android_kernel_xiaomi_sm8350/include/asm-blackfin/processor.h
Bernd Schmidt d5adb029ef [Blackfin] arch: This allows XIP to work with FD-PIC.
Previously, init failed to do anything meaningful;
it turns out that the reason is that FD-PIC has a readonly data
section which can be located in the XIP filesystem, and various address checks
in the kernel reject such addresses for syscall arguments.  Hence, init's
  execve ("/bin/sh", ...)
failed with error code EFAULT.

There's room for improvement here: in case people want to have filesystems
on flash rather than in main memory, _access_ok should be modified to
allow this.

This bug fix is also dedicated to Michael Hennerich.

Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
2008-04-24 03:06:15 +08:00

140 lines
3.3 KiB
C

#ifndef __ASM_BFIN_PROCESSOR_H
#define __ASM_BFIN_PROCESSOR_H
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() ({ __label__ _l; _l: &&_l;})
#include <asm/blackfin.h>
#include <asm/segment.h>
#include <linux/compiler.h>
static inline unsigned long rdusp(void)
{
unsigned long usp;
__asm__ __volatile__("%0 = usp;\n\t":"=da"(usp));
return usp;
}
static inline void wrusp(unsigned long usp)
{
__asm__ __volatile__("usp = %0;\n\t"::"da"(usp));
}
/*
* User space process size: 1st byte beyond user address space.
* Fairly meaningless on nommu. Parts of user programs can be scattered
* in a lot of places, so just disable this by setting it to 0xFFFFFFFF.
*/
#define TASK_SIZE 0xFFFFFFFF
#ifdef __KERNEL__
#define STACK_TOP TASK_SIZE
#endif
#define TASK_UNMAPPED_BASE 0
struct thread_struct {
unsigned long ksp; /* kernel stack pointer */
unsigned long usp; /* user stack pointer */
unsigned short seqstat; /* saved status register */
unsigned long esp0; /* points to SR of stack frame pt_regs */
unsigned long pc; /* instruction pointer */
void * debuggerinfo;
};
#define INIT_THREAD { \
sizeof(init_stack) + (unsigned long) init_stack, 0, \
PS_S, 0, 0 \
}
/*
* Do necessary setup to start up a newly executed thread.
*
* pass the data segment into user programs if it exists,
* it can't hurt anything as far as I can tell
*/
#define start_thread(_regs, _pc, _usp) \
do { \
set_fs(USER_DS); \
(_regs)->pc = (_pc); \
if (current->mm) \
(_regs)->p5 = current->mm->start_data; \
task_thread_info(current)->l1_task_info.stack_start \
= (void *)current->mm->context.stack_start; \
task_thread_info(current)->l1_task_info.lowest_sp = (void *)(_usp); \
memcpy(L1_SCRATCH_TASK_INFO, &task_thread_info(current)->l1_task_info, \
sizeof(*L1_SCRATCH_TASK_INFO)); \
wrusp(_usp); \
} while(0)
/* Forward declaration, a strange C thing */
struct task_struct;
/* Free all resources held by a thread. */
static inline void release_thread(struct task_struct *dead_task)
{
}
#define prepare_to_copy(tsk) do { } while (0)
extern int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags);
/*
* Free current thread data structures etc..
*/
static inline void exit_thread(void)
{
}
/*
* Return saved PC of a blocked thread.
*/
#define thread_saved_pc(tsk) (tsk->thread.pc)
unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) \
({ \
unsigned long eip = 0; \
if ((tsk)->thread.esp0 > PAGE_SIZE && \
MAP_NR((tsk)->thread.esp0) < max_mapnr) \
eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
eip; })
#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
#define cpu_relax() barrier()
/* Get the Silicon Revision of the chip */
static inline uint32_t __pure bfin_revid(void)
{
/* stored in the upper 4 bits */
return bfin_read_CHIPID() >> 28;
}
static inline uint32_t __pure bfin_compiled_revid(void)
{
#if defined(CONFIG_BF_REV_0_0)
return 0;
#elif defined(CONFIG_BF_REV_0_1)
return 1;
#elif defined(CONFIG_BF_REV_0_2)
return 2;
#elif defined(CONFIG_BF_REV_0_3)
return 3;
#elif defined(CONFIG_BF_REV_0_4)
return 4;
#elif defined(CONFIG_BF_REV_0_5)
return 5;
#elif defined(CONFIG_BF_REV_ANY)
return 0xffff;
#else
return -1;
#endif
}
#endif