* Re: [PATCH] PCI: dwc: layerscape: convert to builtin_platform_driver()
From: Michael Walle @ 2021-01-25 19:44 UTC (permalink / raw)
To: Saravana Kannan
Cc: Rob Herring, Lorenzo Pieralisi, Roy Zang, PCI, LKML,
Minghuan Lian, Mingkai Hu, Greg Kroah-Hartman, Bjorn Helgaas,
linuxppc-dev, linux-arm-kernel
In-Reply-To: <CAGETcx-P-MxM+49XdUGBmg5YgnHS=fmz8uewywXvLSFKj=MqRQ@mail.gmail.com>
Am 2021-01-25 19:58, schrieb Saravana Kannan:
> On Mon, Jan 25, 2021 at 8:50 AM Lorenzo Pieralisi
> <lorenzo.pieralisi@arm.com> wrote:
>>
>> On Wed, Jan 20, 2021 at 08:28:36PM +0100, Michael Walle wrote:
>> > [RESEND, fat-fingered the buttons of my mail client and converted
>> > all CCs to BCCs :(]
>> >
>> > Am 2021-01-20 20:02, schrieb Saravana Kannan:
>> > > On Wed, Jan 20, 2021 at 6:24 AM Rob Herring <robh@kernel.org> wrote:
>> > > >
>> > > > On Wed, Jan 20, 2021 at 4:53 AM Michael Walle <michael@walle.cc>
>> > > > wrote:
>> > > > >
>> > > > > fw_devlink will defer the probe until all suppliers are ready. We can't
>> > > > > use builtin_platform_driver_probe() because it doesn't retry after probe
>> > > > > deferral. Convert it to builtin_platform_driver().
>> > > >
>> > > > If builtin_platform_driver_probe() doesn't work with fw_devlink, then
>> > > > shouldn't it be fixed or removed?
>> > >
>> > > I was actually thinking about this too. The problem with fixing
>> > > builtin_platform_driver_probe() to behave like
>> > > builtin_platform_driver() is that these probe functions could be
>> > > marked with __init. But there are also only 20 instances of
>> > > builtin_platform_driver_probe() in the kernel:
>> > > $ git grep ^builtin_platform_driver_probe | wc -l
>> > > 20
>> > >
>> > > So it might be easier to just fix them to not use
>> > > builtin_platform_driver_probe().
>> > >
>> > > Michael,
>> > >
>> > > Any chance you'd be willing to help me by converting all these to
>> > > builtin_platform_driver() and delete builtin_platform_driver_probe()?
>> >
>> > If it just moving the probe function to the _driver struct and
>> > remove the __init annotations. I could look into that.
>>
>> Can I drop this patch then ?
>
> No, please pick it up. Michael and I were talking about doing similar
> changes for other drivers.
Yes please, I was just about to answer, but Saravana beat me.
-michael
^ permalink raw reply
* Re: [PATCH] PCI: dwc: layerscape: convert to builtin_platform_driver()
From: Saravana Kannan @ 2021-01-25 18:58 UTC (permalink / raw)
To: Lorenzo Pieralisi
Cc: Rob Herring, Roy Zang, PCI, LKML, Minghuan Lian, Michael Walle,
Mingkai Hu, Greg Kroah-Hartman, Bjorn Helgaas, linuxppc-dev,
linux-arm-kernel
In-Reply-To: <20210125165041.GA5979@e121166-lin.cambridge.arm.com>
On Mon, Jan 25, 2021 at 8:50 AM Lorenzo Pieralisi
<lorenzo.pieralisi@arm.com> wrote:
>
> On Wed, Jan 20, 2021 at 08:28:36PM +0100, Michael Walle wrote:
> > [RESEND, fat-fingered the buttons of my mail client and converted
> > all CCs to BCCs :(]
> >
> > Am 2021-01-20 20:02, schrieb Saravana Kannan:
> > > On Wed, Jan 20, 2021 at 6:24 AM Rob Herring <robh@kernel.org> wrote:
> > > >
> > > > On Wed, Jan 20, 2021 at 4:53 AM Michael Walle <michael@walle.cc>
> > > > wrote:
> > > > >
> > > > > fw_devlink will defer the probe until all suppliers are ready. We can't
> > > > > use builtin_platform_driver_probe() because it doesn't retry after probe
> > > > > deferral. Convert it to builtin_platform_driver().
> > > >
> > > > If builtin_platform_driver_probe() doesn't work with fw_devlink, then
> > > > shouldn't it be fixed or removed?
> > >
> > > I was actually thinking about this too. The problem with fixing
> > > builtin_platform_driver_probe() to behave like
> > > builtin_platform_driver() is that these probe functions could be
> > > marked with __init. But there are also only 20 instances of
> > > builtin_platform_driver_probe() in the kernel:
> > > $ git grep ^builtin_platform_driver_probe | wc -l
> > > 20
> > >
> > > So it might be easier to just fix them to not use
> > > builtin_platform_driver_probe().
> > >
> > > Michael,
> > >
> > > Any chance you'd be willing to help me by converting all these to
> > > builtin_platform_driver() and delete builtin_platform_driver_probe()?
> >
> > If it just moving the probe function to the _driver struct and
> > remove the __init annotations. I could look into that.
>
> Can I drop this patch then ?
No, please pick it up. Michael and I were talking about doing similar
changes for other drivers.
-Saravana
^ permalink raw reply
* Re: [PATCH] PCI: dwc: layerscape: convert to builtin_platform_driver()
From: Lorenzo Pieralisi @ 2021-01-25 16:50 UTC (permalink / raw)
To: Michael Walle
Cc: Rob Herring, Saravana Kannan, Roy Zang, PCI, linux-kernel,
Minghuan Lian, Mingkai Hu, Greg Kroah-Hartman, Bjorn Helgaas,
linuxppc-dev, linux-arm-kernel
In-Reply-To: <c3e35b90e173b15870a859fd7001a712@walle.cc>
On Wed, Jan 20, 2021 at 08:28:36PM +0100, Michael Walle wrote:
> [RESEND, fat-fingered the buttons of my mail client and converted
> all CCs to BCCs :(]
>
> Am 2021-01-20 20:02, schrieb Saravana Kannan:
> > On Wed, Jan 20, 2021 at 6:24 AM Rob Herring <robh@kernel.org> wrote:
> > >
> > > On Wed, Jan 20, 2021 at 4:53 AM Michael Walle <michael@walle.cc>
> > > wrote:
> > > >
> > > > fw_devlink will defer the probe until all suppliers are ready. We can't
> > > > use builtin_platform_driver_probe() because it doesn't retry after probe
> > > > deferral. Convert it to builtin_platform_driver().
> > >
> > > If builtin_platform_driver_probe() doesn't work with fw_devlink, then
> > > shouldn't it be fixed or removed?
> >
> > I was actually thinking about this too. The problem with fixing
> > builtin_platform_driver_probe() to behave like
> > builtin_platform_driver() is that these probe functions could be
> > marked with __init. But there are also only 20 instances of
> > builtin_platform_driver_probe() in the kernel:
> > $ git grep ^builtin_platform_driver_probe | wc -l
> > 20
> >
> > So it might be easier to just fix them to not use
> > builtin_platform_driver_probe().
> >
> > Michael,
> >
> > Any chance you'd be willing to help me by converting all these to
> > builtin_platform_driver() and delete builtin_platform_driver_probe()?
>
> If it just moving the probe function to the _driver struct and
> remove the __init annotations. I could look into that.
Can I drop this patch then ?
Thanks,
Lorenzo
^ permalink raw reply
* [PATCH v4 23/23] powerpc/syscall: Avoid storing 'current' in another pointer
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
By saving the pointer pointing to thread_info.flags, gcc copies r2
in a non-volatile register.
We know 'current' doesn't change, so avoid that intermediaite pointer.
