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* Re: [PATCH] KVM: PPC: Book3S HV: increase KVMPPC_NR_LPIDS on POWER8 and POWER9
From: Paul Mackerras @ 2020-07-23  6:20 UTC (permalink / raw)
  To: Cédric Le Goater; +Cc: kvm-ppc, linuxppc-dev, Nicholas Piggin, kvm
In-Reply-To: <20200608115714.1139735-1-clg@kaod.org>

On Mon, Jun 08, 2020 at 01:57:14PM +0200, Cédric Le Goater wrote:
> POWER8 and POWER9 have 12-bit LPIDs. Change LPID_RSVD to support up to
> (4096 - 2) guests on these processors. POWER7 is kept the same with a
> limitation of (1024 - 2), but it might be time to drop KVM support for
> POWER7.
> 
> Tested with 2048 guests * 4 vCPUs on a witherspoon system with 512G
> RAM and a bit of swap.
> 
> Signed-off-by: Cédric Le Goater <clg@kaod.org>

Thanks, patch applied to my kvm-ppc-next branch.

Paul.

^ permalink raw reply

* Re: [PATCH kernel] KVM: PPC: Protect kvm_vcpu_read_guest with srcu locks
From: Paul Mackerras @ 2020-07-23  6:19 UTC (permalink / raw)
  To: Alexey Kardashevskiy; +Cc: linuxppc-dev, kvm-ppc
In-Reply-To: <20200609021230.103494-1-aik@ozlabs.ru>

On Tue, Jun 09, 2020 at 12:12:29PM +1000, Alexey Kardashevskiy wrote:
> The kvm_vcpu_read_guest/kvm_vcpu_write_guest used for nested guests
> eventually call srcu_dereference_check to dereference a memslot and
> lockdep produces a warning as neither kvm->slots_lock nor
> kvm->srcu lock is held and kvm->users_count is above zero (>100 in fact).
> 
> This wraps mentioned VCPU read/write helpers in srcu read lock/unlock as
> it is done in other places. This uses vcpu->srcu_idx when possible.
> 
> These helpers are only used for nested KVM so this may explain why
> we did not see these before.
> 
> Here is an example of a warning:
> 
> =============================
> WARNING: suspicious RCU usage
> 5.7.0-rc3-le_dma-bypass.3.2_a+fstn1 #897 Not tainted
> -----------------------------
> include/linux/kvm_host.h:633 suspicious rcu_dereference_check() usage!
> 
> other info that might help us debug this:
> 
> rcu_scheduler_active = 2, debug_locks = 1
> 1 lock held by qemu-system-ppc/2752:
>  #0: c000200359016be0 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x144/0xd80 [kvm]
> 
> stack backtrace:
> CPU: 80 PID: 2752 Comm: qemu-system-ppc Not tainted 5.7.0-rc3-le_dma-bypass.3.2_a+fstn1 #897
> Call Trace:
> [c0002003591ab240] [c000000000b23ab4] dump_stack+0x190/0x25c (unreliable)
> [c0002003591ab2b0] [c00000000023f954] lockdep_rcu_suspicious+0x140/0x164
> [c0002003591ab330] [c008000004a445f8] kvm_vcpu_gfn_to_memslot+0x4c0/0x510 [kvm]
> [c0002003591ab3a0] [c008000004a44c18] kvm_vcpu_read_guest+0xa0/0x180 [kvm]
> [c0002003591ab410] [c008000004ff9bd8] kvmhv_enter_nested_guest+0x90/0xb80 [kvm_hv]
> [c0002003591ab980] [c008000004fe07bc] kvmppc_pseries_do_hcall+0x7b4/0x1c30 [kvm_hv]
> [c0002003591aba10] [c008000004fe5d30] kvmppc_vcpu_run_hv+0x10a8/0x1a30 [kvm_hv]
> [c0002003591abae0] [c008000004a5d954] kvmppc_vcpu_run+0x4c/0x70 [kvm]
> [c0002003591abb10] [c008000004a56e54] kvm_arch_vcpu_ioctl_run+0x56c/0x7c0 [kvm]
> [c0002003591abba0] [c008000004a3ddc4] kvm_vcpu_ioctl+0x4ac/0xd80 [kvm]
> [c0002003591abd20] [c0000000006ebb58] ksys_ioctl+0x188/0x210
> [c0002003591abd70] [c0000000006ebc28] sys_ioctl+0x48/0xb0
> [c0002003591abdb0] [c000000000042764] system_call_exception+0x1d4/0x2e0
> [c0002003591abe20] [c00000000000cce8] system_call_common+0xe8/0x214
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Thanks, patch applied to my kvm-ppc-next branch.

Paul.

^ permalink raw reply

* Re: [PATCH] powerpc/kvm: Enable support for ISA v3.1 guests
From: Paul Mackerras @ 2020-07-23  6:21 UTC (permalink / raw)
  To: Alistair Popple; +Cc: mikey, linuxppc-dev, kvm-ppc, ravi.bangoria
In-Reply-To: <20200602055325.6102-1-alistair@popple.id.au>

On Tue, Jun 02, 2020 at 03:53:25PM +1000, Alistair Popple wrote:
> Adds support for emulating ISAv3.1 guests by adding the appropriate PCR
> and FSCR bits.
> 
> Signed-off-by: Alistair Popple <alistair@popple.id.au>

Thanks, patch applied to my kvm-ppc-next branch.

Paul.

^ permalink raw reply

* Re: [PATCH v6 3/5] KVM: PPC: clean up redundant kvm_run parameters in assembly
From: Paul Mackerras @ 2020-07-23  6:19 UTC (permalink / raw)
  To: Tianjia Zhang
  Cc: wanpengli, kvm, david, heiko.carstens, peterx, linux-mips, hpa,
	kvmarm, linux-s390, frankja, chenhuacai, maz, joro, x86,
	borntraeger, mingo, julien.thierry.kdev, thuth, gor,
	suzuki.poulose, kvm-ppc, bp, tglx, linux-arm-kernel, jmattson,
	tsbogend, cohuck, christoffer.dall, sean.j.christopherson,
	linux-kernel, james.morse, pbonzini, vkuznets, linuxppc-dev
In-Reply-To: <20200623131418.31473-4-tianjia.zhang@linux.alibaba.com>

On Tue, Jun 23, 2020 at 09:14:16PM +0800, Tianjia Zhang wrote:
> In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
> structure. For historical reasons, many kvm-related function parameters
> retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This
> patch does a unified cleanup of these remaining redundant parameters.

Thanks, patch applied to my kvm-ppc-next branch, with fixes.

Paul.

^ permalink raw reply

* Re: [PATCHv3 2/2] powerpc/pseries: update device tree before ejecting hotplug uevents
From: Michael Ellerman @ 2020-07-23  6:41 UTC (permalink / raw)
  To: Pingfan Liu; +Cc: Nathan Lynch, Kexec Mailing List, linuxppc-dev, Hari Bathini
In-Reply-To: <CAFgQCTsgX9XWJ476dxT2csTuuhpaO3KSZN-EewZiZ0mBj3N4aQ@mail.gmail.com>

Pingfan Liu <kernelfans@gmail.com> writes:
> On Wed, Jul 22, 2020 at 12:57 PM Michael Ellerman <mpe@ellerman.id.au> wrote:
>>
>> Pingfan Liu <kernelfans@gmail.com> writes:
>> > A bug is observed on pseries by taking the following steps on rhel:
>>                                                                 ^
>>                                                                 RHEL
>>
>> I assume it happens on mainline too?
> Yes, it does.
>>
> [...]
>> > diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
>> > index 1a3ac3b..def8cb3f 100644
>> > --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
>> > +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
>> > @@ -372,6 +372,7 @@ static int dlpar_remove_lmb(struct drmem_lmb *lmb)
>> >       invalidate_lmb_associativity_index(lmb);
>> >       lmb_clear_nid(lmb);
>> >       lmb->flags &= ~DRCONF_MEM_ASSIGNED;
>> > +     drmem_update_dt();
>>
>> No error checking?
> Hmm, here should be a more careful design. Please see the comment at the end.
>>
>> >       __remove_memory(nid, base_addr, block_sz);
>> >
>> > @@ -607,6 +608,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
>> >
>> >       lmb_set_nid(lmb);
>> >       lmb->flags |= DRCONF_MEM_ASSIGNED;
>> > +     drmem_update_dt();
>>
>> And here ..
>> >
>> >       block_sz = memory_block_size_bytes();
>> >
>> > @@ -625,6 +627,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
>> >               invalidate_lmb_associativity_index(lmb);
>> >               lmb_clear_nid(lmb);
>> >               lmb->flags &= ~DRCONF_MEM_ASSIGNED;
>> > +             drmem_update_dt();
>>
>>
>> And here ..
>>
>> >               __remove_memory(nid, base_addr, block_sz);
>> >       }
>> > @@ -877,9 +880,6 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
>> >               break;
>> >       }
>> >
>> > -     if (!rc)
>> > -             rc = drmem_update_dt();
>> > -
>> >       unlock_device_hotplug();
>> >       return rc;
>>
>> Whereas previously we did check it.
>
> drmem_update_dt() fails iff allocating memory fail.

That's true currently, but it might change in future.

> And in the failed case, even the original code does not roll back the
> effect of __add_memory()/__remove_memory().

Yeah hard to know what the desired behaviour is. If something fails we
at least need to print a message though, not silently swallow it.

> And I plan to do the following in V4: if drmem_update_dt() fails in
> dlpar_add_lmb(), then bails out immediately.

