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* Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
From: Daniel Henrique Barboza @ 2021-03-12 12:18 UTC (permalink / raw)
  To: Cédric Le Goater, David Gibson
  Cc: list@suse.de:PowerPC, linuxppc-dev, Greg Kurz, QEMU Developers
In-Reply-To: <4effbb5e-6f08-03bf-cea0-60c986175668@kaod.org>



On 3/12/21 6:53 AM, Cédric Le Goater wrote:
> On 3/12/21 2:55 AM, David Gibson wrote:
>> On Tue, 9 Mar 2021 18:26:35 +0100
>> Cédric Le Goater <clg@kaod.org> wrote:
>>
>>> On 3/9/21 6:08 PM, Daniel Henrique Barboza wrote:
>>>>
>>>>
>>>> On 3/9/21 12:33 PM, Cédric Le Goater wrote:
>>>>> On 3/8/21 6:13 PM, Greg Kurz wrote:
>>>>>> On Wed, 3 Mar 2021 18:48:50 +0100
>>>>>> Cédric Le Goater <clg@kaod.org> wrote:
>>>>>>   
>>>>>>> The 'chip_id' field of the XIVE CPU structure is used to choose a
>>>>>>> target for a source located on the same chip when possible. This field
>>>>>>> is assigned on the PowerNV platform using the "ibm,chip-id" property
>>>>>>> on pSeries under KVM when NUMA nodes are defined but it is undefined
>>>>>>
>>>>>> This sentence seems to have a syntax problem... like it is missing an
>>>>>> 'and' before 'on pSeries'.
>>>>>
>>>>> ah yes, or simply a comma.
>>>>>   
>>>>>>> under PowerVM. The XIVE source structure has a similar field
>>>>>>> 'src_chip' which is only assigned on the PowerNV platform.
>>>>>>>
>>>>>>> cpu_to_node() returns a compatible value on all platforms, 0 being the
>>>>>>> default node. It will also give us the opportunity to set the affinity
>>>>>>> of a source on pSeries when we can localize them.
>>>>>>>   
>>>>>>
>>>>>> IIUC this relies on the fact that the NUMA node id is == to chip id
>>>>>> on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable
>>>>>> with this change.
>>>>>
>>>>> Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall
>>>>> H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel
>>>>> in Cc:)
>>>   [...]
>>>>>
>>>>> On PowerNV, Linux uses "ibm,associativity" property of the CPU to find
>>>>> the node id. This value is built from the chip id in OPAL, so the
>>>>> value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id"
>>>>> property are unlikely to be different.
>>>>>
>>>>> cpu_to_node(cpu) is used in many places to allocate the structures
>>>>> locally to the owning node. XIVE is not an exception (see below in the
>>>>> same patch), it is better to be consistent and get the same information
>>>>> (node id) using the same routine.
>>>>>
>>>>>
>>>>> In Linux, "ibm,chip-id" is only used in low level PowerNV drivers :
>>>>> LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot
>>>>> unifies the controllers of the system to only expose one the OS. This
>>>>> is problematic and should be changed but it's another topic.
>>>>>
>>>>>   
>>>>>> On the other hand, you have the pSeries case under PowerVM that
>>>>>> doesn't xc->chip_id, which isn't passed to any hcall AFAICT.
>>>>>
>>>>> yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning
>>>>> under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid
>>>>> chip id.
>>>>>
>>>>> QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not
>>>>> always correct btw)
>>>>
>>>>
>>>> If you have a way to reliably reproduce this, let me know and I'll fix it
>>>> up in QEMU.
>>>
>>> with :
>>>
>>>     -smp 4,cores=1,maxcpus=8 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1
>>>
>>> # dmesg | grep numa
>>> [    0.013106] numa: Node 0 CPUs: 0-1
>>> [    0.013136] numa: Node 1 CPUs: 2-3
>>>
>>> # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id
>>> 		ibm,chip-id = <0x01>;
>>> 		ibm,chip-id = <0x02>;
>>> 		ibm,chip-id = <0x00>;
>>> 		ibm,chip-id = <0x03>;
>>>
>>> with :
>>>
>>>    -smp 4,cores=4,maxcpus=8,threads=1 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1
>>>
>>> # dmesg | grep numa
>>> [    0.013106] numa: Node 0 CPUs: 0-1
>>> [    0.013136] numa: Node 1 CPUs: 2-3
>>>
>>> # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id
>>> 		ibm,chip-id = <0x00>;
>>> 		ibm,chip-id = <0x00>;
>>> 		ibm,chip-id = <0x00>;
>>> 		ibm,chip-id = <0x00>;
>>>
>>> I think we should simply remove "ibm,chip-id" since it's not used and
>>> not in the PAPR spec.
>>
>> As I mentioned to Daniel on our call this morning, oddly it *does*
>> appear to be used in the RHEL kernel, even though that's 4.18 based.
>> This patch seems to have caused a minor regression; not in the
>> identification of NUMA nodes, but in the number of sockets shown be
>> lscpu, etc.  See https://bugzilla.redhat.com/show_bug.cgi?id=1934421
>> for more information.
> 
> Yes. The property "ibm,chip-id" is wrongly calculated in QEMU. If we
> remove it, we get with 4.18.0-295.el8.ppc64le or 5.12.0-rc2 :
> 
>     [root@localhost ~]# lscpu
>     Architecture:        ppc64le
>     Byte Order:          Little Endian
>     CPU(s):              128
>     On-line CPU(s) list: 0-127
>     Thread(s) per core:  4
>     Core(s) per socket:  16
>     Socket(s):           2
>     NUMA node(s):        2
>     Model:               2.2 (pvr 004e 1202)
>     Model name:          POWER9 (architected), altivec supported
>     Hypervisor vendor:   KVM
>     Virtualization type: para
>     L1d cache:           32K
>     L1i cache:           32K
>     NUMA node0 CPU(s):   0-63
>     NUMA node1 CPU(s):   64-127
> 
>     [root@localhost ~]# grep . /sys/devices/system/cpu/*/topology/physical_package_id
>     /sys/devices/system/cpu/cpu0/topology/physical_package_id:-1
>     /sys/devices/system/cpu/cpu100/topology/physical_package_id:-1
>     /sys/devices/system/cpu/cpu101/topology/physical_package_id:-1
>     /sys/devices/system/cpu/cpu102/topology/physical_package_id:-1
>     /sys/devices/system/cpu/cpu103/topology/physical_package_id:-1
>     ....
> 
> "ibm,chip-id" is still being used on some occasion on pSeries machines.
> This is wrong :/ The problem is :
> 
>    #define topology_physical_package_id(cpu)      (cpu_to_chip_id(cpu))
> 
> We should be using cpu_to_node().


