[PATCH v2 0/2] Add POWER9 DD2.0 feature, remove idle workarounds in DD2.1

STALE3237d

5 messages, 2 authors, 2017-11-03 · open the first message on its own page

[PATCH v2 0/2] Add POWER9 DD2.0 feature, remove idle workarounds in DD2.1

From: Nicholas Piggin <npiggin@gmail.com>
Date: 2017-11-02 01:55:46

Chnages since v1:
- Change unnecessarily 'inverted else' conditions for the DD2.0
  feature workarounds, noted by mpe.
- One of the cases was incorrect, removing the code in for DD2.0 and
  leaving it in for 2.1. Performance is further slightly improved with
  this case fixed.
  

Nicholas Piggin (2):
  powerpc: add POWER9_DD20 feature
  powerpc/64s: idle skip POWER9 DD1 and DD2.0 specific workarounds on
    DD2.1

 arch/powerpc/include/asm/cputable.h |  5 ++++-
 arch/powerpc/kernel/cputable.c      | 20 ++++++++++++++++++++
 arch/powerpc/kernel/dt_cpu_ftrs.c   |  2 ++
 arch/powerpc/kernel/idle_book3s.S   | 31 ++++++++++++++++++++-----------
 4 files changed, 46 insertions(+), 12 deletions(-)

-- 
2.15.0

[PATCH v2 1/2] powerpc: add POWER9_DD20 feature

From: Nicholas Piggin <npiggin@gmail.com>
Date: 2017-11-02 01:55:49

Cc: Michael Neuling <redacted>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/cputable.h |  5 ++++-
 arch/powerpc/kernel/cputable.c      | 20 ++++++++++++++++++++
 arch/powerpc/kernel/dt_cpu_ftrs.c   |  2 ++
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index a9bf921f4efc..194dc3006446 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h

@@ -215,6 +215,7 @@ enum {
 #define CPU_FTR_DABRX			LONG_ASM_CONST(0x0800000000000000)
 #define CPU_FTR_PMAO_BUG		LONG_ASM_CONST(0x1000000000000000)
 #define CPU_FTR_POWER9_DD1		LONG_ASM_CONST(0x4000000000000000)
+#define CPU_FTR_POWER9_DD20		LONG_ASM_CONST(0x8000000000000000)
 
 #ifndef __ASSEMBLY__

@@ -477,6 +478,7 @@ enum {
 	    CPU_FTR_ARCH_207S | CPU_FTR_TM_COMP | CPU_FTR_ARCH_300)
 #define CPU_FTRS_POWER9_DD1 ((CPU_FTRS_POWER9 | CPU_FTR_POWER9_DD1) & \
 			     (~CPU_FTR_SAO))
+#define CPU_FTRS_POWER9_DD20 (CPU_FTRS_POWER9 | CPU_FTR_POWER9_DD20)
 #define CPU_FTRS_CELL	(CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
 	    CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    CPU_FTR_ALTIVEC_COMP | CPU_FTR_MMCRA | CPU_FTR_SMT | \

@@ -495,7 +497,8 @@ enum {
 	    (CPU_FTRS_POWER4 | CPU_FTRS_PPC970 | CPU_FTRS_POWER5 | \
 	     CPU_FTRS_POWER6 | CPU_FTRS_POWER7 | CPU_FTRS_POWER8E | \
 	     CPU_FTRS_POWER8 | CPU_FTRS_POWER8_DD1 | CPU_FTRS_CELL | \
-	     CPU_FTRS_PA6T | CPU_FTR_VSX | CPU_FTRS_POWER9 | CPU_FTRS_POWER9_DD1)
+	     CPU_FTRS_PA6T | CPU_FTR_VSX | CPU_FTRS_POWER9 | \
+	     CPU_FTRS_POWER9_DD1 | CPU_FTRS_POWER9_DD20)
 #endif
 #else
 enum {

diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index 760872916013..171820190de7 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c