That sounds reasonable.

cheers

^ permalink raw reply

* Re: [PATCH v4 07/12] ppc64/kexec_file: add support to relocate purgatory
From: Michael Ellerman @ 2020-07-23  6:47 UTC (permalink / raw)
  To: Hari Bathini, Andrew Morton
  Cc: kernel test robot, Pingfan Liu, Kexec-ml, Nayna Jain,
	Petr Tesarik, Mahesh J Salgaonkar, Mimi Zohar, lkml, linuxppc-dev,
	Sourabh Jain, Vivek Goyal, Dave Young, Thiago Jung Bauermann,
	Eric Biederman
In-Reply-To: <2037fa32-28be-5995-1c22-c8b01cafe088@linux.ibm.com>

Hari Bathini <hbathini@linux.ibm.com> writes:
> On 22/07/20 9:55 am, Michael Ellerman wrote:
>> Hari Bathini <hbathini@linux.ibm.com> writes:
>>> Right now purgatory implementation is only minimal. But if purgatory
>>> code is to be enhanced to copy memory to the backup region and verify
>>> sha256 digest, relocations may have to be applied to the purgatory.
>>> So, add support to relocate purgatory in kexec_file_load system call
>>> by setting up TOC pointer and applying RELA relocations as needed.
>>>
>>> Reported-by: kernel test robot <lkp@intel.com>
>>> [lkp: In v1, 'struct mem_sym' was declared in parameter list]
>>> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
>>> ---
>>>
>>> * Michael, can you share your opinion on the below:
>>>     - https://lore.kernel.org/patchwork/patch/1272027/
>>>     - My intention in cover note.
>> 
>> It seems like a lot of complexity for little benefit.
>> 
>> AFAICS your final purgatory_64.c is only 36 lines, and all it does is a
>> single (open coded) memcpy().
>> 
>> It seems like we could write that in not many more lines of assembler
>> and avoid all this code.
>
> Hi Michael,
>
> I am not sure if you would agree with me on this, but I am looking at the
> purgatory code as work in progress. As mentioned in the cover note, I intend
> to add log messaging, sha256 verification into purgatory. And also change it
> to position independent executable after moving common purgatory code (sha256
> verification) to arch-independent code.

I've never understood the desire to put more logic into purgatory. It's
the absolute worst place to detect that something's gone wrong, because
we have no facilities in there to do anything useful. We don't even know
what platform we're on.

> When I initially took this up, I wanted to add all the above changes too, but
> cut down on it, in the interest of time, first to get kdump (kexec -s -p)
> working in v5.9 merge window.
>
> But as the logic in patches 07/12 & 08/12 has been tested in kexec-tools code
> a lot of times and there are unlikely to be any changes to them except for
> __kexec_do_relocs() function (afaics), when -PIE would be used, I submitted them.
> With patch 09/12, I tried for a change that uses relocations while is minimal
> for now.
>
> Would you prefer it to be absolutely minimal by dropping patches 7 & 8 for
> now and writing the backup data copy code in assembler?

Yes please.

cheers

^ permalink raw reply

* Re: [PATCH 2/2] powerpc/64s: system call support for scv/rfscv instructions
From: Michael Ellerman @ 2020-07-23  6:47 UTC (permalink / raw)
  To: Nicholas Piggin, linuxppc-dev; +Cc: libc-dev, musl, Nicholas Piggin, linux-api
In-Reply-To: <20200611081203.995112-3-npiggin@gmail.com>

Nicholas Piggin <npiggin@gmail.com> writes:
> diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
> index 2a39c716c343..b2bdc4de1292 100644
> --- a/arch/powerpc/include/asm/ppc-opcode.h
> +++ b/arch/powerpc/include/asm/ppc-opcode.h
> @@ -257,6 +257,7 @@
>  #define PPC_INST_MFVSRD			0x7c000066
>  #define PPC_INST_MTVSRD			0x7c000166
>  #define PPC_INST_SC			0x44000002
> +#define PPC_INST_SCV			0x44000001
...
> @@ -411,6 +412,7 @@
...
> +#define __PPC_LEV(l)	(((l) & 0x7f) << 5)

These conflicted and didn't seem to be used so I dropped them.

> diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
> index 5abe98216dc2..161bfccbc309 100644
> --- a/arch/powerpc/lib/sstep.c
> +++ b/arch/powerpc/lib/sstep.c
> @@ -3378,6 +3382,16 @@ int emulate_step(struct pt_regs *regs, struct ppc_inst instr)
>  		regs->msr = MSR_KERNEL;
>  		return 1;
>  
> +	case SYSCALL_VECTORED_0:	/* scv 0 */
> +		regs->gpr[9] = regs->gpr[13];
> +		regs->gpr[10] = MSR_KERNEL;
> +		regs->gpr[11] = regs->nip + 4;
> +		regs->gpr[12] = regs->msr & MSR_MASK;
> +		regs->gpr[13] = (unsigned long) get_paca();
> +		regs->nip = (unsigned long) &system_call_vectored_emulate;
> +		regs->msr = MSR_KERNEL;
> +		return 1;
> +

This broke the ppc64e build:

  ld: arch/powerpc/lib/sstep.o:(.toc+0x0): undefined reference to `system_call_vectored_emulate'
  make[1]: *** [/home/michael/linux/Makefile:1139: vmlinux] Error 1

I wrapped it in #ifdef CONFIG_PPC64_BOOK3S.

cheers

^ permalink raw reply

* [powerpc:merge] BUILD SUCCESS c27fe454aff795023d2f3f90f41eb1a3104e614f
From: kernel test robot @ 2020-07-23  7:28 UTC (permalink / raw)
  To: Michael Ellerman; +Cc: linuxppc-dev

tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git  merge
branch HEAD: c27fe454aff795023d2f3f90f41eb1a3104e614f  Automatic merge of 'master', 'next' and 'fixes' (2020-07-21 00:00)

elapsed time: 3913m

configs tested: 111
configs skipped: 2

The following configs have been built successfully.
More configs may be tested in the coming days.

arm64                            allyesconfig
arm64                               defconfig
arm64                            allmodconfig
arm64                             allnoconfig
arm                              allyesconfig
arm                              allmodconfig
arm                               allnoconfig
arm                                 defconfig
sh                          rsk7264_defconfig
c6x                                 defconfig
c6x                        evmc6474_defconfig
arm                         shannon_defconfig
powerpc                       ppc64_defconfig
arm                      footbridge_defconfig
s390                             alldefconfig
s390                          debug_defconfig
arm                          pxa3xx_defconfig
m68k                        m5407c3_defconfig
sh                          sdk7780_defconfig
c6x                         dsk6455_defconfig
arm                           h5000_defconfig
i386                             allyesconfig
i386                                defconfig
i386                              debian-10.3
i386                              allnoconfig
ia64                             allmodconfig
ia64                                defconfig
ia64                              allnoconfig
ia64                             allyesconfig
m68k                             allmodconfig
m68k                              allnoconfig
m68k                           sun3_defconfig
m68k                                defconfig
m68k                             allyesconfig
nios2                               defconfig
nios2                            allyesconfig
openrisc                            defconfig
c6x                              allyesconfig
c6x                               allnoconfig
openrisc                         allyesconfig
nds32                               defconfig
nds32                             allnoconfig
csky                             allyesconfig
csky                                defconfig
alpha                               defconfig
alpha                            allyesconfig
xtensa                           allyesconfig
h8300                            allyesconfig
h8300                            allmodconfig
xtensa                              defconfig
arc                                 defconfig
arc                              allyesconfig
sh                               allmodconfig
sh                                allnoconfig
microblaze                        allnoconfig
mips                             allyesconfig
mips                              allnoconfig
mips                             allmodconfig
parisc                            allnoconfig
parisc                              defconfig
parisc                           allyesconfig
parisc                           allmodconfig
powerpc                             defconfig
powerpc                          allyesconfig
powerpc                          rhel-kconfig
powerpc                          allmodconfig
powerpc                           allnoconfig
i386                 randconfig-a001-20200719
i386                 randconfig-a006-20200719
i386                 randconfig-a002-20200719
i386                 randconfig-a005-20200719
i386                 randconfig-a003-20200719
i386                 randconfig-a004-20200719
x86_64               randconfig-a014-20200720
x86_64               randconfig-a015-20200720
x86_64               randconfig-a016-20200720
x86_64               randconfig-a012-20200720
x86_64               randconfig-a013-20200720
x86_64               randconfig-a011-20200720
x86_64               randconfig-a005-20200719
x86_64               randconfig-a002-20200719
x86_64               randconfig-a006-20200719
x86_64               randconfig-a001-20200719
x86_64               randconfig-a003-20200719
x86_64               randconfig-a004-20200719
i386                 randconfig-a015-20200719
i386                 randconfig-a011-20200719
i386                 randconfig-a016-20200719
i386                 randconfig-a012-20200719
i386                 randconfig-a013-20200719
i386                 randconfig-a014-20200719
riscv                            allyesconfig
riscv                             allnoconfig
riscv                               defconfig
riscv                            allmodconfig
s390                             allyesconfig
s390                              allnoconfig
s390                             allmodconfig
s390                                defconfig
sparc                            allyesconfig
sparc                               defconfig
sparc64                             defconfig
sparc64                           allnoconfig
sparc64                          allyesconfig
sparc64                          allmodconfig
x86_64                    rhel-7.6-kselftests
x86_64                               rhel-8.3
x86_64                                  kexec
x86_64                                   rhel
x86_64                                    lkp
x86_64                              fedora-25

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

^ permalink raw reply

* [v4] powerpc/perf: Initialize power10 PMU registers in cpu setup routine
From: Athira Rajeev @ 2020-07-23  7:32 UTC (permalink / raw)
  To: mpe; +Cc: jniethe5, mikey, maddy, linuxppc-dev

Initialize Monitor Mode Control Register 3 (MMCR3)
SPR which is new in power10. For PowerISA v3.1, BHRB disable
is controlled via Monitor Mode Control Register A (MMCRA) bit,
namely "BHRB Recording Disable (BHRBRD)". This patch also initializes
MMCRA BHRBRD to disable BHRB feature at boot for power10.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
---
Dependency:
- On power10 PMU base enablement series V3:
  https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=190462

Changes from v3 -> v4
- Addressed review comments from Jordan and Michael Ellerman.
  This patch was initially part of Power10 PMU base enablement
  series. Moving this as separate patch as suggested by Michael
  Ellerman. Hence dependency of initial series Patch 7 which defines
  MMCRA_BHRB_DISABLE. Addressed review comments from Jordan to make
  sure existing PMU function (__INIT_PMU) will not overwrite ISA 3.1
  updates