IIUC the "real fix" then is this change you mentioned above, together with
this xive patch as well, to stop using ibm,chip-id for good in the pserie
  kernel. With these changes QEMU can remove 'ibm,chip-id' from the pseries
machine without impact. Is this correct?

If that's the case, then I believe it's ok to go forward with the QEMU side
change (just for 6.0.0 and newer machines). Or should I wait for the kernel
changes to be merged upstream first?


Thanks,


DHB


> 
> C.
> 
>>
>> Since the value was used by some PAPR kernels - even if they shouldn't
>> have - I think we should only remove this for newer machine types.  We
>> also need to check what we're not supplying that the guest kernel is
>> showing a different number of sockets than specified on the qemu
>> command line.
>>
>>>
>>> Thanks,
>>>
>>> C.
>>>
>>>   
>>>
>>>   [...]
>>>   [...]
>>>   [...]
>>>   [...]
>>>   [...]
>>>   [...]
>>>   [...]
>>>   [...]
>>>   [...]
>>>
>>
>>
> 

^ permalink raw reply

* [powerpc:merge] BUILD SUCCESS b38521e8bebde04fa31001435ed77a93f83d896e
From: kernel test robot @ 2021-03-12 12:38 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: b38521e8bebde04fa31001435ed77a93f83d896e  Automatic merge of 'fixes' into merge (2021-03-12 11:02)

