/* Spill slot location for the register reg in the spill area under the stack
* pointer sp. reg must be in the range [0..4).
*/
#define SPILL_SLOT(sp, reg) (*(((unsigned long *)(sp)) - 4 + (reg)))
/* Spill slot location for the register reg in the spill area under the stack
* pointer sp for the call8. reg must be in the range [4..8).
*/
#define SPILL_SLOT_CALL8(sp, reg) (*(((unsigned long *)(sp)) - 12 + (reg)))
/* Spill slot location for the register reg in the spill area under the stack
* pointer sp for the call12. reg must be in the range [4..12).
*/
#define SPILL_SLOT_CALL12(sp, reg) (*(((unsigned long *)(sp)) - 16 + (reg)))
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 */
#ifdef CONFIG_HAVE_HW_BREAKPOINT
struct perf_event *ptrace_bp[XCHAL_NUM_IBREAK];
struct perf_event *ptrace_wp[XCHAL_NUM_DBREAK];
#endif
/* Make structure 16 bytes aligned. */
int align[0] __attribute__ ((aligned(16)));
};
/* 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, \
}
/*
* Do necessary setup to start up a newly executed thread.
* Note: When windowed ABI is used for userspace we set-up ps
* as if we did a call4 to the new pc.
* set_thread_state in signal.c depends on it.
*/
#if IS_ENABLED(CONFIG_USER_ABI_CALL0)
#define USER_PS_VALUE ((USER_RING << PS_RING_SHIFT) | \
(1 << PS_UM_BIT) | \
(1 << PS_EXCM_BIT))
#else
#define USER_PS_VALUE (PS_WOE_MASK | \
(1 << PS_CALLINC_SHIFT) | \
(USER_RING << PS_RING_SHIFT) | \
(1 << PS_UM_BIT) | \
(1 << PS_EXCM_BIT))
#endif
/* Clearing a0 terminates the backtrace. */
#define start_thread(regs, new_pc, new_sp) \
do { \
unsigned long syscall = (regs)->syscall; \
unsigned long current_aregs[16]; \
memcpy(current_aregs, (regs)->areg, sizeof(current_aregs)); \
memset((regs), 0, sizeof(*(regs))); \
(regs)->pc = (new_pc); \
(regs)->ps = USER_PS_VALUE; \
memcpy((regs)->areg, current_aregs, sizeof(current_aregs)); \
(regs)->areg[1] = (new_sp); \
(regs)->areg[0] = 0; \
(regs)->wmask = 1; \
(regs)->depc = 0; \
(regs)->windowbase = 0; \
(regs)->windowstart = 1; \
(regs)->syscall = syscall; \
} while (0)
/* Forward declaration */
struct task_struct;
struct mm_struct;
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)->areg[1])
#define cpu_relax() barrier()
/* Special register access. */
#define xtensa_set_sr(x, sr) \
({ \
__asm__ __volatile__ ("wsr %0, "__stringify(sr) :: \
"a"((unsigned int)(x))); \
})
#define xtensa_get_sr(sr) \
({ \
unsigned int v; \
__asm__ __volatile__ ("rsr %0, "__stringify(sr) : "=a"(v)); \
v; \
})
#define xtensa_xsr(x, sr) \
({ \
unsigned int __v__ = (unsigned int)(x); \
__asm__ __volatile__ ("xsr %0, " __stringify(sr) : "+a"(__v__)); \
__v__; \
})
#if XCHAL_HAVE_EXTERN_REGS
static inline void set_er(unsigned long value, unsigned long addr)
{
asm volatile ("wer %0, %1" : : "a" (value), "a" (addr) : "memory");
}
static inline unsigned long get_er(unsigned long addr)
{
register unsigned long value;
asm volatile ("rer %0, %1" : "=a" (value) : "a" (addr) : "memory");
return value;
}
#endif /* XCHAL_HAVE_EXTERN_REGS */
#endif /* __ASSEMBLY__ */
#endif /* _XTENSA_PROCESSOR_H */
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