Changes from v2 -> v3
- Addressed review comment from Michael Ellerman to
  call PMU init from __setup_cpu_power10

 arch/powerpc/kernel/cpu_setup_power.S | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
index efdcfa7..3fa6eef 100644
--- a/arch/powerpc/kernel/cpu_setup_power.S
+++ b/arch/powerpc/kernel/cpu_setup_power.S
@@ -94,13 +94,15 @@ _GLOBAL(__restore_cpu_power8)
 _GLOBAL(__setup_cpu_power10)
 	mflr	r11
 	bl	__init_FSCR_power10
+	bl	__init_PMU
+	bl	__init_PMU_ISA31
 	b	1f
 
 _GLOBAL(__setup_cpu_power9)
 	mflr	r11
 	bl	__init_FSCR
-1:	bl	__init_PMU
-	bl	__init_hvmode_206
+	bl	__init_PMU
+1:	bl	__init_hvmode_206
 	mtlr	r11
 	beqlr
 	li	r0,0
@@ -124,13 +126,15 @@ _GLOBAL(__setup_cpu_power9)
 _GLOBAL(__restore_cpu_power10)
 	mflr	r11
 	bl	__init_FSCR_power10
+	bl	__init_PMU
+	bl	__init_PMU_ISA31
 	b	1f
 
 _GLOBAL(__restore_cpu_power9)
 	mflr	r11
 	bl	__init_FSCR
-1:	bl	__init_PMU
-	mfmsr	r3
+	bl	__init_PMU
+1:	mfmsr	r3
 	rldicl.	r0,r3,4,63
 	mtlr	r11
 	beqlr
@@ -233,3 +237,10 @@ __init_PMU_ISA207:
 	li	r5,0
 	mtspr	SPRN_MMCRS,r5
 	blr
+
+__init_PMU_ISA31:
+	li	r5,0
+	mtspr	SPRN_MMCR3,r5
+	LOAD_REG_IMMEDIATE(r5, MMCRA_BHRB_DISABLE)
+	mtspr	SPRN_MMCRA,r5
+	blr
-- 
1.8.3.1


^ permalink raw reply related

* Re: [v4] powerpc/perf: Initialize power10 PMU registers in cpu setup routine
From: Jordan Niethe @ 2020-07-23  7:40 UTC (permalink / raw)
  To: Athira Rajeev; +Cc: Michael Neuling, maddy, linuxppc-dev
In-Reply-To: <1595489557-2047-1-git-send-email-atrajeev@linux.vnet.ibm.com>

On Thu, Jul 23, 2020 at 5:32 PM Athira Rajeev
<atrajeev@linux.vnet.ibm.com> wrote:
>
> Initialize Monitor Mode Control Register 3 (MMCR3)
> SPR which is new in power10. For PowerISA v3.1, BHRB disable
> is controlled via Monitor Mode Control Register A (MMCRA) bit,
> namely "BHRB Recording Disable (BHRBRD)". This patch also initializes
> MMCRA BHRBRD to disable BHRB feature at boot for power10.
>
> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reviewed-by: Jordan Niethe <jniethe5@gmail.com>
> ---
> Dependency:
> - On power10 PMU base enablement series V3:
>   https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=190462
>
> Changes from v3 -> v4
> - Addressed review comments from Jordan and Michael Ellerman.
>   This patch was initially part of Power10 PMU base enablement
>   series. Moving this as separate patch as suggested by Michael
>   Ellerman. Hence dependency of initial series Patch 7 which defines
>   MMCRA_BHRB_DISABLE. Addressed review comments from Jordan to make
>   sure existing PMU function (__INIT_PMU) will not overwrite ISA 3.1
>   updates
>
> Changes from v2 -> v3
> - Addressed review comment from Michael Ellerman to
>   call PMU init from __setup_cpu_power10
>
>  arch/powerpc/kernel/cpu_setup_power.S | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
> index efdcfa7..3fa6eef 100644
> --- a/arch/powerpc/kernel/cpu_setup_power.S
> +++ b/arch/powerpc/kernel/cpu_setup_power.S
> @@ -94,13 +94,15 @@ _GLOBAL(__restore_cpu_power8)
>  _GLOBAL(__setup_cpu_power10)
>         mflr    r11
>         bl      __init_FSCR_power10
> +       bl      __init_PMU
> +       bl      __init_PMU_ISA31
>         b       1f
>
>  _GLOBAL(__setup_cpu_power9)
>         mflr    r11
>         bl      __init_FSCR
> -1:     bl      __init_PMU
> -       bl      __init_hvmode_206
> +       bl      __init_PMU
> +1:     bl      __init_hvmode_206
>         mtlr    r11
>         beqlr
>         li      r0,0
> @@ -124,13 +126,15 @@ _GLOBAL(__setup_cpu_power9)
>  _GLOBAL(__restore_cpu_power10)
>         mflr    r11
>         bl      __init_FSCR_power10
> +       bl      __init_PMU
> +       bl      __init_PMU_ISA31
>         b       1f
>
>  _GLOBAL(__restore_cpu_power9)
>         mflr    r11
>         bl      __init_FSCR
> -1:     bl      __init_PMU
> -       mfmsr   r3
> +       bl      __init_PMU
> +1:     mfmsr   r3
>         rldicl. r0,r3,4,63
>         mtlr    r11
>         beqlr
> @@ -233,3 +237,10 @@ __init_PMU_ISA207:
>         li      r5,0
>         mtspr   SPRN_MMCRS,r5
>         blr
> +
> +__init_PMU_ISA31:
> +       li      r5,0
> +       mtspr   SPRN_MMCR3,r5
> +       LOAD_REG_IMMEDIATE(r5, MMCRA_BHRB_DISABLE)
> +       mtspr   SPRN_MMCRA,r5
> +       blr
> --
> 1.8.3.1
>

^ permalink raw reply

* [PATCH v3 01/10] powerpc/smp: Fix a warning under !NEED_MULTIPLE_NODES
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

Fix a build warning in a non CONFIG_NEED_MULTIPLE_NODES
"error: _numa_cpu_lookup_table_ undeclared"

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v2 -> v3:
	Removed node caching part. Rewrote the Commit msg (Michael Ellerman)
	Renamed to powerpc/smp: Fix a warning under !NEED_MULTIPLE_NODES

 arch/powerpc/kernel/smp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 73199470c265..edf94ca64eea 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -860,6 +860,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 					GFP_KERNEL, cpu_to_node(cpu));
 		zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
 					GFP_KERNEL, cpu_to_node(cpu));
+#ifdef CONFIG_NEED_MULTIPLE_NODES
 		/*
 		 * numa_node_id() works after this.
 		 */
@@ -868,6 +869,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 			set_cpu_numa_mem(cpu,
 				local_memory_node(numa_cpu_lookup_table[cpu]));
 		}
+#endif
 	}
 
 	/* Init the cpumasks so the boot CPU is related to itself */
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 02/10] powerpc/smp: Merge Power9 topology with Power topology
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

A new sched_domain_topology_level was added just for Power9. However the
same can be achieved by merging powerpc_topology with power9_topology
and makes the code more simpler especially when adding a new sched
domain.

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1 -> v2:
	Replaced a reference to cpu_smt_mask with per_cpu(cpu_sibling_map, cpu)
	since cpu_smt_mask is only defined under CONFIG_SCHED_SMT

 arch/powerpc/kernel/smp.c | 33 ++++++++++-----------------------
 1 file changed, 10 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index edf94ca64eea..283a04e54f52 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1313,7 +1313,7 @@ int setup_profiling_timer(unsigned int multiplier)
 }
 
 #ifdef CONFIG_SCHED_SMT
-/* cpumask of CPUs with asymetric SMT dependancy */
+/* cpumask of CPUs with asymmetric SMT dependency */
 static int powerpc_smt_flags(void)
 {
 	int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
@@ -1326,14 +1326,6 @@ static int powerpc_smt_flags(void)
 }
 #endif
 
-static struct sched_domain_topology_level powerpc_topology[] = {
-#ifdef CONFIG_SCHED_SMT
-	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
-#endif
-	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
-	{ NULL, },
-};
-
 /*
  * P9 has a slightly odd architecture where pairs of cores share an L2 cache.
  * This topology makes it *much* cheaper to migrate tasks between adjacent cores
@@ -1351,7 +1343,13 @@ static int powerpc_shared_cache_flags(void)
  */
 static const struct cpumask *shared_cache_mask(int cpu)
 {
-	return cpu_l2_cache_mask(cpu);
+	if (shared_caches)
+		return cpu_l2_cache_mask(cpu);
+
+	if (has_big_cores)
+		return cpu_smallcore_mask(cpu);
+
+	return per_cpu(cpu_sibling_map, cpu);
 }
 
 #ifdef CONFIG_SCHED_SMT
@@ -1361,7 +1359,7 @@ static const struct cpumask *smallcore_smt_mask(int cpu)
 }
 #endif
 
-static struct sched_domain_topology_level power9_topology[] = {
+static struct sched_domain_topology_level powerpc_topology[] = {
 #ifdef CONFIG_SCHED_SMT
 	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
 #endif
@@ -1386,21 +1384,10 @@ void __init smp_cpus_done(unsigned int max_cpus)
 #ifdef CONFIG_SCHED_SMT
 	if (has_big_cores) {
 		pr_info("Big cores detected but using small core scheduling\n");
-		power9_topology[0].mask = smallcore_smt_mask;
 		powerpc_topology[0].mask = smallcore_smt_mask;
 	}
 #endif
-	/*
-	 * If any CPU detects that it's sharing a cache with another CPU then
-	 * use the deeper topology that is aware of this sharing.
-	 */
-	if (shared_caches) {
-		pr_info("Using shared cache scheduler topology\n");
-		set_sched_topology(power9_topology);
-	} else {
-		pr_info("Using standard scheduler topology\n");
-		set_sched_topology(powerpc_topology);
-	}
+	set_sched_topology(powerpc_topology);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 03/10] powerpc/smp: Move powerpc_topology above
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

Just moving the powerpc_topology description above.
This will help in using functions in this file and avoid declarations.

