FRV: Add support for emulation of userspace atomic ops [try #2]

Use traps 120-126 to emulate atomic cmpxchg32, xchg32, and XOR-, OR-, AND-, SUB- and ADD-to-memory operations for userspace. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
author: David Howells <dhowells@redhat.com> 2008-04-10 11:10:55 -0400
committer: Linus Torvalds <torvalds@linux-foundation.org> 2008-04-10 16:41:29 -0400
commit: e31c243f984628d02f045dc4b622f1e2827860dc (patch)
tree: cd2ac2f33c7da86b515087260d93179b31fd1671
parent: 0c93d8e4d342b1b5cda1037f2527fcf443c80fbc (diff)
4 files changed, 268 insertions, 1 deletions
diff --git a/arch/frv/kernel/entry-table.S b/arch/frv/kernel/entry-table.S
index d3b9253d862a..bf35f33e48c9 100644
--- a/arch/frv/kernel/entry-table.S
+++ b/arch/frv/kernel/entry-table.S
@@ -316,8 +316,14 @@ __trap_fixup_kernel_data_tlb_miss:
        .section        .trap.vector
        .org            TBR_TT_TRAP0 >> 2
        .long           system_call
-        .rept           126
+        .rept           119
        .long           __entry_unsupported_trap
        .endr
+        # userspace atomic op emulation, traps 120-126
+        .rept           7
+        .long           __entry_atomic_op
+        .endr
+        
        .org            TBR_TT_BREAK >> 2
        .long           __entry_debug_exception
diff --git a/arch/frv/kernel/entry.S b/arch/frv/kernel/entry.S
index f36d7f4a7c25..b8a4b94779b1 100644
--- a/arch/frv/kernel/entry.S
+++ b/arch/frv/kernel/entry.S
@@ -656,6 +656,26 @@ __entry_debug_exception:
 ###############################################################################
 #
+# handle atomic operation emulation for userspace
+#
+###############################################################################
+        .globl          __entry_atomic_op
+__entry_atomic_op:
+        LEDS            0x6012
+        sethi.p         %hi(atomic_operation),gr5
+        setlo           %lo(atomic_operation),gr5
+        movsg           esfr1,gr8
+        movsg           epcr0,gr9
+        movsg           esr0,gr10
+        # now that we've accessed the exception regs, we can enable exceptions
+        movsg           psr,gr4
+        ori             gr4,#PSR_ET,gr4
+        movgs           gr4,psr
+        jmpl            @(gr5,gr0)      ; call atomic_operation(esfr1,epcr0,esr0)
+###############################################################################
+#
 # handle media exception
 #
 ###############################################################################
diff --git a/arch/frv/kernel/traps.c b/arch/frv/kernel/traps.c
index 2e6098c85578..2f7e66877f3b 100644
--- a/arch/frv/kernel/traps.c
+++ b/arch/frv/kernel/traps.c
@@ -102,6 +102,233 @@ asmlinkage void illegal_instruction(unsigned long esfr1, unsigned long epcr0, un
 /*****************************************************************************/
 /*
+ * handle atomic operations with errors
+ * - arguments in gr8, gr9, gr10
+ * - original memory value placed in gr5
+ * - replacement memory value placed in gr9
+ */
+asmlinkage void atomic_operation(unsigned long esfr1, unsigned long epcr0,
+                                 unsigned long esr0)
+{
+        static DEFINE_SPINLOCK(atomic_op_lock);
+        unsigned long x, y, z, *p;
+        mm_segment_t oldfs;
+        siginfo_t info;
+        int ret;
+        y = 0;
+        z = 0;
+        oldfs = get_fs();
+        if (!user_mode(__frame))
+                set_fs(KERNEL_DS);
