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* [PATCH] powerpc: Fix "attempt to move .org backwards" error
@ 2013-12-09 19:10 Mahesh J Salgaonkar
  2013-12-09 23:10 ` Stephen Rothwell
  0 siblings, 1 reply; 11+ messages in thread
From: Mahesh J Salgaonkar @ 2013-12-09 19:10 UTC (permalink / raw)
  To: linuxppc-dev, Benjamin Herrenschmidt
  Cc: Stephen Rothwell, linux-next, Paul Mackerras, Linux Kernel

From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>

With recent machine check patch series changes, The exception vectors
starting from 0x4300 are now overflowing with allyesconfig. Fix that by
moving machine_check_common and machine_check_handle_early code out of
that region to make enough room for exception vector area.

Fixes this build error reportes by Stephen:

arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
arch/powerpc/kernel/exceptions-64s.S:958: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:959: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:983: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:984: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:1003: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:1013: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:1014: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:1015: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:1016: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:1017: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:1018: Error: attempt to move .org backwards

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/exceptions-64s.S |  280 +++++++++++++++++-----------------
 1 file changed, 140 insertions(+), 140 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 862b9dd..b5c3313 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -768,146 +768,6 @@ kvmppc_skip_Hinterrupt:
 
 	STD_EXCEPTION_COMMON(0x100, system_reset, .system_reset_exception)
 
