ARM: ep93xx: remove MaverickCrunch support

The MaverickCrunch support for ep93xx never made it into glibc and
was removed from gcc in its 4.8 release in 2012. It is now one of
the last parts of arch/arm/ that fails to build with the clang
integrated assembler, which is unlikely to ever want to support it.

The two alternatives are to force the use of binutils/gas when
building the crunch support, or to remove it entirely.

According to Hartley Sweeten:

 "Martin Guy did a lot of work trying to get the maverick crunch working
  but I was never able to successfully use it for anything. It "kind"
  of works but depending on the EP93xx silicon revision there are still
  a number of hardware bugs that either give imprecise or garbage results.

  I have no problem with removing the kernel support for the maverick
  crunch."

Unless someone else comes up with a good reason to keep it around,
remove it now. This touches mostly the ep93xx platform, but removes
a bit of code from ARM common ptrace and signal frame handling as well.

If there are remaining users of MaverickCrunch, they can use LTS
kernels for at least another five years before kernel support ends.

Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/
Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/
Link: ClangBuiltLinux#1272
Link: https://gcc.gnu.org/legacy-ml/gcc/2008-03/msg01063.html
Cc: "Martin Guy" <martinwguy@[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>

Author: arndb

arch/arm/configs/ep93xx_defconfig

@@ -12,7 +12,6 @@ CONFIG_MODULE_FORCE_UNLOAD=y
 # CONFIG_BLK_DEV_BSG is not set
 CONFIG_PARTITION_ADVANCED=y
 CONFIG_ARCH_EP93XX=y
-CONFIG_CRUNCH=y
 CONFIG_MACH_ADSSPHERE=y
 CONFIG_MACH_EDB9301=y
 CONFIG_MACH_EDB9302=y

arch/arm/include/asm/fpstate.h

@@ -77,14 +77,6 @@ union fp_state {
 
 #define FP_SIZE (sizeof(union fp_state) / sizeof(int))
 
-struct crunch_state {
-	unsigned int	mvdx[16][2];
-	unsigned int	mvax[4][3];
-	unsigned int	dspsc[2];
-};
-
-#define CRUNCH_SIZE	sizeof(struct crunch_state)
-
 #endif
 
 #endif

arch/arm/include/asm/thread_info.h

@@ -65,9 +65,6 @@ struct thread_info {
 	__u32			syscall;	/* syscall number */
 	__u8			used_cp[16];	/* thread used copro */
 	unsigned long		tp_value[2];	/* TLS registers */
-#ifdef CONFIG_CRUNCH
-	struct crunch_state	crunchstate;
-#endif
 	union fp_state		fpstate __attribute__((aligned(8)));
 	union vfp_state		vfpstate;
 #ifdef CONFIG_ARM_THUMBEE
@@ -107,11 +104,6 @@ static inline struct thread_info *current_thread_info(void)
 	((unsigned long)(task_thread_info(tsk)->cpu_context.r7))
 #endif
 
-extern void crunch_task_disable(struct thread_info *);
-extern void crunch_task_copy(struct thread_info *, void *);
-extern void crunch_task_restore(struct thread_info *, void *);
-extern void crunch_task_release(struct thread_info *);
-
 extern void iwmmxt_task_disable(struct thread_info *);
 extern void iwmmxt_task_copy(struct thread_info *, void *);
 extern void iwmmxt_task_restore(struct thread_info *, void *);

arch/arm/include/asm/ucontext.h

@@ -43,17 +43,6 @@ struct ucontext {
  */
 #define DUMMY_MAGIC		0xb0d9ed01
 
-#ifdef CONFIG_CRUNCH
-#define CRUNCH_MAGIC		0x5065cf03
-#define CRUNCH_STORAGE_SIZE	(CRUNCH_SIZE + 8)
-
-struct crunch_sigframe {
-	unsigned long	magic;
-	unsigned long	size;
-	struct crunch_state	storage;
-} __attribute__((__aligned__(8)));
-#endif
-
 #ifdef CONFIG_IWMMXT
 /* iwmmxt_area is 0x98 bytes long, preceded by 8 bytes of signature */
 #define IWMMXT_MAGIC		0x12ef842a
@@ -92,9 +81,6 @@ struct vfp_sigframe
  * one of these.
  */
 struct aux_sigframe {
-#ifdef CONFIG_CRUNCH
-	struct crunch_sigframe	crunch;
-#endif
 #ifdef CONFIG_IWMMXT
 	struct iwmmxt_sigframe	iwmmxt;
 #endif

arch/arm/include/uapi/asm/hwcap.h

@@ -15,7 +15,7 @@
 #define HWCAP_EDSP	(1 << 7)
 #define HWCAP_JAVA	(1 << 8)
 #define HWCAP_IWMMXT	(1 << 9)
-#define HWCAP_CRUNCH	(1 << 10)
+#define HWCAP_CRUNCH	(1 << 10)	/* Obsolete */
 #define HWCAP_THUMBEE	(1 << 11)
 #define HWCAP_NEON	(1 << 12)
 #define HWCAP_VFPv3	(1 << 13)

arch/arm/include/uapi/asm/ptrace.h

@@ -26,8 +26,8 @@
 #define PTRACE_GET_THREAD_AREA	22
 #define PTRACE_SET_SYSCALL	23
 /* PTRACE_SYSCALL is 24 */
-#define PTRACE_GETCRUNCHREGS	25
-#define PTRACE_SETCRUNCHREGS	26
+#define PTRACE_GETCRUNCHREGS	25 /* obsolete */
+#define PTRACE_SETCRUNCHREGS	26 /* obsolete */
 #define PTRACE_GETVFPREGS	27
 #define PTRACE_SETVFPREGS	28
 #define PTRACE_GETHBPREGS	29

