* Re: [PATCH 2/2] powerpc32: add support for csum_add()
From: Joakim Tjernlund @ 2014-09-19 15:46 UTC (permalink / raw)
To: Christophe Leroy; +Cc: scottwood, linuxppc-dev, linux-kernel, Paul Mackerras
In-Reply-To: <20140919135756.A060D1AB26D@localhost.localdomain>
Christophe Leroy <christophe.leroy@c-s.fr> wrote on 2014/09/19 15:57:56:
> +#define HAVE_ARCH_CSUM_ADD
> +static inline __wsum csum_add(__wsum csum, __wsum addend)
> +{
> + __asm__("\n\
> + addc %0,%0,%1 \n\
> + addze %0,%0 \n\
> + "
> + : "=r" (csum)
> + : "r" (addend), "0"(csum));
hmm, I wonder if not this is better written as:
: "+r" (csum): "r" (addend))
Jocke
^ permalink raw reply
* Re: [PATCH 2/2] powerpc32: add support for csum_add()
From: Joakim Tjernlund @ 2014-09-19 15:19 UTC (permalink / raw)
To: Christophe Leroy; +Cc: scottwood, linuxppc-dev, linux-kernel, Paul Mackerras
In-Reply-To: <20140919135756.A060D1AB26D@localhost.localdomain>
Christophe Leroy <christophe.leroy@c-s.fr> wrote on 2014/09/19 15:57:56:
> Subject: [PATCH 2/2] powerpc32: add support for csum_add()
>
> The C version of csum_add() as defined in include/net/checksum.h gives
the
> following assembly:
> 0: 7c 04 1a 14 add r0,r4,r3
> 4: 7c 64 00 10 subfc r3,r4,r0
> 8: 7c 63 19 10 subfe r3,r3,r3
> c: 7c 63 00 50 subf r3,r3,r0
>
> include/net/checksum.h also offers the possibility to define an arch
specific
> function.
> This patch provides a ppc32 specific csum_add() inline function.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>
> ---
Ouch, this is still so. Back in 2010 I reported this to gcc:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43892
Anyway,
Acked-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
^ permalink raw reply
* [PATCH 2/2] powerpc32: add support for csum_add()
From: Christophe Leroy @ 2014-09-19 13:57 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, scottwood
Cc: linuxppc-dev, linux-kernel
The C version of csum_add() as defined in include/net/checksum.h gives the
following assembly:
0: 7c 04 1a 14 add r0,r4,r3
4: 7c 64 00 10 subfc r3,r4,r0
8: 7c 63 19 10 subfe r3,r3,r3
c: 7c 63 00 50 subf r3,r3,r0
include/net/checksum.h also offers the possibility to define an arch specific
function.
This patch provides a ppc32 specific csum_add() inline function.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/include/asm/checksum.h | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h
index cfe806a..a13aa1f 100644
--- a/arch/powerpc/include/asm/checksum.h
+++ b/arch/powerpc/include/asm/checksum.h
@@ -141,6 +141,19 @@ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
{
return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}
+
+#define HAVE_ARCH_CSUM_ADD
+static inline __wsum csum_add(__wsum csum, __wsum addend)
+{
+ __asm__("\n\
+ addc %0,%0,%1 \n\
+ addze %0,%0 \n\
+ "
+ : "=r" (csum)
+ : "r" (addend), "0"(csum));
+ return csum;
+}
+
#endif
#endif
#endif /* __KERNEL__ */
--
2.1.0
^ permalink raw reply related
* [PATCH 1/2] powerpc32: put csum_tcpudp_magic inline
From: Christophe Leroy @ 2014-09-19 13:57 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, scottwood
Cc: linuxppc-dev, linux-kernel
csum_tcpudp_magic() is only a few instructions, and does not modifies any other
register than the returned result. So it is not worth having it as a separate
function and suffer function branching and saving of volatile registers.
This patch makes it inline by use of the already existing csum_tcpudp_nofold()
function.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/include/asm/checksum.h | 15 +++++++++++++++
arch/powerpc/lib/checksum_32.S | 16 ----------------
2 files changed, 15 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h
index 8251a3b..cfe806a 100644
--- a/arch/powerpc/include/asm/checksum.h
+++ b/arch/powerpc/include/asm/checksum.h
@@ -19,6 +19,7 @@
#else
extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
+#ifdef __powerpc64__
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
@@ -27,6 +28,7 @@ extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
unsigned short len,
unsigned short proto,
__wsum sum);
+#endif
/*
* computes the checksum of a memory block at buff, length len,
@@ -127,6 +129,19 @@ static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
#endif
}
+#ifndef __powerpc64__
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
+ unsigned short len,
+ unsigned short proto,
+ __wsum sum)
+{
+ return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
+}
+#endif
#endif
#endif /* __KERNEL__ */
#endif
diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S
index 7874e8a..6d67e05 100644
--- a/arch/powerpc/lib/checksum_32.S
+++ b/arch/powerpc/lib/checksum_32.S
@@ -41,22 +41,6 @@ _GLOBAL(ip_fast_csum)
blr
/*
- * Compute checksum of TCP or UDP pseudo-header:
- * csum_tcpudp_magic(saddr, daddr, len, proto, sum)
- */
-_GLOBAL(csum_tcpudp_magic)
- rlwimi r5,r6,16,0,15 /* put proto in upper half of len */
- addc r0,r3,r4 /* add 4 32-bit words together */
- adde r0,r0,r5
- adde r0,r0,r7
- addze r0,r0 /* add in final carry */
- rlwinm r3,r0,16,0,31 /* fold two halves together */
- add r3,r0,r3
- not r3,r3
- srwi r3,r3,16
- blr
-
-/*
* computes the checksum of a memory block at buff, length len,
* and adds in "sum" (32-bit)
*
--
2.1.0
^ permalink raw reply related
* [PATCH 0/2] powerpc32: Optimise some IP checksum functions.
From: Christophe Leroy @ 2014-09-19 13:57 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, scottwood
Cc: linuxppc-dev, linux-kernel
This patchset provides a few optimisations related to IP checksum functions.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/include/asm/checksum.h | 28 ++++++++++++++++++++++++++++
arch/powerpc/lib/checksum_32.S | 16 ----------------
2 files changed, 28 insertions(+), 16 deletions(-)
^ permalink raw reply
* powerpc32: rearrange instructions order in ip_fast_csum()
From: Christophe Leroy @ 2014-09-19 13:57 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, scottwood
Cc: linuxppc-dev, linux-kernel
On PPC_8xx, lwz has a 2 cycles latency, and branching also takes 2 cycles.