-	/*
-	 * Machine check is different because we use a different
-	 * save area: PACA_EXMC instead of PACA_EXGEN.
-	 */
-	.align	7
-	.globl machine_check_common
-machine_check_common:
-
-	mfspr	r10,SPRN_DAR
-	std	r10,PACA_EXGEN+EX_DAR(r13)
-	mfspr	r10,SPRN_DSISR
-	stw	r10,PACA_EXGEN+EX_DSISR(r13)
-	EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
-	FINISH_NAP
-	DISABLE_INTS
-	ld	r3,PACA_EXGEN+EX_DAR(r13)
-	lwz	r4,PACA_EXGEN+EX_DSISR(r13)
-	std	r3,_DAR(r1)
-	std	r4,_DSISR(r1)
-	bl	.save_nvgprs
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	.machine_check_exception
-	b	.ret_from_except
-
-#define MACHINE_CHECK_HANDLER_WINDUP			\
-	/* Clear MSR_RI before setting SRR0 and SRR1. */\
-	li	r0,MSR_RI;				\
-	mfmsr	r9;		/* get MSR value */	\
-	andc	r9,r9,r0;				\
-	mtmsrd	r9,1;		/* Clear MSR_RI */	\
-	/* Move original SRR0 and SRR1 into the respective regs */	\
-	ld	r9,_MSR(r1);				\
-	mtspr	SPRN_SRR1,r9;				\
-	ld	r3,_NIP(r1);				\
-	mtspr	SPRN_SRR0,r3;				\
-	ld	r9,_CTR(r1);				\
-	mtctr	r9;					\
-	ld	r9,_XER(r1);				\
-	mtxer	r9;					\
-	ld	r9,_LINK(r1);				\
-	mtlr	r9;					\
-	REST_GPR(0, r1);				\
-	REST_8GPRS(2, r1);				\
-	REST_GPR(10, r1);				\
-	ld	r11,_CCR(r1);				\
-	mtcr	r11;					\
-	/* Decrement paca->in_mce. */			\
-	lhz	r12,PACA_IN_MCE(r13);			\
-	subi	r12,r12,1;				\
-	sth	r12,PACA_IN_MCE(r13);			\
-	REST_GPR(11, r1);				\
-	REST_2GPRS(12, r1);				\
-	/* restore original r1. */			\
-	ld	r1,GPR1(r1)
-
-	/*
-	 * Handle machine check early in real mode. We come here with
-	 * ME=1, MMU (IR=0 and DR=0) off and using MC emergency stack.
-	 */
-	.align	7
-	.globl machine_check_handle_early
-machine_check_handle_early:
-BEGIN_FTR_SECTION
-	std	r0,GPR0(r1)	/* Save r0 */
-	EXCEPTION_PROLOG_COMMON_3(0x200)
-	bl	.save_nvgprs
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	.machine_check_early
-	ld	r12,_MSR(r1)
-#ifdef	CONFIG_PPC_P7_NAP
-	/*
-	 * Check if thread was in power saving mode. We come here when any
-	 * of the following is true:
-	 * a. thread wasn't in power saving mode
-	 * b. thread was in power saving mode with no state loss or
-	 *    supervisor state loss
-	 *
-	 * Go back to nap again if (b) is true.
-	 */
-	rlwinm.	r11,r12,47-31,30,31	/* Was it in power saving mode? */
-	beq	4f			/* No, it wasn;t */
-	/* Thread was in power saving mode. Go back to nap again. */
-	cmpwi	r11,2
-	bne	3f
-	/* Supervisor state loss */
-	li	r0,1
-	stb	r0,PACA_NAPSTATELOST(r13)
-3:	bl	.machine_check_queue_event
-	MACHINE_CHECK_HANDLER_WINDUP
-	GET_PACA(r13)
-	ld	r1,PACAR1(r13)
-	b	.power7_enter_nap_mode
-4:
-#endif
-	/*
-	 * Check if we are coming from hypervisor userspace. If yes then we
-	 * continue in host kernel in V mode to deliver the MC event.
-	 */
-	rldicl.	r11,r12,4,63		/* See if MC hit while in HV mode. */
-	beq	5f
-	andi.	r11,r12,MSR_PR		/* See if coming from user. */
-	bne	9f			/* continue in V mode if we are. */
-
-5:
-#ifdef CONFIG_KVM_BOOK3S_64_HV
-	/*
-	 * We are coming from kernel context. Check if we are coming from
-	 * guest. if yes, then we can continue. We will fall through
-	 * do_kvm_200->kvmppc_interrupt to deliver the MC event to guest.
-	 */
-	lbz	r11,HSTATE_IN_GUEST(r13)
-	cmpwi	r11,0			/* Check if coming from guest */
-	bne	9f			/* continue if we are. */
-#endif
-	/*
-	 * At this point we are not sure about what context we come from.
-	 * Queue up the MCE event and return from the interrupt.
-	 * But before that, check if this is an un-recoverable exception.
-	 * If yes, then stay on emergency stack and panic.
-	 */
-	andi.	r11,r12,MSR_RI
-	bne	2f
-1:	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	.unrecoverable_exception
-	b	1b
-2:
-	/*
-	 * Return from MC interrupt.
-	 * Queue up the MCE event so that we can log it later, while
-	 * returning from kernel or opal call.
-	 */
-	bl	.machine_check_queue_event
-	MACHINE_CHECK_HANDLER_WINDUP
-	rfid
-9:
-	/* Deliver the machine check to host kernel in V mode. */
-	MACHINE_CHECK_HANDLER_WINDUP
-	b	machine_check_pSeries
-END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
-
 	STD_EXCEPTION_COMMON_ASYNC(0x500, hardware_interrupt, do_IRQ)
 	STD_EXCEPTION_COMMON_ASYNC(0x900, decrementer, .timer_interrupt)
 	STD_EXCEPTION_COMMON(0x980, hdecrementer, .hdec_interrupt)
@@ -1458,6 +1318,146 @@ _GLOBAL(opal_mc_secondary_handler)
 	b	machine_check_pSeries
 #endif /* CONFIG_PPC_POWERNV */
 