arch/arm/kernel/asm-offsets.c

@@ -63,9 +63,6 @@ int main(void)
 #ifdef CONFIG_IWMMXT
   DEFINE(TI_IWMMXT_STATE,	offsetof(struct thread_info, fpstate.iwmmxt));
 #endif
-#ifdef CONFIG_CRUNCH
-  DEFINE(TI_CRUNCH_STATE,	offsetof(struct thread_info, crunchstate));
-#endif
 #ifdef CONFIG_STACKPROTECTOR_PER_TASK
   DEFINE(TI_STACK_CANARY,	offsetof(struct thread_info, stack_canary));
 #endif

arch/arm/kernel/entry-armv.S

@@ -618,15 +618,9 @@ call_fpe:
 	W(b)	do_fpe				@ CP#1 (FPE)
 	W(b)	do_fpe				@ CP#2 (FPE)
 	ret.w	lr				@ CP#3
-#ifdef CONFIG_CRUNCH
-	b	crunch_task_enable		@ CP#4 (MaverickCrunch)
-	b	crunch_task_enable		@ CP#5 (MaverickCrunch)
-	b	crunch_task_enable		@ CP#6 (MaverickCrunch)
-#else
 	ret.w	lr				@ CP#4
 	ret.w	lr				@ CP#5
 	ret.w	lr				@ CP#6
-#endif
 	ret.w	lr				@ CP#7
 	ret.w	lr				@ CP#8
 	ret.w	lr				@ CP#9

arch/arm/kernel/ptrace.c

@@ -318,32 +318,6 @@ static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
 
 #endif
 
-#ifdef CONFIG_CRUNCH
-/*
- * Get the child Crunch state.
- */
-static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
-{
-	struct thread_info *thread = task_thread_info(tsk);
-
-	crunch_task_disable(thread);  /* force it to ram */
-	return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
-		? -EFAULT : 0;
-}
-
-/*
- * Set the child Crunch state.
- */
-static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
-{
-	struct thread_info *thread = task_thread_info(tsk);
-
-	crunch_task_release(thread);  /* force a reload */
-	return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE)
-		? -EFAULT : 0;
-}
-#endif
-
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 /*
  * Convert a virtual register number into an index for a thread_info
@@ -815,16 +789,6 @@ long arch_ptrace(struct task_struct *child, long request,
 			ret = 0;
 			break;
 
-#ifdef CONFIG_CRUNCH
-		case PTRACE_GETCRUNCHREGS:
-			ret = ptrace_getcrunchregs(child, datap);
-			break;
-
-		case PTRACE_SETCRUNCHREGS:
-			ret = ptrace_setcrunchregs(child, datap);
-			break;
-#endif
-
 #ifdef CONFIG_VFP
 		case PTRACE_GETVFPREGS:
 			ret = copy_regset_to_user(child,

arch/arm/kernel/signal.c

@@ -25,40 +25,6 @@ extern const unsigned long sigreturn_codes[17];
 
 static unsigned long signal_return_offset;
 
-#ifdef CONFIG_CRUNCH
-static int preserve_crunch_context(struct crunch_sigframe __user *frame)
-{
-	char kbuf[sizeof(*frame) + 8];
-	struct crunch_sigframe *kframe;
-
-	/* the crunch context must be 64 bit aligned */
-	kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
-	kframe->magic = CRUNCH_MAGIC;
-	kframe->size = CRUNCH_STORAGE_SIZE;
-	crunch_task_copy(current_thread_info(), &kframe->storage);
-	return __copy_to_user(frame, kframe, sizeof(*frame));
-}
-
-static int restore_crunch_context(char __user **auxp)
-{
-	struct crunch_sigframe __user *frame =
-		(struct crunch_sigframe __user *)*auxp;
-	char kbuf[sizeof(*frame) + 8];
-	struct crunch_sigframe *kframe;
-
-	/* the crunch context must be 64 bit aligned */
-	kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7);
-	if (__copy_from_user(kframe, frame, sizeof(*frame)))
-		return -1;
-	if (kframe->magic != CRUNCH_MAGIC ||
-	    kframe->size != CRUNCH_STORAGE_SIZE)
-		return -1;
-	*auxp += CRUNCH_STORAGE_SIZE;
-	crunch_task_restore(current_thread_info(), &kframe->storage);
-	return 0;
-}
-#endif
-
 #ifdef CONFIG_IWMMXT
 
 static int preserve_iwmmxt_context(struct iwmmxt_sigframe __user *frame)
@@ -205,10 +171,6 @@ static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
 	err |= !valid_user_regs(regs);
 
 	aux = (char __user *) sf->uc.uc_regspace;
-#ifdef CONFIG_CRUNCH
-	if (err == 0)
-		err |= restore_crunch_context(&aux);
-#endif
 #ifdef CONFIG_IWMMXT
 	if (err == 0)
 		err |= restore_iwmmxt_context(&aux);
@@ -321,10 +283,6 @@ setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set)
 	err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
 
 	aux = (struct aux_sigframe __user *) sf->uc.uc_regspace;
-#ifdef CONFIG_CRUNCH
-	if (err == 0)
-		err |= preserve_crunch_context(&aux->crunch);
-#endif
 #ifdef CONFIG_IWMMXT
 	if (err == 0)
 		err |= preserve_iwmmxt_context(&aux->iwmmxt);