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authorPaul Mundt <lethal@linux-sh.org>2007-11-28 14:19:38 +0300
committerPaul Mundt <lethal@linux-sh.org>2008-01-28 07:18:58 +0300
commita23ba43573a24c351640bc19c06c701798fe6e25 (patch)
treeb0d1481379ebe4d4345b7358ddffe16cf6d5c6f6 /arch/sh/kernel/process_64.c
parent4b27c47cf8eddb4153a026e89c7b092598c98b12 (diff)
downloadlinux-a23ba43573a24c351640bc19c06c701798fe6e25.tar.xz
sh: comment tidying for sh64->sh migration.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/kernel/process_64.c')
-rw-r--r--arch/sh/kernel/process_64.c29
1 files changed, 16 insertions, 13 deletions
diff --git a/arch/sh/kernel/process_64.c b/arch/sh/kernel/process_64.c
index 973dd1a3d292..cff3b7dc9c56 100644
--- a/arch/sh/kernel/process_64.c
+++ b/arch/sh/kernel/process_64.c
@@ -421,19 +421,22 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
*/
void exit_thread(void)
{
- /* See arch/sparc/kernel/process.c for the precedent for doing this -- RPC.
-
- The SH-5 FPU save/restore approach relies on last_task_used_math
- pointing to a live task_struct. When another task tries to use the
- FPU for the 1st time, the FPUDIS trap handling (see
- arch/sh64/kernel/fpu.c) will save the existing FPU state to the
- FP regs field within last_task_used_math before re-loading the new
- task's FPU state (or initialising it if the FPU has been used
- before). So if last_task_used_math is stale, and its page has already been
- re-allocated for another use, the consequences are rather grim. Unless we
- null it here, there is no other path through which it would get safely
- nulled. */
-
+ /*
+ * See arch/sparc/kernel/process.c for the precedent for doing
+ * this -- RPC.
+ *
+ * The SH-5 FPU save/restore approach relies on
+ * last_task_used_math pointing to a live task_struct. When
+ * another task tries to use the FPU for the 1st time, the FPUDIS
+ * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
+ * existing FPU state to the FP regs field within
+ * last_task_used_math before re-loading the new task's FPU state
+ * (or initialising it if the FPU has been used before). So if
+ * last_task_used_math is stale, and its page has already been
+ * re-allocated for another use, the consequences are rather
+ * grim. Unless we null it here, there is no other path through
+ * which it would get safely nulled.
+ */
#ifdef CONFIG_SH_FPU
if (last_task_used_math == current) {
last_task_used_math = NULL;