summaryrefslogtreecommitdiff
path: root/arch/m68k/kernel
diff options
context:
space:
mode:
authorMaxim Kuvyrkov <maxim@codesourcery.com>2009-12-07 00:24:27 -0800
committerGeert Uytterhoeven <geert@linux-m68k.org>2010-02-27 18:31:19 +0100
commit9674cdc74d63f346870943ef966a034f8c71ee57 (patch)
treec590640335983c5b1a7f5c9589478bf90fb68d03 /arch/m68k/kernel
parentf54bcdc2b81558a2b7e624cfeb4992422d9265f9 (diff)
m68k: Add NPTL support
This patch adds several syscalls, that provide necessary functionality to support NPTL on m68k/ColdFire. The syscalls are get_thread_area, set_thread_area, atomic_cmpxchg_32 and atomic_barrier. The cmpxchg syscall is required for ColdFire as it doesn't support 'cas' instruction. Also a ptrace call PTRACE_GET_THREAD_AREA is added to allow debugger to inspect the TLS storage. Signed-off-by: Maxim Kuvyrkov <maxim@codesourcery.com> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k/kernel')
-rw-r--r--arch/m68k/kernel/entry.S4
-rw-r--r--arch/m68k/kernel/process.c4
-rw-r--r--arch/m68k/kernel/ptrace.c5
-rw-r--r--arch/m68k/kernel/sys_m68k.c81
4 files changed, 94 insertions, 0 deletions
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 77fc7c16bf48..e136b8cbe9b9 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -761,4 +761,8 @@ sys_call_table:
.long sys_pwritev /* 330 */
.long sys_rt_tgsigqueueinfo
.long sys_perf_event_open
+ .long sys_get_thread_area
+ .long sys_set_thread_area
+ .long sys_atomic_cmpxchg_32 /* 335 */
+ .long sys_atomic_barrier
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index 05296593e718..17c3f325255d 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -251,6 +251,10 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
p->thread.usp = usp;
p->thread.ksp = (unsigned long)childstack;
+
+ if (clone_flags & CLONE_SETTLS)
+ task_thread_info(p)->tp_value = regs->d5;
+
/*
* Must save the current SFC/DFC value, NOT the value when
* the parent was last descheduled - RGH 10-08-96
diff --git a/arch/m68k/kernel/ptrace.c b/arch/m68k/kernel/ptrace.c
index 1fc217e5f06b..616e59752c29 100644
--- a/arch/m68k/kernel/ptrace.c
+++ b/arch/m68k/kernel/ptrace.c
@@ -245,6 +245,11 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
ret = -EFAULT;
break;
+ case PTRACE_GET_THREAD_AREA:
+ ret = put_user(task_thread_info(child)->tp_value,
+ (unsigned long __user *)data);
+ break;
+
default:
ret = ptrace_request(child, request, addr, data);
break;
diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c
index 218f441de667..e3ad2d671973 100644
--- a/arch/m68k/kernel/sys_m68k.c
+++ b/arch/m68k/kernel/sys_m68k.c
@@ -28,6 +28,11 @@
#include <asm/traps.h>
#include <asm/page.h>
#include <asm/unistd.h>
+#include <linux/elf.h>
+#include <asm/tlb.h>
+
+asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
+ unsigned long error_code);
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
@@ -595,3 +600,79 @@ int kernel_execve(const char *filename, char *const argv[], char *const envp[])
: "d" (__a), "d" (__b), "d" (__c));
return __res;
}
+
+asmlinkage unsigned long sys_get_thread_area(void)
+{
+ return current_thread_info()->tp_value;
+}
+
+asmlinkage int sys_set_thread_area(unsigned long tp)
+{
+ current_thread_info()->tp_value = tp;
+ return 0;
+}
+
+/* This syscall gets its arguments in A0 (mem), D2 (oldval) and
+ D1 (newval). */
+asmlinkage int
+sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
+ unsigned long __user * mem)
+{
+ /* This was borrowed from ARM's implementation. */
+ for (;;) {
+ struct mm_struct *mm = current->mm;
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pte_t *pte;
+ spinlock_t *ptl;
+ unsigned long mem_value;
+
+ down_read(&mm->mmap_sem);
+ pgd = pgd_offset(mm, (unsigned long)mem);
+ if (!pgd_present(*pgd))
+ goto bad_access;
+ pmd = pmd_offset(pgd, (unsigned long)mem);
+ if (!pmd_present(*pmd))
+ goto bad_access;
+ pte = pte_offset_map_lock(mm, pmd, (unsigned long)mem, &ptl);
+ if (!pte_present(*pte) || !pte_dirty(*pte)
+ || !pte_write(*pte)) {
+ pte_unmap_unlock(pte, ptl);
+ goto bad_access;
+ }
+
+ mem_value = *mem;
+ if (mem_value == oldval)
+ *mem = newval;
+
+ pte_unmap_unlock(pte, ptl);
+ up_read(&mm->mmap_sem);
+ return mem_value;
+
+ bad_access:
+ up_read(&mm->mmap_sem);
+ /* This is not necessarily a bad access, we can get here if
+ a memory we're trying to write to should be copied-on-write.
+ Make the kernel do the necessary page stuff, then re-iterate.
+ Simulate a write access fault to do that. */
+ {
+ /* The first argument of the function corresponds to
+ D1, which is the first field of struct pt_regs. */
+ struct pt_regs *fp = (struct pt_regs *)&newval;
+
+ /* '3' is an RMW flag. */
+ if (do_page_fault(fp, (unsigned long)mem, 3))
+ /* If the do_page_fault() failed, we don't
+ have anything meaningful to return.
+ There should be a SIGSEGV pending for
+ the process. */
+ return 0xdeadbeef;
+ }
+ }
+}
+
+asmlinkage int sys_atomic_barrier(void)
+{
+ /* no code needed for uniprocs */
+ return 0;
+}