+	/*
+	 * Machine check is different because we use a different
+	 * save area: PACA_EXMC instead of PACA_EXGEN.
+	 */
+	.align	7
+	.globl machine_check_common
+machine_check_common:
+
+	mfspr	r10,SPRN_DAR
+	std	r10,PACA_EXGEN+EX_DAR(r13)
+	mfspr	r10,SPRN_DSISR
+	stw	r10,PACA_EXGEN+EX_DSISR(r13)
+	EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
+	FINISH_NAP
+	DISABLE_INTS
+	ld	r3,PACA_EXGEN+EX_DAR(r13)
+	lwz	r4,PACA_EXGEN+EX_DSISR(r13)
+	std	r3,_DAR(r1)
+	std	r4,_DSISR(r1)
+	bl	.save_nvgprs
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	.machine_check_exception
+	b	.ret_from_except
+
+#define MACHINE_CHECK_HANDLER_WINDUP			\
+	/* Clear MSR_RI before setting SRR0 and SRR1. */\
+	li	r0,MSR_RI;				\
+	mfmsr	r9;		/* get MSR value */	\
+	andc	r9,r9,r0;				\
+	mtmsrd	r9,1;		/* Clear MSR_RI */	\
+	/* Move original SRR0 and SRR1 into the respective regs */	\
+	ld	r9,_MSR(r1);				\
+	mtspr	SPRN_SRR1,r9;				\
+	ld	r3,_NIP(r1);				\
+	mtspr	SPRN_SRR0,r3;				\
+	ld	r9,_CTR(r1);				\
+	mtctr	r9;					\
+	ld	r9,_XER(r1);				\
+	mtxer	r9;					\
+	ld	r9,_LINK(r1);				\
+	mtlr	r9;					\
+	REST_GPR(0, r1);				\
+	REST_8GPRS(2, r1);				\
+	REST_GPR(10, r1);				\
+	ld	r11,_CCR(r1);				\
+	mtcr	r11;					\
+	/* Decrement paca->in_mce. */			\
+	lhz	r12,PACA_IN_MCE(r13);			\
+	subi	r12,r12,1;				\
+	sth	r12,PACA_IN_MCE(r13);			\
+	REST_GPR(11, r1);				\
+	REST_2GPRS(12, r1);				\
+	/* restore original r1. */			\
+	ld	r1,GPR1(r1)
+
+	/*
+	 * Handle machine check early in real mode. We come here with
+	 * ME=1, MMU (IR=0 and DR=0) off and using MC emergency stack.
+	 */
+	.align	7
+	.globl machine_check_handle_early
+machine_check_handle_early:
+BEGIN_FTR_SECTION
+	std	r0,GPR0(r1)	/* Save r0 */
+	EXCEPTION_PROLOG_COMMON_3(0x200)
+	bl	.save_nvgprs
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	.machine_check_early
+	ld	r12,_MSR(r1)
+#ifdef	CONFIG_PPC_P7_NAP
+	/*
+	 * Check if thread was in power saving mode. We come here when any
+	 * of the following is true:
+	 * a. thread wasn't in power saving mode
+	 * b. thread was in power saving mode with no state loss or
+	 *    supervisor state loss
+	 *
+	 * Go back to nap again if (b) is true.
+	 */
+	rlwinm.	r11,r12,47-31,30,31	/* Was it in power saving mode? */
+	beq	4f			/* No, it wasn;t */
+	/* Thread was in power saving mode. Go back to nap again. */
+	cmpwi	r11,2
+	bne	3f
+	/* Supervisor state loss */
+	li	r0,1
+	stb	r0,PACA_NAPSTATELOST(r13)
+3:	bl	.machine_check_queue_event
+	MACHINE_CHECK_HANDLER_WINDUP
+	GET_PACA(r13)
+	ld	r1,PACAR1(r13)
+	b	.power7_enter_nap_mode
+4:
+#endif
+	/*
+	 * Check if we are coming from hypervisor userspace. If yes then we
+	 * continue in host kernel in V mode to deliver the MC event.
+	 */
+	rldicl.	r11,r12,4,63		/* See if MC hit while in HV mode. */
+	beq	5f
+	andi.	r11,r12,MSR_PR		/* See if coming from user. */
+	bne	9f			/* continue in V mode if we are. */
+
+5:
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+	/*
+	 * We are coming from kernel context. Check if we are coming from
+	 * guest. if yes, then we can continue. We will fall through
+	 * do_kvm_200->kvmppc_interrupt to deliver the MC event to guest.
+	 */
+	lbz	r11,HSTATE_IN_GUEST(r13)
+	cmpwi	r11,0			/* Check if coming from guest */
+	bne	9f			/* continue if we are. */
+#endif
+	/*
+	 * At this point we are not sure about what context we come from.
+	 * Queue up the MCE event and return from the interrupt.
+	 * But before that, check if this is an un-recoverable exception.
+	 * If yes, then stay on emergency stack and panic.
+	 */
+	andi.	r11,r12,MSR_RI
+	bne	2f
+1:	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	.unrecoverable_exception
+	b	1b
+2:
+	/*
+	 * Return from MC interrupt.
+	 * Queue up the MCE event so that we can log it later, while
+	 * returning from kernel or opal call.
+	 */
+	bl	.machine_check_queue_event
+	MACHINE_CHECK_HANDLER_WINDUP
+	rfid
+9:
+	/* Deliver the machine check to host kernel in V mode. */
+	MACHINE_CHECK_HANDLER_WINDUP
+	b	machine_check_pSeries
+END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
+
 