+        switch (__frame->tbr & TBR_TT) {
+                /* TIRA gr0,#120
+                 * u32 __atomic_user_cmpxchg32(u32 *ptr, u32 test, u32 new)
+                 */
+        case TBR_TT_ATOMIC_CMPXCHG32:
+                p = (unsigned long *) __frame->gr8;
+                x = __frame->gr9;
+                y = __frame->gr10;
+                for (;;) {
+                        ret = get_user(z, p);
+                        if (ret < 0)
+                                goto error;
+                        if (z != x)
+                                goto done;
+                        spin_lock_irq(&atomic_op_lock);
+                        if (__get_user(z, p) == 0) {
+                                if (z != x)
+                                        goto done2;
+                                if (__put_user(y, p) == 0)
+                                        goto done2;
+                                goto error2;
+                        }
+                        spin_unlock_irq(&atomic_op_lock);
+                }
+                /* TIRA gr0,#121
+                 * u32 __atomic_kernel_xchg32(void *v, u32 new)
+                 */
+        case TBR_TT_ATOMIC_XCHG32:
+                p = (unsigned long *) __frame->gr8;
+                y = __frame->gr9;
+                for (;;) {
+                        ret = get_user(z, p);
+                        if (ret < 0)
+                                goto error;
+                        spin_lock_irq(&atomic_op_lock);
+                        if (__get_user(z, p) == 0) {
+                                if (__put_user(y, p) == 0)
+                                        goto done2;
+                                goto error2;
+                        }
+                        spin_unlock_irq(&atomic_op_lock);
+                }
+                /* TIRA gr0,#122
+                 * ulong __atomic_kernel_XOR_return(ulong i, ulong *v)
+                 */
+        case TBR_TT_ATOMIC_XOR:
+                p = (unsigned long *) __frame->gr8;
+                x = __frame->gr9;
+                for (;;) {
+                        ret = get_user(z, p);
+                        if (ret < 0)
+                                goto error;
+                        spin_lock_irq(&atomic_op_lock);
+                        if (__get_user(z, p) == 0) {
+                                y = x ^ z;
+                                if (__put_user(y, p) == 0)
+                                        goto done2;
+                                goto error2;
+                        }
+                        spin_unlock_irq(&atomic_op_lock);
+                }
+                /* TIRA gr0,#123
+                 * ulong __atomic_kernel_OR_return(ulong i, ulong *v)
+                 */
+        case TBR_TT_ATOMIC_OR:
+                p = (unsigned long *) __frame->gr8;
+                x = __frame->gr9;
+                for (;;) {
+                        ret = get_user(z, p);
+                        if (ret < 0)
+                                goto error;
+                        spin_lock_irq(&atomic_op_lock);
+                        if (__get_user(z, p) == 0) {
+                                y = x ^ z;
+                                if (__put_user(y, p) == 0)
+                                        goto done2;
+                                goto error2;
+                        }
+                        spin_unlock_irq(&atomic_op_lock);
+                }