As the size of the header is minimum 5 words, we can unroll the loop for the
first words to reduce number of branching, and we can re-order the instructions
to limit loading latency.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/lib/checksum_32.S | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S
index 6d67e05..5500704 100644
--- a/arch/powerpc/lib/checksum_32.S
+++ b/arch/powerpc/lib/checksum_32.S
@@ -26,13 +26,17 @@
_GLOBAL(ip_fast_csum)
lwz r0,0(r3)
lwzu r5,4(r3)
- addic. r4,r4,-2
+ addic. r4,r4,-4
addc r0,r0,r5
mtctr r4
blelr-
-1: lwzu r4,4(r3)
- adde r0,r0,r4
+ lwzu r5,4(r3)
+ lwzu r4,4(r3)
+ adde r0,r0,r5
+1: adde r0,r0,r4
+ lwzu r4,4(r3)
bdnz 1b
+ adde r0,r0,r4
addze r0,r0 /* add in final carry */
rlwinm r3,r0,16,0,31 /* fold two halves together */
add r3,r0,r3
--
2.1.0
^ permalink raw reply related
* Re: [PATCH] powerpc/pci: remove duplicate declaration of pci_bus_find_capability
From: Gavin Shan @ 2014-09-19 10:18 UTC (permalink / raw)
To: Wei Yang; +Cc: linuxppc-dev, gwshan
In-Reply-To: <1411118722-6590-1-git-send-email-weiyang@linux.vnet.ibm.com>
On Fri, Sep 19, 2014 at 05:25:22PM +0800, Wei Yang wrote:
>pci_bus_find_capability() is decleared in pci.h, so it is not necessary to do
>it again.
>
>This patch removes it.
>
>Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Thanks,
Gavin
>---
> arch/powerpc/kernel/pci-common.c | 1 -
> 1 file changed, 1 deletion(-)
>
>diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
>index b2814e2..9cfa069 100644
>--- a/arch/powerpc/kernel/pci-common.c
>+++ b/arch/powerpc/kernel/pci-common.c
>@@ -1561,7 +1561,6 @@ EARLY_PCI_OP(write, byte, u8)
> EARLY_PCI_OP(write, word, u16)
> EARLY_PCI_OP(write, dword, u32)
>
>-extern int pci_bus_find_capability (struct pci_bus *bus, unsigned int devfn, int cap);
> int early_find_capability(struct pci_controller *hose, int bus, int devfn,
> int cap)
> {
>--
>1.7.9.5
>
^ permalink raw reply
* [PATCH] powerpc/pci: remove duplicate declaration of pci_bus_find_capability
From: Wei Yang @ 2014-09-19 9:25 UTC (permalink / raw)
To: benh, linuxppc-dev, gwshan; +Cc: Wei Yang
pci_bus_find_capability() is decleared in pci.h, so it is not necessary to do
it again.
This patch removes it.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
---
arch/powerpc/kernel/pci-common.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index b2814e2..9cfa069 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1561,7 +1561,6 @@ EARLY_PCI_OP(write, byte, u8)
EARLY_PCI_OP(write, word, u16)
EARLY_PCI_OP(write, dword, u32)
-extern int pci_bus_find_capability (struct pci_bus *bus, unsigned int devfn, int cap);
int early_find_capability(struct pci_controller *hose, int bus, int devfn,
int cap)
{
--
1.7.9.5
^ permalink raw reply related
* [PATCH v4 06/21] powerpc/8xx: No need to save r10 and r3 when not calling FixupDAR
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
r10 and r3 are only used inside FixupDAR function. So lets save them inside
that function only.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 27 +++++++++++++--------------
1 files changed, 13 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 171c6ef..845abf8 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -482,20 +482,12 @@ InstructionTLBError:
*/
. = 0x1400
DataTLBError:
-#ifdef CONFIG_8xx_CPU6
- stw r3, 8(r0)
-#endif
EXCEPTION_PROLOG_0
- mtspr SPRN_SPRG_SCRATCH2, r10
- mfspr r10, SPRN_DAR
- cmpwi cr0, r10, 0x00f0
+ mfspr r11, SPRN_DAR
+ cmpwi cr0, r11, 0x00f0
beq- FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
-#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0)
-#endif
- mfspr r10,SPRN_SPRG_SCRATCH2
EXCEPTION_EPILOG_0
b DataAccess
@@ -525,6 +517,10 @@ DARFixed:/* Return from dcbx instruction bug workaround */
/* define if you don't want to use self modifying code */
#define NO_SELF_MODIFYING_CODE
FixupDAR:/* Entry point for dcbx workaround. */
+#ifdef CONFIG_8xx_CPU6
+ stw r3, 8(r0)
+#endif
+ mtspr SPRN_SPRG_SCRATCH2, r10
/* fetch instruction from memory. */
mfspr r10, SPRN_SRR0
andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
@@ -540,6 +536,9 @@ FixupDAR:/* Entry point for dcbx workaround. */
mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
lwz r11, 0(r11) /* Get the pte */
+#ifdef CONFIG_8xx_CPU6
+ lwz r3, 8(r0) /* restore r3 from memory */
+#endif
/* concat physical page address(r11) and page offset(r10) */
rlwimi r11, r10, 0, 20, 31
lwz r11,0(r11)
@@ -560,15 +559,13 @@ FixupDAR:/* Entry point for dcbx workaround. */
beq+ 142f
cmpwi cr0, r10, 1964 /* Is icbi? */
beq+ 142f
-141: b DARFixed /* Nope, go back to normal TLB processing */
+141: mfspr r10,SPRN_SPRG_SCRATCH2
+ b DARFixed /* Nope, go back to normal TLB processing */
144: mfspr r10, SPRN_DSISR
rlwinm r10, r10,0,7,5 /* Clear store bit for buggy dcbst insn */
mtspr SPRN_DSISR, r10
142: /* continue, it was a dcbx, dcbi instruction. */
-#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0) /* restore r3 from memory */
-#endif
#ifndef NO_SELF_MODIFYING_CODE
andis. r10,r11,0x1f /* test if reg RA is r0 */
li r10,modified_instr@l
@@ -587,6 +584,7 @@ modified_instr:
bne+ 143f
subf r10,r0,r10 /* r10=r10-r0, only if reg RA is r0 */
143: mtdar r10 /* store faulting EA in DAR */
+ mfspr r10,SPRN_SPRG_SCRATCH2
b DARFixed /* Go back to normal TLB handling */
#else
mfctr r10
@@ -640,6 +638,7 @@ modified_instr:
mfdar r11
mtctr r11 /* restore ctr reg from DAR */
mtdar r10 /* save fault EA to DAR */
+ mfspr r10,SPRN_SPRG_SCRATCH2
b DARFixed /* Go back to normal TLB handling */
/* special handling for r10,r11 since these are modified already */
--
1.7.1
^ permalink raw reply related
* [PATCH v4 13/21] powerpc/8xx: Use PAGE size related consts
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
For PAGE size related operations, use PAGE size consts in order to be able to
use different page size in the futur.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 30 ++++++++++++++++++------------
1 files changed, 18 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 0f571f5..dcaee9f 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -292,9 +292,9 @@ InstructionTLBMiss:
mtspr SPRN_SPRG_SCRATCH2, r10