 /*
  * r13 points to the PACA, r9 contains the saved CR,

^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH] powerpc: Fix "attempt to move .org backwards" error
@ 2014-08-09  5:22 Guenter Roeck
  2014-08-11  0:20 ` Stephen Rothwell
  0 siblings, 1 reply; 11+ messages in thread
From: Guenter Roeck @ 2014-08-09  5:22 UTC (permalink / raw)
  To: Benjamin Herrenschmidt
  Cc: Mahesh Salgaonkar, linuxppc-dev, linux-kernel, Guenter Roeck

Once again, we see

arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
arch/powerpc/kernel/exceptions-64s.S:865: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:866: Error: attempt to move .org backwards
arch/powerpc/kernel/exceptions-64s.S:890: Error: attempt to move .org backwards

when compiling ppc:allmodconfig.

This time the problem has been caused by to commit 0869b6fd209bda
("powerpc/book3s: Add basic infrastructure to handle HMI in Linux"),
which adds functions hmi_exception_early and hmi_exception_after_realmode
into a critical (size-limited) code area, even though that does not appear
to be necessary.

Move those functions to a non-critical area of the file.

Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
Compile tested with all ppc configurations.
The reported checkpatch error appears to be a false positive.

 arch/powerpc/kernel/exceptions-64s.S | 110 +++++++++++++++++------------------
 1 file changed, 55 insertions(+), 55 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 6144d5a..050f79a 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -592,61 +592,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
 	MASKABLE_EXCEPTION_HV_OOL(0xe62, hmi_exception)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe62)
 
-	.globl hmi_exception_early
-hmi_exception_early:
-	EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, 0xe60)
-	mr	r10,r1			/* Save r1			*/
-	ld	r1,PACAEMERGSP(r13)	/* Use emergency stack		*/
-	subi	r1,r1,INT_FRAME_SIZE	/* alloc stack frame		*/
-	std	r9,_CCR(r1)		/* save CR in stackframe	*/
-	mfspr	r11,SPRN_HSRR0		/* Save HSRR0 */
-	std	r11,_NIP(r1)		/* save HSRR0 in stackframe	*/
-	mfspr	r12,SPRN_HSRR1		/* Save SRR1 */
-	std	r12,_MSR(r1)		/* save SRR1 in stackframe	*/
-	std	r10,0(r1)		/* make stack chain pointer	*/
-	std	r0,GPR0(r1)		/* save r0 in stackframe	*/
-	std	r10,GPR1(r1)		/* save r1 in stackframe	*/
-	EXCEPTION_PROLOG_COMMON_2(PACA_EXGEN)
-	EXCEPTION_PROLOG_COMMON_3(0xe60)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	hmi_exception_realmode
-	/* Windup the stack. */
-	/* Clear MSR_RI before setting SRR0 and SRR1. */
-	li	r0,MSR_RI
-	mfmsr	r9			/* get MSR value */
-	andc	r9,r9,r0
-	mtmsrd	r9,1			/* Clear MSR_RI */
-	/* Move original HSRR0 and HSRR1 into the respective regs */
-	ld	r9,_MSR(r1)
-	mtspr	SPRN_HSRR1,r9
-	ld	r3,_NIP(r1)
-	mtspr	SPRN_HSRR0,r3
-	ld	r9,_CTR(r1)
-	mtctr	r9
-	ld	r9,_XER(r1)
-	mtxer	r9
-	ld	r9,_LINK(r1)
-	mtlr	r9
-	REST_GPR(0, r1)
-	REST_8GPRS(2, r1)
-	REST_GPR(10, r1)
-	ld	r11,_CCR(r1)
-	mtcr	r11
-	REST_GPR(11, r1)
-	REST_2GPRS(12, r1)
-	/* restore original r1. */
-	ld	r1,GPR1(r1)
-
-	/*
-	 * Go to virtual mode and pull the HMI event information from
-	 * firmware.
-	 */
-	.globl hmi_exception_after_realmode
-hmi_exception_after_realmode:
-	SET_SCRATCH0(r13)
-	EXCEPTION_PROLOG_0(PACA_EXGEN)
-	b	hmi_exception_hv
-
 	MASKABLE_EXCEPTION_HV_OOL(0xe82, h_doorbell)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe82)
 