@@ -547,6 +547,26 @@ static struct cpu_spec __initdata cpu_specs[] = {
 		.machine_check_early	= __machine_check_early_realmode_p9,
 		.platform		= "power9",
 	},
+	{	/* Power9 DD2.0 */
+		.pvr_mask		= 0xffffefff,
+		.pvr_value		= 0x004e0200,
+		.cpu_name		= "POWER9 (raw)",
+		.cpu_features		= CPU_FTRS_POWER9_DD20,
+		.cpu_user_features	= COMMON_USER_POWER9,
+		.cpu_user_features2	= COMMON_USER2_POWER9,
+		.mmu_features		= MMU_FTRS_POWER9,
+		.icache_bsize		= 128,
+		.dcache_bsize		= 128,
+		.num_pmcs		= 6,
+		.pmc_type		= PPC_PMC_IBM,
+		.oprofile_cpu_type	= "ppc64/power9",
+		.oprofile_type		= PPC_OPROFILE_INVALID,
+		.cpu_setup		= __setup_cpu_power9,
+		.cpu_restore		= __restore_cpu_power9,
+		.flush_tlb		= __flush_tlb_power9,
+		.machine_check_early	= __machine_check_early_realmode_p9,
+		.platform		= "power9",
+	},
 	{	/* Power9 */
 		.pvr_mask		= 0xffff0000,
 		.pvr_value		= 0x004e0000,

diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index 7275fed271af..63b9d7edd63f 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c

@@ -735,6 +735,8 @@ static __init void cpufeatures_cpu_quirks(void)
 	 */
 	if ((version & 0xffffff00) == 0x004e0100)
 		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD1;
+	else if ((version & 0xffffefff) == 0x004e0200)
+		cur_cpu_spec->cpu_features |= CPU_FTR_POWER9_DD20;
 }
 
 static void __init cpufeatures_setup_finished(void)

-- 
2.15.0

[PATCH v2 2/2] powerpc/64s: idle skip POWER9 DD1 and DD2.0 specific workarounds on DD2.1

From: Nicholas Piggin <npiggin@gmail.com>
Date: 2017-11-02 01:55:51

DD2.1 does not have to flush the ERAT after a state-loss idle. It also
does not have to save and restore MMCR0 (although it does have to save
restore in deep idle states, like other PMU registers).

Performance testing was done on a DD2.1 using only the stop0 idle state
(the shallowest state which supports state loss), using context_switch
selftest configured to ping-poing between two threads on the same core
and two different cores.

Performance improvement for same core is 7.0%, different cores is 14.8%.

Reviewed-by: Vaidyanathan Srinivasan <redacted>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/idle_book3s.S | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 175d49f468af..59657783d1d5 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S

@@ -112,12 +112,14 @@ power9_save_additional_sprs:
 	std	r4, STOP_HFSCR(r13)
 
 	mfspr	r3, SPRN_MMCRA
-	mfspr	r4, SPRN_MMCR1
+	mfspr	r4, SPRN_MMCR0
 	std	r3, STOP_MMCRA(r13)
-	std	r4, STOP_MMCR1(r13)
+	std	r4, _MMCR0(r1)
 
-	mfspr	r3, SPRN_MMCR2
-	std	r3, STOP_MMCR2(r13)
+	mfspr	r3, SPRN_MMCR1
+	mfspr	r4, SPRN_MMCR2
+	std	r3, STOP_MMCR1(r13)
+	std	r4, STOP_MMCR2(r13)
 	blr
 
 power9_restore_additional_sprs:

@@ -135,11 +137,14 @@ power9_restore_additional_sprs:
 	ld	r4, STOP_MMCRA(r13)
 	mtspr	SPRN_HFSCR, r3
 	mtspr	SPRN_MMCRA, r4
-	/* We have already restored PACA_MMCR0 */
-	ld	r3, STOP_MMCR1(r13)
-	ld	r4, STOP_MMCR2(r13)
-	mtspr	SPRN_MMCR1, r3
-	mtspr	SPRN_MMCR2, r4
+
+	ld	r3, _MMCR0(r1)
+	ld	r4, STOP_MMCR1(r13)
+	mtspr	SPRN_MMCR0, r3
+	mtspr	SPRN_MMCR1, r4
+
+	ld	r3, STOP_MMCR2(r13)
+	mtspr	SPRN_MMCR2, r3
 	blr
 
 /*

@@ -350,6 +355,7 @@ power_enter_stop:
 	b 	pnv_wakeup_noloss
 
 .Lhandle_esl_ec_set:
+BEGIN_FTR_SECTION
 	/*
 	 * POWER9 DD2 can incorrectly set PMAO when waking up after a
 	 * state-loss idle. Saving and restoring MMCR0 over idle is a

@@ -357,6 +363,7 @@ power_enter_stop:
 	 */
 	mfspr	r4,SPRN_MMCR0
 	std	r4,_MMCR0(r1)
+END_FTR_SECTION_IFSET(CPU_FTR_POWER9_DD1 | CPU_FTR_POWER9_DD20)
 
 /*
  * Check if the requested state is a deep idle state.

@@ -542,15 +549,17 @@ pnv_restore_hyp_resource_arch300:
 	 * then clear bit 60 in MMCRA to ensure the PMU starts running.
 	 */
 	blt	cr3,1f
+BEGIN_FTR_SECTION
 	PPC_INVALIDATE_ERAT
 	ld	r1,PACAR1(r13)
+	ld	r4,_MMCR0(r1)
+	mtspr	SPRN_MMCR0,r4
+END_FTR_SECTION_IFSET(CPU_FTR_POWER9_DD1 | CPU_FTR_POWER9_DD20)
 	mfspr	r4,SPRN_MMCRA
 	ori	r4,r4,(1 << (63-60))
 	mtspr	SPRN_MMCRA,r4
 	xori	r4,r4,(1 << (63-60))
 	mtspr	SPRN_MMCRA,r4
-	ld	r4,_MMCR0(r1)
-	mtspr	SPRN_MMCR0,r4
 1:
 	/*
 	 * POWER ISA 3. Use PSSCR to determine if we

-- 
2.15.0

Re: [PATCH v2 2/2] powerpc/64s: idle skip POWER9 DD1 and DD2.0 specific workarounds on DD2.1

From: Michael Neuling <hidden>
Date: 2017-11-03 01:13:19

On Thu, 2017-11-02 at 12:55 +1100, Nicholas Piggin wrote:

DD2.1 does not have to flush the ERAT after a state-loss idle. It also
does not have to save and restore MMCR0 (although it does have to save
restore in deep idle states, like other PMU registers).

Minor nit, can we do this as two separate commits in case we discover one i=
s
broken.

Performance testing was done on a DD2.1 using only the stop0 idle state
(the shallowest state which supports state loss), using context_switch
selftest configured to ping-poing between two threads on the same core
and two different cores.
=20
Performance improvement for same core is 7.0%, different cores is 14.8%.

Noice!

quoted hunk

Reviewed-by: Vaidyanathan Srinivasan <redacted>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/idle_book3s.S | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)
=20

diff --git a/arch/powerpc/kernel/idle_book3s.S

b/arch/powerpc/kernel/idle_book3s.S
index 175d49f468af..59657783d1d5 100644

--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S

@@ -112,12 +112,14 @@ power9_save_additional_sprs:
 	std	r4, STOP_HFSCR(r13)

