Revert "LinuxKPI: Do not use explicit context in FPU sections on powerpc64"

kmalloc() support within FPU sections will be redone in other way.

This reverts commit b4efc62776.

Sponsored by:	Serenity Cyber Security, LLC
Requested by:	jhb

sys/compat/linuxkpi/common/include/linux/compat.h

@@ -33,6 +33,11 @@
 #include <sys/proc.h>
 #include <sys/malloc.h>
 
+#if defined(__aarch64__) || defined(__arm__) || defined(__amd64__) ||	\
+    defined(__i386__) || defined(__powerpc64__)
+#define	LKPI_HAVE_FPU_CTX
+#endif
+
 struct domainset;
 struct thread;
 struct task_struct;

sys/compat/linuxkpi/common/src/linux_current.c

@@ -43,8 +43,7 @@
 #include <sys/sysctl.h>
 #include <vm/uma.h>
 
-#if defined(__aarch64__) || defined(__arm__) || defined(__amd64__) ||	\
-    defined(__i386__)
+#ifdef LKPI_HAVE_FPU_CTX
 #include <machine/fpu.h>
 #endif
 
@@ -161,8 +160,7 @@ linux_alloc_current(struct thread *td, int flags)
 int
 linux_set_fpu_ctx(struct task_struct *task)
 {
-#if defined(__aarch64__) || defined(__arm__) || defined(__amd64__) ||	\
-    defined(__i386__)
+#ifdef LKPI_HAVE_FPU_CTX
 	if (task->fpu_ctx == NULL && curthread->td_critnest == 0)
 		task->fpu_ctx = fpu_kern_alloc_ctx(FPU_KERN_NOWAIT);
 #endif
@@ -192,8 +190,7 @@ void
 linux_free_current(struct task_struct *ts)
 {
 	mmput(ts->mm);
-#if defined(__aarch64__) || defined(__arm__) || defined(__amd64__) ||	\
-    defined(__i386__)
+#ifdef LKPI_HAVE_FPU_CTX
 	if (ts->fpu_ctx != NULL)
 		fpu_kern_free_ctx(ts->fpu_ctx);
 #endif

sys/compat/linuxkpi/common/src/linux_fpu.c

@@ -35,8 +35,7 @@
 
 #include <asm/fpu/api.h>
 
-#if defined(__aarch64__) || defined(__arm__) || defined(__amd64__) ||	\
-    defined(__i386__) || defined(__powerpc64__)
+#ifdef LKPI_HAVE_FPU_CTX
 
 #include <machine/fpu.h>