mfspr r10, SPRN_SRR0 /* Get effective address of fault */
#ifdef CONFIG_8xx_CPU15
- addi r11, r10, 0x1000
+ addi r11, r10, PAGE_SIZE
tlbie r11
- addi r11, r10, -0x1000
+ addi r11, r10, -PAGE_SIZE
tlbie r11
#endif
@@ -313,7 +313,8 @@ InstructionTLBMiss:
ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
3:
#endif
- rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */
+ /* Extract level 1 index */
+ rlwinm r10, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
lwzx r11, r10, r11 /* Get the level 1 entry */
rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */
beq 2f /* If zero, don't try to find a pte */
@@ -325,7 +326,8 @@ InstructionTLBMiss:
DO_8xx_CPU6(0x2b80, r3)
mtspr SPRN_MI_TWC, r11 /* Set segment attributes */
mfspr r11, SPRN_SRR0 /* Get effective address of fault */
- rlwinm r11, r11, 22, 20, 29 /* Extract level 2 index */
+ /* Extract level 2 index */
+ rlwinm r11, r11, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
lwzx r10, r10, r11 /* Get the pte */
#ifdef CONFIG_SWAP
@@ -385,7 +387,8 @@ DataStoreTLBMiss:
lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
3:
- rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */
+ /* Extract level 1 index */
+ rlwinm r10, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
lwzx r11, r10, r11 /* Get the level 1 entry */
rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */
beq 2f /* If zero, don't try to find a pte */
@@ -394,8 +397,8 @@ DataStoreTLBMiss:
*/
mfspr r10, SPRN_MD_EPN /* Get address of fault */
/* Extract level 2 index */
- rlwinm r10, r10, 22, 20, 29
- rlwimi r10, r11, 0, 0, 19 /* Add level 2 base */
+ rlwinm r10, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
+ rlwimi r10, r11, 0, 0, 32 - PAGE_SHIFT - 1 /* Add level 2 base */
lwz r10, 0(r10) /* Get the pte */
ori r11, r11, 1 /* Set valid bit in physical L2 page */
@@ -526,18 +529,20 @@ FixupDAR:/* Entry point for dcbx workaround. */
beq- 3f /* Branch if user space */
lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
-3: rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */
+ /* Extract level 1 index */
+3: rlwinm r10, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
lwzx r11, r10, r11 /* Get the level 1 entry */
rlwinm r10, r11,0,0,19 /* Extract page descriptor page address */
mfspr r11, SPRN_SRR0 /* Get effective address of fault */
- rlwinm r11, r11, 22, 20, 29 /* Extract level 2 index */
+ /* Extract level 2 index */
+ rlwinm r11, r11, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
lwzx r11, r10, r11 /* Get the pte */
#ifdef CONFIG_8xx_CPU6
lwz r3, 8(r0) /* restore r3 from memory */
#endif
/* concat physical page address(r11) and page offset(r10) */
mfspr r10, SPRN_SRR0
- rlwimi r11, r10, 0, 20, 31
+ rlwimi r11, r10, 0, 32 - PAGE_SHIFT, 31
lwz r11,0(r11)
/* Check if it really is a dcbx instruction. */
/* dcbt and dcbtst does not generate DTLB Misses/Errors,
@@ -913,12 +918,13 @@ set_dec_cpu6:
.globl sdata
sdata:
.globl empty_zero_page
+ .align PAGE_SHIFT
empty_zero_page:
- .space 4096
+ .space PAGE_SIZE
.globl swapper_pg_dir
swapper_pg_dir:
- .space 4096
+ .space PGD_TABLE_SIZE
/* Room for two PTE table poiners, usually the kernel and current user
* pointer to their respective root page table (pgdir).
--
1.7.1
^ permalink raw reply related
* [PATCH v4 08/21] powerpc/8xx: No need to restore registers and save them again.
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
In DTLBError handler there is not need to restore r10, r11 and cr registers
after fixing DAR as they are saved again to the same place just after.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 5f04d5f..e5a250c 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -478,8 +478,8 @@ DataTLBError:
cmpwi cr0, r11, 0x00f0
beq- FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
- EXCEPTION_EPILOG_0
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG_1
+ EXCEPTION_PROLOG_2
mfspr r10,SPRN_DSISR
stw r10,_DSISR(r11)
mr r5,r10
--
1.7.1
^ permalink raw reply related
* [PATCH v4 09/21] powerpc/8xx: Optimize verification in FixupDAR
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
By XORing the upper part of the instruction code, we get a value that can
directly be verified with the second test and we can remove the first test.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 6 ++----
1 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index e5a250c..5037420 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -542,10 +542,8 @@ FixupDAR:/* Entry point for dcbx workaround. */
/* Check if it really is a dcbx instruction. */
/* dcbt and dcbtst does not generate DTLB Misses/Errors,
* no need to include them here */
- srwi r10, r11, 26 /* check if major OP code is 31 */
- cmpwi cr0, r10, 31
- bne- 141f
- rlwinm r10, r11, 0, 21, 30
+ xoris r10, r11, 0x7c00 /* check if major OP code is 31 */
+ rlwinm r10, r10, 0, 21, 5
cmpwi cr0, r10, 2028 /* Is dcbz? */
beq+ 142f
cmpwi cr0, r10, 940 /* Is dcbi? */
--
1.7.1
^ permalink raw reply related
* [PATCH v4 11/21] powerpc/8xx: Use M_TW instead of M_TWB
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
Use M_TW instead of M_TWB for storing Level 1 table address as M_TWB requires
4k aligned tables, which is only the case with 4k pages.
Consequently, we have to calculate the level 1 table index by ourselves.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 48 ++++++++++++++++++---------------
1 files changed, 26 insertions(+), 22 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 4a49ff3..ad15070 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -276,8 +276,8 @@ SystemCall:
. = 0x1100
/*
* For the MPC8xx, this is a software tablewalk to load the instruction
- * TLB. It is modelled after the example in the Motorola manual. The task
- * switch loads the M_TWB register with the pointer to the first level table.
+ * TLB. The task switch loads the M_TW register with the pointer to the first
+ * level table.
* If we discover there is no second level table (value is zero) or if there
* is an invalid pte, we load that into the TLB, which causes another fault
* into the TLB Error interrupt where we can handle such problems.
