1 files changed, 107 insertions, 0 deletions
diff --git a/arch/alpha/lib/ev67-strlen_user.S b/arch/alpha/lib/ev67-strlen_user.S
new file mode 100644
index 000000000000..57e0d77b81a6
--- /dev/null
+++ b/arch/alpha/lib/ev67-strlen_user.S
@@ -0,0 +1,107 @@
+/*
+ * arch/alpha/lib/ev67-strlen_user.S
+ * 21264 version contributed by Rick Gorton <rick.gorton@api-networks.com>
+ *
+ * Return the length of the string including the NULL terminator
+ * (strlen+1) or zero if an error occurred.
+ *
+ * In places where it is critical to limit the processing time,
+ * and the data is not trusted, strnlen_user() should be used.
+ * It will return a value greater than its second argument if
+ * that limit would be exceeded. This implementation is allowed
+ * to access memory beyond the limit, but will not cross a page
+ * boundary when doing so.
+ *
+ * Much of the information about 21264 scheduling/coding comes from:
+ *      Compiler Writer's Guide for the Alpha 21264
+ *      abbreviated as 'CWG' in other comments here
+ *      ftp.digital.com/pub/Digital/info/semiconductor/literature/dsc-library.html
+ * Scheduling notation:
+ *      E       - either cluster
+ *      U       - upper subcluster; U0 - subcluster U0; U1 - subcluster U1
+ *      L       - lower subcluster; L0 - subcluster L0; L1 - subcluster L1
+ * Try not to change the actual algorithm if possible for consistency.
+ */
+#include <asm/regdef.h>
+/* Allow an exception for an insn; exit if we get one.  */
+#define EX(x,y...)                      \
+        99: x,##y;                      \
+        .section __ex_table,"a";        \
+        .long 99b - .;                  \
+        lda v0, $exception-99b(zero);   \
+        .previous
+        .set noreorder
+        .set noat
+        .text
+        .globl __strlen_user
+        .ent __strlen_user
+        .frame sp, 0, ra
+        .align 4
+__strlen_user:
+        ldah    a1, 32767(zero) # do not use plain strlen_user() for strings
+                                # that might be almost 2 GB long; you should
+                                # be using strnlen_user() instead
+        nop
+        nop
+        nop
+        .globl __strnlen_user
+        .align 4
+__strnlen_user:
+        .prologue 0
+        EX( ldq_u t0, 0(a0) )   # L : load first quadword (a0 may be misaligned)
+        lda     t1, -1(zero)    # E :
+        insqh   t1, a0, t1      # U :
+        andnot  a0, 7, v0       # E :
+        or      t1, t0, t0      # E :
+        subq    a0, 1, a0       # E : get our +1 for the return 
+        cmpbge  zero, t0, t1    # E : t1 <- bitmask: bit i == 1 <==> i-th byte == 0
+        subq    a1, 7, t2       # E :
+        subq    a0, v0, t0      # E :
+        bne     t1, $found      # U :
+        addq    t2, t0, t2      # E :
+        addq    a1, 1, a1       # E :
+        nop                     # E :
+        nop                     # E :
+        .align 4
+$loop:  ble     t2, $limit      # U :
+        EX( ldq t0, 8(v0) )     # L :
+        nop                     # E :
+        nop                     # E :
+        cmpbge  zero, t0, t1    # E :
+        subq    t2, 8, t2       # E :
+        addq    v0, 8, v0       # E : addr += 8
+        beq     t1, $loop       # U :
+$found: cttz    t1, t2          # U0 :
+        addq    v0, t2, v0      # E :
+        subq    v0, a0, v0      # E :
+        ret                     # L0 :
+$exception:
+        nop
+        nop
+        nop
+        ret
+        .align 4                # currently redundant
+$limit:
+        nop
+        nop
+        subq    a1, t2, v0
+        ret
+        .end __strlen_user

diff --git a/arch/alpha/lib/ev67-strlen_user.S b/arch/alpha/lib/ev67-strlen_user.S new file mode 100644 index 000000000000..57e0d77b81a6 --- /dev/null +++ b/arch/alpha/lib/ev67-strlen_user.S
@@ -0,0 +1,107 @@
	1	/*
	2	* arch/alpha/lib/ev67-strlen_user.S
	3	* 21264 version contributed by Rick Gorton <rick.gorton@api-networks.com>
	4	*
	5	* Return the length of the string including the NULL terminator
	6	* (strlen+1) or zero if an error occurred.