No other functional changes

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/smp.c | 116 +++++++++++++++++++-------------------
 1 file changed, 58 insertions(+), 58 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 283a04e54f52..a685915e5941 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -818,6 +818,64 @@ static int init_cpu_l1_cache_map(int cpu)
 	return err;
 }
 
+static bool shared_caches;
+
+#ifdef CONFIG_SCHED_SMT
+/* cpumask of CPUs with asymmetric SMT dependency */
+static int powerpc_smt_flags(void)
+{
+	int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
+
+	if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
+		printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
+		flags |= SD_ASYM_PACKING;
+	}
+	return flags;
+}
+#endif
+
+/*
+ * P9 has a slightly odd architecture where pairs of cores share an L2 cache.
+ * This topology makes it *much* cheaper to migrate tasks between adjacent cores
+ * since the migrated task remains cache hot. We want to take advantage of this
+ * at the scheduler level so an extra topology level is required.
+ */
+static int powerpc_shared_cache_flags(void)
+{
+	return SD_SHARE_PKG_RESOURCES;
+}
+
+/*
+ * We can't just pass cpu_l2_cache_mask() directly because
+ * returns a non-const pointer and the compiler barfs on that.
+ */
+static const struct cpumask *shared_cache_mask(int cpu)
+{
+	if (shared_caches)
+		return cpu_l2_cache_mask(cpu);
+
+	if (has_big_cores)
+		return cpu_smallcore_mask(cpu);
+
+	return per_cpu(cpu_sibling_map, cpu);
+}
+
+#ifdef CONFIG_SCHED_SMT
+static const struct cpumask *smallcore_smt_mask(int cpu)
+{
+	return cpu_smallcore_mask(cpu);
+}
+#endif
+
+static struct sched_domain_topology_level powerpc_topology[] = {
+#ifdef CONFIG_SCHED_SMT
+	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
+#endif
+	{ shared_cache_mask, powerpc_shared_cache_flags, SD_INIT_NAME(CACHE) },
+	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
+	{ NULL, },
+};
+
 static int init_big_cores(void)
 {
 	int cpu;
@@ -1247,8 +1305,6 @@ static void add_cpu_to_masks(int cpu)
 			set_cpus_related(cpu, i, cpu_core_mask);
 }
 
-static bool shared_caches;
-
 /* Activate a secondary processor. */
 void start_secondary(void *unused)
 {
@@ -1312,62 +1368,6 @@ int setup_profiling_timer(unsigned int multiplier)
 	return 0;
 }
 
-#ifdef CONFIG_SCHED_SMT
-/* cpumask of CPUs with asymmetric SMT dependency */
-static int powerpc_smt_flags(void)
-{
-	int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
-
-	if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
-		printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
-		flags |= SD_ASYM_PACKING;
-	}
-	return flags;
-}
-#endif
-
-/*
- * P9 has a slightly odd architecture where pairs of cores share an L2 cache.
- * This topology makes it *much* cheaper to migrate tasks between adjacent cores
- * since the migrated task remains cache hot. We want to take advantage of this
- * at the scheduler level so an extra topology level is required.
- */
-static int powerpc_shared_cache_flags(void)
-{
-	return SD_SHARE_PKG_RESOURCES;
-}
-
-/*
- * We can't just pass cpu_l2_cache_mask() directly because
- * returns a non-const pointer and the compiler barfs on that.
- */
-static const struct cpumask *shared_cache_mask(int cpu)
-{
-	if (shared_caches)
-		return cpu_l2_cache_mask(cpu);
-
-	if (has_big_cores)
-		return cpu_smallcore_mask(cpu);
-
-	return per_cpu(cpu_sibling_map, cpu);
-}
-
-#ifdef CONFIG_SCHED_SMT
-static const struct cpumask *smallcore_smt_mask(int cpu)
-{
-	return cpu_smallcore_mask(cpu);
-}
-#endif
-
-static struct sched_domain_topology_level powerpc_topology[] = {
-#ifdef CONFIG_SCHED_SMT
-	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
-#endif
-	{ shared_cache_mask, powerpc_shared_cache_flags, SD_INIT_NAME(CACHE) },
-	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
-	{ NULL, },
-};
-
 void __init smp_cpus_done(unsigned int max_cpus)
 {
 	/*
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 04/10] powerpc/smp: Move topology fixups into a new function
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

Move topology fixup based on the platform attributes into its own
function which is called just before set_sched_topology.

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v2 -> v3:
	Rewrote changelog (Gautham)
	Renamed to powerpc/smp: Move topology fixups into  a new function

 arch/powerpc/kernel/smp.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index a685915e5941..da27f6909be1 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1368,6 +1368,16 @@ int setup_profiling_timer(unsigned int multiplier)
 	return 0;
 }
 
+static void fixup_topology(void)
+{
+#ifdef CONFIG_SCHED_SMT
+	if (has_big_cores) {
+		pr_info("Big cores detected but using small core scheduling\n");
+		powerpc_topology[0].mask = smallcore_smt_mask;
+	}
+#endif
+}
+
 void __init smp_cpus_done(unsigned int max_cpus)
 {
 	/*
@@ -1381,12 +1391,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
 	dump_numa_cpu_topology();
 
-#ifdef CONFIG_SCHED_SMT
-	if (has_big_cores) {
-		pr_info("Big cores detected but using small core scheduling\n");
-		powerpc_topology[0].mask = smallcore_smt_mask;
-	}
-#endif
+	fixup_topology();
 	set_sched_topology(powerpc_topology);
 }
 
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 05/10] powerpc/smp: Dont assume l2-cache to be superset of sibling
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

Current code assumes that cpumask of cpus sharing a l2-cache mask will
always be a superset of cpu_sibling_mask.

Lets stop that assumption. cpu_l2_cache_mask is a superset of
cpu_sibling_mask if and only if shared_caches is set.

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1 -> v2:
	Set cpumask after verifying l2-cache. (Gautham)

 arch/powerpc/kernel/smp.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index da27f6909be1..d997c7411664 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1194,6 +1194,7 @@ static bool update_mask_by_l2(int cpu, struct cpumask *(*mask_fn)(int))
 	if (!l2_cache)
 		return false;
 
+	cpumask_set_cpu(cpu, mask_fn(cpu));
 	for_each_cpu(i, cpu_online_mask) {
 		/*
 		 * when updating the marks the current CPU has not been marked
@@ -1276,29 +1277,30 @@ static void add_cpu_to_masks(int cpu)
 	 * add it to it's own thread sibling mask.
 	 */
 	cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
+	cpumask_set_cpu(cpu, cpu_core_mask(cpu));
 
 	for (i = first_thread; i < first_thread + threads_per_core; i++)
 		if (cpu_online(i))
 			set_cpus_related(i, cpu, cpu_sibling_mask);
 
 	add_cpu_to_smallcore_masks(cpu);
-	/*
-	 * Copy the thread sibling mask into the cache sibling mask
-	 * and mark any CPUs that share an L2 with this CPU.
-	 */
-	for_each_cpu(i, cpu_sibling_mask(cpu))
-		set_cpus_related(cpu, i, cpu_l2_cache_mask);
 	update_mask_by_l2(cpu, cpu_l2_cache_mask);
 
-	/*
-	 * Copy the cache sibling mask into core sibling mask and mark
-	 * any CPUs on the same chip as this CPU.
-	 */
-	for_each_cpu(i, cpu_l2_cache_mask(cpu))
-		set_cpus_related(cpu, i, cpu_core_mask);
+	if (pkg_id == -1) {
+		struct cpumask *(*mask)(int) = cpu_sibling_mask;
+
+		/*
+		 * Copy the sibling mask into core sibling mask and
+		 * mark any CPUs on the same chip as this CPU.
+		 */
+		if (shared_caches)
+			mask = cpu_l2_cache_mask;
+
+		for_each_cpu(i, mask(cpu))
+			set_cpus_related(cpu, i, cpu_core_mask);
 
-	if (pkg_id == -1)
 		return;
+	}
 
 	for_each_cpu(i, cpu_online_mask)
 		if (get_physical_package_id(i) == pkg_id)
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 07/10] powerpc/numa: Detect support for coregroup
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

Add support for grouping cores based on the device-tree classification.
- The last domain in the associativity domains always refers to the
core.
- If primary reference domain happens to be the penultimate domain in
the associativity domains device-tree property, then there are no
coregroups. However if its not a penultimate domain, then there are
coregroups. There can be more than one coregroup. For now we would be
interested in the last or the smallest coregroups.

