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xtensa: clean up exception handling structure 

Instead of using flat array of longs use normal C structure and generate
EXC_TABLE_* constants in the asm-offsets.c

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
hifive-unleashed-5.1
Max Filippov 2017-12-15 16:08:16 -08:00
parent c130d3be84
commit f21a79cab3
5 changed files with 56 additions and 32 deletions
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12
arch/xtensa/include/asm/ptrace.h
View File

@ -39,18 +39,6 @@
* +-----------------------+ --------
*/
/* Offsets for exception_handlers[] (3 x 64-entries x 4-byte tables). */
#define EXC_TABLE_KSTK 0x004 /* Kernel Stack */
#define EXC_TABLE_DOUBLE_SAVE 0x008 /* Double exception save area for a0 */
#define EXC_TABLE_FIXUP 0x00c /* Fixup handler */
#define EXC_TABLE_PARAM 0x010 /* For passing a parameter to fixup */
#define EXC_TABLE_SYSCALL_SAVE 0x014 /* For fast syscall handler */
#define EXC_TABLE_FAST_USER 0x100 /* Fast user exception handler */
#define EXC_TABLE_FAST_KERNEL 0x200 /* Fast kernel exception handler */
#define EXC_TABLE_DEFAULT 0x300 /* Default C-Handler */
#define EXC_TABLE_SIZE 0x400
#ifndef __ASSEMBLY__
#include <asm/coprocessor.h>

1
arch/xtensa/include/asm/regs.h
View File

@ -76,6 +76,7 @@
#define EXCCAUSE_COPROCESSOR5_DISABLED 37
#define EXCCAUSE_COPROCESSOR6_DISABLED 38
#define EXCCAUSE_COPROCESSOR7_DISABLED 39
#define EXCCAUSE_N 64
/* PS register fields. */

23
arch/xtensa/include/asm/traps.h
View File

@ -12,6 +12,29 @@
#include <asm/ptrace.h>
/*
* Per-CPU exception handling data structure.
* EXCSAVE1 points to it.
*/
struct exc_table {
/* Kernel Stack */
void *kstk;
/* Double exception save area for a0 */
unsigned long double_save;
/* Fixup handler */
void *fixup;
/* For passing a parameter to fixup */
void *fixup_param;
/* For fast syscall handler */
unsigned long syscall_save;
/* Fast user exception handlers */
void *fast_user_handler[EXCCAUSE_N];
/* Fast kernel exception handlers */
void *fast_kernel_handler[EXCCAUSE_N];
/* Default C-Handlers */
void *default_handler[EXCCAUSE_N];
};
/*
* handler must be either of the following:
* void (*)(struct pt_regs *regs);

13
arch/xtensa/kernel/asm-offsets.c
View File

@ -132,5 +132,18 @@ int main(void)
offsetof(struct debug_table, icount_level_save));
#endif
/* struct exc_table */
DEFINE(EXC_TABLE_KSTK, offsetof(struct exc_table, kstk));
DEFINE(EXC_TABLE_DOUBLE_SAVE, offsetof(struct exc_table, double_save));
DEFINE(EXC_TABLE_FIXUP, offsetof(struct exc_table, fixup));
DEFINE(EXC_TABLE_PARAM, offsetof(struct exc_table, fixup_param));
DEFINE(EXC_TABLE_SYSCALL_SAVE,
offsetof(struct exc_table, syscall_save));
DEFINE(EXC_TABLE_FAST_USER,
offsetof(struct exc_table, fast_user_handler));
DEFINE(EXC_TABLE_FAST_KERNEL,
offsetof(struct exc_table, fast_kernel_handler));
DEFINE(EXC_TABLE_DEFAULT, offsetof(struct exc_table, default_handler));
return 0;
}

39
arch/xtensa/kernel/traps.c
View File

@ -159,8 +159,7 @@ COPROCESSOR(7),
* 2. it is a temporary memory buffer for the exception handlers.
*/
DEFINE_PER_CPU(unsigned long, exc_table[EXC_TABLE_SIZE/4]);
DEFINE_PER_CPU(struct exc_table, exc_table);
DEFINE_PER_CPU(struct debug_table, debug_table);
void die(const char*, struct pt_regs*, long);
@ -368,28 +367,28 @@ do_debug(struct pt_regs *regs)
}
static void set_handler(int idx, void *handler)
{
unsigned int cpu;
for_each_possible_cpu(cpu)
per_cpu(exc_table, cpu)[idx] = (unsigned long)handler;
}
#define set_handler(type, cause, handler) \
do { \
unsigned int cpu; \
\
for_each_possible_cpu(cpu) \
per_cpu(exc_table, cpu).type[cause] = (handler);\
} while (0)
/* Set exception C handler - for temporary use when probing exceptions */
void * __init trap_set_handler(int cause, void *handler)
{
void *previous = (void *)per_cpu(exc_table, 0)[
EXC_TABLE_DEFAULT / 4 + cause];
set_handler(EXC_TABLE_DEFAULT / 4 + cause, handler);
void *previous = per_cpu(exc_table, 0).default_handler[cause];
set_handler(default_handler, cause, handler);
return previous;
}
static void trap_init_excsave(void)
{
unsigned long excsave1 = (unsigned long)this_cpu_ptr(exc_table);
unsigned long excsave1 = (unsigned long)this_cpu_ptr(&exc_table);
__asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1));
}
@ -421,10 +420,10 @@ void __init trap_init(void)
/* Setup default vectors. */
for(i = 0; i < 64; i++) {
set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception);
set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception);
set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled);
for (i = 0; i < EXCCAUSE_N; i++) {
set_handler(fast_user_handler, i, user_exception);
set_handler(fast_kernel_handler, i, kernel_exception);
set_handler(default_handler, i, do_unhandled);
}
/* Setup specific handlers. */
@ -436,11 +435,11 @@ void __init trap_init(void)
void *handler = dispatch_init_table[i].handler;
if (fast == 0)
set_handler (EXC_TABLE_DEFAULT/4 + cause, handler);
set_handler(default_handler, cause, handler);
if (fast && fast & USER)
set_handler (EXC_TABLE_FAST_USER/4 + cause, handler);
set_handler(fast_user_handler, cause, handler);
if (fast && fast & KRNL)
set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler);
set_handler(fast_kernel_handler, cause, handler);
}
/* Initialize EXCSAVE_1 to hold the address of the exception table. */