+                /* TIRA gr0,#124
+                 * ulong __atomic_kernel_AND_return(ulong i, ulong *v)
+                 */
+        case TBR_TT_ATOMIC_AND:
+                p = (unsigned long *) __frame->gr8;
+                x = __frame->gr9;
+                for (;;) {
+                        ret = get_user(z, p);
+                        if (ret < 0)
+                                goto error;
+                        spin_lock_irq(&atomic_op_lock);
+                        if (__get_user(z, p) == 0) {
+                                y = x & z;
+                                if (__put_user(y, p) == 0)
+                                        goto done2;
+                                goto error2;
+                        }
+                        spin_unlock_irq(&atomic_op_lock);
+                }
+                /* TIRA gr0,#125
+                 * int __atomic_user_sub_return(atomic_t *v, int i)
+                 */
+        case TBR_TT_ATOMIC_SUB:
+                p = (unsigned long *) __frame->gr8;
+                x = __frame->gr9;
+                for (;;) {
+                        ret = get_user(z, p);
+                        if (ret < 0)
+                                goto error;
+                        spin_lock_irq(&atomic_op_lock);
+                        if (__get_user(z, p) == 0) {
+                                y = z - x;
+                                if (__put_user(y, p) == 0)
+                                        goto done2;
+                                goto error2;
+                        }
+                        spin_unlock_irq(&atomic_op_lock);
+                }
+                /* TIRA gr0,#126
+                 * int __atomic_user_add_return(atomic_t *v, int i)
+                 */
+        case TBR_TT_ATOMIC_ADD:
+                p = (unsigned long *) __frame->gr8;
+                x = __frame->gr9;
+                for (;;) {
+                        ret = get_user(z, p);
+                        if (ret < 0)
+                                goto error;
+                        spin_lock_irq(&atomic_op_lock);
+                        if (__get_user(z, p) == 0) {
+                                y = z + x;
+                                if (__put_user(y, p) == 0)
+                                        goto done2;
+                                goto error2;
+                        }
+                        spin_unlock_irq(&atomic_op_lock);
+                }
+        default:
+                BUG();
+        }
+done2:
+        spin_unlock_irq(&atomic_op_lock);
+done:
+        if (!user_mode(__frame))
+                set_fs(oldfs);
+        __frame->gr5 = z;
+        __frame->gr9 = y;
+        return;
+error2:
+        spin_unlock_irq(&atomic_op_lock);
+error:
+        if (!user_mode(__frame))
+                set_fs(oldfs);
+        __frame->pc -= 4;
+        die_if_kernel("-- Atomic Op Error --\n");
+        info.si_signo   = SIGSEGV;
+        info.si_code    = SEGV_ACCERR;
+        info.si_errno   = 0;
+        info.si_addr    = (void *) __frame->pc;
+        force_sig_info(info.si_signo, &info, current);
+}
+/*****************************************************************************/
+/*
 *
 */
 asmlinkage void media_exception(unsigned long msr0, unsigned long msr1)
diff --git a/include/asm-frv/spr-regs.h b/include/asm-frv/spr-regs.h
index c2a541ef828d..01e6af5e99b8 100644
--- a/include/asm-frv/spr-regs.h