elapsed time: 729m

configs tested: 147
configs skipped: 2

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

gcc tested configs:
arm                                 defconfig
arm64                            allyesconfig
arm64                               defconfig
arm                              allyesconfig
arm                              allmodconfig
powerpc                 mpc836x_rdk_defconfig
mips                        qi_lb60_defconfig
powerpc                     tqm8555_defconfig
openrisc                 simple_smp_defconfig
powerpc                     stx_gp3_defconfig
powerpc                      pmac32_defconfig
powerpc                     mpc512x_defconfig
powerpc                     kilauea_defconfig
powerpc                      ppc44x_defconfig
sh                        edosk7705_defconfig
nds32                            alldefconfig
powerpc                    socrates_defconfig
sh                           se7712_defconfig
arm                          collie_defconfig
riscv                               defconfig
powerpc                    ge_imp3a_defconfig
sh                             sh03_defconfig
arm                             mxs_defconfig
sh                        dreamcast_defconfig
arm                          ixp4xx_defconfig
h8300                               defconfig
arc                          axs101_defconfig
sh                   sh7724_generic_defconfig
m68k                         apollo_defconfig
arm                         lpc32xx_defconfig
m68k                          multi_defconfig
powerpc                     mpc5200_defconfig
mips                  maltasmvp_eva_defconfig
powerpc                  mpc866_ads_defconfig
powerpc                      ep88xc_defconfig
sh                        sh7763rdp_defconfig
arm                        neponset_defconfig
powerpc                      tqm8xx_defconfig
arm                       cns3420vb_defconfig
arc                        nsim_700_defconfig
powerpc                 mpc85xx_cds_defconfig
powerpc                 mpc832x_rdb_defconfig
arm64                            alldefconfig
sh                          r7785rp_defconfig
arc                           tb10x_defconfig
arm                        keystone_defconfig
arm                        trizeps4_defconfig
sparc                               defconfig
parisc                generic-64bit_defconfig
mips                          malta_defconfig
m68k                        mvme147_defconfig
powerpc                      ppc40x_defconfig
powerpc                     tqm8548_defconfig
arm                         s3c6400_defconfig
mips                        nlm_xlr_defconfig
arm                          iop32x_defconfig
sparc                       sparc32_defconfig
powerpc                 mpc836x_mds_defconfig
xtensa                generic_kc705_defconfig
powerpc                     tqm5200_defconfig
sparc                            allyesconfig
arc                        nsimosci_defconfig
ia64                             allmodconfig
ia64                                defconfig
ia64                             allyesconfig
m68k                             allmodconfig
m68k                                defconfig
m68k                             allyesconfig
nios2                               defconfig
arc                              allyesconfig
nds32                             allnoconfig
nds32                               defconfig
nios2                            allyesconfig
csky                                defconfig
alpha                               defconfig
alpha                            allyesconfig
xtensa                           allyesconfig
h8300                            allyesconfig
arc                                 defconfig
sh                               allmodconfig
parisc                              defconfig
s390                             allyesconfig
s390                             allmodconfig
parisc                           allyesconfig
s390                                defconfig
i386                             allyesconfig
i386                               tinyconfig
i386                                defconfig
mips                             allyesconfig
mips                             allmodconfig
powerpc                          allyesconfig
powerpc                          allmodconfig
powerpc                           allnoconfig
i386                 randconfig-a001-20210311
i386                 randconfig-a005-20210311
i386                 randconfig-a003-20210311
i386                 randconfig-a002-20210311
i386                 randconfig-a004-20210311
i386                 randconfig-a006-20210311
x86_64               randconfig-a011-20210312
x86_64               randconfig-a016-20210312
x86_64               randconfig-a013-20210312
x86_64               randconfig-a014-20210312
x86_64               randconfig-a015-20210312
x86_64               randconfig-a012-20210312
i386                 randconfig-a013-20210311
i386                 randconfig-a016-20210311
i386                 randconfig-a011-20210311
i386                 randconfig-a014-20210311
i386                 randconfig-a015-20210311
i386                 randconfig-a012-20210311
i386                 randconfig-a013-20210312
i386                 randconfig-a016-20210312
i386                 randconfig-a011-20210312
i386                 randconfig-a015-20210312
i386                 randconfig-a014-20210312
i386                 randconfig-a012-20210312
x86_64               randconfig-a006-20210311
x86_64               randconfig-a001-20210311
x86_64               randconfig-a005-20210311
x86_64               randconfig-a002-20210311
x86_64               randconfig-a003-20210311
x86_64               randconfig-a004-20210311
riscv                    nommu_virt_defconfig
riscv                             allnoconfig
riscv                          rv32_defconfig
riscv                            allmodconfig
riscv                    nommu_k210_defconfig
riscv                            allyesconfig
x86_64                           allyesconfig
x86_64                    rhel-7.6-kselftests
x86_64                              defconfig
x86_64                               rhel-8.3
x86_64                      rhel-8.3-kbuiltin
x86_64                                  kexec

clang tested configs:
x86_64               randconfig-a006-20210312
x86_64               randconfig-a001-20210312
x86_64               randconfig-a005-20210312
x86_64               randconfig-a003-20210312
x86_64               randconfig-a002-20210312
x86_64               randconfig-a004-20210312
x86_64               randconfig-a011-20210311
x86_64               randconfig-a016-20210311
x86_64               randconfig-a013-20210311
x86_64               randconfig-a015-20210311
x86_64               randconfig-a014-20210311
x86_64               randconfig-a012-20210311

