ppc64: put paca in r13 and fix non zero boot cpu

arch/ppc64/kernel/entry.S

@@ -64,7 +64,8 @@ _GLOBAL(DoSyscall)
 #ifdef SHOW_SYSCALLS_TASK
 	LOADBASE(r31,show_syscalls_task)
 	ld	r31,show_syscalls_task@l(r31)
-	cmp	0,r13,r31
+	ld	r10,PACACURRENT(r13)
+	cmp	0,r10,r31
 	bne	1f
 #endif
 	LOADADDR(r3,7f)
@@ -78,7 +79,7 @@ _GLOBAL(DoSyscall)
 	LOADADDR(r3,77f)
 	ld	r4,GPR8(r1)
 	ld	r5,GPR9(r1)
-	mr	r6,r13
+	ld	r6, PACACURRENT(r13)
 	bl	.printk
 	ld	r0,GPR0(r1)
 	ld	r3,GPR3(r1)
@@ -129,7 +130,8 @@ _GLOBAL(ret_from_syscall_1)
 20:	std	r3,RESULT(r1)	/* Save result */
 #ifdef SHOW_SYSCALLS
 #ifdef SHOW_SYSCALLS_TASK
-	cmp	0,r13,r31
+	ld	r10, PACACURRENT(13)
+	cmp	0,r10,r31
 	bne	91f
 #endif
 	mr	r4,r3
@@ -289,9 +291,8 @@ _GLOBAL(_switch)
 	std	r23,_CCR(r1)
 	std	r1,KSP(r3)	/* Set old stack pointer */
 
-	mfspr	r5,SPRG3	/* Get paca */
-	addi	r13,r4,-THREAD	/* Convert THREAD to 'current' */
-	std	r13,PACACURRENT(r5)	/* Set new 'current' */
+	addi	r6,r4,-THREAD	/* Convert THREAD to 'current' */
+	std	r6,PACACURRENT(r13)	/* Set new 'current' */
 
 #ifdef CONFIG_PPC_ISERIES
 #error fixme
@@ -335,6 +336,7 @@ irq_recheck:
 	CHECKANYINT(r3,r4)
 	beq+	4f	/* skip do_IRQ if no interrupts */
 
+#warning FIX ISERIES
 	mfspr	r5,SPRG3
 	li	r3,0
 	stb	r3,PACAPROCENABLED(r5)	/* ensure we are disabled */
@@ -370,9 +372,15 @@ recheck:
 	bne	do_work
 
 	addi	r0,r1,INT_FRAME_SIZE	/* size of frame */
-	std	r0,THREAD+KSP(r13)	/* save kernel stack pointer */
-	mfspr   r4,SPRG3		/* current task's PACA */
-	std	r1,PACAKSAVE(r4)	/* save exception stack pointer */
+	ld	r4,PACACURRENT(r13)
+	std	r0,THREAD+KSP(r4)	/* save kernel stack pointer */
+	std	r1,PACAKSAVE(r13)	/* save exception stack pointer */
+
+	/*
+	 * r13 is our per cpu area, only restore it if we are returning to
+	 * userspace
+	 */
+	REST_GPR(13,r1)
 
 restore:
 	ld	r3,_CTR(r1)
@@ -389,25 +397,33 @@ restore:
 	stdcx.	r0,0,r1		/* to clear the reservation */
 
 #ifdef DO_SOFT_DISABLE
+	/* XXX do this in do_work, r13 isnt valid here */
 	ld	r0,SOFTE(r1)
 	stb	r0,PACAPROCENABLED(r13)
 #endif
 
 	ld	r0,_MSR(r1)
 	mtspr	SRR1,r0
+
 	ld	r2,_CCR(r1)
 	mtcrf	0xFF,r2
 	ld	r2,_NIP(r1)
 	mtspr	SRR0,r2
-	REST_GPR(13,r1)
+
 	ld	r0,GPR0(r1)
 	ld	r2,GPR2(r1)
 	ld	r3,GPR3(r1)
 	ld	r4,GPR4(r1)
 	ld	r1,GPR1(r1)
 
+	/*
+	 *  What if we took an exception and stole this segment, we may
+	 * fault on the above addresses and globber SRR0/1. Should check RI
+	 * bit and repeat - Anton
+	 */
 	rfid
 