@@ -299,7 +299,6 @@ InstructionTLBMiss:
#endif
DO_8xx_CPU6(0x3780, r3)
mtspr SPRN_MD_EPN, r10 /* Have to use MD_EPN for walk, MI_EPN can't */
- mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
@@ -307,14 +306,17 @@ InstructionTLBMiss:
#ifdef CONFIG_MODULES
/* Only modules will cause ITLB Misses as we always
* pin the first 8MB of kernel memory */
- andi. r11, r10, 0x0800 /* Address >= 0x80000000 */
+ andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
+#endif
+ mfspr r11, SPRN_M_TW /* Get level 1 table base address */
+#ifdef CONFIG_MODULES
beq 3f
- lis r11, swapper_pg_dir@h
- ori r11, r11, swapper_pg_dir@l
- rlwimi r10, r11, 0, 2, 19
+ lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
+ ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
3:
#endif
- lwz r11, 0(r10) /* Get the level 1 entry */
+ rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */
+ lwzx r11, r10, r11 /* Get the level 1 entry */
rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */
beq 2f /* If zero, don't try to find a pte */
@@ -375,18 +377,19 @@ DataStoreTLBMiss:
#endif
EXCEPTION_PROLOG_0
mtspr SPRN_SPRG_SCRATCH2, r10
- mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */
+ mfspr r10, SPRN_MD_EPN
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
- andi. r11, r10, 0x0800
+ andis. r11, r10, 0x8000
+ mfspr r11, SPRN_M_TW /* Get level 1 table base address */
beq 3f
- lis r11, swapper_pg_dir@h
- ori r11, r11, swapper_pg_dir@l
- rlwimi r10, r11, 0, 2, 19
+ lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
+ ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
3:
- lwz r11, 0(r10) /* Get the level 1 entry */
+ rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */
+ lwzx r11, r10, r11 /* Get the level 1 entry */
rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */
beq 2f /* If zero, don't try to find a pte */
@@ -523,12 +526,12 @@ FixupDAR:/* Entry point for dcbx workaround. */
andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
DO_8xx_CPU6(0x3780, r3)
mtspr SPRN_MD_EPN, r10
- mfspr r11, SPRN_M_TWB /* Get level 1 table entry address */
+ mfspr r11, SPRN_M_TW /* Get level 1 table base address */
beq- 3f /* Branch if user space */
lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
- rlwimi r11, r10, 32-20, 0xffc /* r11 = r11&~0xffc|(r10>>20)&0xffc */
-3: lwz r11, 0(r11) /* Get the level 1 entry */
+3: rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */
+ lwzx r11, r10, r11 /* Get the level 1 entry */
DO_8xx_CPU6(0x3b80, r3)
mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
@@ -537,6 +540,7 @@ FixupDAR:/* Entry point for dcbx workaround. */
lwz r3, 8(r0) /* restore r3 from memory */
#endif
/* concat physical page address(r11) and page offset(r10) */
+ mfspr r10, SPRN_SRR0
rlwimi r11, r10, 0, 20, 31
lwz r11,0(r11)
/* Check if it really is a dcbx instruction. */
@@ -692,11 +696,11 @@ start_here:
#ifdef CONFIG_8xx_CPU6
lis r4, cpu6_errata_word@h
ori r4, r4, cpu6_errata_word@l
- li r3, 0x3980
+ li r3, 0x3f80
stw r3, 12(r4)
lwz r3, 12(r4)
#endif
- mtspr SPRN_M_TWB, r6
+ mtspr SPRN_M_TW, r6
lis r4,2f@h
ori r4,r4,2f@l
tophys(r4,r4)
@@ -870,10 +874,10 @@ _GLOBAL(set_context)
lis r6, cpu6_errata_word@h
ori r6, r6, cpu6_errata_word@l
tophys (r4, r4)
- li r7, 0x3980
+ li r7, 0x3f80
stw r7, 12(r6)
lwz r7, 12(r6)
- mtspr SPRN_M_TWB, r4 /* Update MMU base address */
+ mtspr SPRN_M_TW, r4 /* Update MMU base address */
li r7, 0x3380
stw r7, 12(r6)
lwz r7, 12(r6)
@@ -881,7 +885,7 @@ _GLOBAL(set_context)
#else
mtspr SPRN_M_CASID,r3 /* Update context */
tophys (r4, r4)
- mtspr SPRN_M_TWB, r4 /* and pgd */
+ mtspr SPRN_M_TW, r4 /* and pgd */
#endif
SYNC
blr
--
1.7.1
^ permalink raw reply related
* [PATCH v4 15/21] powerpc/8xx: Implement 16k pages
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
This patch activates the handling of 16k pages on the MPC8xx.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/Kconfig | 2 +-
arch/powerpc/include/asm/mmu-8xx.h | 2 ++
arch/powerpc/kernel/head_8xx.S | 4 ++++
3 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5f44d3b..dc5f64e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -518,7 +518,7 @@ config PPC_4K_PAGES
bool "4k page size"
config PPC_16K_PAGES
- bool "16k page size" if 44x
+ bool "16k page size" if 44x || PPC_8xx
config PPC_64K_PAGES
bool "64k page size" if 44x || PPC_STD_MMU_64 || PPC_BOOK3E_64
diff --git a/arch/powerpc/include/asm/mmu-8xx.h b/arch/powerpc/include/asm/mmu-8xx.h
index 3d11d3c..986b9e1 100644
--- a/arch/powerpc/include/asm/mmu-8xx.h
+++ b/arch/powerpc/include/asm/mmu-8xx.h
@@ -56,6 +56,7 @@
* additional information from the MI_EPN, and MI_TWC registers.
*/
#define SPRN_MI_RPN 790
+#define MI_SPS16K 0x00000008 /* Small page size (0 = 4k, 1 = 16k) */
/* Define an RPN value for mapping kernel memory to large virtual
* pages for boot initialization. This has real page number of 0,
@@ -129,6 +130,7 @@
* additional information from the MD_EPN, and MD_TWC registers.
*/
#define SPRN_MD_RPN 798
+#define MD_SPS16K 0x00000008 /* Small page size (0 = 4k, 1 = 16k) */
/* This is a temporary storage register that could be used to save
* a processor working register during a tablewalk.
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 8966262..4dd6be0 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -45,7 +45,11 @@
* Value for the bits that have fixed value in RPN entries.
* Also used for tagging DAR for DTLBerror.
*/
+#ifdef CONFIG_PPC_16K_PAGES
+#define RPN_PATTERN (0x00f0 | MD_SPS16K)
+#else
#define RPN_PATTERN 0x00f0
+#endif
__HEAD
_ENTRY(_stext);
--
1.7.1
^ permalink raw reply related
* [PATCH v4 20/21] powerpc/8xx: Use DAR to save r3 for CPU6 ERRATA
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
As we are not using anymore DAR to save registers, it is now available for
saving the r3 register used for CPU6 ERRATA handling. Therefore we can
remove the major hack which was to use memory location 0 to save r3.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v3:
- New
Changes in v4:
- Fixed the patch as it didn't apply.
arch/powerpc/kernel/head_8xx.S | 33 +++++++++++++++------------------
1 file changed, 15 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index e21f0b2..3e8e341 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -83,13 +83,6 @@ _ENTRY(_start);
* 8M 1:1. I also mapped an additional I/O space 1:1 so we can get to
* the "internal" processor registers before MMU_init is called.