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

^ permalink raw reply

* [powerpc:fixes] BUILD SUCCESS 0b736881c8f1a6cd912f7a9162b9e097b28c1c30
From: kernel test robot @ 2021-03-12 12:38 UTC (permalink / raw)
  To: Michael Ellerman; +Cc: linuxppc-dev

tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git fixes
branch HEAD: 0b736881c8f1a6cd912f7a9162b9e097b28c1c30  powerpc/traps: unrecoverable_exception() is not an interrupt handler

elapsed time: 732m

configs tested: 106
configs skipped: 20

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

gcc tested configs:
nds32                            alldefconfig
powerpc                    socrates_defconfig
sh                           se7712_defconfig
arm                          collie_defconfig
riscv                               defconfig
powerpc                    ge_imp3a_defconfig
sh                             sh03_defconfig
arm                             mxs_defconfig
sh                        dreamcast_defconfig
arm                          ixp4xx_defconfig
h8300                               defconfig
arc                          axs101_defconfig
sh                   sh7724_generic_defconfig
m68k                         apollo_defconfig
arm                         lpc32xx_defconfig
m68k                          multi_defconfig
powerpc                  mpc866_ads_defconfig
powerpc                      ep88xc_defconfig
sh                        sh7763rdp_defconfig
arm                        neponset_defconfig
sh                 kfr2r09-romimage_defconfig
ia64                          tiger_defconfig
arm                       netwinder_defconfig
arm                        magician_defconfig
mips                        bcm63xx_defconfig
powerpc                 mpc832x_rdb_defconfig
arm64                            alldefconfig
sh                          r7785rp_defconfig
arc                           tb10x_defconfig
arm                        keystone_defconfig
arm                        trizeps4_defconfig
sparc                               defconfig
parisc                generic-64bit_defconfig
mips                          malta_defconfig
m68k                        mvme147_defconfig
powerpc                      ppc40x_defconfig
powerpc                     tqm8548_defconfig
arm                         s3c6400_defconfig
mips                        nlm_xlr_defconfig
arm                          iop32x_defconfig
sparc                       sparc32_defconfig
sh                        edosk7705_defconfig
powerpc                 mpc836x_mds_defconfig
arm                                 defconfig
ia64                             allmodconfig
ia64                                defconfig
ia64                             allyesconfig
m68k                             allmodconfig
m68k                                defconfig
m68k                             allyesconfig
nios2                               defconfig
arc                              allyesconfig
nds32                             allnoconfig
nds32                               defconfig
nios2                            allyesconfig
csky                                defconfig
alpha                               defconfig
alpha                            allyesconfig
xtensa                           allyesconfig
h8300                            allyesconfig
arc                                 defconfig
sh                               allmodconfig
parisc                              defconfig
s390                             allyesconfig
s390                             allmodconfig
parisc                           allyesconfig
s390                                defconfig
i386                             allyesconfig
sparc                            allyesconfig
i386                               tinyconfig
i386                                defconfig
mips                             allyesconfig
mips                             allmodconfig
powerpc                          allyesconfig
powerpc                          allmodconfig
powerpc                           allnoconfig
i386                 randconfig-a001-20210311
i386                 randconfig-a005-20210311
i386                 randconfig-a003-20210311
i386                 randconfig-a002-20210311
i386                 randconfig-a004-20210311
i386                 randconfig-a006-20210311
i386                 randconfig-a013-20210311
i386                 randconfig-a016-20210311
i386                 randconfig-a011-20210311
i386                 randconfig-a014-20210311
i386                 randconfig-a015-20210311
i386                 randconfig-a012-20210311
x86_64               randconfig-a006-20210311
x86_64               randconfig-a001-20210311
x86_64               randconfig-a005-20210311
x86_64               randconfig-a002-20210311
x86_64               randconfig-a003-20210311
x86_64               randconfig-a004-20210311
x86_64                           allyesconfig
x86_64                    rhel-7.6-kselftests
x86_64                              defconfig
x86_64                               rhel-8.3
x86_64                      rhel-8.3-kbuiltin
x86_64                                  kexec

clang tested configs:
x86_64               randconfig-a011-20210311
x86_64               randconfig-a016-20210311
x86_64               randconfig-a013-20210311
x86_64               randconfig-a015-20210311
x86_64               randconfig-a014-20210311
x86_64               randconfig-a012-20210311