@@ -1306,6 +1251,61 @@ fwnmi_data_area:
 	. = 0x8000
 #endif /* defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV) */
 
+	.globl hmi_exception_early
+hmi_exception_early:
+	EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, 0xe60)
+	mr	r10,r1			/* Save r1			*/
+	ld	r1,PACAEMERGSP(r13)	/* Use emergency stack		*/
+	subi	r1,r1,INT_FRAME_SIZE	/* alloc stack frame		*/
+	std	r9,_CCR(r1)		/* save CR in stackframe	*/
+	mfspr	r11,SPRN_HSRR0		/* Save HSRR0 */
+	std	r11,_NIP(r1)		/* save HSRR0 in stackframe	*/
+	mfspr	r12,SPRN_HSRR1		/* Save SRR1 */
+	std	r12,_MSR(r1)		/* save SRR1 in stackframe	*/
+	std	r10,0(r1)		/* make stack chain pointer	*/
+	std	r0,GPR0(r1)		/* save r0 in stackframe	*/
+	std	r10,GPR1(r1)		/* save r1 in stackframe	*/
+	EXCEPTION_PROLOG_COMMON_2(PACA_EXGEN)
+	EXCEPTION_PROLOG_COMMON_3(0xe60)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	hmi_exception_realmode
+	/* Windup the stack. */
+	/* Clear MSR_RI before setting SRR0 and SRR1. */
+	li	r0,MSR_RI
+	mfmsr	r9			/* get MSR value */
+	andc	r9,r9,r0
+	mtmsrd	r9,1			/* Clear MSR_RI */
+	/* Move original HSRR0 and HSRR1 into the respective regs */
+	ld	r9,_MSR(r1)
+	mtspr	SPRN_HSRR1,r9
+	ld	r3,_NIP(r1)
+	mtspr	SPRN_HSRR0,r3
+	ld	r9,_CTR(r1)
+	mtctr	r9
+	ld	r9,_XER(r1)
+	mtxer	r9
+	ld	r9,_LINK(r1)
+	mtlr	r9
+	REST_GPR(0, r1)
+	REST_8GPRS(2, r1)
+	REST_GPR(10, r1)
+	ld	r11,_CCR(r1)
+	mtcr	r11
+	REST_GPR(11, r1)
+	REST_2GPRS(12, r1)
+	/* restore original r1. */
+	ld	r1,GPR1(r1)
+
+	/*
+	 * Go to virtual mode and pull the HMI event information from
+	 * firmware.
+	 */
+	.globl hmi_exception_after_realmode
+hmi_exception_after_realmode:
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
+	b	hmi_exception_hv
+
 #ifdef CONFIG_PPC_POWERNV
 _GLOBAL(opal_mc_secondary_handler)
 	HMT_MEDIUM_PPR_DISCARD
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 11+ messages in thread
* [PATCH] powerpc: Fix "attempt to move .org backwards" error
@ 2013-04-26  3:51 Paul Mackerras
  2013-04-26  4:13 ` Chen Gang
  2013-04-27  9:34 ` Mike Qiu
  0 siblings, 2 replies; 11+ messages in thread
From: Paul Mackerras @ 2013-04-26  3:51 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Chen Gang, Mike Qiu

Building a 64-bit powerpc kernel with PR KVM enabled currently gives
this error:

  AS      arch/powerpc/kernel/head_64.o
arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
arch/powerpc/kernel/exceptions-64s.S:258: Error: attempt to move .org backwards
make[2]: *** [arch/powerpc/kernel/head_64.o] Error 1

This happens because the MASKABLE_EXCEPTION_PSERIES macro turns into
33 instructions, but we only have space for 32 at the decrementer
interrupt vector (from 0x900 to 0x980).