Reduces null_syscall benchmark by 2 cycles (322 => 320 cycles)
On PPC64, gcc seems to know that 'current' is not changing, and it keeps
it in a non volatile register to avoid multiple read of 'current' in paca.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/syscall.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index 47ae55f94d1c..72e0b18b88d8 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -186,7 +186,6 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
struct pt_regs *regs,
long scv)
{
- unsigned long *ti_flagsp = ¤t_thread_info()->flags;
unsigned long ti_flags;
unsigned long ret = 0;
@@ -202,7 +201,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
/* Check whether the syscall is issued inside a restartable sequence */
rseq_syscall(regs);
- ti_flags = *ti_flagsp;
+ ti_flags = current_thread_info()->flags;
if (unlikely(r3 >= (unsigned long)-MAX_ERRNO) && !scv) {
if (likely(!(ti_flags & (_TIF_NOERROR | _TIF_RESTOREALL)))) {
@@ -216,7 +215,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
ret = _TIF_RESTOREALL;
else
regs->gpr[3] = r3;
- clear_bits(_TIF_PERSYSCALL_MASK, ti_flagsp);
+ clear_bits(_TIF_PERSYSCALL_MASK, ¤t_thread_info()->flags);
} else {
regs->gpr[3] = r3;
}
@@ -228,7 +227,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
again:
local_irq_disable();
- ti_flags = READ_ONCE(*ti_flagsp);
+ ti_flags = READ_ONCE(current_thread_info()->flags);
while (unlikely(ti_flags & (_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM))) {
local_irq_enable();
if (ti_flags & _TIF_NEED_RESCHED) {
@@ -244,7 +243,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
do_notify_resume(regs, ti_flags);
}
local_irq_disable();
- ti_flags = READ_ONCE(*ti_flagsp);
+ ti_flags = READ_ONCE(current_thread_info()->flags);
}
if (IS_ENABLED(CONFIG_PPC_BOOK3S) && IS_ENABLED(CONFIG_PPC_FPU)) {
--
2.25.0
^ permalink raw reply related
* [PATCH v4 22/23] powerpc/syscall: Optimise checks in beginning of system_call_exception()
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
Combine all tests of regs->msr into a single logical one.
Before the patch:
0: 81 6a 00 84 lwz r11,132(r10)
4: 90 6a 00 88 stw r3,136(r10)
8: 69 60 00 02 xori r0,r11,2
c: 54 00 ff fe rlwinm r0,r0,31,31,31
10: 0f 00 00 00 twnei r0,0
14: 69 63 40 00 xori r3,r11,16384
18: 54 63 97 fe rlwinm r3,r3,18,31,31
1c: 0f 03 00 00 twnei r3,0
20: 69 6b 80 00 xori r11,r11,32768
24: 55 6b 8f fe rlwinm r11,r11,17,31,31
28: 0f 0b 00 00 twnei r11,0
After the patch:
0: 81 6a 00 84 lwz r11,132(r10)
4: 90 6a 00 88 stw r3,136(r10)
8: 7d 6b 58 f8 not r11,r11
c: 71 6b c0 02 andi. r11,r11,49154
10: 0f 0b 00 00 twnei r11,0
6 cycles less on powerpc 8xx (328 => 322 cycles).
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/syscall.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index a40775daa88b..47ae55f94d1c 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -28,6 +28,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
unsigned long r0, struct pt_regs *regs)
{
syscall_fn f;
+ unsigned long expected_msr;
regs->orig_gpr3 = r3;
@@ -39,10 +40,13 @@ notrace long system_call_exception(long r3, long r4, long r5,
trace_hardirqs_off(); /* finish reconciling */
+ expected_msr = MSR_PR;
if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x))
- BUG_ON(!(regs->msr & MSR_RI));
- BUG_ON(!(regs->msr & MSR_PR));
- BUG_ON(arch_irq_disabled_regs(regs));
+ expected_msr |= MSR_RI;
+ if (IS_ENABLED(CONFIG_PPC32))
+ expected_msr |= MSR_EE;
+ BUG_ON((regs->msr & expected_msr) ^ expected_msr);
+ BUG_ON(IS_ENABLED(CONFIG_PPC64) && arch_irq_disabled_regs(regs));
#ifdef CONFIG_PPC_PKEY
if (mmu_has_feature(MMU_FTR_PKEY)) {
--
2.25.0
^ permalink raw reply related
* [PATCH v4 21/23] powerpc/syscall: Remove FULL_REGS verification in system_call_exception
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
For book3s/64, FULL_REGS() is 'true' at all time, so the test voids.
For others, non volatile registers are saved inconditionally.
So the verification is pointless.
Should one fail to do it, it would anyway be caught by the
CHECK_FULL_REGS() in copy_thread() as we have removed the
special versions ppc_fork() and friends.
null_syscall benchmark reduction 4 cycles (332 => 328 cycles)
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/syscall.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index 30f8a397a522..a40775daa88b 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -42,7 +42,6 @@ notrace long system_call_exception(long r3, long r4, long r5,
if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x))
BUG_ON(!(regs->msr & MSR_RI));
BUG_ON(!(regs->msr & MSR_PR));
- BUG_ON(!FULL_REGS(regs));
BUG_ON(arch_irq_disabled_regs(regs));
#ifdef CONFIG_PPC_PKEY
--
2.25.0
^ permalink raw reply related
* [PATCH v4 20/23] powerpc/syscall: Do not check unsupported scv vector on PPC32
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
Only PPC64 has scv. No need to check the 0x7ff0 trap on PPC32.
And ignore the scv parameter in syscall_exit_prepare (Save 14 cycles
346 => 332 cycles)
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 1 -
arch/powerpc/kernel/syscall.c | 7 +++++--
2 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 9922a04650f7..6ae9c7bcb06c 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -343,7 +343,6 @@ transfer_to_syscall:
ret_from_syscall:
addi r4,r1,STACK_FRAME_OVERHEAD
- li r5,0
bl syscall_exit_prepare
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
/* If the process has its own DBCR0 value, load it up. The internal
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index 476909b11051..30f8a397a522 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -86,7 +86,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
local_irq_enable();
if (unlikely(current_thread_info()->flags & _TIF_SYSCALL_DOTRACE)) {
- if (unlikely(regs->trap == 0x7ff0)) {
+ if (IS_ENABLED(CONFIG_PPC64) && unlikely(regs->trap == 0x7ff0)) {
/* Unsupported scv vector */
_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
return regs->gpr[3];
@@ -109,7 +109,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
r8 = regs->gpr[8];
} else if (unlikely(r0 >= NR_syscalls)) {
- if (unlikely(regs->trap == 0x7ff0)) {
+ if (IS_ENABLED(CONFIG_PPC64) && unlikely(regs->trap == 0x7ff0)) {
/* Unsupported scv vector */
_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
return regs->gpr[3];
@@ -187,6 +187,9 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
unsigned long ti_flags;
unsigned long ret = 0;
+ if (IS_ENABLED(CONFIG_PPC32))
+ scv = 0;
+
CT_WARN_ON(ct_state() == CONTEXT_USER);
kuap_check();
--
2.25.0
^ permalink raw reply related
* [PATCH v4 19/23] powerpc/syscall: Avoid stack frame in likely part of system_call_exception()
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
When r3 is not modified, reload it from regs->orig_r3 to free
volatile registers. This avoids a stack frame for the likely part
of system_call_exception()
Before the patch:
c000b4d4 <system_call_exception>:
c000b4d4: 7c 08 02 a6 mflr r0
c000b4d8: 94 21 ff e0 stwu r1,-32(r1)
c000b4dc: 93 e1 00 1c stw r31,28(r1)
c000b4e0: 90 01 00 24 stw r0,36(r1)
c000b4e4: 90 6a 00 88 stw r3,136(r10)
c000b4e8: 81 6a 00 84 lwz r11,132(r10)
c000b4ec: 69 6b 00 02 xori r11,r11,2
c000b4f0: 55 6b ff fe rlwinm r11,r11,31,31,31
c000b4f4: 0f 0b 00 00 twnei r11,0
c000b4f8: 81 6a 00 a0 lwz r11,160(r10)
c000b4fc: 55 6b 07 fe clrlwi r11,r11,31
c000b500: 0f 0b 00 00 twnei r11,0
c000b504: 7c 0c 42 e6 mftb r0
c000b508: 83 e2 00 08 lwz r31,8(r2)
c000b50c: 81 82 00 28 lwz r12,40(r2)
c000b510: 90 02 00 24 stw r0,36(r2)
c000b514: 7d 8c f8 50 subf r12,r12,r31
c000b518: 7c 0c 02 14 add r0,r12,r0
c000b51c: 90 02 00 08 stw r0,8(r2)
c000b520: 7c 10 13 a6 mtspr 80,r0
c000b524: 81 62 00 70 lwz r11,112(r2)
c000b528: 71 60 86 91 andi. r0,r11,34449
c000b52c: 40 82 00 34 bne c000b560 <system_call_exception+0x8c>
c000b530: 2b 89 01 b6 cmplwi cr7,r9,438
c000b534: 41 9d 00 64 bgt cr7,c000b598 <system_call_exception+0xc4>
c000b538: 3d 40 c0 5c lis r10,-16292
c000b53c: 55 29 10 3a rlwinm r9,r9,2,0,29
c000b540: 39 4a 41 e8 addi r10,r10,16872
c000b544: 80 01 00 24 lwz r0,36(r1)
c000b548: 7d 2a 48 2e lwzx r9,r10,r9
c000b54c: 7c 08 03 a6 mtlr r0
c000b550: 7d 29 03 a6 mtctr r9
c000b554: 83 e1 00 1c lwz r31,28(r1)
c000b558: 38 21 00 20 addi r1,r1,32
c000b55c: 4e 80 04 20 bctr
After the patch:
c000b4d4 <system_call_exception>:
c000b4d4: 81 6a 00 84 lwz r11,132(r10)
c000b4d8: 90 6a 00 88 stw r3,136(r10)
c000b4dc: 69 6b 00 02 xori r11,r11,2
c000b4e0: 55 6b ff fe rlwinm r11,r11,31,31,31
c000b4e4: 0f 0b 00 00 twnei r11,0
c000b4e8: 80 6a 00 a0 lwz r3,160(r10)
c000b4ec: 54 63 07 fe clrlwi r3,r3,31
c000b4f0: 0f 03 00 00 twnei r3,0
c000b4f4: 7d 6c 42 e6 mftb r11
c000b4f8: 81 82 00 08 lwz r12,8(r2)
c000b4fc: 80 02 00 28 lwz r0,40(r2)
c000b500: 91 62 00 24 stw r11,36(r2)
c000b504: 7c 00 60 50 subf r0,r0,r12
c000b508: 7d 60 5a 14 add r11,r0,r11
c000b50c: 91 62 00 08 stw r11,8(r2)
c000b510: 7c 10 13 a6 mtspr 80,r0
c000b514: 80 62 00 70 lwz r3,112(r2)
c000b518: 70 6b 86 91 andi. r11,r3,34449
c000b51c: 40 82 00 28 bne c000b544 <system_call_exception+0x70>
c000b520: 2b 89 01 b6 cmplwi cr7,r9,438
c000b524: 41 9d 00 84 bgt cr7,c000b5a8 <system_call_exception+0xd4>
c000b528: 80 6a 00 88 lwz r3,136(r10)
c000b52c: 3d 40 c0 5c lis r10,-16292
c000b530: 55 29 10 3a rlwinm r9,r9,2,0,29
c000b534: 39 4a 41 e4 addi r10,r10,16868
c000b538: 7d 2a 48 2e lwzx r9,r10,r9
c000b53c: 7d 29 03 a6 mtctr r9
c000b540: 4e 80 04 20 bctr
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/syscall.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index a3510fa4e641..476909b11051 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -115,6 +115,9 @@ notrace long system_call_exception(long r3, long r4, long r5,
return regs->gpr[3];
}
return -ENOSYS;
+ } else {
+ /* Restore r3 from orig_gpr3 to free up a volatile reg */
+ r3 = regs->orig_gpr3;
}
/* May be faster to do array_index_nospec? */
--
2.25.0
^ permalink raw reply related
* [PATCH v4 18/23] powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
system_call_exception() checks MSR_PR and BUGs if a syscall
is issued from kernel mode.