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

^ permalink raw reply

* [powerpc:fixes-test] BUILD SUCCESS cb6627c4919fb7023111d362391add9f848d2a91
From: kernel test robot @ 2021-03-12 12:38 UTC (permalink / raw)
  To: Michael Ellerman; +Cc: linuxppc-dev

tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git fixes-test
branch HEAD: cb6627c4919fb7023111d362391add9f848d2a91  powerpc/eeh: Fix build failure with CONFIG_PROC_FS=n

elapsed time: 731m

configs tested: 106
configs skipped: 20

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

gcc tested configs:
nds32                            alldefconfig
powerpc                    socrates_defconfig
sh                           se7712_defconfig
arm                          collie_defconfig
riscv                               defconfig
powerpc                    ge_imp3a_defconfig
sh                             sh03_defconfig
arm                             mxs_defconfig
sh                        dreamcast_defconfig
arm                          ixp4xx_defconfig
h8300                               defconfig
arc                          axs101_defconfig
sh                   sh7724_generic_defconfig
m68k                         apollo_defconfig
arm                         lpc32xx_defconfig
m68k                          multi_defconfig
powerpc                  mpc866_ads_defconfig
powerpc                      ep88xc_defconfig
sh                        sh7763rdp_defconfig
arm                        neponset_defconfig
sh                 kfr2r09-romimage_defconfig
ia64                          tiger_defconfig
arm                       netwinder_defconfig
arm                        magician_defconfig
mips                        bcm63xx_defconfig
powerpc                 mpc832x_rdb_defconfig
arm64                            alldefconfig
sh                          r7785rp_defconfig
arc                           tb10x_defconfig
arm                        keystone_defconfig
arm                        trizeps4_defconfig
sparc                               defconfig
parisc                generic-64bit_defconfig
mips                          malta_defconfig
m68k                        mvme147_defconfig
powerpc                      ppc40x_defconfig
powerpc                     tqm8548_defconfig
arm                         s3c6400_defconfig
mips                        nlm_xlr_defconfig
arm                          iop32x_defconfig
sparc                       sparc32_defconfig
sh                        edosk7705_defconfig
powerpc                 mpc836x_mds_defconfig
arm                                 defconfig
ia64                             allmodconfig
ia64                                defconfig
ia64                             allyesconfig
m68k                             allmodconfig
m68k                                defconfig
m68k                             allyesconfig
nios2                               defconfig
arc                              allyesconfig
nds32                             allnoconfig
nds32                               defconfig
nios2                            allyesconfig
csky                                defconfig
alpha                               defconfig
alpha                            allyesconfig
xtensa                           allyesconfig
h8300                            allyesconfig
arc                                 defconfig
sh                               allmodconfig
parisc                              defconfig
s390                             allyesconfig
s390                             allmodconfig
parisc                           allyesconfig
s390                                defconfig
i386                             allyesconfig
sparc                            allyesconfig
i386                               tinyconfig
i386                                defconfig
mips                             allyesconfig
mips                             allmodconfig
powerpc                          allyesconfig
powerpc                          allmodconfig
powerpc                           allnoconfig
i386                 randconfig-a001-20210311
i386                 randconfig-a005-20210311
i386                 randconfig-a003-20210311
i386                 randconfig-a002-20210311
i386                 randconfig-a004-20210311
i386                 randconfig-a006-20210311
i386                 randconfig-a013-20210311
i386                 randconfig-a016-20210311
i386                 randconfig-a011-20210311
i386                 randconfig-a014-20210311
i386                 randconfig-a015-20210311
i386                 randconfig-a012-20210311
x86_64               randconfig-a006-20210311
x86_64               randconfig-a001-20210311
x86_64               randconfig-a005-20210311
x86_64               randconfig-a002-20210311
x86_64               randconfig-a003-20210311
x86_64               randconfig-a004-20210311
x86_64                           allyesconfig
x86_64                    rhel-7.6-kselftests
x86_64                              defconfig
x86_64                               rhel-8.3
x86_64                      rhel-8.3-kbuiltin
x86_64                                  kexec

clang tested configs:
x86_64               randconfig-a011-20210311
x86_64               randconfig-a016-20210311
x86_64               randconfig-a013-20210311
x86_64               randconfig-a015-20210311
x86_64               randconfig-a014-20210311
x86_64               randconfig-a012-20210311