+++ b/include/asm-frv/spr-regs.h
@@ -99,9 +99,23 @@
 #define TBR_TT_TRAP1            (0x81 << 4)
 #define TBR_TT_TRAP2            (0x82 << 4)
 #define TBR_TT_TRAP3            (0x83 << 4)
+#define TBR_TT_TRAP120          (0xf8 << 4)
+#define TBR_TT_TRAP121          (0xf9 << 4)
+#define TBR_TT_TRAP122          (0xfa << 4)
+#define TBR_TT_TRAP123          (0xfb << 4)
+#define TBR_TT_TRAP124          (0xfc << 4)
+#define TBR_TT_TRAP125          (0xfd << 4)
 #define TBR_TT_TRAP126          (0xfe << 4)
 #define TBR_TT_BREAK            (0xff << 4)
+#define TBR_TT_ATOMIC_CMPXCHG32 TBR_TT_TRAP120
+#define TBR_TT_ATOMIC_XCHG32    TBR_TT_TRAP121
+#define TBR_TT_ATOMIC_XOR       TBR_TT_TRAP122
+#define TBR_TT_ATOMIC_OR        TBR_TT_TRAP123
+#define TBR_TT_ATOMIC_AND       TBR_TT_TRAP124
+#define TBR_TT_ATOMIC_SUB       TBR_TT_TRAP125
+#define TBR_TT_ATOMIC_ADD       TBR_TT_TRAP126
 #define __get_TBR()     ({ unsigned long x; asm volatile("movsg tbr,%0" : "=r"(x)); x; })
 /*
author	David Howells <dhowells@redhat.com>	2008-04-10 11:10:55 -0400
committer	Linus Torvalds <torvalds@linux-foundation.org>	2008-04-10 16:41:29 -0400
commit	e31c243f984628d02f045dc4b622f1e2827860dc (patch)
tree	cd2ac2f33c7da86b515087260d93179b31fd1671
parent	0c93d8e4d342b1b5cda1037f2527fcf443c80fbc (diff)

diff --git a/arch/frv/kernel/entry-table.S b/arch/frv/kernel/entry-table.S index d3b9253d862a..bf35f33e48c9 100644 --- a/arch/frv/kernel/entry-table.S +++ b/arch/frv/kernel/entry-table.S
@@ -316,8 +316,14 @@ __trap_fixup_kernel_data_tlb_miss:
316	.section .trap.vector	316	.section .trap.vector
317	.org TBR_TT_TRAP0 >> 2	317	.org TBR_TT_TRAP0 >> 2
318	.long system_call	318	.long system_call
319	.rept 126	319	.rept 119
320	.long __entry_unsupported_trap	320	.long __entry_unsupported_trap
321	.endr	321	.endr
		322
		323	# userspace atomic op emulation, traps 120-126
		324	.rept 7
		325	.long __entry_atomic_op
		326	.endr
		327
322	.org TBR_TT_BREAK >> 2	328	.org TBR_TT_BREAK >> 2
323	.long __entry_debug_exception	329	.long __entry_debug_exception


diff --git a/arch/frv/kernel/entry.S b/arch/frv/kernel/entry.S index f36d7f4a7c25..b8a4b94779b1 100644 --- a/arch/frv/kernel/entry.S +++ b/arch/frv/kernel/entry.S
@@ -656,6 +656,26 @@ __entry_debug_exception:
656		656
657	###############################################################################	657	###############################################################################
658	#	658	#
		659	# handle atomic operation emulation for userspace
		660	#
		661	###############################################################################
		662	.globl __entry_atomic_op
		663	__entry_atomic_op:
		664	LEDS 0x6012
		665	sethi.p %hi(atomic_operation),gr5
		666	setlo %lo(atomic_operation),gr5
		667	movsg esfr1,gr8
		668	movsg epcr0,gr9
		669	movsg esr0,gr10
		670
		671	# now that we've accessed the exception regs, we can enable exceptions
		672	movsg psr,gr4
		673	ori gr4,#PSR_ET,gr4
		674	movgs gr4,psr
		675	jmpl @(gr5,gr0) ; call atomic_operation(esfr1,epcr0,esr0)
		676
		677	###############################################################################
		678	#
659	# handle media exception	679	# handle media exception
660	#	680	#
661	###############################################################################	681	###############################################################################


diff --git a/arch/frv/kernel/traps.c b/arch/frv/kernel/traps.c index 2e6098c85578..2f7e66877f3b 100644 --- a/arch/frv/kernel/traps.c +++ b/arch/frv/kernel/traps.c
