[xtensa-cvscommit] linux/arch/xtensa/kernel sys.S,1.3,1.4 sysxtensa.c,1.2,1.3

[<joe...@us...>]

Update of /cvsroot/xtensa/linux/arch/xtensa/kernel
In directory sc8-pr-cvs1:/tmp/cvs-serv5812/arch/xtensa/kernel

Modified Files:
	sys.S sysxtensa.c 
Log Message:

Add kernel support for additional atomic operations that user tasks cannot perform themselves.  glibc will use them.

Index: sys.S
===================================================================
RCS file: /cvsroot/xtensa/linux/arch/xtensa/kernel/sys.S,v
retrieving revision 1.3
retrieving revision 1.4
diff -C2 -d -r1.3 -r1.4
*** sys.S	13 Feb 2003 00:17:21 -0000	1.3
--- sys.S	21 Mar 2003 18:11:53 -0000	1.4
***************
*** 98,102 ****
  	/* Same as handle_sys_kernel, except user-mode version.  The
  	 * distinct kernel and user versions avoid the overhead of
! 	 * testing PS.PSTK bit to determine whether to branch to
  	 * handle_kernel or handle_user. */
  
--- 98,102 ----
  	/* Same as handle_sys_kernel, except user-mode version.  The
  	 * distinct kernel and user versions avoid the overhead of
! 	 * testing PS.UM bit to determine whether to branch to
  	 * handle_kernel or handle_user. */
  
***************
*** 207,210 ****
--- 207,212 ----
  
  
+ /* XTFIXME:  The last three unhandled cases present an optimization opportunity. */
+ 
  	.data
  	.align	4
***************
*** 212,217 ****
  	.word	quick_unhandled
  	.word	quick_atomic_set
  
! #if XTENSA_SYSXTENSA_COUNT != 2
  #error Number of sysxtensa calls and registered handlers are different
  #endif
--- 214,222 ----
  	.word	quick_unhandled
  	.word	quick_atomic_set
+ 	.word	quick_unhandled
+ 	.word	quick_unhandled
+ 	.word	quick_unhandled
  
! #if XTENSA_SYSXTENSA_COUNT != 5
  #error Number of sysxtensa calls and registered handlers are different
  #endif
***************
*** 867,876 ****
  	/*  Make PS suitable for windowed-register calls in kernel:
  	 *	INTLEVEL = 0	// clear for panic() and printk()
! 	 *	EXCM = 0	// leave exception mode
! 	 *	PSTK (UM) = 0   // enter kernel mode
! 	 *	RING = 0	// assume kernel memory
! 	 *	OWB = 0		// don't care
! 	 *	CALLINC = 0	// don't care
! 	 *	WOE = 1		// required for "entry" insn
  	 */
  	movi	a7, XCHAL_PS_WOE_MASK
--- 872,881 ----
  	/*  Make PS suitable for windowed-register calls in kernel:
  	 *	INTLEVEL = 0	// clear for panic() and printk()
! 	 *	EXCM     = 0	// leave exception mode
! 	 *	UM       = 0	// enter kernel mode
! 	 *	RING     = 0	// assume kernel memory
! 	 *	OWB      = 0	// don't care
! 	 *	CALLINC  = 0	// don't care
! 	 *	WOE      = 1	// required for "entry" insn
  	 */
  	movi	a7, XCHAL_PS_WOE_MASK

Index: sysxtensa.c
===================================================================
RCS file: /cvsroot/xtensa/linux/arch/xtensa/kernel/sysxtensa.c,v
retrieving revision 1.2
retrieving revision 1.3
diff -C2 -d -r1.2 -r1.3
*** sysxtensa.c	28 Feb 2003 01:53:09 -0000	1.2
--- sysxtensa.c	21 Mar 2003 18:11:53 -0000	1.3
***************
*** 31,37 ****
  
  	switch(cmd) {
! 	case XTENSA_ATOMIC_SET: {
  
  		/* Sets value atomically and returns original value. */
  
  		p = (int *) arg1;
--- 31,39 ----
  
  	switch(cmd) {
! 	case XTENSA_ATOMIC_SET:
! 	{
  
  		/* Sets value atomically and returns original value. */
+ 		/* int sysxtensa (XTENSA_ATOMIC_SET, ptr, val, unused); */
  
