[PATCH v2 1/2] powerpc/44x: Don't support 440 when CONFIG_PPC_47x is set

Subsystems: linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Madhavan Srinivasan, Linus Torvalds

STALE2146d LANDED

Status: Landed in mainline as 8b8319b181fd on 2020-12-03.

3 messages, 2 authors, 2020-12-10 · open the first message on its own page

[PATCH v2 1/2] powerpc/44x: Don't support 440 when CONFIG_PPC_47x is set

From: Christophe Leroy <hidden>
Date: 2020-10-18 17:25:23 

As stated in platform/44x/Kconfig, CONFIG_PPC_47x is not
compatible with 440 and 460 variants.

This is confirmed in asm/cache.h as L1_CACHE_SHIFT is different
for 47x, meaning a kernel built for 47x will not run correctly
on a 440.

In cputable, opt out all 440 and 460 variants when CONFIG_PPC_47x
is set. Also add a default match dedicated to 470.

Signed-off-by: Christophe Leroy <redacted>
---
 arch/powerpc/include/asm/cputable.h |  9 +++++----
 arch/powerpc/include/asm/mmu.h      |  7 +++----
 arch/powerpc/kernel/cputable.c      | 29 +++++++++++++++++++++--------
 3 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index d88bcb79f16d..4a0ddf66bd4a 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -523,11 +523,10 @@ enum {
 #ifdef CONFIG_40x
 	    CPU_FTRS_40X |
 #endif
-#ifdef CONFIG_44x
-	    CPU_FTRS_44X | CPU_FTRS_440x6 |
-#endif
 #ifdef CONFIG_PPC_47x
 	    CPU_FTRS_47X | CPU_FTR_476_DD2 |
+#elif defined(CONFIG_44x)
+	    CPU_FTRS_44X | CPU_FTRS_440x6 |
 #endif
 #ifdef CONFIG_E200
 	    CPU_FTRS_E200 |
@@ -596,7 +595,9 @@ enum {
 #ifdef CONFIG_40x
 	    CPU_FTRS_40X &
 #endif
-#ifdef CONFIG_44x
+#ifdef CONFIG_PPC_47x
+	    CPU_FTRS_47X &
+#elif defined(CONFIG_44x)
 	    CPU_FTRS_44X & CPU_FTRS_440x6 &
 #endif
 #ifdef CONFIG_E200
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index a1769c0426f2..bf5d3b5291f1 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -162,15 +162,14 @@ enum {
 #ifdef CONFIG_40x
 		MMU_FTR_TYPE_40x |
 #endif
-#ifdef CONFIG_44x
+#ifdef CONFIG_PPC_47x
+		MMU_FTR_TYPE_47x | MMU_FTR_USE_TLBIVAX_BCAST | MMU_FTR_LOCK_BCAST_INVAL |
+#elif defined(CONFIG_44x)
 		MMU_FTR_TYPE_44x |
 #endif
 #if defined(CONFIG_E200) || defined(CONFIG_E500)
 		MMU_FTR_TYPE_FSL_E | MMU_FTR_BIG_PHYS | MMU_FTR_USE_TLBILX |
 #endif
-#ifdef CONFIG_PPC_47x
-		MMU_FTR_TYPE_47x | MMU_FTR_USE_TLBIVAX_BCAST | MMU_FTR_LOCK_BCAST_INVAL |
-#endif
 #ifdef CONFIG_PPC_BOOK3S_32
 		MMU_FTR_USE_HIGH_BATS |
 #endif
diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index 492c0b36aff6..cf80e6c8ed5e 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -1533,6 +1533,7 @@ static struct cpu_spec __initdata cpu_specs[] = {
 