*
- * The TLB code currently contains a major hack. Since I use the condition
- * code register, I have to save and restore it. I am out of registers, so
- * I just store it in memory location 0 (the TLB handlers are not reentrant).
- * To avoid making any decisions, I need to use the "segment" valid bit
- * in the first level table, but that would require many changes to the
- * Linux page directory/table functions that I don't want to do right now.
- *
* -- Dan
*/
.globl __start
@@ -304,7 +297,7 @@ SystemCall:
*/
InstructionTLBMiss:
#ifdef CONFIG_8xx_CPU6
- stw r3, 8(r0)
+ mtspr SPRN_DAR, r3
#endif
EXCEPTION_PROLOG_0
mtspr SPRN_SPRG_SCRATCH2, r10
@@ -349,7 +342,10 @@ InstructionTLBMiss:
#ifdef CONFIG_SWAP
andi. r11, r10, _PAGE_ACCESSED | _PAGE_PRESENT
cmpwi cr0, r11, _PAGE_ACCESSED | _PAGE_PRESENT
+ li r11, RPN_PATTERN
bne- cr0, 2f
+#else
+ li r11, RPN_PATTERN
#endif
/* The Linux PTE won't go exactly into the MMU TLB.
* Software indicator bits 21 and 28 must be clear.
@@ -357,28 +353,29 @@ InstructionTLBMiss:
* set. All other Linux PTE bits control the behavior
* of the MMU.
*/
- li r11, RPN_PATTERN
rlwimi r10, r11, 0, 0x07f8 /* Set 24-27, clear 21-23,28 */
MTSPR_CPU6(SPRN_MI_RPN, r10, r3) /* Update TLB entry */
/* Restore registers */
#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0)
+ mfspr r3, SPRN_DAR
+ mtspr SPRN_DAR, r11 /* Tag DAR */
#endif
mfspr r10, SPRN_SPRG_SCRATCH2
EXCEPTION_EPILOG_0
rfi
2:
- mfspr r11, SPRN_SRR1
+ mfspr r10, SPRN_SRR1
/* clear all error bits as TLB Miss
* sets a few unconditionally
*/
- rlwinm r11, r11, 0, 0xffff
- mtspr SPRN_SRR1, r11
+ rlwinm r10, r10, 0, 0xffff
+ mtspr SPRN_SRR1, r10
/* Restore registers */
#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0)
+ mfspr r3, SPRN_DAR
+ mtspr SPRN_DAR, r11 /* Tag DAR */
#endif
mfspr r10, SPRN_SPRG_SCRATCH2
b InstructionTLBError1
@@ -386,7 +383,7 @@ InstructionTLBMiss:
. = 0x1200
DataStoreTLBMiss:
#ifdef CONFIG_8xx_CPU6
- stw r3, 8(r0)
+ mtspr SPRN_DAR, r3
#endif
EXCEPTION_PROLOG_0
mtspr SPRN_SPRG_SCRATCH2, r10
@@ -457,7 +454,7 @@ DataStoreTLBMiss:
/* Restore registers */
#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0)
+ mfspr r3, SPRN_DAR
#endif
mtspr SPRN_DAR, r11 /* Tag DAR */
mfspr r10, SPRN_SPRG_SCRATCH2
@@ -527,7 +524,7 @@ DARFixed:/* Return from dcbx instruction bug workaround */
#define NO_SELF_MODIFYING_CODE
FixupDAR:/* Entry point for dcbx workaround. */
#ifdef CONFIG_8xx_CPU6
- stw r3, 8(r0)
+ mtspr SPRN_DAR, r3
#endif
mtspr SPRN_SPRG_SCRATCH2, r10
/* fetch instruction from memory. */
@@ -546,7 +543,7 @@ FixupDAR:/* Entry point for dcbx workaround. */
rlwinm r11, r11, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
lwzx r11, r10, r11 /* Get the pte */
#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0) /* restore r3 from memory */
+ mfspr r3, SPRN_DAR
#endif
/* concat physical page address(r11) and page offset(r10) */
mfspr r10, SPRN_SRR0
--
2.1.0
^ permalink raw reply related
* [PATCH v4 17/21] powerpc/8xx: set PTE bit 22 off TLBmiss
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
No need to re-set this bit at each TLB miss. Let's set it in the PTE.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- Removed PPC405 related macro from PPC8xx specific code
- PTE_NONE_MASK doesn't need PAGE_ACCESSED in Linux 2.6
Changes in v4:
- None
arch/powerpc/include/asm/pgtable-ppc32.h | 20 ++++++++++++++++++++
arch/powerpc/include/asm/pte-8xx.h | 7 +++++--
arch/powerpc/kernel/head_8xx.S | 10 ++--------
3 files changed, 27 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index 47edde8..35a9b44 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h
@@ -172,6 +172,25 @@ static inline unsigned long pte_update(pte_t *p,
#ifdef PTE_ATOMIC_UPDATES
unsigned long old, tmp;
+#ifdef CONFIG_PPC_8xx
+ unsigned long tmp2;
+
+ __asm__ __volatile__("\
+1: lwarx %0,0,%4\n\
+ andc %1,%0,%5\n\
+ or %1,%1,%6\n\
+ /* 0x200 == Extended encoding, bit 22 */ \
+ /* Bit 22 has to be 1 if neither _PAGE_USER nor _PAGE_RW are set */ \
+ rlwimi %1,%1,32-2,0x200\n /* get _PAGE_USER */ \
+ rlwinm %3,%1,32-1,0x200\n /* get _PAGE_RW */ \
+ or %1,%3,%1\n\
+ xori %1,%1,0x200\n"
+" stwcx. %1,0,%4\n\
+ bne- 1b"
+ : "=&r" (old), "=&r" (tmp), "=m" (*p), "=&r" (tmp2)
+ : "r" (p), "r" (clr), "r" (set), "m" (*p)
+ : "cc" );
+#else /* CONFIG_PPC_8xx */
__asm__ __volatile__("\
1: lwarx %0,0,%3\n\
andc %1,%0,%4\n\
@@ -182,6 +201,7 @@ static inline unsigned long pte_update(pte_t *p,
: "=&r" (old), "=&r" (tmp), "=m" (*p)
: "r" (p), "r" (clr), "r" (set), "m" (*p)
: "cc" );
+#endif /* CONFIG_PPC_8xx */
#else /* PTE_ATOMIC_UPDATES */
unsigned long old = pte_val(*p);
*p = __pte((old & ~clr) | set);
diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h
index d44826e..daa4616 100644
--- a/arch/powerpc/include/asm/pte-8xx.h
+++ b/arch/powerpc/include/asm/pte-8xx.h
@@ -48,19 +48,22 @@
*/
#define _PAGE_RW 0x0400 /* lsb PP bits, inverted in HW */
#define _PAGE_USER 0x0800 /* msb PP bits */
+/* set when neither _PAGE_USER nor _PAGE_RW are set */
+#define _PAGE_KNLRO 0x0200