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1 -> v2:
	Explained Coregroup in commit msg (Michael Ellerman)

 arch/powerpc/include/asm/smp.h |  1 +
 arch/powerpc/kernel/smp.c      |  1 +
 arch/powerpc/mm/numa.c         | 34 +++++++++++++++++++++-------------
 3 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 49a25e2400f2..5bdc17a7049f 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -28,6 +28,7 @@
 extern int boot_cpuid;
 extern int spinning_secondaries;
 extern u32 *cpu_to_phys_id;
+extern bool coregroup_enabled;
 
 extern void cpu_die(void);
 extern int cpu_to_chip_id(int cpu);
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 6f5877f6496e..cbca4a8c3314 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -74,6 +74,7 @@ static DEFINE_PER_CPU(int, cpu_state) = { 0 };
 
 struct task_struct *secondary_current;
 bool has_big_cores;
+bool coregroup_enabled;
 
 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
 DEFINE_PER_CPU(cpumask_var_t, cpu_smallcore_map);
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index bc5b2e8112c8..3248160c0327 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -886,7 +886,9 @@ static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
 static void __init find_possible_nodes(void)
 {
 	struct device_node *rtas;
-	u32 numnodes, i;
+	const __be32 *domains;
+	int prop_length, max_nodes;
+	u32 i;
 
 	if (!numa_enabled)
 		return;
@@ -895,25 +897,31 @@ static void __init find_possible_nodes(void)
 	if (!rtas)
 		return;
 
-	if (of_property_read_u32_index(rtas, "ibm,current-associativity-domains",
-				min_common_depth, &numnodes)) {
-		/*
-		 * ibm,current-associativity-domains is a fairly recent
-		 * property. If it doesn't exist, then fallback on
-		 * ibm,max-associativity-domains. Current denotes what the
-		 * platform can support compared to max which denotes what the
-		 * Hypervisor can support.
-		 */
-		if (of_property_read_u32_index(rtas, "ibm,max-associativity-domains",
-				min_common_depth, &numnodes))
+	/*
+	 * ibm,current-associativity-domains is a fairly recent property. If
+	 * it doesn't exist, then fallback on ibm,max-associativity-domains.
+	 * Current denotes what the platform can support compared to max
+	 * which denotes what the Hypervisor can support.
+	 */
+	domains = of_get_property(rtas, "ibm,current-associativity-domains",
+					&prop_length);
+	if (!domains) {
+		domains = of_get_property(rtas, "ibm,max-associativity-domains",
+					&prop_length);
+		if (!domains)
 			goto out;
 	}
 
-	for (i = 0; i < numnodes; i++) {
+	max_nodes = of_read_number(&domains[min_common_depth], 1);
+	for (i = 0; i < max_nodes; i++) {
 		if (!node_possible(i))
 			node_set(i, node_possible_map);
 	}
 
+	prop_length /= sizeof(int);
+	if (prop_length > min_common_depth + 2)
+		coregroup_enabled = 1;
+
 out:
 	of_node_put(rtas);
 }
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 08/10] powerpc/smp: Allocate cpumask only after searching thread group
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

If allocated earlier and the search fails, then cpumask need to be
freed. However cpu_l1_cache_map can be allocated after we search thread
group.

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/smp.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index cbca4a8c3314..7d8d44cbab11 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -797,10 +797,6 @@ static int init_cpu_l1_cache_map(int cpu)
 	if (err)
 		goto out;
 
-	zalloc_cpumask_var_node(&per_cpu(cpu_l1_cache_map, cpu),
-				GFP_KERNEL,
-				cpu_to_node(cpu));
-
 	cpu_group_start = get_cpu_thread_group_start(cpu, &tg);
 
 	if (unlikely(cpu_group_start == -1)) {
@@ -809,6 +805,9 @@ static int init_cpu_l1_cache_map(int cpu)
 		goto out;
 	}
 
+	zalloc_cpumask_var_node(&per_cpu(cpu_l1_cache_map, cpu),
+				GFP_KERNEL, cpu_to_node(cpu));
+
 	for (i = first_thread; i < first_thread + threads_per_core; i++) {
 		int i_group_start = get_cpu_thread_group_start(i, &tg);
 
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 09/10] powerpc/smp: Create coregroup domain
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

Add percpu coregroup maps and masks to create coregroup domain.
If a coregroup doesn't exist, the coregroup domain will be degenerated
in favour of SMT/CACHE domain.

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v2 -> v3:
	Add optimization for mask updation under coregroup_support

Changelog v1 -> v2:
	Moved coregroup topology fixup to fixup_topology (Gautham)

 arch/powerpc/include/asm/topology.h | 10 +++++++
 arch/powerpc/kernel/smp.c           | 44 +++++++++++++++++++++++++++++
 arch/powerpc/mm/numa.c              |  5 ++++
 3 files changed, 59 insertions(+)

diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
index f0b6300e7dd3..6609174918ab 100644
--- a/arch/powerpc/include/asm/topology.h
+++ b/arch/powerpc/include/asm/topology.h
@@ -88,12 +88,22 @@ static inline int cpu_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
 
 #if defined(CONFIG_NUMA) && defined(CONFIG_PPC_SPLPAR)
 extern int find_and_online_cpu_nid(int cpu);
+extern int cpu_to_coregroup_id(int cpu);
 #else
 static inline int find_and_online_cpu_nid(int cpu)
 {
 	return 0;
 }
 
+static inline int cpu_to_coregroup_id(int cpu)
+{
+#ifdef CONFIG_SMP
+	return cpu_to_core_id(cpu);
+#else
+	return 0;
+#endif
+}
+
 #endif /* CONFIG_NUMA && CONFIG_PPC_SPLPAR */
 
 #include <asm-generic/topology.h>
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 7d8d44cbab11..1faedde3e406 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -80,6 +80,7 @@ DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
 DEFINE_PER_CPU(cpumask_var_t, cpu_smallcore_map);
 DEFINE_PER_CPU(cpumask_var_t, cpu_l2_cache_map);
 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
+DEFINE_PER_CPU(cpumask_var_t, cpu_coregroup_map);
 
 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
 EXPORT_PER_CPU_SYMBOL(cpu_l2_cache_map);
@@ -91,6 +92,7 @@ enum {
 	smt_idx,
 #endif
 	bigcore_idx,
+	mc_idx,
 	die_idx,
 };
 
@@ -869,6 +871,21 @@ static const struct cpumask *smallcore_smt_mask(int cpu)
 }
 #endif
 
+static struct cpumask *cpu_coregroup_mask(int cpu)
+{
+	return per_cpu(cpu_coregroup_map, cpu);
+}
+
+static bool has_coregroup_support(void)
+{
+	return coregroup_enabled;
+}
+
+static const struct cpumask *cpu_mc_mask(int cpu)
+{
+	return cpu_coregroup_mask(cpu);
+}
+
 static const struct cpumask *cpu_bigcore_mask(int cpu)
 {
 	return per_cpu(cpu_sibling_map, cpu);
@@ -879,6 +896,7 @@ static struct sched_domain_topology_level powerpc_topology[] = {
 	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
 #endif
 	{ cpu_bigcore_mask, SD_INIT_NAME(BIGCORE) },
+	{ cpu_mc_mask, SD_INIT_NAME(MC) },
 	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
 	{ NULL, },
 };
@@ -925,6 +943,10 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 					GFP_KERNEL, cpu_to_node(cpu));
 		zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
 					GFP_KERNEL, cpu_to_node(cpu));
+		if (has_coregroup_support())
+			zalloc_cpumask_var_node(&per_cpu(cpu_coregroup_map, cpu),
+						GFP_KERNEL, cpu_to_node(cpu));
+
 #ifdef CONFIG_NEED_MULTIPLE_NODES
 		/*
 		 * numa_node_id() works after this.
@@ -942,6 +964,9 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 	cpumask_set_cpu(boot_cpuid, cpu_l2_cache_mask(boot_cpuid));
 	cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
 
+	if (has_coregroup_support())
+		cpumask_set_cpu(boot_cpuid, cpu_coregroup_mask(boot_cpuid));
+
 	init_big_cores();
 	if (has_big_cores) {
 		cpumask_set_cpu(boot_cpuid,
@@ -1233,6 +1258,8 @@ static void remove_cpu_from_masks(int cpu)
 		set_cpus_unrelated(cpu, i, cpu_sibling_mask);
 		if (has_big_cores)
 			set_cpus_unrelated(cpu, i, cpu_smallcore_mask);
+		if (has_coregroup_support())
+			set_cpus_unrelated(cpu, i, cpu_coregroup_mask);
 	}
 }
 #endif
@@ -1293,6 +1320,20 @@ static void add_cpu_to_masks(int cpu)
 	add_cpu_to_smallcore_masks(cpu);
 	update_mask_by_l2(cpu, cpu_l2_cache_mask);
 
+	if (has_coregroup_support()) {
+		int coregroup_id = cpu_to_coregroup_id(cpu);
+
+		cpumask_set_cpu(cpu, cpu_coregroup_mask(cpu));
+		for_each_cpu_and(i, cpu_online_mask, cpu_cpu_mask(cpu)) {
+			int fcpu = cpu_first_thread_sibling(i);
+
+			if (fcpu == first_thread)
+				set_cpus_related(cpu, i, cpu_coregroup_mask);
+			else if (coregroup_id == cpu_to_coregroup_id(i))
+				set_cpus_related(cpu, i, cpu_coregroup_mask);
+		}
+	}
+
 	if (pkg_id == -1) {
 		struct cpumask *(*mask)(int) = cpu_sibling_mask;
 
@@ -1384,6 +1425,9 @@ int setup_profiling_timer(unsigned int multiplier)
 
 static void fixup_topology(void)
 {
+	if (!has_coregroup_support())
+		powerpc_topology[mc_idx].mask = cpu_bigcore_mask;
+
 	if (shared_caches) {
 		pr_info("Using shared cache scheduler topology\n");
 		powerpc_topology[bigcore_idx].mask = shared_cache_mask;
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 3248160c0327..ef8aa580da21 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1216,6 +1216,11 @@ int find_and_online_cpu_nid(int cpu)
 	return new_nid;
 }
 
+int cpu_to_coregroup_id(int cpu)
+{
+	return cpu_to_core_id(cpu);
+}
+
 static int topology_update_init(void)
 {
 	topology_inited = 1;
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 10/10] powerpc/smp: Implement cpu_to_coregroup_id
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

Lookup the coregroup id from the associativity array.

If unable to detect the coregroup id, fallback on the core id.
This way, ensure sched_domain degenerates and an extra sched domain is
not created.

Ideally this function should have been implemented in
arch/powerpc/kernel/smp.c. However if its implemented in mm/numa.c, we
don't need to find the primary domain again.

If the device-tree mentions more than one coregroup, then kernel
implements only the last or the smallest coregroup, which currently
corresponds to the penultimate domain in the device-tree.