No need to handle it anymore from the ASM entry code.
null_syscall reduction 2 cycles (348 => 346 cycles)
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 30 ------------------------------
arch/powerpc/kernel/head_32.h | 3 ---
arch/powerpc/kernel/head_booke.h | 3 ---
3 files changed, 36 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index ce5fdb23ed7c..9922a04650f7 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -416,36 +416,6 @@ ret_from_kernel_thread:
li r3,0
b ret_from_syscall
- /*
- * System call was called from kernel. We get here with SRR1 in r9.
- * Mark the exception as recoverable once we have retrieved SRR0,
- * trap a warning and return ENOSYS with CR[SO] set.
- */
- .globl ret_from_kernel_syscall
-ret_from_kernel_syscall:
- mfspr r9, SPRN_SRR0
- mfspr r10, SPRN_SRR1
-#if !defined(CONFIG_4xx) && !defined(CONFIG_BOOKE)
- LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR|MSR_DR))
- mtmsr r11
-#endif
-
-0: trap
- EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
-
- li r3, ENOSYS
- crset so
-#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
- mtspr SPRN_NRI, r0
-#endif
- mtspr SPRN_SRR0, r9
- mtspr SPRN_SRR1, r10
- rfi
-#ifdef CONFIG_40x
- b . /* Prevent prefetch past rfi */
-#endif
-_ASM_NOKPROBE_SYMBOL(ret_from_kernel_syscall)
-
/*
* Top-level page fault handling.
* This is in assembler because if do_page_fault tells us that
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index c2aa0d8f1f63..c0de4acbe3f8 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -118,8 +118,6 @@
.macro SYSCALL_ENTRY trapno
mfspr r9, SPRN_SRR1
mfspr r10, SPRN_SRR0
- andi. r11, r9, MSR_PR
- beq- 99f
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL) /* can take exceptions */
lis r12, 1f@h
ori r12, r12, 1f@l
@@ -176,7 +174,6 @@
3:
#endif
b transfer_to_syscall /* jump to handler */
-99: b ret_from_kernel_syscall
.endm
.macro save_dar_dsisr_on_stack reg1, reg2, sp
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index faff094b650e..7af84e1e717b 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -106,10 +106,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
#endif
mfspr r9, SPRN_SRR1
BOOKE_CLEAR_BTB(r11)
- andi. r11, r9, MSR_PR
lwz r11, TASK_STACK - THREAD(r10)
rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */
- beq- 99f
ALLOC_STACK_FRAME(r11, THREAD_SIZE - INT_FRAME_SIZE)
stw r12, _CCR(r11) /* save various registers */
mflr r12
@@ -157,7 +155,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
3:
b transfer_to_syscall /* jump to handler */
-99: b ret_from_kernel_syscall
.endm
/* To handle the additional exception priority levels on 40x and Book-E
--
2.25.0
^ permalink raw reply related
* [PATCH v4 17/23] powerpc/syscall: implement system call entry/exit logic in C for PPC32
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
That's port of PPC64 syscall entry/exit logic in C to PPC32.
Performancewise on 8xx:
Before : 304 cycles on null_syscall
After : 348 cycles on null_syscall
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 227 ++++---------------------------
arch/powerpc/kernel/head_32.h | 16 ---
arch/powerpc/kernel/head_booke.h | 15 --
3 files changed, 29 insertions(+), 229 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 97dc28a68465..ce5fdb23ed7c 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -329,117 +329,22 @@ stack_ovf:
_ASM_NOKPROBE_SYMBOL(stack_ovf)
#endif
-#ifdef CONFIG_TRACE_IRQFLAGS
-trace_syscall_entry_irq_off:
- /*
- * Syscall shouldn't happen while interrupts are disabled,
- * so let's do a warning here.
- */
-0: trap
- EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
- bl trace_hardirqs_on
-
- /* Now enable for real */
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE)
- mtmsr r10
-
- REST_GPR(0, r1)
- REST_4GPRS(3, r1)
- REST_2GPRS(7, r1)
- b DoSyscall
-#endif /* CONFIG_TRACE_IRQFLAGS */
-
.globl transfer_to_syscall
transfer_to_syscall:
SAVE_NVGPRS(r1)
#ifdef CONFIG_PPC_BOOK3S_32
kuep_lock r11, r12
#endif
-#ifdef CONFIG_TRACE_IRQFLAGS
- andi. r12,r9,MSR_EE
- beq- trace_syscall_entry_irq_off
-#endif /* CONFIG_TRACE_IRQFLAGS */
-/*
- * Handle a system call.
- */
- .stabs "arch/powerpc/kernel/",N_SO,0,0,0f
- .stabs "entry_32.S",N_SO,0,0,0f
-0:
-
-_GLOBAL(DoSyscall)
- stw r3,ORIG_GPR3(r1)
- li r12,0
- stw r12,RESULT(r1)
-#ifdef CONFIG_TRACE_IRQFLAGS
- /* Make sure interrupts are enabled */
- mfmsr r11
- andi. r12,r11,MSR_EE
- /* We came in with interrupts disabled, we WARN and mark them enabled
- * for lockdep now */
-0: tweqi r12, 0
- EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
-#endif /* CONFIG_TRACE_IRQFLAGS */
- lwz r11,TI_FLAGS(r2)
- andi. r11,r11,_TIF_SYSCALL_DOTRACE
- bne- syscall_dotrace
-syscall_dotrace_cont:
- cmplwi 0,r0,NR_syscalls
- lis r10,sys_call_table@h
- ori r10,r10,sys_call_table@l
- slwi r0,r0,2
- bge- 66f
-
- barrier_nospec_asm
- /*
- * Prevent the load of the handler below (based on the user-passed
- * system call number) being speculatively executed until the test
- * against NR_syscalls and branch to .66f above has
- * committed.