#define _PMD_PRESENT 0x0001
#define _PMD_BAD 0x0ff0
#define _PMD_PAGE_MASK 0x000c
#define _PMD_PAGE_8M 0x000c
-#define _PTE_NONE_MASK _PAGE_ACCESSED
+#define _PTE_NONE_MASK _PAGE_KNLRO
/* Until my rework is finished, 8xx still needs atomic PTE updates */
#define PTE_ATOMIC_UPDATES 1
/* We need to add _PAGE_SHARED to kernel pages */
-#define _PAGE_KERNEL_RO (_PAGE_SHARED)
+#define _PAGE_KERNEL_RO (_PAGE_SHARED | _PAGE_KNLRO)
+#define _PAGE_KERNEL_ROX (_PAGE_EXEC | _PAGE_KNLRO)
#define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE)
#endif /* __KERNEL__ */
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index a7af26e..48d3de8 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -445,14 +445,8 @@ DataStoreTLBMiss:
and r11, r11, r10
rlwimi r10, r11, 0, _PAGE_PRESENT
#endif
- /* Honour kernel RO, User NA */
- /* 0x200 == Extended encoding, bit 22 */
- rlwimi r10, r10, 32-2, 0x200 /* Copy USER to bit 22, 0x200 */
- /* r11 = (r10 & _PAGE_RW) >> 1 */
- rlwinm r11, r10, 32-1, 0x200
- or r10, r11, r10
- /* invert RW and 0x200 bits */
- xori r10, r10, _PAGE_RW | 0x200
+ /* invert RW */
+ xori r10, r10, _PAGE_RW
/* The Linux PTE won't go exactly into the MMU TLB.
* Software indicator bits 22 and 28 must be clear.
--
2.1.0
^ permalink raw reply related
* [PATCH v4 18/21] powerpc/8xx: _PMD_PRESENT already set in level 1 entries
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
When a PMD entry is valid, _PMD_PRESENT is set. Therefore, forcing that bit
during TLB loading is useless.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 2 --
1 files changed, 0 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 48d3de8..bb7c816 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -340,7 +340,6 @@ InstructionTLBMiss:
/* We have a pte table, so load the MI_TWC with the attributes
* for this "segment."
*/
- ori r11,r11,1 /* Set valid bit */
MTSPR_CPU6(SPRN_MI_TWC, r11, r3) /* Set segment attributes */
mfspr r11, SPRN_SRR0 /* Get effective address of fault */
/* Extract level 2 index */
@@ -417,7 +416,6 @@ DataStoreTLBMiss:
rlwimi r10, r11, 0, 0, 32 - PAGE_SHIFT - 1 /* Add level 2 base */
lwz r10, 0(r10) /* Get the pte */
- ori r11, r11, 1 /* Set valid bit in physical L2 page */
/* Insert the Guarded flag into the TWC from the Linux PTE.
* It is bit 27 of both the Linux PTE and the TWC (at least
* I got that right :-). It will be better when we can put
--
1.7.1
^ permalink raw reply related
* [PATCH v4 16/21] powerpc/8xx: Better readibility of ERRATA CPU6 handling
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
This patch hiddes that SPR address needed for CPU6 ERRATA handling in the macro.
Then we don't have to worry about this address directly in the code.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 29 ++++++++++++++++-------------
1 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 4dd6be0..a7af26e 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -33,12 +33,19 @@
/* Macro to make the code more readable. */
#ifdef CONFIG_8xx_CPU6
-#define DO_8xx_CPU6(val, reg) \
- li reg, val; \
- stw reg, 12(r0); \
- lwz reg, 12(r0);
+#define SPRN_MI_TWC_ADDR 0x2b80
+#define SPRN_MI_RPN_ADDR 0x2d80
+#define SPRN_MD_TWC_ADDR 0x3b80
+#define SPRN_MD_RPN_ADDR 0x3d80
+
+#define MTSPR_CPU6(spr, reg, treg) \
+ li treg, spr##_ADDR; \
+ stw treg, 12(r0); \
+ lwz treg, 12(r0); \
+ mtspr spr, reg
#else
-#define DO_8xx_CPU6(val, reg)
+#define MTSPR_CPU6(spr, reg, treg) \
+ mtspr spr, reg
#endif
/*
@@ -334,8 +341,7 @@ InstructionTLBMiss:
* for this "segment."
*/
ori r11,r11,1 /* Set valid bit */
- DO_8xx_CPU6(0x2b80, r3)
- mtspr SPRN_MI_TWC, r11 /* Set segment attributes */
+ MTSPR_CPU6(SPRN_MI_TWC, r11, r3) /* Set segment attributes */
mfspr r11, SPRN_SRR0 /* Get effective address of fault */
/* Extract level 2 index */
rlwinm r11, r11, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
@@ -354,8 +360,7 @@ InstructionTLBMiss:
*/
li r11, RPN_PATTERN
rlwimi r10, r11, 0, 0x07f8 /* Set 24-27, clear 21-23,28 */
- DO_8xx_CPU6(0x2d80, r3)
- mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
+ MTSPR_CPU6(SPRN_MI_RPN, r10, r3) /* Update TLB entry */
/* Restore registers */
#ifdef CONFIG_8xx_CPU6
@@ -424,8 +429,7 @@ DataStoreTLBMiss:
* It is bit 25 in the Linux PTE and bit 30 in the TWC
*/
rlwimi r11, r10, 32-5, 30, 30
- DO_8xx_CPU6(0x3b80, r3)
- mtspr SPRN_MD_TWC, r11
+ MTSPR_CPU6(SPRN_MD_TWC, r11, r3)
/* Both _PAGE_ACCESSED and _PAGE_PRESENT has to be set.
* We also need to know if the insn is a load/store, so:
@@ -458,8 +462,7 @@ DataStoreTLBMiss:
*/
2: li r11, RPN_PATTERN
rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */
- DO_8xx_CPU6(0x3d80, r3)
- mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
+ MTSPR_CPU6(SPRN_MD_RPN, r10, r3) /* Update TLB entry */
/* Restore registers */
#ifdef CONFIG_8xx_CPU6
--
1.7.1
^ permalink raw reply related
* [PATCH v4 21/21] powerpc/8xx: Invalidate non present TLB as early as possible
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
8xx sometimes need to load a invalid/non-present TLBs in
it DTLB asm handler.
