xstate_enable_boot_cpu() is, as the name implies, only used on the
boot CPU; furthermore, it invokes alloc_bootmem(), which is __init;
hence it needs to be tagged __init rather than __cpuinit.
Furthermore, it is *not* safe in the long run to rely on CPU 0 only
coming online during the early boot -- at some point we're going to
support offlining (and re-onlining) the boot CPU, and at that point we
must not call xstate_enable_boot_cpu() again.
The code is a fair bit more obscure than one would like, because the
__ref overrides aren't quite powerful enough.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <
4C476236.
1020302@zytor.com>
/*
* Enable the extended processor state save/restore feature
*/
/*
* Enable the extended processor state save/restore feature
*/
-static inline void xstate_enable(u64 mask)
+static inline void xstate_enable(void)
{
set_in_cr4(X86_CR4_OSXSAVE);
{
set_in_cr4(X86_CR4_OSXSAVE);
- xsetbv(XCR_XFEATURE_ENABLED_MASK, mask);
+ xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);
/*
* Enable and initialize the xsave feature.
*/
/*
* Enable and initialize the xsave feature.
*/
-static void __cpuinit xstate_enable_boot_cpu(void)
+static void __init xstate_enable_boot_cpu(void)
{
unsigned int eax, ebx, ecx, edx;
{
unsigned int eax, ebx, ecx, edx;
*/
pcntxt_mask = pcntxt_mask & XCNTXT_MASK;
*/
pcntxt_mask = pcntxt_mask & XCNTXT_MASK;
- xstate_enable(pcntxt_mask);
/*
* Recompute the context size for enabled features
/*
* Recompute the context size for enabled features
pcntxt_mask, xstate_size);
}
pcntxt_mask, xstate_size);
}
+/*
+ * For the very first instance, this calls xstate_enable_boot_cpu();
+ * for all subsequent instances, this calls xstate_enable().
+ *
+ * This is somewhat obfuscated due to the lack of powerful enough
+ * overrides for the section checks.
+ */
void __cpuinit xsave_init(void)
{
void __cpuinit xsave_init(void)
{
+ static __refdata void (*next_func)(void) = xstate_enable_boot_cpu;
+ void (*this_func)(void);
+
if (!cpu_has_xsave)
return;
if (!cpu_has_xsave)
return;
- /*
- * Boot processor to setup the FP and extended state context info.
- */
- if (!smp_processor_id())
- xstate_enable_boot_cpu();
- else
- xstate_enable(pcntxt_mask);
+ this_func = next_func;
+ next_func = xstate_enable;
+ this_func();