- */
+ /* Calling convention has r9 = orig r0, r10 = regs */
+ mr r9,r0
+ addi r10,r1,STACK_FRAME_OVERHEAD
+ bl system_call_exception
- lwzx r10,r10,r0 /* Fetch system call handler [ptr] */
- mtlr r10
- addi r9,r1,STACK_FRAME_OVERHEAD
- PPC440EP_ERR42
- blrl /* Call handler */
- .globl ret_from_syscall
ret_from_syscall:
-#ifdef CONFIG_DEBUG_RSEQ
- /* Check whether the syscall is issued inside a restartable sequence */
- stw r3,GPR3(r1)
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl rseq_syscall
- lwz r3,GPR3(r1)
-#endif
- mr r6,r3
- /* disable interrupts so current_thread_info()->flags can't change */
- LOAD_REG_IMMEDIATE(r10,MSR_KERNEL) /* doesn't include MSR_EE */
- /* Note: We don't bother telling lockdep about it */
- mtmsr r10
- lwz r9,TI_FLAGS(r2)
- li r8,-MAX_ERRNO
- andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
- bne- syscall_exit_work
- cmplw 0,r3,r8
- blt+ syscall_exit_cont
- lwz r11,_CCR(r1) /* Load CR */
- neg r3,r3
- oris r11,r11,0x1000 /* Set SO bit in CR */
- stw r11,_CCR(r1)
-syscall_exit_cont:
- lwz r8,_MSR(r1)
-#ifdef CONFIG_TRACE_IRQFLAGS
- /* If we are going to return from the syscall with interrupts
- * off, we trace that here. It shouldn't normally happen.
- */
- andi. r10,r8,MSR_EE
- bne+ 1f
- stw r3,GPR3(r1)
- bl trace_hardirqs_off
- lwz r3,GPR3(r1)
-1:
-#endif /* CONFIG_TRACE_IRQFLAGS */
+ addi r4,r1,STACK_FRAME_OVERHEAD
+ li r5,0
+ bl syscall_exit_prepare
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
/* If the process has its own DBCR0 value, load it up. The internal
debug mode bit tells us that dbcr0 should be loaded. */
@@ -453,34 +358,39 @@ syscall_exit_cont:
cmplwi cr0,r5,0
bne- 2f
#endif /* CONFIG_PPC_47x */
-1:
-BEGIN_FTR_SECTION
- lwarx r7,0,r1
-END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
- stwcx. r0,0,r1 /* to clear the reservation */
- ACCOUNT_CPU_USER_EXIT(r2, r5, r7)
#ifdef CONFIG_PPC_BOOK3S_32
kuep_unlock r5, r7
#endif
- kuap_check r2, r4
lwz r4,_LINK(r1)
lwz r5,_CCR(r1)
mtlr r4
- mtcr r5
lwz r7,_NIP(r1)
- lwz r2,GPR2(r1)
- lwz r1,GPR1(r1)
+ lwz r8,_MSR(r1)
+ cmpwi r3,0
+ lwz r3,GPR3(r1)
syscall_exit_finish:
-#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
- mtspr SPRN_NRI, r0
-#endif
mtspr SPRN_SRR0,r7
mtspr SPRN_SRR1,r8
+
+ bne 3f
+ mtcr r5
+
+1: lwz r2,GPR2(r1)
+ lwz r1,GPR1(r1)
rfi
-#ifdef CONFIG_40x
- b . /* Prevent prefetch past rfi */
-#endif
-_ASM_NOKPROBE_SYMBOL(syscall_exit_finish)
+
+3: mtcr r5
+ lwz r4,_CTR(r1)
+ lwz r5,_XER(r1)
+ REST_NVGPRS(r1)
+ mtctr r4
+ mtxer r5
+ lwz r0,GPR0(r1)
+ lwz r3,GPR3(r1)
+ REST_8GPRS(4,r1)
+ lwz r12,GPR12(r1)
+ b 1b
+
#ifdef CONFIG_44x
2: li r7,0
iccci r0,r0
@@ -488,9 +398,6 @@ _ASM_NOKPROBE_SYMBOL(syscall_exit_finish)
b 1b
#endif /* CONFIG_44x */
-66: li r3,-ENOSYS
- b ret_from_syscall
-
.globl ret_from_fork
ret_from_fork:
REST_NVGPRS(r1)
@@ -509,82 +416,6 @@ ret_from_kernel_thread:
li r3,0
b ret_from_syscall
-/* Traced system call support */
-syscall_dotrace:
- SAVE_NVGPRS(r1)
- li r0,0xc00
- stw r0,_TRAP(r1)
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl do_syscall_trace_enter
- /*
- * Restore argument registers possibly just changed.
- * We use the return value of do_syscall_trace_enter
- * for call number to look up in the table (r0).
- */
- mr r0,r3
- lwz r3,GPR3(r1)
- lwz r4,GPR4(r1)
- lwz r5,GPR5(r1)
- lwz r6,GPR6(r1)
- lwz r7,GPR7(r1)
- lwz r8,GPR8(r1)
- REST_NVGPRS(r1)
-
- cmplwi r0,NR_syscalls
- /* Return code is already in r3 thanks to do_syscall_trace_enter() */
- bge- ret_from_syscall
- b syscall_dotrace_cont
-
-syscall_exit_work:
- andi. r0,r9,_TIF_RESTOREALL
- beq+ 0f
- REST_NVGPRS(r1)
- b 2f
-0: cmplw 0,r3,r8
- blt+ 1f
- andi. r0,r9,_TIF_NOERROR
- bne- 1f
- lwz r11,_CCR(r1) /* Load CR */
- neg r3,r3
- oris r11,r11,0x1000 /* Set SO bit in CR */
- stw r11,_CCR(r1)
-
-1: stw r6,RESULT(r1) /* Save result */
- stw r3,GPR3(r1) /* Update return value */
-2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
- beq 4f
-
- /* Clear per-syscall TIF flags if any are set. */
-
- li r11,_TIF_PERSYSCALL_MASK
- addi r12,r2,TI_FLAGS
-3: lwarx r8,0,r12
- andc r8,r8,r11
- stwcx. r8,0,r12
- bne- 3b
-
-4: /* Anything which requires enabling interrupts? */
- andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP)
- beq ret_from_except
-
- /* Re-enable interrupts. There is no need to trace that with
- * lockdep as we are supposed to have IRQs on at this point
- */
- ori r10,r10,MSR_EE
- mtmsr r10
-
- /* Save NVGPRS if they're not saved already */
- lwz r4,_TRAP(r1)
- andi. r4,r4,1
- beq 5f
- SAVE_NVGPRS(r1)
- li r4,0xc00
- stw r4,_TRAP(r1)
-5:
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl do_syscall_trace_leave
- b ret_from_except_full
-
/*
* System call was called from kernel. We get here with SRR1 in r9.
* Mark the exception as recoverable once we have retrieved SRR0,
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 7b12736ec546..c2aa0d8f1f63 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -162,9 +162,6 @@
internal debug mode bit to do this. */
lwz r12,THREAD_DBCR0(r12)
andis. r12,r12,DBCR0_IDM@h
-#endif
- ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
-#if defined(CONFIG_40x)
beq+ 3f
/* From user and task is ptraced - load up global dbcr0 */
li r12,-1 /* clear all pending debug events */
@@ -176,21 +173,8 @@
lwz r12,4(r11)
addi r12,r12,-1
stw r12,4(r11)
-#endif
-
3:
-#ifdef CONFIG_TRACE_IRQFLAGS
- /*
- * If MSR is changing we need to keep interrupts disabled at this point
- * otherwise we might risk taking an interrupt before we tell lockdep
- * they are enabled.
- */
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL)
- rlwimi r10, r9, 0, MSR_EE
-#else
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE)
#endif
- mtmsr r10
b transfer_to_syscall /* jump to handler */
99: b ret_from_kernel_syscall
.endm
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 626e716576ce..faff094b650e 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -138,7 +138,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
internal debug mode bit to do this. */
lwz r12,THREAD_DBCR0(r10)
andis. r12,r12,DBCR0_IDM@h
- ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
beq+ 3f
/* From user and task is ptraced - load up global dbcr0 */
li r12,-1 /* clear all pending debug events */
@@ -157,20 +156,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
stw r12,4(r11)
3:
-#ifdef CONFIG_TRACE_IRQFLAGS
- /*
- * If MSR is changing we need to keep interrupts disabled at this point
- * otherwise we might risk taking an interrupt before we tell lockdep
- * they are enabled.
- */
- lis r10, MSR_KERNEL@h
- ori r10, r10, MSR_KERNEL@l
- rlwimi r10, r9, 0, MSR_EE
-#else
- lis r10, (MSR_KERNEL | MSR_EE)@h
- ori r10, r10, (MSR_KERNEL | MSR_EE)@l
-#endif
- mtmsr r10
b transfer_to_syscall /* jump to handler */
99: b ret_from_kernel_syscall
.endm
--
2.25.0
^ permalink raw reply related
* [PATCH v4 16/23] powerpc/32: Always save non volatile GPRs at syscall entry
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
In preparation for porting syscall entry/exit to C, inconditionally
save non volatile general purpose registers.
Commit 965dd3ad3076 ("powerpc/64/syscall: Remove non-volatile GPR save
optimisation") provides detailed explanation.