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by : Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1 -> v2:
	Move coregroup_enabled before getting associativity (Gautham)

 arch/powerpc/mm/numa.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index ef8aa580da21..608e0fa61019 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1218,6 +1218,26 @@ int find_and_online_cpu_nid(int cpu)
 
 int cpu_to_coregroup_id(int cpu)
 {
+	__be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
+	int index;
+
+	if (cpu < 0 || cpu > nr_cpu_ids)
+		return -1;
+
+	if (!coregroup_enabled)
+		goto out;
+
+	if (!firmware_has_feature(FW_FEATURE_VPHN))
+		goto out;
+
+	if (vphn_get_associativity(cpu, associativity))
+		goto out;
+
+	index = of_read_number(associativity, 1);
+	if (index > min_common_depth + 1)
+		return of_read_number(&associativity[index - 1], 1);
+
+out:
 	return cpu_to_core_id(cpu);
 }
 
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 06/10] powerpc/smp: Generalize 2nd sched domain
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Michael Neuling,
	Srikar Dronamraju, Peter Zijlstra, Jordan Niethe, LKML,
	Nicholas Piggin, Valentin Schneider, Oliver O'Halloran,
	linuxppc-dev, Ingo Molnar
In-Reply-To: <20200723085116.4731-1-srikar@linux.vnet.ibm.com>

Currently "CACHE" domain happens to be the 2nd sched domain as per
powerpc_topology. This domain will collapse if cpumask of l2-cache is
same as SMT domain. However we could generalize this domain such that it
could mean either be a "CACHE" domain or a "BIGCORE" domain.

While setting up the "CACHE" domain, check if shared_cache is already
set.

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1 -> v2:
	Moved shared_cache topology fixup to fixup_topology (Gautham)

 arch/powerpc/kernel/smp.c | 49 ++++++++++++++++++++++++++++-----------
 1 file changed, 35 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index d997c7411664..6f5877f6496e 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -85,6 +85,14 @@ EXPORT_PER_CPU_SYMBOL(cpu_l2_cache_map);
 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
 EXPORT_SYMBOL_GPL(has_big_cores);
 
+enum {
+#ifdef CONFIG_SCHED_SMT
+	smt_idx,
+#endif
+	bigcore_idx,
+	die_idx,
+};
+
 #define MAX_THREAD_LIST_SIZE	8
 #define THREAD_GROUP_SHARE_L1   1
 struct thread_groups {
@@ -851,13 +859,7 @@ static int powerpc_shared_cache_flags(void)
  */
 static const struct cpumask *shared_cache_mask(int cpu)
 {
-	if (shared_caches)
-		return cpu_l2_cache_mask(cpu);
-
-	if (has_big_cores)
-		return cpu_smallcore_mask(cpu);
-
-	return per_cpu(cpu_sibling_map, cpu);
+	return per_cpu(cpu_l2_cache_map, cpu);
 }
 
 #ifdef CONFIG_SCHED_SMT
@@ -867,11 +869,16 @@ static const struct cpumask *smallcore_smt_mask(int cpu)
 }
 #endif
 
+static const struct cpumask *cpu_bigcore_mask(int cpu)
+{
+	return per_cpu(cpu_sibling_map, cpu);
+}
+
 static struct sched_domain_topology_level powerpc_topology[] = {
 #ifdef CONFIG_SCHED_SMT
 	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
 #endif
-	{ shared_cache_mask, powerpc_shared_cache_flags, SD_INIT_NAME(CACHE) },
+	{ cpu_bigcore_mask, SD_INIT_NAME(BIGCORE) },
 	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
 	{ NULL, },
 };
@@ -1311,7 +1318,6 @@ static void add_cpu_to_masks(int cpu)
 void start_secondary(void *unused)
 {
 	unsigned int cpu = smp_processor_id();
-	struct cpumask *(*sibling_mask)(int) = cpu_sibling_mask;
 
 	mmgrab(&init_mm);
 	current->active_mm = &init_mm;
@@ -1337,14 +1343,20 @@ void start_secondary(void *unused)
 	/* Update topology CPU masks */
 	add_cpu_to_masks(cpu);
 
-	if (has_big_cores)
-		sibling_mask = cpu_smallcore_mask;
 	/*
 	 * Check for any shared caches. Note that this must be done on a
 	 * per-core basis because one core in the pair might be disabled.
 	 */
-	if (!cpumask_equal(cpu_l2_cache_mask(cpu), sibling_mask(cpu)))
-		shared_caches = true;
+	if (!shared_caches) {
+		struct cpumask *(*sibling_mask)(int) = cpu_sibling_mask;
+		struct cpumask *mask = cpu_l2_cache_mask(cpu);
+
+		if (has_big_cores)
+			sibling_mask = cpu_smallcore_mask;
+
+		if (cpumask_weight(mask) > cpumask_weight(sibling_mask(cpu)))
+			shared_caches = true;
+	}
 
 	set_numa_node(numa_cpu_lookup_table[cpu]);
 	set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu]));
@@ -1372,10 +1384,19 @@ int setup_profiling_timer(unsigned int multiplier)
 
 static void fixup_topology(void)
 {
+	if (shared_caches) {
+		pr_info("Using shared cache scheduler topology\n");
+		powerpc_topology[bigcore_idx].mask = shared_cache_mask;
+#ifdef CONFIG_SCHED_DEBUG
+		powerpc_topology[bigcore_idx].name = "CACHE";
+#endif
+		powerpc_topology[bigcore_idx].sd_flags = powerpc_shared_cache_flags;
+	}
+
 #ifdef CONFIG_SCHED_SMT
 	if (has_big_cores) {
 		pr_info("Big cores detected but using small core scheduling\n");
-		powerpc_topology[0].mask = smallcore_smt_mask;
+		powerpc_topology[smt_idx].mask = smallcore_smt_mask;
 	}
 #endif
 }
-- 
2.18.2


^ permalink raw reply related

* [PATCH v3 00/10] Coregroup support on Powerpc
From: Srikar Dronamraju @ 2020-07-23  8:51 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: Nathan Lynch, Gautham R Shenoy, Oliver OHalloran, Michael Neuling,
	Srikar Dronamraju, Michael Ellerman, Peter Zijlstra,
	Jordan Niethe, Anton Blanchard, LKML, Valentin Schneider,
	Nick Piggin, linuxppc-dev, Ingo Molnar

Changelog v2 -> v3:
v2: https://lore.kernel.org/linuxppc-dev/20200721113814.32284-1-srikar@linux.vnet.ibm.com/t/#u

powerpc/smp: Cache node for reuse
	Removed node caching part. Rewrote the Commit msg (Michael Ellerman)
	Renamed to powerpc/smp: Fix a warning under !NEED_MULTIPLE_NODES

powerpc/smp: Enable small core scheduling sooner
	Rewrote changelog (Gautham)
	Renamed to powerpc/smp: Move topology fixups into  a new function

powerpc/smp: Create coregroup domain
	Add optimization for mask updation under coregroup_support

Changelog v1 -> v2:
v1: https://lore.kernel.org/linuxppc-dev/20200714043624.5648-1-srikar@linux.vnet.ibm.com/t/#u

powerpc/smp: Merge Power9 topology with Power topology
	Replaced a reference to cpu_smt_mask with per_cpu(cpu_sibling_map, cpu)
	since cpu_smt_mask is only defined under CONFIG_SCHED_SMT

powerpc/smp: Enable small core scheduling sooner
	Restored the previous info msg (Jordan)
	Moved big core topology fixup to fixup_topology (Gautham)

powerpc/smp: Dont assume l2-cache to be superset of sibling
	Set cpumask after verifying l2-cache. (Gautham)

powerpc/smp: Generalize 2nd sched domain
	Moved shared_cache topology fixup to fixup_topology (Gautham)

Powerpc/numa: Detect support for coregroup
	Explained Coregroup in commit msg (Michael Ellerman)

Powerpc/smp: Create coregroup domain
	Moved coregroup topology fixup to fixup_topology (Gautham)

powerpc/smp: Implement cpu_to_coregroup_id
	Move coregroup_enabled before getting associativity (Gautham)

powerpc/smp: Provide an ability to disable coregroup
	Patch dropped (Michael Ellerman)

Cleanup of existing powerpc topologies and add coregroup support on
Powerpc. Coregroup is a group of (subset of) cores of a DIE that share
a resource.

Patch 7 of this patch series: "Powerpc/numa: Detect support for coregroup"
depends on
https://lore.kernel.org/linuxppc-dev/20200707140644.7241-1-srikar@linux.vnet.ibm.com/t/#u
However it should be easy to rebase the patch without the above patch.

This patch series is based on top of current powerpc/next tree + the
above patch.

On Power 8 Systems
------------------
$ tail /proc/cpuinfo
processor	: 255
cpu		: POWER8 (architected), altivec supported
clock		: 3724.000000MHz
revision	: 2.1 (pvr 004b 0201)

timebase	: 512000000
platform	: pSeries
model		: IBM,8408-E8E
machine		: CHRP IBM,8408-E8E
MMU		: Hash

Before the patchset
-------------------
$ cat /proc/sys/kernel/sched_domain/cpu0/domain*/name
SMT
DIE
NUMA
NUMA
$ head /proc/schedstat
version 15
timestamp 4295534931
cpu0 0 0 0 0 0 0 41389823338 17682779896 14117
domain0 00000000,00000000,00000000,00000000,00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,00000000,00000000,00000000,00000000,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 00000000,00000000,00000000,00000000,00000000,00000000,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain3 ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu1 0 0 0 0 0 0 27087859050 152273672 10396
domain0 00000000,00000000,00000000,00000000,00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,00000000,00000000,00000000,00000000,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

After the patchset
------------------
$ cat /proc/sys/kernel/sched_domain/cpu0/domain*/name
SMT
DIE
NUMA
NUMA
$ head /proc/schedstat
version 15
timestamp 4295534931
cpu0 0 0 0 0 0 0 41389823338 17682779896 14117
domain0 00000000,00000000,00000000,00000000,00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,00000000,00000000,00000000,00000000,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 00000000,00000000,00000000,00000000,00000000,00000000,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain3 ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu1 0 0 0 0 0 0 27087859050 152273672 10396
domain0 00000000,00000000,00000000,00000000,00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,00000000,00000000,00000000,00000000,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

