/*
* Blackfin architecture-dependent process handling
*
* Copyright 2004-2009 Analog Devices Inc.
*
* Licensed under the GPL-2 or later
*/
#include <linux/module.h>
#include <linux/unistd.h>
#include <linux/user.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/tick.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <asm/blackfin.h>
#include <asm/fixed_code.h>
#include <asm/mem_map.h>
#include <asm/irq.h>
asmlinkage void ret_from_fork(void);
/* Points to the SDRAM backup memory for the stack that is currently in
* L1 scratchpad memory.
*/
void *current_l1_stack_save;
/* The number of tasks currently using a L1 stack area. The SRAM is
* allocated/deallocated whenever this changes from/to zero.
*/
int nr_l1stack_tasks;
/* Start and length of the area in L1 scratchpad memory which we've allocated
* for process stacks.
*/
void *l1_stack_base;
unsigned long l1_stack_len;
void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);
/*
* The idle loop on BFIN
*/
#ifdef CONFIG_IDLE_L1
void arch_cpu_idle(void)__attribute__((l1_text));
#endif
/*
* This is our default idle handler. We need to disable
* interrupts here to ensure we don't miss a wakeup call.
*/
void arch_cpu_idle(void)
{
#ifdef CONFIG_IPIPE
ipipe_suspend_domain();
#endif
hard_local_irq_disable();
if (!need_resched())
idle_with_irq_disabled();
hard_local_irq_enable();
}
#ifdef CONFIG_HOTPLUG_CPU
void arch_cpu_idle_dead(void)
{
cpu_die();
}
#endif
/*
* 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
*/
void start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
{
regs->pc = new_ip;
if (current->mm)
regs->p5 = current->mm->start_data;
#ifndef CONFIG_SMP
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 *)new_sp;
memcpy(L1_SCRATCH_TASK_INFO, &task_thread_info(current)->l1_task_info,
sizeof(*L1_SCRATCH_TASK_INFO));
#endif
wrusp(new_sp);
}
EXPORT_SYMBOL_GPL(start_thread);
void flush_thread(void)
{
}
asmlinkage int bfin_clone(unsigned long clone_flags, unsigned long newsp)
{
#ifdef __ARCH_SYNC_CORE_DCACHE
if (current->nr_cpus_allowed == num_possible_cpus())
set_cpus_allowed_ptr(current, cpumask_of(smp_processor_id()));
#endif
if (newsp)
newsp -= 12;
return do_fork(clone_flags, newsp, 0, NULL, NULL);
}
int
copy_thread(unsigned long clone_flags,
unsigned long usp, unsigned long topstk,
struct task_struct *p)
{
struct pt_regs *childregs;
unsigned long *v;
childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
v = ((unsigned long *)childregs) - 2;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
v[0] = usp;
v[1] = topstk;
childregs->orig_p0 = -1;
childregs->ipend = 0x8000;
__asm__ __volatile__("%0 = syscfg;":"=da"(childregs->syscfg):);
p->thread.usp = 0;
} else {
*childregs = *current_pt_regs();
childregs->r0 = 0;
p->thread.usp = usp ? : rdusp();
v[0] = v[1] = 0;
}
p->thread.ksp = (unsigned long)v;
p->thread.pc = (unsigned long)ret_from_fork;
return 0;
}
unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = (unsigned long)p;
fp = p->thread.usp;
do {
if (fp < stack_page + sizeof(struct thread_info) ||
fp >= 8184 + stack_page)
return 0;
pc = ((unsigned long *)fp)[1];
if (!in_sched_functions(pc))
return pc;
fp = *(unsigned long *)fp;
}
while (count++ < 16);
return 0;
}
void finish_atomic_sections (struct pt_regs *regs)
{
int __user *up0 = (int __user *)regs->p0;
switch (regs->pc) {
default:
/* not in middle of an atomic step, so resume like normal */
return;
case ATOMIC_XCHG32 + 2:
put_user(regs->r1, up0);
break;
case ATOMIC_CAS32 + 2:
case ATOMIC_CAS32 + 4:
if (regs->r0 == regs->r1)
case ATOMIC_CAS32 + 6:
put_user(regs->r2, up0);
break;
case ATOMIC_ADD32 + 2:
regs->r0 = regs->r1 + regs->r0;
/* fall through */
case ATOMIC_ADD32 + 4:
put_user(regs->r0, up0);
break;
case ATOMIC_SUB32 + 2:
regs->r0 = regs->r1 - regs->r0;
/* fall through */
case ATOMIC_SUB32 + 4:
put_user(regs->r0, up0);
break;
case ATOMIC_IOR32 + 2:
regs->r0 = regs->r1 | regs->r0;
/* fall through */
case ATOMIC_IOR32 + 4:
put_user(regs->r0, up0);
break;
case ATOMIC_AND32 + 2:
regs->r0 = regs->r1 & regs->r0;
/* fall through */
case ATOMIC_AND32 + 4:
put_user(regs->r0, up0);
break;
case ATOMIC_XOR32 + 2:
regs->r0 = regs->r1 ^ regs->r0;
/* fall through */
case ATOMIC_XOR32 + 4:
put_user(regs->r0, up0);
break;
}
/*
* We've finished the atomic section, and the only thing left for
* userspace is to do a RTS, so we might as well handle that too
* since we need to update the PC anyways.
*/
regs->pc = regs->rets;
}
static inline
int in_mem(unsigned long addr, unsigned long size,
unsigned long start, unsigned long end)
{
return addr >= start && addr + size <= end;
}
static inline
int in_mem_const_off(unsigned long addr, unsigned long size, unsigned long off,
unsigned long const_addr, unsigned long const_size)
{
return const_size &&
in_mem(addr, size, const_addr + off, const_addr + const_size);
}
static inline
int in_mem_const(unsigned long addr, unsigned long size,
unsigned long const_addr, unsigned long const_size)
{
return in_mem_const_off(addr, size, 0, const_addr, const_size);
}
#ifdef CONFIG_BF60x
#define ASYNC_ENABLED(bnum, bctlnum) 1
#else
#define ASYNC_ENABLED(bnum, bctlnum) \
({ \
(bfin_read_EBIU_AMGCTL() & 0xe) < ((bnum + 1) << 1) ? 0 : \
bfin_read_EBIU_AMBCTL##bctlnum() & B##bnum##RDYEN ? 0 : \
1; \
})
#endif
/*
* We can't read EBIU banks that aren't enabled or we end up hanging
* on the access to the async space. Make sure we validate accesses
* that cross async banks too.
* 0 - found, but unusable
* 1 - found & usable
* 2 - not found
*/
static
int in_async(unsigned long addr, unsigned long size)
{
if (addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE) {
if (!ASYNC_ENABLED(0, 0))
return 0;
if (addr + size <= ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE)
return 1;
size -= ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE - addr;
addr = ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE;
}
if (addr >= ASYNC_BANK1_BASE && addr < ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE) {
if (!ASYNC_ENABLED(1, 0))
return 0;
if (addr + size <= ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE)
return 1;
size -= ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE - addr;
addr = ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE;
}
if (addr >= ASYNC_BANK2_BASE && addr < ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE) {
if (!ASYNC_ENABLED(2, 1))
return 0;
if (addr + size <= ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE)
return 1;
size -= ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE - addr;
addr = ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE;
}
if (addr >= ASYNC_BANK3_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE) {
if (ASYNC_ENABLED(3, 1))
return 0;
if (addr + size <= ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE)
return 1;
return 0;
}
/* not within async bounds */
return 2;
}
int bfin_mem_access_type(unsigned long addr, unsigned long size)
{
int cpu = raw_smp_processor_id();
/* Check that things do not wrap around */
if (addr > ULONG_MAX - size)
return -EFAULT;
if (in_mem(addr, size, FIXED_CODE_START, physical_mem_end))
return BFIN_MEM_ACCESS_CORE;
if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH))
