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authorDaniel Vetter <daniel.vetter@ffwll.ch>2015-08-06 15:27:09 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2015-08-06 15:27:09 +0300
commit06059d5090118b047c5b6a621c8b57a068f7ce2c (patch)
tree47431df1c04c02dfb7ecea479321142c56ad17cc /arch/x86/kernel/fpu/init.c
parent80aa93128653c5f2502053c0d9740b336d975667 (diff)
parent8c10342cb48f3140d9abeadcfd2fa6625d447282 (diff)
downloadlinux-06059d5090118b047c5b6a621c8b57a068f7ce2c.tar.xz
Merge tag 'topic/drm-misc-2015-07-28' into drm-intel-next-queued
We need a few core drm patches to be able to merge Maarten's series to convert DPMS over to atomic. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to 'arch/x86/kernel/fpu/init.c')
-rw-r--r--arch/x86/kernel/fpu/init.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 32826791e675..0b39173dd971 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -4,6 +4,8 @@
#include <asm/fpu/internal.h>
#include <asm/tlbflush.h>
+#include <linux/sched.h>
+
/*
* Initialize the TS bit in CR0 according to the style of context-switches
* we are using:
@@ -136,6 +138,43 @@ static void __init fpu__init_system_generic(void)
unsigned int xstate_size;
EXPORT_SYMBOL_GPL(xstate_size);
+/* Enforce that 'MEMBER' is the last field of 'TYPE': */
+#define CHECK_MEMBER_AT_END_OF(TYPE, MEMBER) \
+ BUILD_BUG_ON(sizeof(TYPE) != offsetofend(TYPE, MEMBER))
+
+/*
+ * We append the 'struct fpu' to the task_struct:
+ */
+static void __init fpu__init_task_struct_size(void)
+{
+ int task_size = sizeof(struct task_struct);
+
+ /*
+ * Subtract off the static size of the register state.
+ * It potentially has a bunch of padding.
+ */
+ task_size -= sizeof(((struct task_struct *)0)->thread.fpu.state);
+
+ /*
+ * Add back the dynamically-calculated register state
+ * size.
+ */
+ task_size += xstate_size;
+
+ /*
+ * We dynamically size 'struct fpu', so we require that
+ * it be at the end of 'thread_struct' and that
+ * 'thread_struct' be at the end of 'task_struct'. If
+ * you hit a compile error here, check the structure to
+ * see if something got added to the end.
+ */
+ CHECK_MEMBER_AT_END_OF(struct fpu, state);
+ CHECK_MEMBER_AT_END_OF(struct thread_struct, fpu);
+ CHECK_MEMBER_AT_END_OF(struct task_struct, thread);
+
+ arch_task_struct_size = task_size;
+}
+
/*
* Set up the xstate_size based on the legacy FPU context size.
*
@@ -287,6 +326,7 @@ void __init fpu__init_system(struct cpuinfo_x86 *c)
fpu__init_system_generic();
fpu__init_system_xstate_size_legacy();
fpu__init_system_xstate();
+ fpu__init_task_struct_size();
fpu__init_system_ctx_switch();
}