Replace broken implementation of fuswintr() and suswintr() by functions

which return -1 as well as on tier 1 archs. Remove block_userspace_access
used only in these implementations.

(1) These functions may be called in interrupt context and pcb_onfault
can be already set in this time. Thus, prior pcb_onfault must be saved
and restored afterwards.

(2) The check that an abort came either from nested interrupt or while
in critical section or holding not sleepable lock must be avoided for
this case.

These functions are called only for profiling reason, so there will be
only small gain by making the code more complex.

6 files changed, 6 insertions, 142 deletions

diff --git a/sys/arm/arm/cpufunc_asm_xscale.S b/sys/arm/arm/cpufunc_asm_xscale.S
index 3031b8c..8b9848c 100644
--- a/sys/arm/arm/cpufunc_asm_xscale.S
+++ b/sys/arm/arm/cpufunc_asm_xscale.S
@@ -80,9 +80,6 @@ __FBSDID("$FreeBSD$");
  */
 #define	DCACHE_SIZE		0x00008000
 
-.Lblock_userspace_access:
-	.word	_C_LABEL(block_userspace_access)
-
 /*
  * CPWAIT -- Canonical method to wait for CP15 update.
  * From: Intel 80200 manual, section 2.3.3.
@@ -137,11 +134,6 @@ ENTRY(xscale_setttb)
 	mrs	r3, cpsr
 	orr	r1, r3, #(PSR_I | PSR_F)
 	msr	cpsr_fsxc, r1
-#else
-	ldr	r3, .Lblock_userspace_access
-	ldr	r2, [r3]
-	orr	r1, r2, #1
-	str	r1, [r3]
 #endif
 	stmfd	sp!, {r0-r3, lr}
 	bl	_C_LABEL(xscale_cache_cleanID)
@@ -165,8 +157,6 @@ ENTRY(xscale_setttb)
 
 #ifdef CACHE_CLEAN_BLOCK_INTR
 	msr	cpsr_fsxc, r3
-#else
-	str	r2, [r3]
 #endif
 	RET
 END(xscale_setttb)
@@ -273,14 +263,9 @@ _C_LABEL(xscale_minidata_clean_size):
 #define	XSCALE_CACHE_CLEAN_UNBLOCK					\
 	msr	cpsr_fsxc, r3
 #else
-#define	XSCALE_CACHE_CLEAN_BLOCK					\
-	ldr	r3, .Lblock_userspace_access			;	\
-	ldr	ip, [r3]					;	\
-	orr	r0, ip, #1					;	\
-	str	r0, [r3]
+#define	XSCALE_CACHE_CLEAN_BLOCK
 
-#define	XSCALE_CACHE_CLEAN_UNBLOCK					\
-	str	ip, [r3]
+#define	XSCALE_CACHE_CLEAN_UNBLOCK
 #endif /* CACHE_CLEAN_BLOCK_INTR */
 
 #define	XSCALE_CACHE_CLEAN_PROLOGUE					\
diff --git a/sys/arm/arm/cpufunc_asm_xscale_c3.S b/sys/arm/arm/cpufunc_asm_xscale_c3.S
index cb770a8..4e2c999 100644
--- a/sys/arm/arm/cpufunc_asm_xscale_c3.S
+++ b/sys/arm/arm/cpufunc_asm_xscale_c3.S
@@ -82,9 +82,6 @@ __FBSDID("$FreeBSD$");
  */
 #define	DCACHE_SIZE		0x00008000
 
-.Lblock_userspace_access:
-	.word	_C_LABEL(block_userspace_access)
-
 /*
  * CPWAIT -- Canonical method to wait for CP15 update.
  * From: Intel 80200 manual, section 2.3.3.
@@ -130,16 +127,8 @@ __FBSDID("$FreeBSD$");
 	msr	cpsr_fsxc, r4					;	\
 	ldmfd	sp!, {r4}
 #else
-#define	XSCALE_CACHE_CLEAN_BLOCK					\
-	stmfd	sp!, {r4}					;	\
-	ldr	r4, .Lblock_userspace_access			;	\
-	ldr	ip, [r4]					;	\
-	orr	r0, ip, #1					;	\
-	str	r0, [r4]
-
-#define	XSCALE_CACHE_CLEAN_UNBLOCK					\
-	str	ip, [r3]					;	\
-	ldmfd	sp!, {r4}
+#define	XSCALE_CACHE_CLEAN_BLOCK
+#define	XSCALE_CACHE_CLEAN_UNBLOCK
 #endif /* CACHE_CLEAN_BLOCK_INTR */
 
 
@@ -352,11 +341,6 @@ ENTRY(xscalec3_setttb)
 	mrs	r3, cpsr
 	orr	r1, r3, #(PSR_I | PSR_F)
 	msr	cpsr_fsxc, r1
-#else
-	ldr	r3, .Lblock_userspace_access
-	ldr	r2, [r3]
-	orr	r1, r2, #1
-	str	r1, [r3]
 #endif
 	stmfd	sp!, {r0-r3, lr}
 	bl	_C_LABEL(xscalec3_cache_cleanID)
diff --git a/sys/arm/arm/elf_trampoline.c b/sys/arm/arm/elf_trampoline.c
index e25a849..22f0f44 100644
--- a/sys/arm/arm/elf_trampoline.c
+++ b/sys/arm/arm/elf_trampoline.c
@@ -125,7 +125,6 @@ static int      arm_dcache_l2_assoc;
 static int      arm_dcache_l2_linesize;
 