On Power 9 (with device-tree enablement to show coregroups).
(hunks for mimicing a coregroup was posted at
https://lore.kernel.org/linuxppc-dev/20200714043624.5648-1-srikar@linux.vnet.ibm.com/t/#m2cb09bb11c7a93257d6123d1d27edb8212f8af21)
-----------------------------------------------------------
$ tail /proc/cpuinfo
processor	: 127
cpu		: POWER9 (architected), altivec supported
clock		: 3000.000000MHz
revision	: 2.2 (pvr 004e 0202)

timebase	: 512000000
platform	: pSeries
model		: IBM,9008-22L
machine		: CHRP IBM,9008-22L
MMU		: Hash

Before patchset
--------------
$ cat /proc/sys/kernel/sched_domain/cpu0/domain*/name
SMT
CACHE
DIE
NUMA

$ head /proc/schedstat
version 15
timestamp 4318242208
cpu0 0 0 0 0 0 0 28077107004 4773387362 78205
domain0 00000000,00000000,00000000,00000055 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 00000000,00000000,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain3 ffffffff,ffffffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu1 0 0 0 0 0 0 24177439200 413887604 75393
domain0 00000000,00000000,00000000,000000aa 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

After patchset
--------------
$ cat /proc/sys/kernel/sched_domain/cpu0/domain*/name
SMT
CACHE
MC
DIE
NUMA

$ head /proc/schedstat
version 15
timestamp 4318242208
cpu0 0 0 0 0 0 0 28077107004 4773387362 78205
domain0 00000000,00000000,00000000,00000055 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 00000000,00000000,00000000,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain3 00000000,00000000,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain4 ffffffff,ffffffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu1 0 0 0 0 0 0 24177439200 413887604 75393
domain0 00000000,00000000,00000000,000000aa 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Nick Piggin <npiggin@au1.ibm.com>
Cc: Oliver OHalloran <oliveroh@au1.ibm.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@linux.ibm.com>
Cc: Anton Blanchard <anton@au1.ibm.com>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.ibm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>

Srikar Dronamraju (10):
  powerpc/smp: Fix a warning under !NEED_MULTIPLE_NODES
  powerpc/smp: Merge Power9 topology with Power topology
  powerpc/smp: Move powerpc_topology above
  powerpc/smp: Move topology fixups into  a new function
  powerpc/smp: Dont assume l2-cache to be superset of sibling
  powerpc/smp: Generalize 2nd sched domain
  powerpc/numa: Detect support for coregroup
  powerpc/smp: Allocate cpumask only after searching thread group
  powerpc/smp: Create coregroup domain
  powerpc/smp: Implement cpu_to_coregroup_id

 arch/powerpc/include/asm/smp.h      |   1 +
 arch/powerpc/include/asm/topology.h |  10 ++
 arch/powerpc/kernel/smp.c           | 245 +++++++++++++++++-----------
 arch/powerpc/mm/numa.c              |  59 +++++--
 4 files changed, 210 insertions(+), 105 deletions(-)

-- 
2.18.2


^ permalink raw reply

* [PATCH v5 00/10] powerpc/watchpoint: Enable 2nd DAWR on baremetal and powervm
From: Ravi Bangoria @ 2020-07-23  9:08 UTC (permalink / raw)
  To: mpe, mikey
  Cc: christophe.leroy, ravi.bangoria, rogealve, miltonm, peterz,
	fweisbec, oleg, npiggin, linux-kernel, paulus, jolsa, jniethe5,
	pedromfc, naveen.n.rao, linuxppc-dev, mingo

Last series[1] was to add basic infrastructure support for more than
one watchpoint on Book3S powerpc. This series actually enables the 2nd 
DAWR for baremetal and powervm. Kvm guest is still not supported.

v4: https://lore.kernel.org/r/20200717040958.70561-1-ravi.bangoria@linux.ibm.com

v4->v5:
 - Using hardcoded values instead of macros HBP_NUM_ONE and HBP_NUM_TWO.
   Comment above HBP_NUM_MAX changed to explain it's value.
 - Included CPU_FTR_DAWR1 into CPU_FTRS_POWER10
 - Using generic function feat_enable() instead of
   feat_enable_debug_facilities_v31() to enable CPU_FTR_DAWR1.
 - ISA still includes 512B boundary in match criteria. But that's a
   documentation mistake. Mentioned about this in the last patch.
 - Rebased to powerpc/next
 - Added Jordan's Reviewed-by/Tested-by tags

[1]: https://lore.kernel.org/linuxppc-dev/20200514111741.97993-1-ravi.bangoria@linux.ibm.com/

Ravi Bangoria (10):
  powerpc/watchpoint: Fix 512 byte boundary limit
  powerpc/watchpoint: Fix DAWR exception constraint
  powerpc/watchpoint: Fix DAWR exception for CACHEOP
  powerpc/watchpoint: Enable watchpoint functionality on power10 guest
  powerpc/dt_cpu_ftrs: Add feature for 2nd DAWR
  powerpc/watchpoint: Set CPU_FTR_DAWR1 based on pa-features bit
  powerpc/watchpoint: Rename current H_SET_MODE DAWR macro
  powerpc/watchpoint: Guest support for 2nd DAWR hcall
  powerpc/watchpoint: Return available watchpoints dynamically
  powerpc/watchpoint: Remove 512 byte boundary

 arch/powerpc/include/asm/cputable.h       |  8 +-
 arch/powerpc/include/asm/hvcall.h         |  3 +-
 arch/powerpc/include/asm/hw_breakpoint.h  |  4 +-
 arch/powerpc/include/asm/machdep.h        |  2 +-
 arch/powerpc/include/asm/plpar_wrappers.h |  7 +-
 arch/powerpc/kernel/dawr.c                |  2 +-
 arch/powerpc/kernel/dt_cpu_ftrs.c         |  1 +
 arch/powerpc/kernel/hw_breakpoint.c       | 98 +++++++++++++++--------
 arch/powerpc/kernel/prom.c                |  2 +
 arch/powerpc/kvm/book3s_hv.c              |  2 +-
 arch/powerpc/platforms/pseries/setup.c    |  7 +-
 11 files changed, 91 insertions(+), 45 deletions(-)

-- 
2.26.2


^ permalink raw reply

* [PATCH v5 01/10] powerpc/watchpoint: Fix 512 byte boundary limit
From: Ravi Bangoria @ 2020-07-23  9:08 UTC (permalink / raw)
  To: mpe, mikey
  Cc: christophe.leroy, ravi.bangoria, rogealve, miltonm, peterz,
	fweisbec, oleg, npiggin, linux-kernel, paulus, jolsa, jniethe5,
	pedromfc, naveen.n.rao, linuxppc-dev, mingo
In-Reply-To: <20200723090813.303838-1-ravi.bangoria@linux.ibm.com>

Milton Miller reported that we are aligning start and end address to
wrong size SZ_512M. It should be SZ_512. Fix that.

While doing this change I also found a case where ALIGN() comparison
fails. Within a given aligned range, ALIGN() of two addresses does not
match when start address is pointing to the first byte and end address
is pointing to any other byte except the first one. But that's not true
for ALIGN_DOWN(). ALIGN_DOWN() of any two addresses within that range
will always point to the first byte. So use ALIGN_DOWN() instead of
ALIGN().

Fixes: e68ef121c1f4 ("powerpc/watchpoint: Use builtin ALIGN*() macros")
Reported-by: Milton Miller <miltonm@us.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Jordan Niethe <jniethe5@gmail.com>
---
 arch/powerpc/kernel/hw_breakpoint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 0000daf0e1da..031e6defc08e 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -419,7 +419,7 @@ static int hw_breakpoint_validate_len(struct arch_hw_breakpoint *hw)
 	if (dawr_enabled()) {
 		max_len = DAWR_MAX_LEN;
 		/* DAWR region can't cross 512 bytes boundary */
-		if (ALIGN(start_addr, SZ_512M) != ALIGN(end_addr - 1, SZ_512M))
+		if (ALIGN_DOWN(start_addr, SZ_512) != ALIGN_DOWN(end_addr - 1, SZ_512))
 			return -EINVAL;
 	} else if (IS_ENABLED(CONFIG_PPC_8xx)) {
 		/* 8xx can setup a range without limitation */
-- 
2.26.2


^ permalink raw reply related

* [PATCH v5 02/10] powerpc/watchpoint: Fix DAWR exception constraint
From: Ravi Bangoria @ 2020-07-23  9:08 UTC (permalink / raw)
  To: mpe, mikey
  Cc: christophe.leroy, ravi.bangoria, rogealve, miltonm, peterz,
	fweisbec, oleg, npiggin, linux-kernel, paulus, jolsa, jniethe5,
	pedromfc, naveen.n.rao, linuxppc-dev, mingo
In-Reply-To: <20200723090813.303838-1-ravi.bangoria@linux.ibm.com>

Pedro Miraglia Franco de Carvalho noticed that on p8/p9, DAR value is
inconsistent with different type of load/store. Like for byte,word
etc. load/stores, DAR is set to the address of the first byte of
overlap between watch range and real access. But for quadword load/
store it's sometime set to the address of the first byte of real
access whereas sometime set to the address of the first byte of
overlap. This issue has been fixed in p10. In p10(ISA 3.1), DAR is
always set to the address of the first byte of overlap. Commit 27985b2a640e
("powerpc/watchpoint: Don't ignore extraneous exceptions blindly")
wrongly assumes that DAR is set to the address of the first byte of
overlap for all load/stores on p8/p9 as well. Fix that. With the fix,
we now rely on 'ea' provided by analyse_instr(). If analyse_instr()
fails, generate event unconditionally on p8/p9, and on p10 generate
event only if DAR is within a DAWR range.

Note: 8xx is not affected.