@@ -102,6 +102,233 @@ asmlinkage void illegal_instruction(unsigned long esfr1, unsigned long epcr0, un
102		102
103	/*****************************************************************************/	103	/*****************************************************************************/
104	/*	104	/*
		105	* handle atomic operations with errors
		106	* - arguments in gr8, gr9, gr10
		107	* - original memory value placed in gr5
		108	* - replacement memory value placed in gr9
		109	*/
		110	asmlinkage void atomic_operation(unsigned long esfr1, unsigned long epcr0,
		111	unsigned long esr0)
		112	{
		113	static DEFINE_SPINLOCK(atomic_op_lock);
		114	unsigned long x, y, z, *p;
		115	mm_segment_t oldfs;
		116	siginfo_t info;
		117	int ret;
		118
		119	y = 0;
		120	z = 0;
		121
		122	oldfs = get_fs();
		123	if (!user_mode(__frame))
		124	set_fs(KERNEL_DS);
		125
		126	switch (__frame->tbr & TBR_TT) {
		127	/* TIRA gr0,#120
		128	* u32 __atomic_user_cmpxchg32(u32 *ptr, u32 test, u32 new)
		129	*/
		130	case TBR_TT_ATOMIC_CMPXCHG32:
		131	p = (unsigned long *) __frame->gr8;
		132	x = __frame->gr9;
		133	y = __frame->gr10;
		134
		135	for (;;) {
		136	ret = get_user(z, p);
		137	if (ret < 0)
		138	goto error;
		139
		140	if (z != x)
		141	goto done;
		142
		143	spin_lock_irq(&atomic_op_lock);
		144
		145	if (__get_user(z, p) == 0) {
		146	if (z != x)
		147	goto done2;
		148
		149	if (__put_user(y, p) == 0)
		150	goto done2;
		151	goto error2;
		152	}
		153
		154	spin_unlock_irq(&atomic_op_lock);
		155	}
		156
		157	/* TIRA gr0,#121
		158	* u32 __atomic_kernel_xchg32(void *v, u32 new)
		159	*/
		160	case TBR_TT_ATOMIC_XCHG32:
		161	p = (unsigned long *) __frame->gr8;
		162	y = __frame->gr9;
		163
		164	for (;;) {
		165	ret = get_user(z, p);
		166	if (ret < 0)
		167	goto error;
		168
		169	spin_lock_irq(&atomic_op_lock);
		170
		171	if (__get_user(z, p) == 0) {
		172	if (__put_user(y, p) == 0)
		173	goto done2;
		174	goto error2;
		175	}
		176
		177	spin_unlock_irq(&atomic_op_lock);
		178	}
		179
		180	/* TIRA gr0,#122
		181	* ulong __atomic_kernel_XOR_return(ulong i, ulong *v)
		182	*/
		183	case TBR_TT_ATOMIC_XOR:
		184	p = (unsigned long *) __frame->gr8;
		185	x = __frame->gr9;
		186
		187	for (;;) {
		188	ret = get_user(z, p);
		189	if (ret < 0)
		190	goto error;
		191
		192	spin_lock_irq(&atomic_op_lock);
		193
		194	if (__get_user(z, p) == 0) {
		195	y = x ^ z;
		196	if (__put_user(y, p) == 0)
		197	goto done2;
		198	goto error2;
		199	}
		200
		201	spin_unlock_irq(&atomic_op_lock);
		202	}
		203
		204	/* TIRA gr0,#123
		205	* ulong __atomic_kernel_OR_return(ulong i, ulong *v)
		206	*/
		207	case TBR_TT_ATOMIC_OR:
		208	p = (unsigned long *) __frame->gr8;
		209	x = __frame->gr9;
		210
		211	for (;;) {
		212	ret = get_user(z, p);
		213	if (ret < 0)
		214	goto error;
		215
		216	spin_lock_irq(&atomic_op_lock);
		217
		218	if (__get_user(z, p) == 0) {
		219	y = x ^ z;
		220	if (__put_user(y, p) == 0)
		221	goto done2;
		222	goto error2;
		223	}
		224
		225	spin_unlock_irq(&atomic_op_lock);
		226	}
		227
		228	/* TIRA gr0,#124
		229	* ulong __atomic_kernel_AND_return(ulong i, ulong *v)
		230	*/
		231	case TBR_TT_ATOMIC_AND:
		232	p = (unsigned long *) __frame->gr8;
		233	x = __frame->gr9;
		234
		235	for (;;) {
		236	ret = get_user(z, p);
		237	if (ret < 0)
		238	goto error;
		239
		240	spin_lock_irq(&atomic_op_lock);
		241
		242	if (__get_user(z, p) == 0) {