 #endif /* CONFIG_40x */
 #ifdef CONFIG_44x
+#ifndef CONFIG_PPC_47x
 	{
 		.pvr_mask		= 0xf0000fff,
 		.pvr_value		= 0x40000850,
@@ -1815,7 +1816,19 @@ static struct cpu_spec __initdata cpu_specs[] = {
 		.machine_check		= machine_check_440A,
 		.platform		= "ppc440",
 	},
-#ifdef CONFIG_PPC_47x
+	{	/* default match */
+		.pvr_mask		= 0x00000000,
+		.pvr_value		= 0x00000000,
+		.cpu_name		= "(generic 44x PPC)",
+		.cpu_features		= CPU_FTRS_44X,
+		.cpu_user_features	= COMMON_USER_BOOKE,
+		.mmu_features		= MMU_FTR_TYPE_44x,
+		.icache_bsize		= 32,
+		.dcache_bsize		= 32,
+		.machine_check		= machine_check_4xx,
+		.platform		= "ppc440",
+	}
+#else /* CONFIG_PPC_47x */
 	{ /* 476 DD2 core */
 		.pvr_mask		= 0xffffffff,
 		.pvr_value		= 0x11a52080,
@@ -1872,19 +1885,19 @@ static struct cpu_spec __initdata cpu_specs[] = {
 		.machine_check		= machine_check_47x,
 		.platform		= "ppc470",
 	},
-#endif /* CONFIG_PPC_47x */
 	{	/* default match */
 		.pvr_mask		= 0x00000000,
 		.pvr_value		= 0x00000000,
-		.cpu_name		= "(generic 44x PPC)",
-		.cpu_features		= CPU_FTRS_44X,
+		.cpu_name		= "(generic 47x PPC)",
+		.cpu_features		= CPU_FTRS_47X,
 		.cpu_user_features	= COMMON_USER_BOOKE,
-		.mmu_features		= MMU_FTR_TYPE_44x,
+		.mmu_features		= MMU_FTR_TYPE_47x,
 		.icache_bsize		= 32,
-		.dcache_bsize		= 32,
-		.machine_check		= machine_check_4xx,
-		.platform		= "ppc440",
+		.dcache_bsize		= 128,
+		.machine_check		= machine_check_47x,
+		.platform		= "ppc470",
 	}
+#endif /* CONFIG_PPC_47x */
 #endif /* CONFIG_44x */
 #ifdef CONFIG_E200
 	{	/* e200z5 */
-- 
2.25.0

[PATCH v2 2/2] powerpc/44x: Don't support 47x code and non 47x code at the same time

From: Christophe Leroy <hidden>
Date: 2020-10-18 17:25:31 

440/460 variants and 470 variants are not compatible, no
need to make code supporting both and using MMU features.

Just use CONFIG_PPC_47x to decide what to build.

Signed-off-by: Christophe Leroy <redacted>
---
v2: Move outside #ifdef CONFIG_PPC_47x a label "1:" used by 44x
---
 arch/powerpc/kernel/entry_32.S   | 11 +++--------
 arch/powerpc/mm/nohash/tlb_low.S | 29 +++++++----------------------
 2 files changed, 10 insertions(+), 30 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 8cdc8bcde703..a425360deabb 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -439,15 +439,13 @@ syscall_exit_cont:
 	andis.	r10,r0,DBCR0_IDM@h
 	bnel-	load_dbcr0
 #endif
-#ifdef CONFIG_44x
-BEGIN_MMU_FTR_SECTION
+#ifdef CONFIG_PPC_47x
 	lis	r4,icache_44x_need_flush@ha
 	lwz	r5,icache_44x_need_flush@l(r4)
 	cmplwi	cr0,r5,0
 	bne-	2f
+#endif /* CONFIG_PPC_47x */
 1:
-END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_47x)
-#endif /* CONFIG_44x */
 BEGIN_FTR_SECTION
 	lwarx	r7,0,r1
 END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
@@ -948,10 +946,7 @@ restore_kuap:
 