  		p = (int *) arg1;
***************
*** 59,62 ****
--- 61,141 ----
  			     : "=a" (tmp), "=a" (retval)
  			     : "a" (p), "a" (arg2), "i" (-EFAULT)
+ 			     : "a15"
+ 			     );
+ 		goto out;
+ 	}
+ 
+ 	case XTENSA_ATOMIC_EXG_ADD:
+ 	case XTENSA_ATOMIC_ADD:
+ 	{
+ 
+ 		/* Atomically add value to memory, return original value. */
+ 
+ 		/* int sysxtensa (XTENSA_ATOMIC_EXG_ADD, ptr, val, unused); */
+ 		/* int sysxtensa (XTENSA_ATOMIC_ADD,     ptr, val, unused); */
+ 
+ 		p = (int *) arg1;
+ 		retval = verify_area(VERIFY_WRITE, p, sizeof(*p));
+ 		if (retval)
+ 			return retval;
+ 
+ 		__asm__ __volatile__( 
+ 			     "     rsil    a15, "XTSTR(LOCKLEVEL)"\n"
+ 			     "1:   l32i    %1, %2, 0              \n"
+ 			     "     add     %3, %3, %1             \n"
+ 			     "2:   s32i    %3, %2, 0              \n"
+ 			     "5:   wsr     a15, "XTSTR(PS)"       \n"
+ 			     "     rsync                          \n"
+ 			     "     .section .fixup,\"ax\"         \n"
+ 			     "     .align  4                      \n"
+ 			     "6:   .word   5b                     \n"
+ 			     "7:   l32r    %0, 6b                 \n"
+ 			     "     movi    %1, %4                 \n"
+ 			     "     jx      %0                     \n"
+ 			     "     .previous                      \n"
+ 			     "     .section __ex_table,\"a\"      \n"
+ 			     "     .word   1b, 7b                 \n"
+ 			     "     .word   2b, 7b                 \n"
+ 			     "     .previous                      \n"
+ 			     : "=a" (tmp), "=a" (retval)
+ 			     : "a" (p), "a" (arg2), "i" (-EFAULT)
+ 			     : "a15"
+ 			     );
+ 		goto out;
+ 	}
+ 
+ 	case XTENSA_ATOMIC_CMP_SWP:
+ 	{
+ 		/* Atomically store newval iif *ptr == oldval */
+ 		/* int sysxtensa (XTENSA_ATOMIC_CMP_SWP, ptr, oldval, newval); */
+ 
+ 		p = (int *) arg1;
+ 		retval = verify_area(VERIFY_WRITE, p, sizeof(*p));
+ 		if (retval)
+ 			return retval;
+ 
+ 		__asm__ __volatile__( 
+ 			     "     rsil    a15, "XTSTR(LOCKLEVEL)"\n"
+ 			     "1:   l32i    %1, %2, 0              \n"
+ 			     "     beq     %1, %3, 2f		  \n"
+ 			     "     movi    %1, 0                  \n"
+ 			     "     j       5f                     \n"
+ 			     "2:   s32i    %4, %2, 0              \n"
+ 			     "     movi    %1, 1                  \n"
+ 			     "5:   wsr     a15, "XTSTR(PS)"       \n"
+ 			     "     rsync                          \n"
+ 			     "     .section .fixup,\"ax\"         \n"
+ 			     "     .align  4                      \n"
+ 			     "6:   .word   5b                     \n"
+ 			     "7:   l32r    %0, 6b                 \n"
+ 			     "     movi    %1, %5                 \n"
+ 			     "     jx      %0                     \n"
+ 			     "     .previous                      \n"
+ 			     "     .section __ex_table,\"a\"      \n"
+ 			     "     .word   1b, 7b                 \n"
+ 			     "     .word   2b, 7b                 \n"
+ 			     "     .previous                      \n"
+ 			     : "=a" (tmp), "=a" (retval)
+ 			     : "a" (p), "a" (arg2), "a" (arg3), "i" (-EFAULT)
  			     : "a15"
  			     );