+/* Note: this must change if we start using the  TIF_NOTIFY_RESUME bit */
 do_work:
 	/* Enable interrupts */
 	ori	r10,r10,MSR_EE|MSR_RI
@@ -419,15 +435,12 @@ do_work:
 	b	recheck
 
 1:	andi.	r0,r3,_TIF_SIGPENDING
-	beq	2f
+	beq	recheck
 	li	r3,0
 	addi	r4,r1,STACK_FRAME_OVERHEAD
 	bl	.do_signal
 	b	recheck
 
-2:	/* nobody uses the TIF_NOTIFY_RESUME bit yet */
-	b	recheck
-
 /*
  * On CHRP, the Run-Time Abstraction Services (RTAS) have to be
  * called with the MMU off.
@@ -446,7 +459,7 @@ _GLOBAL(enter_rtas)
 	 * RTAS might touch to the stack.  (r0, r3-r13 are caller saved)
    	 */
 	SAVE_GPR(2, r1)			/* Save the TOC */
-	SAVE_GPR(13, r1)		/* Save current */
+	SAVE_GPR(13, r1)		/* Save paca */
 	SAVE_8GPRS(14, r1)		/* Save the non-volatiles */
 	SAVE_10GPRS(22, r1)		/* ditto */
 
@@ -465,14 +478,13 @@ _GLOBAL(enter_rtas)
 	mfsrr1	r10
 	std	r10,_SRR1(r1)
 
-	/* Unfortunatly, the stack pointer and the MSR are also clobbered,
-	 * so they are saved in the PACA (SPRG3) which allows us to restore
+	/* Unfortunately, the stack pointer and the MSR are also clobbered,
+	 * so they are saved in the PACA which allows us to restore
 	 * our original state after RTAS returns.
          */
-	mfspr	r4,SPRG3		/* Get PACA */
-	std	r1,PACAR1(r4)
+	std	r1,PACAR1(r13)
 	mfmsr	r6
-        std	r6,PACASAVEDMSR(r4)
+        std	r6,PACASAVEDMSR(r13)
 
 	/* Setup our real return addr */	
 	SET_REG_TO_LABEL(r4,.rtas_return_loc)
@@ -516,13 +528,11 @@ _STATIC(rtas_return_loc)
 _STATIC(rtas_restore_regs)
 	/* relocation is on at this point */
 	REST_GPR(2, r1)			/* Restore the TOC */
-	REST_GPR(13, r1)		/* Restore current */
+	REST_GPR(13, r1)		/* Restore paca */
 	REST_8GPRS(14, r1)		/* Restore the non-volatiles */
 	REST_10GPRS(22, r1)		/* ditto */
 
-	/* put back current in r13 */
-        mfspr	r4,SPRG3
-	ld	r13,PACACURRENT(r4)
+	mfspr	r13,SPRG3
 
 	ld	r4,_CCR(r1)
 	mtcr	r4
@@ -555,7 +565,7 @@ _GLOBAL(enter_prom)
 	 * PROM might touch to the stack.  (r0, r3-r13 are caller saved)
    	 */
 	SAVE_8GPRS(2, r1)		/* Save the TOC & incoming param(s) */
-	SAVE_GPR(13, r1)		/* Save current */
+	SAVE_GPR(13, r1)		/* Save paca */
 	SAVE_8GPRS(14, r1)		/* Save the non-volatiles */
 	SAVE_10GPRS(22, r1)		/* ditto */
 
@@ -600,7 +610,7 @@ _GLOBAL(enter_prom)
         isync
 
 	REST_8GPRS(2, r1)		/* Restore the TOC & param(s) */
-	REST_GPR(13, r1)		/* Restore current */
+	REST_GPR(13, r1)		/* Restore paca */
 	REST_8GPRS(14, r1)		/* Restore the non-volatiles */
 	REST_10GPRS(22, r1)		/* ditto */
 	blrl				/* Entering PROM here... */
@@ -611,7 +621,7 @@ _GLOBAL(enter_prom)
         isync
 