	7	*
	8	* In places where it is critical to limit the processing time,
	9	* and the data is not trusted, strnlen_user() should be used.
	10	* It will return a value greater than its second argument if
	11	* that limit would be exceeded. This implementation is allowed
	12	* to access memory beyond the limit, but will not cross a page
	13	* boundary when doing so.
	14	*
	15	* Much of the information about 21264 scheduling/coding comes from:
	16	* Compiler Writer's Guide for the Alpha 21264
	17	* abbreviated as 'CWG' in other comments here
	18	* ftp.digital.com/pub/Digital/info/semiconductor/literature/dsc-library.html
	19	* Scheduling notation:
	20	* E - either cluster
	21	* U - upper subcluster; U0 - subcluster U0; U1 - subcluster U1
	22	* L - lower subcluster; L0 - subcluster L0; L1 - subcluster L1
	23	* Try not to change the actual algorithm if possible for consistency.
	24	*/
	25
	26	#include <asm/regdef.h>
	27
	28
	29	/* Allow an exception for an insn; exit if we get one. */
	30	#define EX(x,y...) \
	31	99: x,##y; \
	32	.section __ex_table,"a"; \
	33	.long 99b - .; \
	34	lda v0, $exception-99b(zero); \
	35	.previous
	36
	37
	38	.set noreorder
	39	.set noat
	40	.text
	41
	42	.globl __strlen_user
	43	.ent __strlen_user
	44	.frame sp, 0, ra
	45
	46	.align 4
	47	__strlen_user:
	48	ldah a1, 32767(zero) # do not use plain strlen_user() for strings
	49	# that might be almost 2 GB long; you should
	50	# be using strnlen_user() instead
	51	nop
	52	nop
	53	nop
	54
	55	.globl __strnlen_user
	56
	57	.align 4
	58	__strnlen_user:
	59	.prologue 0
	60	EX( ldq_u t0, 0(a0) ) # L : load first quadword (a0 may be misaligned)
	61	lda t1, -1(zero) # E :
	62
	63	insqh t1, a0, t1 # U :
	64	andnot a0, 7, v0 # E :
	65	or t1, t0, t0 # E :
	66	subq a0, 1, a0 # E : get our +1 for the return
	67
	68	cmpbge zero, t0, t1 # E : t1 <- bitmask: bit i == 1 <==> i-th byte == 0
	69	subq a1, 7, t2 # E :
	70	subq a0, v0, t0 # E :
	71	bne t1, $found # U :
	72
	73	addq t2, t0, t2 # E :
	74	addq a1, 1, a1 # E :
	75	nop # E :
	76	nop # E :
	77
	78	.align 4
	79	$loop: ble t2, $limit # U :
	80	EX( ldq t0, 8(v0) ) # L :
	81	nop # E :
	82	nop # E :
	83
	84	cmpbge zero, t0, t1 # E :
	85	subq t2, 8, t2 # E :
	86	addq v0, 8, v0 # E : addr += 8
	87	beq t1, $loop # U :
	88
	89	$found: cttz t1, t2 # U0 :
	90	addq v0, t2, v0 # E :
	91	subq v0, a0, v0 # E :
	92	ret # L0 :
	93
	94	$exception:
	95	nop
	96	nop
	97	nop
	98	ret
	99
	100	.align 4 # currently redundant
	101	$limit:
	102	nop
	103	nop
	104	subq a1, t2, v0
	105	ret
	106
	107	.end __strlen_user