This increases the number of cycles by 24 cycles on 8xx with
null_syscall benchmark (280 => 304 cycles)
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 46 +-----------------------
arch/powerpc/kernel/head_32.h | 2 +-
arch/powerpc/kernel/head_booke.h | 2 +-
arch/powerpc/kernel/syscalls/syscall.tbl | 20 +++--------
4 files changed, 8 insertions(+), 62 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index b1e36602c013..97dc28a68465 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -351,6 +351,7 @@ trace_syscall_entry_irq_off:
.globl transfer_to_syscall
transfer_to_syscall:
+ SAVE_NVGPRS(r1)
#ifdef CONFIG_PPC_BOOK3S_32
kuep_lock r11, r12
#endif
@@ -614,51 +615,6 @@ ret_from_kernel_syscall:
#endif
_ASM_NOKPROBE_SYMBOL(ret_from_kernel_syscall)
-/*
- * The fork/clone functions need to copy the full register set into
- * the child process. Therefore we need to save all the nonvolatile
- * registers (r13 - r31) before calling the C code.
- */
- .globl ppc_fork
-ppc_fork:
- SAVE_NVGPRS(r1)
- lwz r0,_TRAP(r1)
- rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
- stw r0,_TRAP(r1) /* register set saved */
- b sys_fork
-
- .globl ppc_vfork
-ppc_vfork:
- SAVE_NVGPRS(r1)
- lwz r0,_TRAP(r1)
- rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
- stw r0,_TRAP(r1) /* register set saved */
- b sys_vfork
-
- .globl ppc_clone
-ppc_clone:
- SAVE_NVGPRS(r1)
- lwz r0,_TRAP(r1)
- rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
- stw r0,_TRAP(r1) /* register set saved */
- b sys_clone
-
- .globl ppc_clone3
-ppc_clone3:
- SAVE_NVGPRS(r1)
- lwz r0,_TRAP(r1)
- rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
- stw r0,_TRAP(r1) /* register set saved */
- b sys_clone3
-
- .globl ppc_swapcontext
-ppc_swapcontext:
- SAVE_NVGPRS(r1)
- lwz r0,_TRAP(r1)
- rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
- stw r0,_TRAP(r1) /* register set saved */
- b sys_swapcontext
-
/*
* Top-level page fault handling.
* This is in assembler because if do_page_fault tells us that
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 24dc326e0d56..7b12736ec546 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -148,7 +148,7 @@
stw r2,GPR2(r11)
addi r10,r10,STACK_FRAME_REGS_MARKER@l
stw r9,_MSR(r11)
- li r2, \trapno + 1
+ li r2, \trapno
stw r10,8(r11)
stw r2,_TRAP(r11)
SAVE_GPR(0, r11)
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index b3c502c503a0..626e716576ce 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -124,7 +124,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
stw r2,GPR2(r11)
addi r12, r12, STACK_FRAME_REGS_MARKER@l
stw r9,_MSR(r11)
- li r2, \trapno + 1
+ li r2, \trapno
stw r12, 8(r11)
stw r2,_TRAP(r11)
SAVE_GPR(0, r11)
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index f744eb5cba88..96b2157f0371 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -9,9 +9,7 @@
#
0 nospu restart_syscall sys_restart_syscall
1 nospu exit sys_exit
-2 32 fork ppc_fork sys_fork
-2 64 fork sys_fork
-2 spu fork sys_ni_syscall
+2 nospu fork sys_fork
3 common read sys_read
4 common write sys_write
5 common open sys_open compat_sys_open
@@ -160,9 +158,7 @@
119 32 sigreturn sys_sigreturn compat_sys_sigreturn
119 64 sigreturn sys_ni_syscall
119 spu sigreturn sys_ni_syscall
-120 32 clone ppc_clone sys_clone
-120 64 clone sys_clone
-120 spu clone sys_ni_syscall
+120 nospu clone sys_clone
121 common setdomainname sys_setdomainname
122 common uname sys_newuname
123 common modify_ldt sys_ni_syscall
@@ -244,9 +240,7 @@
186 spu sendfile sys_sendfile64
187 common getpmsg sys_ni_syscall
188 common putpmsg sys_ni_syscall
-189 32 vfork ppc_vfork sys_vfork
-189 64 vfork sys_vfork
-189 spu vfork sys_ni_syscall
+189 nospu vfork sys_vfork
190 common ugetrlimit sys_getrlimit compat_sys_getrlimit
191 common readahead sys_readahead compat_sys_readahead
192 32 mmap2 sys_mmap2 compat_sys_mmap2
@@ -322,9 +316,7 @@
248 32 clock_nanosleep sys_clock_nanosleep_time32
248 64 clock_nanosleep sys_clock_nanosleep
248 spu clock_nanosleep sys_clock_nanosleep
-249 32 swapcontext ppc_swapcontext compat_sys_swapcontext
-249 64 swapcontext sys_swapcontext
-249 spu swapcontext sys_ni_syscall
+249 nospu swapcontext sys_swapcontext compat_sys_swapcontext
250 common tgkill sys_tgkill
251 32 utimes sys_utimes_time32
251 64 utimes sys_utimes
@@ -522,9 +514,7 @@
432 common fsmount sys_fsmount
433 common fspick sys_fspick
434 common pidfd_open sys_pidfd_open
-435 32 clone3 ppc_clone3 sys_clone3
-435 64 clone3 sys_clone3
-435 spu clone3 sys_ni_syscall
+435 nospu clone3 sys_clone3
436 common close_range sys_close_range
437 common openat2 sys_openat2
438 common pidfd_getfd sys_pidfd_getfd
--
2.25.0
^ permalink raw reply related
* [PATCH v4 15/23] powerpc/syscall: Change condition to check MSR_RI
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
In system_call_exception(), MSR_RI also needs to be checked on 8xx.
Only booke and 40x doesn't have MSR_RI.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/syscall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index b66cfcbcb755..a3510fa4e641 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -39,7 +39,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
trace_hardirqs_off(); /* finish reconciling */
- if (IS_ENABLED(CONFIG_PPC_BOOK3S))
+ if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x))
BUG_ON(!(regs->msr & MSR_RI));
BUG_ON(!(regs->msr & MSR_PR));
BUG_ON(!FULL_REGS(regs));
--
2.25.0
^ permalink raw reply related
* [PATCH v4 14/23] powerpc/syscall: Save r3 in regs->orig_r3
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
Save r3 in regs->orig_r3 in system_call_exception()
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_64.S | 1 -
arch/powerpc/kernel/syscall.c | 2 ++
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index aa1af139d947..a562a4240aa6 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -278,7 +278,6 @@ END_BTB_FLUSH_SECTION
std r10,_LINK(r1)
std r11,_TRAP(r1)
std r12,_CCR(r1)
- std r3,ORIG_GPR3(r1)
addi r10,r1,STACK_FRAME_OVERHEAD
ld r11,exception_marker@toc(r2)
std r11,-16(r10) /* "regshere" marker */
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index cb415170b8f2..b66cfcbcb755 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -29,6 +29,8 @@ notrace long system_call_exception(long r3, long r4, long r5,
{
syscall_fn f;
+ regs->orig_gpr3 = r3;
+
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
BUG_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
--
2.25.0
^ permalink raw reply related
* [PATCH v4 13/23] powerpc/syscall: Use is_compat_task()
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
Instead of hard comparing task flags with _TIF_32BIT, use
is_compat_task(). The advantage is that it returns 0 on PPC32
allthough _TIF_32BIT is always set.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/syscall.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index bf9bf4b5bc41..cb415170b8f2 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -2,6 +2,8 @@
#include <linux/context_tracking.h>
#include <linux/err.h>
+#include <linux/compat.h>
+
#include <asm/asm-prototypes.h>
#include <asm/kup.h>
#include <asm/cputime.h>
@@ -116,7 +118,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
/* May be faster to do array_index_nospec? */
barrier_nospec();
- if (unlikely(is_32bit_task())) {
+ if (unlikely(is_compat_task())) {
f = (void *)compat_sys_call_table[r0];
r3 &= 0x00000000ffffffffULL;
--
2.25.0
^ permalink raw reply related
* [PATCH v4 12/23] powerpc/syscall: Make syscall.c buildable on PPC32
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
ifdef out specific PPC64 stuff to allow building
syscall.c on PPC32.
