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/20210802141245.1146772-1-arnd@kernel.org/
Link: https://lore.kernel.org/linux-arm-kernel/20210226164345.3889993-1-arnd@kernel.org/
Link: https://github.com/ClangBuiltLinux/linux/issues/1272
Link: https://gcc.gnu.org/legacy-ml/gcc/2008-03/msg01063.html
Cc: "Martin Guy" <martinwguy@martinwguy@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

4 files changed, 0 insertions, 87 deletions

diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index 70993af22d80..64944701bf6a 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/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
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 0ea8529a4872..241b73d64df7 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/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
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 2771e682220b..b008859680bc 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/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,
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index a3a38d0a4c85..1162bea3d66f 100644
--- a/arch/arm/kernel/signal.c
+++ b/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);