X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/8ad349bb6ed4a0be06e34c92be0d98b92e078db4..5d5c5d0d5b79ade9a973d55186ffda2638ba2b6e:/osfmk/ppc/hw_lock.s

diff --git a/osfmk/ppc/hw_lock.s b/osfmk/ppc/hw_lock.s
index 3b49b7566..5d842da0d 100644
--- a/osfmk/ppc/hw_lock.s
+++ b/osfmk/ppc/hw_lock.s
@@ -40,6 +40,7 @@
 #define	WAIT_FLAG		0x02
 #define	WANT_UPGRADE	0x04
 #define	WANT_EXCL		0x08
+#define	PRIV_EXCL		0x8000
 
 #define TH_FN_OWNED		0x01
 
@@ -2012,8 +2013,10 @@ LEXT(lck_rw_lock_exclusive)
 			.globl	EXT(lock_write)
 LEXT(lock_write)
 #endif
+			lis		r7,0xFFFF
+			ori		r7,r7,(WANT_EXCL|WANT_UPGRADE|ILK_LOCKED)
 rwleloop:	lwarx	r5,RW_DATA,r3					; Grab the lock value
-			rlwinm.	r7,r5,30,1,31					; Can we have it?
+			and.	r8,r5,r7						; Can we have it?
 			ori		r6,r5,WANT_EXCL					; Mark Exclusive
 			bne--	rwlespin						; Branch if cannot be held
 			stwcx.	r6,RW_DATA,r3					; Update lock word
@@ -2046,14 +2049,21 @@ LEXT(lock_read)
 #endif
 rwlsloop:	lwarx	r5,RW_DATA,r3					; Grab the lock value
 			andi.	r7,r5,WANT_EXCL|WANT_UPGRADE|ILK_LOCKED	; Can we have it?
+			bne--	rwlsopt							; Branch if cannot be held
+rwlsloopres:
 			addis	r6,r5,1							; Increment read cnt
-			bne--	rwlsspin						; Branch if cannot be held
 			stwcx.	r6,RW_DATA,r3					; Update lock word
 			bne--	rwlsloop
 			.globl  EXT(rwlsPatch_isync)
 LEXT(rwlsPatch_isync)
 			isync
 			blr
+rwlsopt:
+			andi.	r7,r5,PRIV_EXCL|ILK_LOCKED		; Can we have it?
+			bne--	rwlsspin						; Branch if cannot be held
+			lis		r7,0xFFFF						; Get read cnt mask
+			and.	r8,r5,r7						; Is it shared
+			bne		rwlsloopres						; Branch if can be held
 rwlsspin:
 			li		r4,lgKillResv					; Killing field
 			stwcx.	r4,0,r4							; Kill it
@@ -2200,8 +2210,9 @@ rwtlsloop:	lwarx	r5,RW_DATA,r3					; Grab the lock value
 			andi.	r7,r5,ILK_LOCKED				; Test interlock flag
 			bne--	rwtlsspin						; Branch if interlocked
 			andi.	r7,r5,WANT_EXCL|WANT_UPGRADE	; So, can we have it?
+			bne--	rwtlsopt						; Branch if held exclusive
+rwtlsloopres:
 			addis	r6,r5,1							; Increment read cnt
-			bne--	rwtlsfail						; Branch if held exclusive
 			stwcx.	r6,RW_DATA,r3					; Update lock word
 			bne--	rwtlsloop
 			.globl  EXT(rwtlsPatch_isync)
@@ -2209,6 +2220,12 @@ LEXT(rwtlsPatch_isync)
 			isync
 			li		r3,1							; Return TRUE
 			blr
+rwtlsopt:
+			andi.	r7,r5,PRIV_EXCL					; Can we have it?
+			bne--	rwtlsfail						; Branch if cannot be held
+			lis		r7,0xFFFF						; Get read cnt mask
+			and.	r8,r5,r7						; Is it shared
+			bne		rwtlsloopres					; Branch if can be held
 rwtlsfail:
 			li		r3,0							; Return FALSE
 			blr