In the code generated by the MASKABLE_EXCEPTION_PSERIES macro, we
currently have two instances of the HMT_MEDIUM macro, which has the
effect of setting the SMT thread priority to medium.  One is the
first instruction, and is overwritten by a no-op on processors where
we save the PPR (processor priority register), that is, POWER7 or
later.  The other is after we have saved the PPR.

In order to reduce the code at 0x900 by one instruction, we omit the
first HMT_MEDIUM.  On processors without SMT this will have no effect
since HMT_MEDIUM is a no-op there.  On POWER5 and RS64 machines this
will mean that the first few instructions take a little longer in the
case where a decrementer interrupt occurs when the hardware thread is
running at low SMT priority.  On POWER6 and later machines, the
hardware automatically boosts the thread priority when a decrementer
interrupt is taken if the thread priority was below medium, so this
change won't make any difference.

The alternative would be to branch out of line after saving the CFAR.
However, that would incur an extra overhead on all processors, whereas
the approach adopted here only adds overhead on older threaded processors.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/include/asm/exception-64s.h |    2 +-
 arch/powerpc/kernel/exceptions-64s.S     |    7 ++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 05e6d2e..8e5fae8 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -414,7 +414,6 @@ label##_relon_hv:						\
 #define SOFTEN_NOTEST_HV(vec)		_SOFTEN_TEST(EXC_HV, vec)
 
 #define __MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)		\
-	HMT_MEDIUM_PPR_DISCARD;						\
 	SET_SCRATCH0(r13);    /* save r13 */				\
 	EXCEPTION_PROLOG_0(PACA_EXGEN);					\
 	__EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec);			\
@@ -427,6 +426,7 @@ label##_relon_hv:						\
 	. = loc;							\
 	.globl label##_pSeries;						\
 label##_pSeries:							\
+	HMT_MEDIUM_PPR_DISCARD;						\
 	_MASKABLE_EXCEPTION_PSERIES(vec, label,				\
 				    EXC_STD, SOFTEN_TEST_PR)
 
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 56bd923..574db3f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -235,6 +235,7 @@ instruction_access_slb_pSeries:
 	.globl hardware_interrupt_hv;
 hardware_interrupt_pSeries:
 hardware_interrupt_hv:
+	HMT_MEDIUM_PPR_DISCARD
 	BEGIN_FTR_SECTION
 		_MASKABLE_EXCEPTION_PSERIES(0x502, hardware_interrupt,
 					    EXC_HV, SOFTEN_TEST_HV)
@@ -254,7 +255,11 @@ hardware_interrupt_hv:
 	STD_EXCEPTION_PSERIES(0x800, 0x800, fp_unavailable)
 	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0x800)
 
-	MASKABLE_EXCEPTION_PSERIES(0x900, 0x900, decrementer)
+	. = 0x900
+	.globl decrementer_pSeries
+decrementer_pSeries:
+	_MASKABLE_EXCEPTION_PSERIES(0x900, decrementer, EXC_STD, SOFTEN_TEST_PR)
+
 	STD_EXCEPTION_HV(0x980, 0x982, hdecrementer)
 
 	MASKABLE_EXCEPTION_PSERIES(0xa00, 0xa00, doorbell_super)
-- 
1.7.10.4

^ permalink raw reply related	[flat|nested] 11+ messages in thread
end of thread, other threads:[~2014-08-11 16:25 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-12-09 19:10 [PATCH] powerpc: Fix "attempt to move .org backwards" error Mahesh J Salgaonkar
2013-12-09 23:10 ` Stephen Rothwell
2013-12-09 23:26   ` Benjamin Herrenschmidt
2014-02-12  5:22     ` Stephen Rothwell
2014-02-15 18:02       ` Guenter Roeck
  -- strict thread matches above, loose matches on Subject: below --
2014-08-09  5:22 Guenter Roeck
2014-08-11  0:20 ` Stephen Rothwell
2014-08-11 16:25   ` Guenter Roeck
2013-04-26  3:51 Paul Mackerras
2013-04-26  4:13 ` Chen Gang
2013-04-27  9:34 ` Mike Qiu

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