These must be invalidated separaly as linux mm doesn't.
Commit 5efab4a02c89c252fb4cce097aafde5f8208dbfe was invalidating them in
arch/powerpc/mm/fault.c.
This patch does the invalidation earlier in order to free the TLB as soon as
possible. This also has the advantage of removing some 8xx specific code from
fault.c
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v3:
- New
Changes in v4:
- None (but impacted by changes in patch 3 and 7)
arch/powerpc/kernel/head_8xx.S | 15 ++++++++++-----
arch/powerpc/mm/fault.c | 7 -------
2 files changed, 10 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 4964adf..3d4b8ee 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -475,8 +475,11 @@ InstructionTLBError1:
EXCEPTION_PROLOG_2
mr r4,r12
mr r5,r9
+ andis. r10,r5,0x4000
+ beq+ 1f
+ tlbie r4
/* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
- EXC_XFER_LITE(0x400, handle_page_fault)
+1: EXC_XFER_LITE(0x400, handle_page_fault)
/* This is the data TLB error on the MPC8xx. This could be due to
* many reasons, including a dirty update to a pte. We bail out to
@@ -492,11 +495,13 @@ DataTLBError:
DARFixed:/* Return from dcbx instruction bug workaround */
EXCEPTION_PROLOG_1
EXCEPTION_PROLOG_2
- mfspr r10,SPRN_DSISR
- stw r10,_DSISR(r11)
- mr r5,r10
+ mfspr r5,SPRN_DSISR
+ stw r5,_DSISR(r11)
mfspr r4,SPRN_DAR
- li r10,RPN_PATTERN
+ andis. r10,r5,0x4000
+ beq+ 1f
+ tlbie r4
+1: li r10,RPN_PATTERN
mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
/* 0x300 is DataAccess exception, needed by bad_page_fault() */
EXC_XFER_LITE(0x300, handle_page_fault)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 51ab9e7..9885aad 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -43,7 +43,6 @@
#include <asm/tlbflush.h>
#include <asm/siginfo.h>
#include <asm/debug.h>
-#include <mm/mmu_decl.h>
#include "icswx.h"
@@ -368,12 +367,6 @@ good_area:
goto bad_area;
#endif /* CONFIG_6xx */
#if defined(CONFIG_8xx)
- /* 8xx sometimes need to load a invalid/non-present TLBs.
- * These must be invalidated separately as linux mm don't.
- */
- if (error_code & 0x40000000) /* no translation? */
- _tlbil_va(address, 0, 0, 0);
-
/* The MPC8xx seems to always set 0x80000000, which is
* "undefined". Of those that can be set, this is the only
* one which seems bad.
--
2.1.0
^ permalink raw reply related
* [PATCH v4 19/21] powerpc/8xx: Don't restore regs to save them again.
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
There is not need to restore r10, r11 and cr registers at this end of ITLBmiss
handler as they are saved again to the same place in ITLBError handler we are
jumping to.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index f372984..bcf0a43 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -383,8 +383,7 @@ InstructionTLBMiss:
lwz r3, 8(r0)
#endif
mfspr r10, SPRN_SPRG_SCRATCH2
- EXCEPTION_EPILOG_0
- b InstructionTLBError
+ b InstructionTLBError1
. = 0x1200
DataStoreTLBMiss:
@@ -473,7 +472,10 @@ DataStoreTLBMiss:
*/
. = 0x1300
InstructionTLBError:
- EXCEPTION_PROLOG
+ EXCEPTION_PROLOG_0
+InstructionTLBError1:
+ EXCEPTION_PROLOG_1
+ EXCEPTION_PROLOG_2
mr r4,r12
mr r5,r9
/* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
--
2.1.0
^ permalink raw reply related
* [PATCH v4 14/21] powerpc/8xx: Const for TLB RPN forced value
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
Value 0x00f0 is used to force bits in TLB level 2 entry. This value is linked
to the page size and will vary when we change the page size. Lets define a const
for it in order to have it at only one place.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index e8d8263..d777e3c 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -40,6 +40,13 @@
#else
#define DO_8xx_CPU6(val, reg)
#endif
+
+/*
+ * Value for the bits that have fixed value in RPN entries.
+ * Also used for tagging DAR for DTLBerror.
+ */
+#define RPN_PATTERN 0x00f0
+
__HEAD
_ENTRY(_stext);
_ENTRY(_start);
@@ -211,7 +218,7 @@ MachineCheck:
EXCEPTION_PROLOG
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
- li r5,0x00f0
+ li r5,RPN_PATTERN
mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
stw r5,_DSISR(r11)
@@ -239,7 +246,7 @@ Alignment:
EXCEPTION_PROLOG
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
- li r5,0x00f0
+ li r5,RPN_PATTERN
mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
stw r5,_DSISR(r11)
@@ -343,7 +350,7 @@ InstructionTLBMiss:
* set. All other Linux PTE bits control the behavior
* of the MMU.
*/
- li r11, 0x00f0
+ li r11, RPN_PATTERN
rlwimi r10, r11, 0, 0x07f8 /* Set 24-27, clear 21-23,28 */
DO_8xx_CPU6(0x2d80, r3)
mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
@@ -447,7 +454,7 @@ DataStoreTLBMiss:
* set. All other Linux PTE bits control the behavior
* of the MMU.
*/
-2: li r11, 0x00f0
+2: li r11, RPN_PATTERN
rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */
DO_8xx_CPU6(0x3d80, r3)
mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
@@ -482,7 +489,7 @@ DataTLBError:
EXCEPTION_PROLOG_0
mfspr r11, SPRN_DAR
- cmpwi cr0, r11, 0x00f0
+ cmpwi cr0, r11, RPN_PATTERN
beq- FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
EXCEPTION_PROLOG_1
@@ -491,7 +498,7 @@ DARFixed:/* Return from dcbx instruction bug workaround */
stw r10,_DSISR(r11)
mr r5,r10
mfspr r4,SPRN_DAR
- li r10,0x00f0
+ li r10,RPN_PATTERN
mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
/* 0x300 is DataAccess exception, needed by bad_page_fault() */
EXC_XFER_LITE(0x300, handle_page_fault)
--
2.1.0
^ permalink raw reply related
* [PATCH v4 12/21] powerpc/8xx: Don't use MD_TWC for walk
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
MD_TWC can only be used properly with 4k pages.