=20
 	mfspr	r3, SPRN_MMCRA
-	mfspr	r4, SPRN_MMCR1
+	mfspr	r4, SPRN_MMCR0
 	std	r3, STOP_MMCRA(r13)
-	std	r4, STOP_MMCR1(r13)
+	std	r4, _MMCR0(r1)
=20
-	mfspr	r3, SPRN_MMCR2
-	std	r3, STOP_MMCR2(r13)
+	mfspr	r3, SPRN_MMCR1
+	mfspr	r4, SPRN_MMCR2
+	std	r3, STOP_MMCR1(r13)
+	std	r4, STOP_MMCR2(r13)
 	blr
=20
 power9_restore_additional_sprs:

@@ -135,11 +137,14 @@ power9_restore_additional_sprs:
 	ld	r4, STOP_MMCRA(r13)
 	mtspr	SPRN_HFSCR, r3
 	mtspr	SPRN_MMCRA, r4
-	/* We have already restored PACA_MMCR0 */
-	ld	r3, STOP_MMCR1(r13)
-	ld	r4, STOP_MMCR2(r13)
-	mtspr	SPRN_MMCR1, r3
-	mtspr	SPRN_MMCR2, r4
+
+	ld	r3, _MMCR0(r1)
+	ld	r4, STOP_MMCR1(r13)
+	mtspr	SPRN_MMCR0, r3
+	mtspr	SPRN_MMCR1, r4
+
+	ld	r3, STOP_MMCR2(r13)
+	mtspr	SPRN_MMCR2, r3
 	blr

=20
 /*

@@ -350,6 +355,7 @@ power_enter_stop:
 	b 	pnv_wakeup_noloss

=20
 .Lhandle_esl_ec_set:
+BEGIN_FTR_SECTION
 	/*
 	 * POWER9 DD2 can incorrectly set PMAO when waking up after a
 	 * state-loss idle. Saving and restoring MMCR0 over idle is a

@@ -357,6 +363,7 @@ power_enter_stop:
 	 */
 	mfspr	r4,SPRN_MMCR0
 	std	r4,_MMCR0(r1)
+END_FTR_SECTION_IFSET(CPU_FTR_POWER9_DD1 | CPU_FTR_POWER9_DD20)

=20
 /*
  * Check if the requested state is a deep idle state.

@@ -542,15 +549,17 @@ pnv_restore_hyp_resource_arch300:
 	 * then clear bit 60 in MMCRA to ensure the PMU starts running.
 	 */
 	blt	cr3,1f
+BEGIN_FTR_SECTION
 	PPC_INVALIDATE_ERAT
 	ld	r1,PACAR1(r13)
+	ld	r4,_MMCR0(r1)
+	mtspr	SPRN_MMCR0,r4
+END_FTR_SECTION_IFSET(CPU_FTR_POWER9_DD1 | CPU_FTR_POWER9_DD20)
 	mfspr	r4,SPRN_MMCRA
 	ori	r4,r4,(1 << (63-60))
 	mtspr	SPRN_MMCRA,r4
 	xori	r4,r4,(1 << (63-60))
 	mtspr	SPRN_MMCRA,r4
-	ld	r4,_MMCR0(r1)
-	mtspr	SPRN_MMCR0,r4
 1:
 	/*
 	 * POWER ISA 3. Use PSSCR to determine if we

Re: [PATCH v2 2/2] powerpc/64s: idle skip POWER9 DD1 and DD2.0 specific workarounds on DD2.1

From: Nicholas Piggin <npiggin@gmail.com>
Date: 2017-11-03 04:22:19

On Fri, 03 Nov 2017 12:13:19 +1100
Michael Neuling [off-list ref] wrote:

On Thu, 2017-11-02 at 12:55 +1100, Nicholas Piggin wrote:

quoted

DD2.1 does not have to flush the ERAT after a state-loss idle. It also
does not have to save and restore MMCR0 (although it does have to save
restore in deep idle states, like other PMU registers).

Minor nit, can we do this as two separate commits in case we discover one is
broken.

Good idea, resent.

Thanks,
Nick

`h`	back out one level
`j`	next message in thread
`k`	previous message in thread
`l`	drill in
`Esc`	close help / fold thread tree
`?`	toggle this help