return cpu == 0 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA;
if (in_mem_const(addr, size, L1_SCRATCH_START, L1_SCRATCH_LENGTH))
return cpu == 0 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT;
if (in_mem_const(addr, size, L1_DATA_A_START, L1_DATA_A_LENGTH))
return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
if (in_mem_const(addr, size, L1_DATA_B_START, L1_DATA_B_LENGTH))
return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
#ifdef COREB_L1_CODE_START
if (in_mem_const(addr, size, COREB_L1_CODE_START, COREB_L1_CODE_LENGTH))
return cpu == 1 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA;
if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH))
return cpu == 1 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT;
if (in_mem_const(addr, size, COREB_L1_DATA_A_START, COREB_L1_DATA_A_LENGTH))
return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
if (in_mem_const(addr, size, COREB_L1_DATA_B_START, COREB_L1_DATA_B_LENGTH))
return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
#endif
if (in_mem_const(addr, size, L2_START, L2_LENGTH))
return BFIN_MEM_ACCESS_CORE;
if (addr >= SYSMMR_BASE)
return BFIN_MEM_ACCESS_CORE_ONLY;
switch (in_async(addr, size)) {
case 0: return -EFAULT;
case 1: return BFIN_MEM_ACCESS_CORE;
case 2: /* fall through */;
}
if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH))
return BFIN_MEM_ACCESS_CORE;
if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH))
return BFIN_MEM_ACCESS_DMA;
return -EFAULT;
}
#if defined(CONFIG_ACCESS_CHECK)
#ifdef CONFIG_ACCESS_OK_L1
__attribute__((l1_text))
#endif
/* Return 1 if access to memory range is OK, 0 otherwise */
int _access_ok(unsigned long addr, unsigned long size)
{
int aret;
if (size == 0)
return 1;
/* Check that things do not wrap around */
if (addr > ULONG_MAX - size)
return 0;
if (segment_eq(get_fs(), KERNEL_DS))
return 1;
#ifdef CONFIG_MTD_UCLINUX
if (1)
#else
if (0)
#endif
{
if (in_mem(addr, size, memory_start, memory_end))
return 1;
if (in_mem(addr, size, memory_mtd_end, physical_mem_end))
return 1;
# ifndef CONFIG_ROMFS_ON_MTD
if (0)
# endif
/* For XIP, allow user space to use pointers within the ROMFS. */
if (in_mem(addr, size, memory_mtd_start, memory_mtd_end))
return 1;
} else {
if (in_mem(addr, size, memory_start, physical_mem_end))
return 1;
}
if (in_mem(addr, size, (unsigned long)__init_begin, (unsigned long)__init_end))
return 1;
if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH))
return 1;
if (in_mem_const_off(addr, size, _etext_l1 - _stext_l1, L1_CODE_START, L1_CODE_LENGTH))
return 1;
if (in_mem_const_off(addr, size, _ebss_l1 - _sdata_l1, L1_DATA_A_START, L1_DATA_A_LENGTH))
return 1;
if (in_mem_const_off(addr, size, _ebss_b_l1 - _sdata_b_l1, L1_DATA_B_START, L1_DATA_B_LENGTH))
return 1;
#ifdef COREB_L1_CODE_START
if (in_mem_const(addr, size, COREB_L1_CODE_START, COREB_L1_CODE_LENGTH))
return 1;
if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH))
return 1;
if (in_mem_const(addr, size, COREB_L1_DATA_A_START, COREB_L1_DATA_A_LENGTH))
return 1;
if (in_mem_const(addr, size, COREB_L1_DATA_B_START, COREB_L1_DATA_B_LENGTH))
return 1;
#endif
#ifndef CONFIG_EXCEPTION_L1_SCRATCH
if (in_mem_const(addr, size, (unsigned long)l1_stack_base, l1_stack_len))
return 1;
#endif
aret = in_async(addr, size);
if (aret < 2)
return aret;
if (in_mem_const_off(addr, size, _ebss_l2 - _stext_l2, L2_START, L2_LENGTH))
return 1;
if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH))
return 1;
if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH))
return 1;
return 0;
}
EXPORT_SYMBOL(_access_ok);
#endif /* CONFIG_ACCESS_CHECK */