Modify Makefile to always build syscall.o
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/Makefile | 4 ++--
arch/powerpc/kernel/syscall.c | 9 +++++----
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 1cbc51fc82fd..23c127db0d0c 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -46,10 +46,10 @@ obj-y := cputable.o syscalls.o \
prom.o traps.o setup-common.o \
udbg.o misc.o io.o misc_$(BITS).o \
of_platform.o prom_parse.o firmware.o \
- hw_breakpoint_constraints.o
+ hw_breakpoint_constraints.o syscall.o
obj-y += ptrace/
obj-$(CONFIG_PPC64) += setup_64.o \
- paca.o nvram_64.o note.o syscall.o
+ paca.o nvram_64.o note.o
obj-$(CONFIG_COMPAT) += sys_ppc32.o signal_32.o
obj-$(CONFIG_VDSO32) += vdso32/
obj-$(CONFIG_PPC_WATCHDOG) += watchdog.o
diff --git a/arch/powerpc/kernel/syscall.c b/arch/powerpc/kernel/syscall.c
index b627a6384029..bf9bf4b5bc41 100644
--- a/arch/powerpc/kernel/syscall.c
+++ b/arch/powerpc/kernel/syscall.c
@@ -39,7 +39,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
BUG_ON(!(regs->msr & MSR_RI));
BUG_ON(!(regs->msr & MSR_PR));
BUG_ON(!FULL_REGS(regs));
- BUG_ON(regs->softe != IRQS_ENABLED);
+ BUG_ON(arch_irq_disabled_regs(regs));
#ifdef CONFIG_PPC_PKEY
if (mmu_has_feature(MMU_FTR_PKEY)) {
@@ -77,7 +77,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
* frame, or if the unwinder was taught the first stack frame always
* returns to user with IRQS_ENABLED, this store could be avoided!
*/
- regs->softe = IRQS_ENABLED;
+ irq_soft_mask_regs_set_state(regs, IRQS_ENABLED);
local_irq_enable();
@@ -147,6 +147,7 @@ static notrace inline bool prep_irq_for_enabled_exit(bool clear_ri)
__hard_EE_RI_disable();
else
__hard_irq_disable();
+#ifdef CONFIG_PPC64
if (unlikely(lazy_irq_pending_nocheck())) {
/* Took an interrupt, may have more exit work to do. */
if (clear_ri)
@@ -158,7 +159,7 @@ static notrace inline bool prep_irq_for_enabled_exit(bool clear_ri)
}
local_paca->irq_happened = 0;
irq_soft_mask_set(IRQS_ENABLED);
-
+#endif
return true;
}
@@ -281,7 +282,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
return ret;
}
-#ifdef CONFIG_PPC_BOOK3S /* BOOK3E not yet using this */
+#ifdef CONFIG_PPC_BOOK3S_64 /* BOOK3E not yet using this */
notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr)
{
#ifdef CONFIG_PPC_BOOK3E
--
2.25.0
^ permalink raw reply related
* [PATCH v4 11/23] powerpc/syscall: Rename syscall_64.c into syscall.c
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
syscall_64.c will be reused almost as is for PPC32.
Rename it syscall.c
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/Makefile | 2 +-
arch/powerpc/kernel/{syscall_64.c => syscall.c} | 0
2 files changed, 1 insertion(+), 1 deletion(-)
rename arch/powerpc/kernel/{syscall_64.c => syscall.c} (100%)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index fe2ef598e2ea..1cbc51fc82fd 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -49,7 +49,7 @@ obj-y := cputable.o syscalls.o \
hw_breakpoint_constraints.o
obj-y += ptrace/
obj-$(CONFIG_PPC64) += setup_64.o \
- paca.o nvram_64.o note.o syscall_64.o
+ paca.o nvram_64.o note.o syscall.o
obj-$(CONFIG_COMPAT) += sys_ppc32.o signal_32.o
obj-$(CONFIG_VDSO32) += vdso32/
obj-$(CONFIG_PPC_WATCHDOG) += watchdog.o
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall.c
similarity index 100%
rename from arch/powerpc/kernel/syscall_64.c
rename to arch/powerpc/kernel/syscall.c
--
2.25.0
^ permalink raw reply related
* [PATCH v4 10/23] powerpc/irq: Add stub irq_soft_mask_return() for PPC32
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
To allow building syscall_64.c smoothly on PPC32, add stub version
of irq_soft_mask_return().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/hw_irq.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 4739f61e632c..56a98936a6a9 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -330,6 +330,11 @@ static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned l
}
#else /* CONFIG_PPC64 */
+static inline notrace unsigned long irq_soft_mask_return(void)
+{
+ return 0;
+}
+
static inline unsigned long arch_local_save_flags(void)
{
return mfmsr();
--
2.25.0
^ permalink raw reply related
* [PATCH v4 09/23] powerpc/irq: Rework helpers that manipulate MSR[EE/RI]
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
In preparation of porting PPC32 to C syscall entry/exit,
rewrite the following helpers as static inline functions and
add support for PPC32 in them:
__hard_irq_enable()
__hard_irq_disable()
__hard_EE_RI_disable()
__hard_RI_enable()
Then use them in PPC32 version of arch_local_irq_disable()
and arch_local_irq_enable() to avoid code duplication.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/hw_irq.h | 75 +++++++++++++++++++++----------
arch/powerpc/include/asm/reg.h | 1 +
2 files changed, 52 insertions(+), 24 deletions(-)
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index ed0c3b049dfd..4739f61e632c 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -50,6 +50,55 @@
#ifndef __ASSEMBLY__
+static inline void __hard_irq_enable(void)
+{
+ if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+ wrtee(MSR_EE);
+ else if (IS_ENABLED(CONFIG_PPC_8xx))
+ wrtspr(SPRN_EIE);
+ else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+ __mtmsrd(MSR_EE | MSR_RI, 1);
+ else
+ mtmsr(mfmsr() | MSR_EE);
+}
+
+static inline void __hard_irq_disable(void)
+{
+ if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+ wrtee(0);
+ else if (IS_ENABLED(CONFIG_PPC_8xx))
+ wrtspr(SPRN_EID);
+ else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+ __mtmsrd(MSR_RI, 1);
+ else
+ mtmsr(mfmsr() & ~MSR_EE);
+}
+
+static inline void __hard_EE_RI_disable(void)
+{
+ if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+ wrtee(0);
+ else if (IS_ENABLED(CONFIG_PPC_8xx))
+ wrtspr(SPRN_NRI);
+ else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+ __mtmsrd(0, 1);
+ else
+ mtmsr(mfmsr() & ~(MSR_EE | MSR_RI));
+}
+
+static inline void __hard_RI_enable(void)
+{
+ if (IS_ENABLED(CONFIG_BOOKE) || IS_ENABLED(CONFIG_40x))
+ return;
+
+ if (IS_ENABLED(CONFIG_PPC_8xx))
+ wrtspr(SPRN_EID);
+ else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+ __mtmsrd(MSR_RI, 1);
+ else
+ mtmsr(mfmsr() | MSR_RI);
+}
+
#ifdef CONFIG_PPC64
#include <asm/paca.h>
@@ -212,18 +261,6 @@ static inline bool arch_irqs_disabled(void)
#endif /* CONFIG_PPC_BOOK3S */
-#ifdef CONFIG_PPC_BOOK3E
-#define __hard_irq_enable() wrtee(MSR_EE)
-#define __hard_irq_disable() wrtee(0)
-#define __hard_EE_RI_disable() wrtee(0)
-#define __hard_RI_enable() do { } while (0)
-#else
-#define __hard_irq_enable() __mtmsrd(MSR_EE|MSR_RI, 1)
-#define __hard_irq_disable() __mtmsrd(MSR_RI, 1)
-#define __hard_EE_RI_disable() __mtmsrd(0, 1)
-#define __hard_RI_enable() __mtmsrd(MSR_RI, 1)
-#endif
-
#define hard_irq_disable() do { \
unsigned long flags; \
__hard_irq_disable(); \
@@ -322,22 +359,12 @@ static inline unsigned long arch_local_irq_save(void)
static inline void arch_local_irq_disable(void)
{
- if (IS_ENABLED(CONFIG_BOOKE))
- wrtee(0);
- else if (IS_ENABLED(CONFIG_PPC_8xx))
- wrtspr(SPRN_EID);
- else
- mtmsr(mfmsr() & ~MSR_EE);
+ __hard_irq_disable();
}
static inline void arch_local_irq_enable(void)
{
- if (IS_ENABLED(CONFIG_BOOKE))
- wrtee(MSR_EE);
- else if (IS_ENABLED(CONFIG_PPC_8xx))
- wrtspr(SPRN_EIE);
- else
- mtmsr(mfmsr() | MSR_EE);
+ __hard_irq_enable();
}
static inline bool arch_irqs_disabled_flags(unsigned long flags)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index e40a921d78f9..d05dca30604d 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1375,6 +1375,7 @@
#define mtmsr(v) asm volatile("mtmsr %0" : \
: "r" ((unsigned long)(v)) \
: "memory")
+#define __mtmsrd(v, l) BUILD_BUG()
#define __MTMSR "mtmsr"
#endif
--
2.25.0
^ permalink raw reply related
* [PATCH v4 05/23] powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
In preparation of porting powerpc32 to C syscall entry/exit,
rename kuap_check_amr() and kuap_get_and_check_amr() as kuap_check()
and kuap_get_and_check(), and move in the generic asm/kup.h the stub
for when CONFIG_PPC_KUAP is not selected.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/book3s/64/kup.h | 24 ++----------------------
arch/powerpc/include/asm/kup.h | 9 ++++++++-
arch/powerpc/kernel/syscall_64.c | 12 ++++++------
3 files changed, 16 insertions(+), 29 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index f50f72e535aa..1507681ad4ef 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -281,7 +281,7 @@ static inline void kuap_kernel_restore(struct pt_regs *regs,
*/
}
-static inline unsigned long kuap_get_and_check_amr(void)
+static inline unsigned long kuap_get_and_check(void)
{
if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) {
unsigned long amr = mfspr(SPRN_AMR);
@@ -292,27 +292,7 @@ static inline unsigned long kuap_get_and_check_amr(void)
return 0;
}
-#else /* CONFIG_PPC_PKEY */
-
-static inline void kuap_user_restore(struct pt_regs *regs)
-{
-}
-
-static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr)
-{
-}
-
-static inline unsigned long kuap_get_and_check_amr(void)
-{
- return 0;
-}
-
-#endif /* CONFIG_PPC_PKEY */
-
-
-#ifdef CONFIG_PPC_KUAP
-
-static inline void kuap_check_amr(void)
+static inline void kuap_check(void)
{
if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
WARN_ON_ONCE(mfspr(SPRN_AMR) != AMR_KUAP_BLOCKED);
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index bf221a2a523e..6ef9f9cfbed0 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -66,7 +66,14 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
return false;
}
-static inline void kuap_check_amr(void) { }
+static inline void kuap_check(void) { }
+static inline void kuap_user_restore(struct pt_regs *regs) { }
+static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long amr) { }
+
+static inline unsigned long kuap_get_and_check(void)
+{
+ return 0;
+}
/*
* book3s/64/kup-radix.h defines these functions for the !KUAP case to flush
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 32f72965da26..b627a6384029 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -65,7 +65,7 @@ notrace long system_call_exception(long r3, long r4, long r5,
isync();
} else
#endif
- kuap_check_amr();
+ kuap_check();
account_cpu_user_entry();
@@ -181,7 +181,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
CT_WARN_ON(ct_state() == CONTEXT_USER);
- kuap_check_amr();
+ kuap_check();
regs->result = r3;
@@ -303,7 +303,7 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
* We don't need to restore AMR on the way back to userspace for KUAP.