Fixes: 27985b2a640e ("powerpc/watchpoint: Don't ignore extraneous exceptions blindly")
Fixes: 74c6881019b7 ("powerpc/watchpoint: Prepare handler to handle more than one watchpoint")
Reported-by: Pedro Miraglia Franco de Carvalho <pedromfc@br.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
---
 arch/powerpc/kernel/hw_breakpoint.c | 72 ++++++++++++++++-------------
 1 file changed, 41 insertions(+), 31 deletions(-)

diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 031e6defc08e..a971e22aea81 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -498,11 +498,11 @@ static bool dar_in_user_range(unsigned long dar, struct arch_hw_breakpoint *info
 	return ((info->address <= dar) && (dar - info->address < info->len));
 }
 
-static bool dar_user_range_overlaps(unsigned long dar, int size,
-				    struct arch_hw_breakpoint *info)
+static bool ea_user_range_overlaps(unsigned long ea, int size,
+				   struct arch_hw_breakpoint *info)
 {
-	return ((dar < info->address + info->len) &&
-		(dar + size > info->address));
+	return ((ea < info->address + info->len) &&
+		(ea + size > info->address));
 }
 
 static bool dar_in_hw_range(unsigned long dar, struct arch_hw_breakpoint *info)
@@ -515,20 +515,22 @@ static bool dar_in_hw_range(unsigned long dar, struct arch_hw_breakpoint *info)
 	return ((hw_start_addr <= dar) && (hw_end_addr > dar));
 }
 
-static bool dar_hw_range_overlaps(unsigned long dar, int size,
-				  struct arch_hw_breakpoint *info)
+static bool ea_hw_range_overlaps(unsigned long ea, int size,
+				 struct arch_hw_breakpoint *info)
 {
 	unsigned long hw_start_addr, hw_end_addr;
 
 	hw_start_addr = ALIGN_DOWN(info->address, HW_BREAKPOINT_SIZE);
 	hw_end_addr = ALIGN(info->address + info->len, HW_BREAKPOINT_SIZE);
 
-	return ((dar < hw_end_addr) && (dar + size > hw_start_addr));
+	return ((ea < hw_end_addr) && (ea + size > hw_start_addr));
 }
 
 /*
  * If hw has multiple DAWR registers, we also need to check all
  * dawrx constraint bits to confirm this is _really_ a valid event.
+ * If type is UNKNOWN, but privilege level matches, consider it as
+ * a positive match.
  */
 static bool check_dawrx_constraints(struct pt_regs *regs, int type,
 				    struct arch_hw_breakpoint *info)
@@ -553,7 +555,8 @@ static bool check_dawrx_constraints(struct pt_regs *regs, int type,
  * including extraneous exception. Otherwise return false.
  */
 static bool check_constraints(struct pt_regs *regs, struct ppc_inst instr,
-			      int type, int size, struct arch_hw_breakpoint *info)
+			      unsigned long ea, int type, int size,
+			      struct arch_hw_breakpoint *info)
 {
 	bool in_user_range = dar_in_user_range(regs->dar, info);
 	bool dawrx_constraints;
@@ -569,22 +572,27 @@ static bool check_constraints(struct pt_regs *regs, struct ppc_inst instr,
 	}
 
 	if (unlikely(ppc_inst_equal(instr, ppc_inst(0)))) {
-		if (in_user_range)
-			return true;
+		if (cpu_has_feature(CPU_FTR_ARCH_31) &&
+		    !dar_in_hw_range(regs->dar, info))
+			return false;
 
-		if (dar_in_hw_range(regs->dar, info)) {
-			info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
-			return true;
-		}
-		return false;
+		return true;
 	}
 
 	dawrx_constraints = check_dawrx_constraints(regs, type, info);
 
-	if (dar_user_range_overlaps(regs->dar, size, info))
+	if (type == UNKNOWN) {
+		if (cpu_has_feature(CPU_FTR_ARCH_31) &&
+		    !dar_in_hw_range(regs->dar, info))
+			return false;
+
 		return dawrx_constraints;
+	}
 
-	if (dar_hw_range_overlaps(regs->dar, size, info)) {
+	if (ea_user_range_overlaps(ea, size, info))
+		return dawrx_constraints;
+
+	if (ea_hw_range_overlaps(ea, size, info)) {
 		if (dawrx_constraints) {
 			info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
 			return true;
@@ -594,7 +602,7 @@ static bool check_constraints(struct pt_regs *regs, struct ppc_inst instr,
 }
 
 static void get_instr_detail(struct pt_regs *regs, struct ppc_inst *instr,
-			     int *type, int *size, bool *larx_stcx)
+			     int *type, int *size, unsigned long *ea)
 {
 	struct instruction_op op;
 
@@ -602,16 +610,18 @@ static void get_instr_detail(struct pt_regs *regs, struct ppc_inst *instr,
 		return;
 
 	analyse_instr(&op, regs, *instr);
-
-	/*
-	 * Set size = 8 if analyse_instr() fails. If it's a userspace
-	 * watchpoint(valid or extraneous), we can notify user about it.
-	 * If it's a kernel watchpoint, instruction  emulation will fail
-	 * in stepping_handler() and watchpoint will be disabled.
-	 */
 	*type = GETTYPE(op.type);
-	*size = !(*type == UNKNOWN) ? GETSIZE(op.type) : 8;
-	*larx_stcx = (*type == LARX || *type == STCX);
+	*ea = op.ea;
+#ifdef __powerpc64__
+	if (!(regs->msr & MSR_64BIT))
+		*ea &= 0xffffffffUL;
+#endif
+	*size = GETSIZE(op.type);
+}
+
+static bool is_larx_stcx_instr(int type)
+{
+	return type == LARX || type == STCX;
 }
 
 /*
@@ -678,7 +688,7 @@ int hw_breakpoint_handler(struct die_args *args)
 	struct ppc_inst instr = ppc_inst(0);
 	int type = 0;
 	int size = 0;
-	bool larx_stcx = false;
+	unsigned long ea;
 
 	/* Disable breakpoints during exception handling */
 	hw_breakpoint_disable();
@@ -692,7 +702,7 @@ int hw_breakpoint_handler(struct die_args *args)
 	rcu_read_lock();
 
 	if (!IS_ENABLED(CONFIG_PPC_8xx))
-		get_instr_detail(regs, &instr, &type, &size, &larx_stcx);
+		get_instr_detail(regs, &instr, &type, &size, &ea);
 
 	for (i = 0; i < nr_wp_slots(); i++) {
 		bp[i] = __this_cpu_read(bp_per_reg[i]);
@@ -702,7 +712,7 @@ int hw_breakpoint_handler(struct die_args *args)
 		info[i] = counter_arch_bp(bp[i]);
 		info[i]->type &= ~HW_BRK_TYPE_EXTRANEOUS_IRQ;
 
-		if (check_constraints(regs, instr, type, size, info[i])) {
+		if (check_constraints(regs, instr, ea, type, size, info[i])) {
 			if (!IS_ENABLED(CONFIG_PPC_8xx) &&
 			    ppc_inst_equal(instr, ppc_inst(0))) {
 				handler_error(bp[i], info[i]);
@@ -744,7 +754,7 @@ int hw_breakpoint_handler(struct die_args *args)
 	}
 
 	if (!IS_ENABLED(CONFIG_PPC_8xx)) {
-		if (larx_stcx) {
+		if (is_larx_stcx_instr(type)) {
 			for (i = 0; i < nr_wp_slots(); i++) {
 				if (!hit[i])
 					continue;
-- 
2.26.2


^ permalink raw reply related

* [PATCH v5 03/10] powerpc/watchpoint: Fix DAWR exception for CACHEOP
From: Ravi Bangoria @ 2020-07-23  9:08 UTC (permalink / raw)
  To: mpe, mikey
  Cc: christophe.leroy, ravi.bangoria, rogealve, miltonm, peterz,
	fweisbec, oleg, npiggin, linux-kernel, paulus, jolsa, jniethe5,
	pedromfc, naveen.n.rao, linuxppc-dev, mingo
In-Reply-To: <20200723090813.303838-1-ravi.bangoria@linux.ibm.com>

'ea' returned by analyse_instr() needs to be aligned down to cache
block size for CACHEOP instructions. analyse_instr() does not set
size for CACHEOP, thus size also needs to be calculated manually.

Fixes: 27985b2a640e ("powerpc/watchpoint: Don't ignore extraneous exceptions blindly")
Fixes: 74c6881019b7 ("powerpc/watchpoint: Prepare handler to handle more than one watchpoint")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
---
 arch/powerpc/kernel/hw_breakpoint.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index a971e22aea81..c55e67bab271 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -538,7 +538,12 @@ static bool check_dawrx_constraints(struct pt_regs *regs, int type,
 	if (OP_IS_LOAD(type) && !(info->type & HW_BRK_TYPE_READ))
 		return false;
 
-	if (OP_IS_STORE(type) && !(info->type & HW_BRK_TYPE_WRITE))
+	/*
+	 * The Cache Management instructions other than dcbz never
+	 * cause a match. i.e. if type is CACHEOP, the instruction
+	 * is dcbz, and dcbz is treated as Store.
+	 */
+	if ((OP_IS_STORE(type) || type == CACHEOP) && !(info->type & HW_BRK_TYPE_WRITE))
 		return false;
 
 	if (is_kernel_addr(regs->nip) && !(info->type & HW_BRK_TYPE_KERNEL))
@@ -601,6 +606,15 @@ static bool check_constraints(struct pt_regs *regs, struct ppc_inst instr,
 	return false;
 }
 
+static int cache_op_size(void)
+{
+#ifdef __powerpc64__
+	return ppc64_caches.l1d.block_size;
+#else
+	return L1_CACHE_BYTES;
+#endif
+}
+
 static void get_instr_detail(struct pt_regs *regs, struct ppc_inst *instr,
 			     int *type, int *size, unsigned long *ea)
 {
@@ -616,7 +630,12 @@ static void get_instr_detail(struct pt_regs *regs, struct ppc_inst *instr,
 	if (!(regs->msr & MSR_64BIT))
 		*ea &= 0xffffffffUL;
 #endif
+
 	*size = GETSIZE(op.type);
+	if (*type == CACHEOP) {
+		*size = cache_op_size();
+		*ea &= ~(*size - 1);
+	}
 }
 
 static bool is_larx_stcx_instr(int type)
-- 
2.26.2


^ permalink raw reply related


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