 
-int block_userspace_access = 0;
 extern int arm9_dcache_sets_inc;
 extern int arm9_dcache_sets_max;
 extern int arm9_dcache_index_max;
diff --git a/sys/arm/arm/fusu.S b/sys/arm/arm/fusu.S
index 54d263c..ba50e67 100644
--- a/sys/arm/arm/fusu.S
+++ b/sys/arm/arm/fusu.S
@@ -183,51 +183,10 @@ END(fusword)
  */
 
 ENTRY(fuswintr)
-	ldr	r3, =(VM_MAXUSER_ADDRESS-1)
-	cmp	r0, r3
-	mvncs	r0, #0
-	RETc(cs)
-
-	ldr	r2, Lblock_userspace_access
-	ldr	r2, [r2]
-	teq	r2, #0
-	mvnne	r0, #0x00000000
-	RETne
-
-	GET_PCB(r2)
-	ldr	r2, [r2]
-
-#ifdef DIAGNOSTIC
-	teq	r2, #0x00000000
-	beq	.Lfusupcbfault
-#endif
-
-	adr	r1, _C_LABEL(fusubailout)
-	str	r1, [r2, #PCB_ONFAULT]
-
-	ldrbt	r3, [r0], #1
-	ldrbt	ip, [r0]
-#ifdef __ARMEB__
-	orr	r0, ip, r3, asl #8
-#else
-	orr	r0, r3, ip, asl #8
-#endif
-
-	mov	r1, #0x00000000
-	str	r1, [r2, #PCB_ONFAULT]
+	mov	r0, #-1
 	RET
 END(fuswintr)
 
-Lblock_userspace_access:
-	.word	_C_LABEL(block_userspace_access)
-
-	.data
-	.align	2
-	.global	_C_LABEL(block_userspace_access)
-_C_LABEL(block_userspace_access):
-	.word	0
-	.text
-
 /*
  * fubyte(caddr_t uaddr);
  * Fetch a byte from the user's address space.
@@ -268,20 +227,6 @@ END(fubyte)
 	mvn	r0, #0x00000000
 	RET
 
-/*
- * Handle faults from [fs]u*().  Clean up and return -1.  This differs from
- * fusufault() in that trap() will recognise it and return immediately rather
- * than trying to page fault.
- */
-
-/* label must be global as fault.c references it */
-	.global	_C_LABEL(fusubailout)
-_C_LABEL(fusubailout):
-	mov	r0, #0x00000000
-	str	r0, [r2, #PCB_ONFAULT]
-	mvn	r0, #0x00000000
-	RET
-
 #ifdef DIAGNOSTIC
 /*
  * Handle earlier faults from [fs]u*(), due to no pcb
@@ -335,39 +280,7 @@ END(suword)
  */
 
 ENTRY(suswintr)
-	ldr	r3, =(VM_MAXUSER_ADDRESS-1)
-	cmp	r0, r3
-	mvncs	r0, #0
-	RETc(cs)
-
-	ldr	r2, Lblock_userspace_access
-	ldr	r2, [r2]
-	teq	r2, #0
-	mvnne	r0, #0x00000000
-	RETne
-
-	GET_PCB(r2)
-	ldr	r2, [r2]
-
-#ifdef DIAGNOSTIC
-	teq	r2, #0x00000000
-	beq	.Lfusupcbfault
-#endif
-
-	adr	r3, _C_LABEL(fusubailout)
-	str	r3, [r2, #PCB_ONFAULT]
-
-#ifdef __ARMEB__
-	mov	ip, r1, lsr #8
-	strbt	ip, [r0], #1
-#else
-	strbt	r1, [r0], #1
-	mov	r1, r1, lsr #8
-#endif
-	strbt	r1, [r0]
-
-	mov	r0, #0x00000000
-	str	r0, [r2, #PCB_ONFAULT]
+	mov	r0, #-1
 	RET
 END(suswintr)
 
diff --git a/sys/arm/arm/trap-v6.c b/sys/arm/arm/trap-v6.c
index 88aec53..9c07999 100644
--- a/sys/arm/arm/trap-v6.c
+++ b/sys/arm/arm/trap-v6.c
@@ -70,7 +70,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/dtrace_bsd.h>
 #endif
 
-extern char fusubailout[];
 extern char cachebailout[];
 
 #ifdef DEBUG
@@ -445,13 +444,6 @@ abort_handler(struct trapframe *tf, int prefetch)
 		goto out;
 	}
 
-	/* fusubailout is used by [fs]uswintr to avoid page faulting. */
-	if (__predict_false(pcb->pcb_onfault == fusubailout)) {
-		tf->tf_r0 = EFAULT;
-		tf->tf_pc = (register_t)pcb->pcb_onfault;
-		return;
-	}
-
 	va = trunc_page(far);
 	if (va >= KERNBASE) {
 		/*
diff --git a/sys/arm/arm/trap.c b/sys/arm/arm/trap.c
index e43ec8e..eb4d683 100644
--- a/sys/arm/arm/trap.c
+++ b/sys/arm/arm/trap.c
@@ -111,8 +111,6 @@ __FBSDID("$FreeBSD$");
 
 #define ReadWord(a)	(*((volatile unsigned int *)(a)))
 
-extern char fusubailout[];
-
 #ifdef DEBUG
 int last_fault_code;	/* For the benefit of pmap_fault_fixup() */
 #endif
@@ -255,13 +253,6 @@ abort_handler(struct trapframe *tf, int type)
 	 * the MMU.
 	 */
 
-	/* fusubailout is used by [fs]uswintr to avoid page faulting */
-	if (__predict_false(pcb->pcb_onfault == fusubailout)) {
-		tf->tf_r0 = EFAULT;
-		tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
-		return;
-	}
-
 	/*
 	 * Make sure the Program Counter is sane. We could fall foul of
 	 * someone executing Thumb code, in which case the PC might not