So lets calculate level 2 table index by ourselves.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- No need to save r11 in cr, we can do without modifying r11 in DataStoreTLBMiss
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 28 ++++++++++++----------------
1 files changed, 12 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index ad15070..0f571f5 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -297,8 +297,6 @@ InstructionTLBMiss:
addi r11, r10, -0x1000
tlbie r11
#endif
- DO_8xx_CPU6(0x3780, r3)
- mtspr SPRN_MD_EPN, r10 /* Have to use MD_EPN for walk, MI_EPN can't */
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
@@ -326,10 +324,9 @@ InstructionTLBMiss:
ori r11,r11,1 /* Set valid bit */
DO_8xx_CPU6(0x2b80, r3)
mtspr SPRN_MI_TWC, r11 /* Set segment attributes */
- DO_8xx_CPU6(0x3b80, r3)
- mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
- mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
- lwz r10, 0(r11) /* Get the pte */
+ mfspr r11, SPRN_SRR0 /* Get effective address of fault */
+ rlwinm r11, r11, 22, 20, 29 /* Extract level 2 index */
+ lwzx r10, r10, r11 /* Get the pte */
#ifdef CONFIG_SWAP
andi. r11, r10, _PAGE_ACCESSED | _PAGE_PRESENT
@@ -395,12 +392,13 @@ DataStoreTLBMiss:
/* We have a pte table, so load fetch the pte from the table.
*/
- ori r11, r11, 1 /* Set valid bit in physical L2 page */
- DO_8xx_CPU6(0x3b80, r3)
- mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
- mfspr r10, SPRN_MD_TWC /* ....and get the pte address */
+ mfspr r10, SPRN_MD_EPN /* Get address of fault */
+ /* Extract level 2 index */
+ rlwinm r10, r10, 22, 20, 29
+ rlwimi r10, r11, 0, 0, 19 /* Add level 2 base */
lwz r10, 0(r10) /* Get the pte */
+ ori r11, r11, 1 /* Set valid bit in physical L2 page */
/* Insert the Guarded flag into the TWC from the Linux PTE.
* It is bit 27 of both the Linux PTE and the TWC (at least
* I got that right :-). It will be better when we can put
@@ -524,18 +522,16 @@ FixupDAR:/* Entry point for dcbx workaround. */
/* fetch instruction from memory. */
mfspr r10, SPRN_SRR0
andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
- DO_8xx_CPU6(0x3780, r3)
- mtspr SPRN_MD_EPN, r10
mfspr r11, SPRN_M_TW /* Get level 1 table base address */
beq- 3f /* Branch if user space */
lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
3: rlwinm r10, r10, 12, 20, 29 /* Extract level 1 index */
lwzx r11, r10, r11 /* Get the level 1 entry */
- DO_8xx_CPU6(0x3b80, r3)
- mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
- mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
- lwz r11, 0(r11) /* Get the pte */
+ rlwinm r10, r11,0,0,19 /* Extract page descriptor page address */
+ mfspr r11, SPRN_SRR0 /* Get effective address of fault */
+ rlwinm r11, r11, 22, 20, 29 /* Extract level 2 index */
+ lwzx r11, r10, r11 /* Get the pte */
#ifdef CONFIG_8xx_CPU6
lwz r3, 8(r0) /* restore r3 from memory */
#endif
--
1.7.1
^ permalink raw reply related
* [PATCH v4 07/21] powerpc/8xx: DataAccess exception not generated by MPC8xx
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
DataAccess exception is never generated by MPC8xx so do the job directly where
it is used to avoid an unnecessary branching.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- arch/powerpc/mm/fault.c uses the vector number, so make sure it understands
the new ones.
Changes in v4:
- Removing the change to mm/fault.c, faking the exception id to make mm/fault
think it comes from DataAccess.
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index a535576..570c1ee 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -219,19 +219,10 @@ MachineCheck:
EXC_XFER_STD(0x200, machine_check_exception)
/* Data access exception.
- * This is "never generated" by the MPC8xx. We jump to it for other
- * translation errors.
+ * This is "never generated" by the MPC8xx.
*/
. = 0x300
DataAccess:
- EXCEPTION_PROLOG
- mfspr r10,SPRN_DSISR
- stw r10,_DSISR(r11)
- mr r5,r10
- mfspr r4,SPRN_DAR
- li r10,0x00f0
- mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
- EXC_XFER_LITE(0x300, handle_page_fault)
/* Instruction access exception.
* This is "never generated" by the MPC8xx.
@@ -491,7 +482,15 @@ DataTLBError:
beq- FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
EXCEPTION_EPILOG_0
- b DataAccess
+ EXCEPTION_PROLOG
+ mfspr r10,SPRN_DSISR
+ stw r10,_DSISR(r11)
+ mr r5,r10
+ mfspr r4,SPRN_DAR
+ li r10,0x00f0
+ mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
+ /* 0x300 is DataAccess exception, needed by bad_page_fault() */
+ EXC_XFER_LITE(0x300, handle_page_fault)
EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_EE)
--
2.1.0
^ permalink raw reply related
* [PATCH v4 05/21] powerpc/8xx: Fix comment about DIRTY update
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
Since commit 2321f33790a6c5b80322d907a92d5739e7521a13, dirty handling is not
handled here anymore. So we fix the comment.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index e4086d6..10054b8 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -479,12 +479,8 @@ InstructionTLBError:
EXC_XFER_LITE(0x400, handle_page_fault)
/* This is the data TLB error on the MPC8xx. This could be due to
- * many reasons, including a dirty update to a pte. We can catch that
- * one here, but anything else is an error. First, we track down the
- * Linux pte. If it is valid, write access is allowed, but the
- * page dirty bit is not set, we will set it and reload the TLB. For
- * any other case, we bail out to a higher level function that can
- * handle it.
+ * many reasons, including a dirty update to a pte. We bail out to
+ * a higher level function that can handle it.
*/
. = 0x1400
DataTLBError:
--
2.1.0
^ permalink raw reply related
* [PATCH v4 10/21] powerpc/8xx: Duplicate two insns instead of branching
From: Christophe Leroy @ 2014-09-19 8:36 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras
Cc: scottwood, linuxppc-dev, linux-kernel
Branching takes two cycles on MPC8xx. Lets duplicate the two instructions
and avoid the branching.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
arch/powerpc/kernel/head_8xx.S | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 5037420..4a49ff3 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -638,9 +638,11 @@ modified_instr:
/* special handling for r10,r11 since these are modified already */
153: mfspr r11, SPRN_SPRG_SCRATCH1 /* load r11 from SPRN_SPRG_SCRATCH1 */
- b 155f
+ add r10, r10, r11 /* add it */
+ mfctr r11 /* restore r11 */
+ b 151b
154: mfspr r11, SPRN_SPRG_SCRATCH0 /* load r10 from SPRN_SPRG_SCRATCH0 */
-155: add r10, r10, r11 /* add it */
+ add r10, r10, r11 /* add it */
mfctr r11 /* restore r11 */
b 151b
#endif
--
1.7.1
^ permalink raw reply related
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