* AMR can only have been unlocked if we interrupted the kernel.
*/
- kuap_check_amr();
+ kuap_check();
local_irq_save(flags);
@@ -381,7 +381,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
unsigned long *ti_flagsp = ¤t_thread_info()->flags;
unsigned long flags;
unsigned long ret = 0;
- unsigned long amr;
+ unsigned long kuap;
if (IS_ENABLED(CONFIG_PPC_BOOK3S) && unlikely(!(regs->msr & MSR_RI)))
unrecoverable_exception(regs);
@@ -394,7 +394,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
if (TRAP(regs) != 0x700)
CT_WARN_ON(ct_state() == CONTEXT_USER);
- amr = kuap_get_and_check_amr();
+ kuap = kuap_get_and_check();
if (unlikely(*ti_flagsp & _TIF_EMULATE_STACK_STORE)) {
clear_bits(_TIF_EMULATE_STACK_STORE, ti_flagsp);
@@ -446,7 +446,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
* which would cause Read-After-Write stalls. Hence, we take the AMR
* value from the check above.
*/
- kuap_kernel_restore(regs, amr);
+ kuap_kernel_restore(regs, kuap);
return ret;
}
--
2.25.0
^ permalink raw reply related
* [PATCH v4 06/23] powerpc/32s: Create C version of kuap_user/kernel_restore() and friends
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
In preparation of porting PPC32 to C syscall entry/exit,
create C version of kuap_user_restore() and kuap_kernel_restore()
and kuap_check() and kuap_get_and_check() on book3s/32.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/book3s/32/kup.h | 33 ++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index a0117a9d5b06..a3e72e1141c5 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -103,6 +103,39 @@ static inline void kuap_update_sr(u32 sr, u32 addr, u32 end)
isync(); /* Context sync required after mtsrin() */
}
+static inline void kuap_user_restore(struct pt_regs *regs)
+{
+}
+
+static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+{
+ u32 addr = kuap & 0xf0000000;
+ u32 end = kuap << 28;
+
+ if (unlikely(!kuap))
+ return;
+
+ current->thread.kuap = 0;
+ kuap_update_sr(mfsrin(addr) & ~SR_KS, addr, end); /* Clear Ks */
+}
+
+static inline void kuap_check(void)
+{
+ if (!IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+ return;
+
+ WARN_ON_ONCE(current->thread.kuap != 0);
+}
+
+static inline unsigned long kuap_get_and_check(void)
+{
+ unsigned long kuap = current->thread.kuap;
+
+ WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != 0);
+
+ return kuap;
+}
+
static __always_inline void allow_user_access(void __user *to, const void __user *from,
u32 size, unsigned long dir)
{
--
2.25.0
^ permalink raw reply related
* [PATCH v4 08/23] powerpc/irq: Add helper to set regs->softe
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
regs->softe doesn't exist on PPC32.
Add irq_soft_mask_regs_set_state() helper to set regs->softe.
This helper will void on PPC32.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/hw_irq.h | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 614957f74cee..ed0c3b049dfd 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -38,6 +38,8 @@
#define PACA_IRQ_MUST_HARD_MASK (PACA_IRQ_EE)
#endif
+#endif /* CONFIG_PPC64 */
+
/*
* flags for paca->irq_soft_mask
*/
@@ -46,8 +48,6 @@
#define IRQS_PMI_DISABLED 2
#define IRQS_ALL_DISABLED (IRQS_DISABLED | IRQS_PMI_DISABLED)
-#endif /* CONFIG_PPC64 */
-
#ifndef __ASSEMBLY__
#ifdef CONFIG_PPC64
@@ -287,6 +287,10 @@ extern void irq_set_pending_from_srr1(unsigned long srr1);
extern void force_external_irq_replay(void);
+static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
+{
+ regs->softe = val;
+}
#else /* CONFIG_PPC64 */
static inline unsigned long arch_local_save_flags(void)
@@ -355,6 +359,9 @@ static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
static inline void may_hard_irq_enable(void) { }
+static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
+{
+}
#endif /* CONFIG_PPC64 */
#define ARCH_IRQ_INIT_FLAGS IRQ_NOREQUEST
--
2.25.0
^ permalink raw reply related
* [PATCH v4 07/23] powerpc/8xx: Create C version of kuap_user/kernel_restore() and friends
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
In preparation of porting PPC32 to C syscall entry/exit,
create C version of kuap_user_restore() and kuap_kernel_restore()
and kuap_check() and kuap_get_and_check() on 8xx
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/nohash/32/kup-8xx.h | 27 ++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 17a4a616436f..5ca6c375f767 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -34,6 +34,33 @@
#include <asm/reg.h>
+static inline void kuap_user_restore(struct pt_regs *regs)
+{
+}
+
+static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long kuap)
+{
+ mtspr(SPRN_MD_AP, kuap);
+}
+
+static inline void kuap_check(void)
+{
+ if (!IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+ return;
+
+ WARN_ON_ONCE(mfspr(SPRN_MD_AP) >> 16 != MD_APG_KUAP >> 16);
+}
+
+static inline unsigned long kuap_get_and_check(void)
+{
+ unsigned long kuap = mfspr(SPRN_MD_AP);
+
+ if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+ WARN_ON_ONCE(mfspr(SPRN_MD_AP) >> 16 != MD_APG_KUAP >> 16);
+
+ return kuap;
+}
+
static inline void allow_user_access(void __user *to, const void __user *from,
unsigned long size, unsigned long dir)
{
--
2.25.0
^ permalink raw reply related
* [PATCH v4 02/23] powerpc/32: Always enable data translation on syscall entry
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
If the code can use a stack in vm area, it can also use a
stack in linear space.
Simplify code by removing old non VMAP stack code on PPC32 in syscall.
