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authorAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
committerAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
commitb4b6116a13633898cf868f2f103c96a90c4c20f8 (patch)
tree93d1b7e2cfcdf473d8d4ff3ad141fa864f8491f6 /arch/blackfin/kernel/process.c
parentedd4be777c953e5faafc80d091d3084b4343f5d3 (diff)
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fedora kernel: d9aad82f3319f3cfd1aebc01234254ef0c37ad84v3.3.2-1
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/blackfin/kernel/process.c')
-rw-r--r--arch/blackfin/kernel/process.c514
1 files changed, 514 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c
new file mode 100644
index 00000000000..8dd0416673c
--- /dev/null
+++ b/arch/blackfin/kernel/process.c
@@ -0,0 +1,514 @@
+/*
+ * 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>
+
+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;
+
+/*
+ * Powermanagement idle function, if any..
+ */
+void (*pm_idle)(void) = NULL;
+EXPORT_SYMBOL(pm_idle);
+
+void (*pm_power_off)(void) = NULL;
+EXPORT_SYMBOL(pm_power_off);
+
+/*
+ * The idle loop on BFIN
+ */
+#ifdef CONFIG_IDLE_L1
+static void default_idle(void)__attribute__((l1_text));
+void 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.
+ */
+static void default_idle(void)
+{
+#ifdef CONFIG_IPIPE
+ ipipe_suspend_domain();
+#endif
+ hard_local_irq_disable();
+ if (!need_resched())
+ idle_with_irq_disabled();
+
+ hard_local_irq_enable();
+}
+
+/*
+ * The idle thread. We try to conserve power, while trying to keep
+ * overall latency low. The architecture specific idle is passed
+ * a value to indicate the level of "idleness" of the system.
+ */
+void cpu_idle(void)
+{
+ /* endless idle loop with no priority at all */
+ while (1) {
+ void (*idle)(void) = pm_idle;
+
+#ifdef CONFIG_HOTPLUG_CPU
+ if (cpu_is_offline(smp_processor_id()))
+ cpu_die();
+#endif
+ if (!idle)
+ idle = default_idle;
+ tick_nohz_idle_enter();
+ rcu_idle_enter();
+ while (!need_resched())
+ idle();
+ rcu_idle_exit();
+ tick_nohz_idle_exit();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
+}
+
+/*
+ * This gets run with P1 containing the
+ * function to call, and R1 containing
+ * the "args". Note P0 is clobbered on the way here.
+ */
+void kernel_thread_helper(void);
+__asm__(".section .text\n"
+ ".align 4\n"
+ "_kernel_thread_helper:\n\t"
+ "\tsp += -12;\n\t"
+ "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
+
+/*
+ * Create a kernel thread.
+ */
+pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
+{
+ struct pt_regs regs;
+
+ memset(&regs, 0, sizeof(regs));
+
+ regs.r1 = (unsigned long)arg;
+ regs.p1 = (unsigned long)fn;
+ regs.pc = (unsigned long)kernel_thread_helper;
+ regs.orig_p0 = -1;
+ /* Set bit 2 to tell ret_from_fork we should be returning to kernel
+ mode. */
+ regs.ipend = 0x8002;
+ __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
+ return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
+ NULL);
+}
+EXPORT_SYMBOL(kernel_thread);
+
+/*
+ * 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_vfork(struct pt_regs *regs)
+{
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
+ NULL);
+}
+
+asmlinkage int bfin_clone(struct pt_regs *regs)
+{
+ unsigned long clone_flags;
+ unsigned long newsp;
+
+#ifdef __ARCH_SYNC_CORE_DCACHE
+ if (current->rt.nr_cpus_allowed == num_possible_cpus())
+ set_cpus_allowed_ptr(current, cpumask_of(smp_processor_id()));
+#endif
+
+ /* syscall2 puts clone_flags in r0 and usp in r1 */
+ clone_flags = regs->r0;
+ newsp = regs->r1;
+ if (!newsp)
+ newsp = rdusp();
+ else
+ newsp -= 12;
+ return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
+}
+
+int
+copy_thread(unsigned long clone_flags,
+ unsigned long usp, unsigned long topstk,
+ struct task_struct *p, struct pt_regs *regs)
+{
+ struct pt_regs *childregs;
+
+ childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
+ *childregs = *regs;
+ childregs->r0 = 0;
+
+ p->thread.usp = usp;
+ p->thread.ksp = (unsigned long)childregs;
+ p->thread.pc = (unsigned long)ret_from_fork;
+
+ return 0;
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+asmlinkage int sys_execve(const char __user *name,
+ const char __user *const __user *argv,
+ const char __user *const __user *envp)
+{
+ int error;
+ char *filename;
+ struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
+
+ filename = getname(name);
+ error = PTR_ERR(filename);
+ if (IS_ERR(filename))
+ return error;
+ error = do_execve(filename, argv, envp, regs);
+ putname(filename);
+ return error;
+}
+
+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);
+}
+#define ASYNC_ENABLED(bnum, bctlnum) \
+({ \
+ (bfin_read_EBIU_AMGCTL() & 0xe) < ((bnum + 1) << 1) ? 0 : \
+ bfin_read_EBIU_AMBCTL##bctlnum() & B##bnum##RDYEN ? 0 : \
+ 1; \
+})
+/*
+ * 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 */