		243	y = x & z;
		244	if (__put_user(y, p) == 0)
		245	goto done2;
		246	goto error2;
		247	}
		248
		249	spin_unlock_irq(&atomic_op_lock);
		250	}
		251
		252	/* TIRA gr0,#125
		253	* int __atomic_user_sub_return(atomic_t *v, int i)
		254	*/
		255	case TBR_TT_ATOMIC_SUB:
		256	p = (unsigned long *) __frame->gr8;
		257	x = __frame->gr9;
		258
		259	for (;;) {
		260	ret = get_user(z, p);
		261	if (ret < 0)
		262	goto error;
		263
		264	spin_lock_irq(&atomic_op_lock);
		265
		266	if (__get_user(z, p) == 0) {
		267	y = z - x;
		268	if (__put_user(y, p) == 0)
		269	goto done2;
		270	goto error2;
		271	}
		272
		273	spin_unlock_irq(&atomic_op_lock);
		274	}
		275
		276	/* TIRA gr0,#126
		277	* int __atomic_user_add_return(atomic_t *v, int i)
		278	*/
		279	case TBR_TT_ATOMIC_ADD:
		280	p = (unsigned long *) __frame->gr8;
		281	x = __frame->gr9;
		282
		283	for (;;) {
		284	ret = get_user(z, p);
		285	if (ret < 0)
		286	goto error;
		287
		288	spin_lock_irq(&atomic_op_lock);
		289
		290	if (__get_user(z, p) == 0) {
		291	y = z + x;
		292	if (__put_user(y, p) == 0)
		293	goto done2;
		294	goto error2;
		295	}
		296
		297	spin_unlock_irq(&atomic_op_lock);
		298	}
		299
		300	default:
		301	BUG();
		302	}
		303
		304	done2:
		305	spin_unlock_irq(&atomic_op_lock);
		306	done:
		307	if (!user_mode(__frame))
		308	set_fs(oldfs);
		309	__frame->gr5 = z;
		310	__frame->gr9 = y;
		311	return;
		312
		313	error2:
		314	spin_unlock_irq(&atomic_op_lock);
		315	error:
		316	if (!user_mode(__frame))
		317	set_fs(oldfs);
		318	__frame->pc -= 4;
		319
		320	die_if_kernel("-- Atomic Op Error --\n");
		321
		322	info.si_signo = SIGSEGV;
		323	info.si_code = SEGV_ACCERR;
		324	info.si_errno = 0;
		325	info.si_addr = (void *) __frame->pc;
		326
		327	force_sig_info(info.si_signo, &info, current);
		328	}
		329
		330	/*****************************************************************************/
		331	/*
105	*	332	*
106	*/	333	*/
107	asmlinkage void media_exception(unsigned long msr0, unsigned long msr1)	334	asmlinkage void media_exception(unsigned long msr0, unsigned long msr1)


diff --git a/include/asm-frv/spr-regs.h b/include/asm-frv/spr-regs.h index c2a541ef828d..01e6af5e99b8 100644 --- a/include/asm-frv/spr-regs.h +++ b/include/asm-frv/spr-regs.h
@@ -99,9 +99,23 @@
99	#define TBR_TT_TRAP1 (0x81 << 4)	99	#define TBR_TT_TRAP1 (0x81 << 4)
100	#define TBR_TT_TRAP2 (0x82 << 4)	100	#define TBR_TT_TRAP2 (0x82 << 4)
101	#define TBR_TT_TRAP3 (0x83 << 4)	101	#define TBR_TT_TRAP3 (0x83 << 4)
		102	#define TBR_TT_TRAP120 (0xf8 << 4)
		103	#define TBR_TT_TRAP121 (0xf9 << 4)
		104	#define TBR_TT_TRAP122 (0xfa << 4)
		105	#define TBR_TT_TRAP123 (0xfb << 4)
		106	#define TBR_TT_TRAP124 (0xfc << 4)
		107	#define TBR_TT_TRAP125 (0xfd << 4)
102	#define TBR_TT_TRAP126 (0xfe << 4)	108	#define TBR_TT_TRAP126 (0xfe << 4)
103	#define TBR_TT_BREAK (0xff << 4)	109	#define TBR_TT_BREAK (0xff << 4)
104		110
		111	#define TBR_TT_ATOMIC_CMPXCHG32 TBR_TT_TRAP120
		112	#define TBR_TT_ATOMIC_XCHG32 TBR_TT_TRAP121
		113	#define TBR_TT_ATOMIC_XOR TBR_TT_TRAP122
		114	#define TBR_TT_ATOMIC_OR TBR_TT_TRAP123
		115	#define TBR_TT_ATOMIC_AND TBR_TT_TRAP124
		116	#define TBR_TT_ATOMIC_SUB TBR_TT_TRAP125
		117	#define TBR_TT_ATOMIC_ADD TBR_TT_TRAP126
		118
105	#define __get_TBR() ({ unsigned long x; asm volatile("movsg tbr,%0" : "=r"(x)); x; })	119	#define __get_TBR() ({ unsigned long x; asm volatile("movsg tbr,%0" : "=r"(x)); x; })
106		120
107	/*	121	/*