That means the data translation is now re-enabled early in
syscall entry in all cases, not only when using VMAP stacks.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 23 +----------------------
arch/powerpc/kernel/head_booke.h | 2 --
2 files changed, 1 insertion(+), 24 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index a2f72c966baf..fdc07beab844 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -118,7 +118,6 @@
.macro SYSCALL_ENTRY trapno
mfspr r12,SPRN_SPRG_THREAD
mfspr r9, SPRN_SRR1
-#ifdef CONFIG_VMAP_STACK
mfspr r11, SPRN_SRR0
mtctr r11
andi. r11, r9, MSR_PR
@@ -126,30 +125,16 @@
lwz r1,TASK_STACK-THREAD(r12)
beq- 99f
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
- li r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
+ LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
mtmsr r10
isync
tovirt(r12, r12)
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
-#else
- andi. r11, r9, MSR_PR
- lwz r11,TASK_STACK-THREAD(r12)
- beq- 99f
- addi r11, r11, THREAD_SIZE - INT_FRAME_SIZE
- tophys(r11, r11)
- stw r1,GPR1(r11)
- stw r1,0(r11)
- tovirt(r1, r11) /* set new kernel sp */
-#endif
mflr r10
stw r10, _LINK(r11)
-#ifdef CONFIG_VMAP_STACK
mfctr r10
-#else
- mfspr r10,SPRN_SRR0
-#endif
stw r10,_NIP(r11)
mfcr r10
rlwinm r10,r10,0,4,2 /* Clear SO bit in CR */
@@ -157,11 +142,7 @@
#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
#else
-#ifdef CONFIG_VMAP_STACK
LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~MSR_IR) /* can take exceptions */
-#else
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR|MSR_DR)) /* can take exceptions */
-#endif
mtmsr r10 /* (except for mach check in rtas) */
#endif
lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
@@ -190,7 +171,6 @@
li r12,-1 /* clear all pending debug events */
mtspr SPRN_DBSR,r12
lis r11,global_dbcr0@ha
- tophys(r11,r11)
addi r11,r11,global_dbcr0@l
lwz r12,0(r11)
mtspr SPRN_DBCR0,r12
@@ -200,7 +180,6 @@
#endif
3:
- tovirt_novmstack r2, r2 /* set r2 to current */
lis r11, transfer_to_syscall@h
ori r11, r11, transfer_to_syscall@l
#ifdef CONFIG_TRACE_IRQFLAGS
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index bf33af714d11..706cd9368992 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -144,7 +144,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
li r12,-1 /* clear all pending debug events */
mtspr SPRN_DBSR,r12
lis r11,global_dbcr0@ha
- tophys(r11,r11)
addi r11,r11,global_dbcr0@l
#ifdef CONFIG_SMP
lwz r10, TASK_CPU(r2)
@@ -158,7 +157,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
stw r12,4(r11)
3:
- tovirt(r2, r2) /* set r2 to current */
lis r11, transfer_to_syscall@h
ori r11, r11, transfer_to_syscall@l
#ifdef CONFIG_TRACE_IRQFLAGS
--
2.25.0
^ permalink raw reply related
* [PATCH v4 00/23] powerpc/32: Implement C syscall entry/exit
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
This series implements C syscall entry/exit for PPC32. It reuses
the work already done for PPC64.
This series is based on Nick's v6 series "powerpc: interrupt wrappers".
Patch 1 is a bug fix submitted separately but this series depends on it.
Patches 2-4 are an extract from the series "powerpc/32: Reduce head
complexity and re-activate MMU earlier". The changes here are limited
to system calls. That series will be respined to only contain exception
related changes and the syscall changes will remain in this series.
Patches 5-16 are preparatory changes.
Patch 17 is THE patch that changes to C syscall entry/exit
Patches 18-23 are optimisations.
In terms on performance we have the following number of cycles on an
8xx running null_syscall benchmark:
- mainline: 296 cycles
- after patch 4: 283 cycles
- after patch 16: 304 cycles
- after patch 17: 348 cycles
- at the end of the series: 320 cycles
So in summary, we have a degradation of performance of 8% on null_syscall.
I think it is not a big degradation, it is worth it.
v4 is the first mature version.
Christophe Leroy (23):
powerpc/32s: Add missing call to kuep_lock on syscall entry
powerpc/32: Always enable data translation on syscall entry
powerpc/32: On syscall entry, enable instruction translation at the
same time as data
powerpc/32: Reorder instructions to avoid using CTR in syscall entry
powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr()
generic
powerpc/32s: Create C version of kuap_user/kernel_restore() and
friends
powerpc/8xx: Create C version of kuap_user/kernel_restore() and
friends
powerpc/irq: Add helper to set regs->softe
powerpc/irq: Rework helpers that manipulate MSR[EE/RI]
powerpc/irq: Add stub irq_soft_mask_return() for PPC32
powerpc/syscall: Rename syscall_64.c into syscall.c
powerpc/syscall: Make syscall.c buildable on PPC32
powerpc/syscall: Use is_compat_task()
powerpc/syscall: Save r3 in regs->orig_r3
powerpc/syscall: Change condition to check MSR_RI
powerpc/32: Always save non volatile GPRs at syscall entry
powerpc/syscall: implement system call entry/exit logic in C for PPC32
powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry
powerpc/syscall: Avoid stack frame in likely part of
system_call_exception()
powerpc/syscall: Do not check unsupported scv vector on PPC32
powerpc/syscall: Remove FULL_REGS verification in
system_call_exception
powerpc/syscall: Optimise checks in beginning of
system_call_exception()
powerpc/syscall: Avoid storing 'current' in another pointer
arch/powerpc/include/asm/book3s/32/kup.h | 33 ++
arch/powerpc/include/asm/book3s/64/kup.h | 24 +-
arch/powerpc/include/asm/hw_irq.h | 91 ++++--
arch/powerpc/include/asm/kup.h | 9 +-
arch/powerpc/include/asm/nohash/32/kup-8xx.h | 27 ++
arch/powerpc/include/asm/reg.h | 1 +
arch/powerpc/kernel/Makefile | 4 +-
arch/powerpc/kernel/entry_32.S | 305 ++----------------
arch/powerpc/kernel/entry_64.S | 1 -
arch/powerpc/kernel/head_32.h | 76 +----
arch/powerpc/kernel/head_booke.h | 27 +-
.../kernel/{syscall_64.c => syscall.c} | 57 ++--
arch/powerpc/kernel/syscalls/syscall.tbl | 20 +-
13 files changed, 225 insertions(+), 450 deletions(-)
rename arch/powerpc/kernel/{syscall_64.c => syscall.c} (90%)
--
2.25.0
^ permalink raw reply
* [PATCH v4 03/23] powerpc/32: On syscall entry, enable instruction translation at the same time as data
From: Christophe Leroy @ 2021-01-25 14:48 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin,
msuchanek
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1611585031.git.christophe.leroy@csgroup.eu>
On 40x and 8xx, kernel text is pinned.
On book3s/32, kernel text is mapped by BATs.
Enable instruction translation at the same time as data translation, it
makes things simpler.
MSR_RI can also be set at the same time because srr0/srr1 are already
saved and r1 is set properly.
On booke, translation is always on, so at the end all PPC32
have translation on early.
This reduces null_syscall benchmark by 13 cycles on 8xx
(296 ==> 283 cycles).
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 26 +++++++++-----------------
arch/powerpc/kernel/head_booke.h | 7 ++-----
2 files changed, 11 insertions(+), 22 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index fdc07beab844..4029c51dce5d 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -125,9 +125,13 @@
lwz r1,TASK_STACK-THREAD(r12)
beq- 99f
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
- mtmsr r10
- isync
+ LOAD_REG_IMMEDIATE(r10, MSR_KERNEL) /* can take exceptions */
+ mtspr SPRN_SRR1, r10
+ lis r10, 1f@h
+ ori r10, r10, 1f@l
+ mtspr SPRN_SRR0, r10
+ rfi
+1:
tovirt(r12, r12)
stw r11,GPR1(r1)
stw r11,0(r1)
@@ -141,9 +145,6 @@
stw r10,_CCR(r11) /* save registers */
#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
-#else
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~MSR_IR) /* can take exceptions */
- mtmsr r10 /* (except for mach check in rtas) */
#endif
lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
stw r2,GPR2(r11)
@@ -180,8 +181,6 @@
#endif
3:
- lis r11, transfer_to_syscall@h
- ori r11, r11, transfer_to_syscall@l
#ifdef CONFIG_TRACE_IRQFLAGS
/*
* If MSR is changing we need to keep interrupts disabled at this point
@@ -193,15 +192,8 @@
#else
LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE)
#endif
-#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
- mtspr SPRN_NRI, r0
-#endif
- mtspr SPRN_SRR1,r10
- mtspr SPRN_SRR0,r11
- rfi /* jump to handler, enable MMU */
-#ifdef CONFIG_40x
- b . /* Prevent prefetch past rfi */
-#endif
+ mtmsr r10
+ b transfer_to_syscall /* jump to handler */
99: b ret_from_kernel_syscall
.endm
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 706cd9368992..b3c502c503a0 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -157,8 +157,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
stw r12,4(r11)
3:
- lis r11, transfer_to_syscall@h
- ori r11, r11, transfer_to_syscall@l
#ifdef CONFIG_TRACE_IRQFLAGS
/*
* If MSR is changing we need to keep interrupts disabled at this point
@@ -172,9 +170,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
lis r10, (MSR_KERNEL | MSR_EE)@h
ori r10, r10, (MSR_KERNEL | MSR_EE)@l
#endif
- mtspr SPRN_SRR1,r10
- mtspr SPRN_SRR0,r11
- rfi /* jump to handler, enable MMU */
+ mtmsr r10
+ b transfer_to_syscall /* jump to handler */
99: b ret_from_kernel_syscall
.endm
--
2.25.0
^ permalink raw reply related
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