 	/* interrupts are hard-disabled at this point */
 restore:
-#ifdef CONFIG_44x
-BEGIN_MMU_FTR_SECTION
-	b	1f
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
+#if defined(CONFIG_44x) && !defined(CONFIG_PPC_47x)
 	lis	r4,icache_44x_need_flush@ha
 	lwz	r5,icache_44x_need_flush@l(r4)
 	cmplwi	cr0,r5,0
diff --git a/arch/powerpc/mm/nohash/tlb_low.S b/arch/powerpc/mm/nohash/tlb_low.S
index eaeee402f96e..68797e072f55 100644
--- a/arch/powerpc/mm/nohash/tlb_low.S
+++ b/arch/powerpc/mm/nohash/tlb_low.S
@@ -92,36 +92,25 @@ _GLOBAL(__tlbil_va)
 	tlbsx.	r6,0,r3
 	bne	10f
 	sync
-BEGIN_MMU_FTR_SECTION
-	b	2f
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
+#ifndef CONFIG_PPC_47x
 	/* On 440 There are only 64 TLB entries, so r3 < 64, which means bit
 	 * 22, is clear.  Since 22 is the V bit in the TLB_PAGEID, loading this
 	 * value will invalidate the TLB entry.
 	 */
 	tlbwe	r6,r6,PPC44x_TLB_PAGEID
-	isync
-10:	wrtee	r10
-	blr
-2:
-#ifdef CONFIG_PPC_47x
+#else
 	oris	r7,r6,0x8000	/* specify way explicitly */
 	clrrwi	r4,r3,12	/* get an EPN for the hashing with V = 0 */
 	ori	r4,r4,PPC47x_TLBE_SIZE
 	tlbwe   r4,r7,0		/* write it */
+#endif /* !CONFIG_PPC_47x */
 	isync
-	wrtee	r10
+10:	wrtee	r10
 	blr
-#else /* CONFIG_PPC_47x */
-1:	trap
-	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0;
-#endif /* !CONFIG_PPC_47x */
 
 _GLOBAL(_tlbil_all)
 _GLOBAL(_tlbil_pid)
-BEGIN_MMU_FTR_SECTION
-	b	2f
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
+#ifndef CONFIG_PPC_47x
 	li	r3,0
 	sync
 
@@ -136,8 +125,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
 
 	isync
 	blr
-2:
-#ifdef CONFIG_PPC_47x
+#else
 	/* 476 variant. There's not simple way to do this, hopefully we'll
 	 * try to limit the amount of such full invalidates
 	 */
@@ -179,11 +167,8 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
 	b	1b		/* Then loop */
 1:	isync			/* Sync shadows */
 	wrtee	r11
-#else /* CONFIG_PPC_47x */
-1:	trap
-	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0;
-#endif /* !CONFIG_PPC_47x */
 	blr
+#endif /* !CONFIG_PPC_47x */
 
 #ifdef CONFIG_PPC_47x
 
-- 
2.25.0

Re: [PATCH v2 1/2] powerpc/44x: Don't support 440 when CONFIG_PPC_47x is set

From: Michael Ellerman <hidden>
Date: 2020-12-10 11:34:56 

On Sun, 18 Oct 2020 17:25:17 +0000 (UTC), Christophe Leroy wrote:
As stated in platform/44x/Kconfig, CONFIG_PPC_47x is not
compatible with 440 and 460 variants.

This is confirmed in asm/cache.h as L1_CACHE_SHIFT is different
for 47x, meaning a kernel built for 47x will not run correctly
on a 440.

[...]
Applied to powerpc/next.

[1/2] powerpc/44x: Don't support 440 when CONFIG_PPC_47x is set
      https://git.kernel.org/powerpc/c/8b8319b181fd9d6821703fef1228b4dcde613a16
[2/2] powerpc/44x: Don't support 47x code and non 47x code at the same time
      https://git.kernel.org/powerpc/c/1f69aa0b89240653fdf708aada6a3d968447cce7

cheers
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