 	REST_GPR(2, r1)			/* Restore the TOC */
-	REST_GPR(13, r1)		/* Restore current */
+	REST_GPR(13, r1)		/* Restore paca */
 	REST_8GPRS(14, r1)		/* Restore the non-volatiles */
 	REST_10GPRS(22, r1)		/* ditto */
 

arch/ppc64/kernel/misc.S

@@ -66,6 +66,7 @@ _GLOBAL(get_sp)
 #ifdef CONFIG_PPC_ISERIES
 /* unsigned long __no_use_save_flags(void) */
 _GLOBAL(__no_use_save_flags)
+#warning FIX ISERIES
 	mfspr	r4,SPRG3
 	lbz	r3,PACAPROCENABLED(r4)
 	blr
@@ -78,6 +79,7 @@ _GLOBAL(__no_use_restore_flags)
  * sense anyway.
  *    -- Cort
  */
+#warning FIX ISERIES
 	mfspr	r6,SPRG3
 	lbz	r5,PACAPROCENABLED(r6)
 	 /* Check if things are setup the way we want _already_. */
@@ -99,6 +101,7 @@ _GLOBAL(__no_use_restore_flags)
 	blr
 
 _GLOBAL(__no_use_cli)
+#warning FIX ISERIES
 	mfspr	r5,SPRG3
 	lbz	r3,PACAPROCENABLED(r5)
 	li	r4,0
@@ -106,6 +109,7 @@ _GLOBAL(__no_use_cli)
 	blr			/* Done */
 
 _GLOBAL(__no_use_sti)
+#warning FIX ISERIES
 	mfspr	r6,SPRG3
 	li	r3,1
 	stb	r3,PACAPROCENABLED(r6)

arch/ppc64/kernel/process.c

@@ -175,9 +175,8 @@ copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 	childregs = (struct pt_regs *) sp;
 	*childregs = *regs;
 	if ((childregs->msr & MSR_PR) == 0) {
-		/* for kernel thread, set `current' and stackptr in new task */
+		/* for kernel thread, set stackptr in new task */
 		childregs->gpr[1] = sp + sizeof(struct pt_regs);
-		childregs->gpr[13] = (unsigned long) p;
 		p->thread.regs = NULL;	/* no user register state */
 		clear_ti_thread_flag(p->thread_info, TIF_32BIT);
 #ifdef CONFIG_PPC_ISERIES

arch/ppc64/kernel/smp.c

@@ -152,6 +152,7 @@ static void smp_iSeries_probe(void)
 	for (i=0; i < MAX_PACAS; ++i) {
 		lpPaca = paca[i].xLpPacaPtr;
 		if ( lpPaca->xDynProcStatus < 2 ) {
+			paca[i].active = 1;
 			++np;
 			paca[i].next_jiffy_update_tb = paca[0].next_jiffy_update_tb;
 		}

arch/ppc64/kernel/time.c

@@ -269,7 +269,7 @@ int timer_interrupt(struct pt_regs * regs)
 #ifdef CONFIG_SMP
 		smp_local_timer_interrupt(regs);
 #endif
-		if (cpu == 0) {
+		if (cpu == boot_cpuid) {
 			write_lock(&xtime_lock);
 			tb_last_stamp = lpaca->next_jiffy_update_tb;
 			do_timer(regs);

include/asm-ppc64/current.h

 #ifndef _PPC64_CURRENT_H
 #define _PPC64_CURRENT_H
 
+#include <asm/paca.h>
+
 /*
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -10,6 +12,9 @@
  * Use r13 for current since the ppc64 ABI reserves it - Anton
  */
 
-register struct task_struct *current asm ("r13");
+#include <asm/thread_info.h>
+
+#define get_current()   ((struct task_struct *)(get_paca()->xCurrent))
+#define current         get_current()
 
 #endif /* !(_PPC64_CURRENT_H) */

include/asm-ppc64/paca.h

@@ -45,7 +45,8 @@
 #define MAX_PACAS MAX_PROCESSORS * 2
 
 extern struct paca_struct paca[];
-#define get_paca() ((struct paca_struct *)mfspr(SPRG3))
+register struct paca_struct *local_paca asm("r13");
+#define get_paca()	local_paca
 
 /*============================================================================
  * Name_______:	paca