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

^ permalink raw reply

* [powerpc:next-test] BUILD SUCCESS acc48fec3ae30fd2c049c39582e1c4fdf25480ee
From: kernel test robot @ 2021-03-12 12:38 UTC (permalink / raw)
  To: Michael Ellerman; +Cc: linuxppc-dev

tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next-test
branch HEAD: acc48fec3ae30fd2c049c39582e1c4fdf25480ee  powerpc/uprobes: Validation for prefixed instruction

elapsed time: 727m

configs tested: 120
configs skipped: 2

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

gcc tested configs:
arm                                 defconfig
arm64                            allyesconfig
arm64                               defconfig
arm                              allyesconfig
arm                              allmodconfig
arm                             mxs_defconfig
sh                   secureedge5410_defconfig
ia64                          tiger_defconfig
arm                           spitz_defconfig
ia64                             alldefconfig
arm                         mv78xx0_defconfig
arm                          exynos_defconfig
m68k                        m5272c3_defconfig
arm                         nhk8815_defconfig
powerpc                      tqm8xx_defconfig
arm                     davinci_all_defconfig
powerpc                      pasemi_defconfig
powerpc                     powernv_defconfig
arm                   milbeaut_m10v_defconfig
arm                       versatile_defconfig
m68k                        m5307c3_defconfig
mips                      pistachio_defconfig
sh                 kfr2r09-romimage_defconfig
x86_64                           allyesconfig
arm                       netwinder_defconfig
arm                        magician_defconfig
mips                        bcm63xx_defconfig
powerpc                 mpc832x_rdb_defconfig
arm64                            alldefconfig
sh                          r7785rp_defconfig
arc                           tb10x_defconfig
arm                        keystone_defconfig
arm                        trizeps4_defconfig
mips                          malta_defconfig
mips                        nlm_xlr_defconfig
arm                  colibri_pxa270_defconfig
arm                        oxnas_v6_defconfig
powerpc                        icon_defconfig
arm                     eseries_pxa_defconfig
arm                         bcm2835_defconfig
arc                      axs103_smp_defconfig
mips                           ci20_defconfig
sh                           se7721_defconfig
powerpc                    ge_imp3a_defconfig
sh                          kfr2r09_defconfig
arm                        mvebu_v7_defconfig
mips                         tb0287_defconfig
nios2                         10m50_defconfig
arm                         palmz72_defconfig
alpha                               defconfig
sh                        sh7757lcr_defconfig
sh                          rsk7201_defconfig
ia64                             allmodconfig
ia64                                defconfig
ia64                             allyesconfig
m68k                             allmodconfig
m68k                                defconfig
m68k                             allyesconfig
nios2                               defconfig
arc                              allyesconfig
nds32                             allnoconfig
nds32                               defconfig
nios2                            allyesconfig
csky                                defconfig
alpha                            allyesconfig
xtensa                           allyesconfig
h8300                            allyesconfig
arc                                 defconfig
sh                               allmodconfig
parisc                              defconfig
s390                             allyesconfig
s390                             allmodconfig
parisc                           allyesconfig
s390                                defconfig
i386                             allyesconfig
sparc                            allyesconfig
sparc                               defconfig
i386                               tinyconfig
i386                                defconfig
mips                             allyesconfig
mips                             allmodconfig
powerpc                          allyesconfig
powerpc                          allmodconfig
powerpc                           allnoconfig
x86_64               randconfig-a006-20210311
x86_64               randconfig-a001-20210311
x86_64               randconfig-a005-20210311
x86_64               randconfig-a002-20210311
x86_64               randconfig-a003-20210311
x86_64               randconfig-a004-20210311
i386                 randconfig-a001-20210311
i386                 randconfig-a005-20210311
i386                 randconfig-a003-20210311
i386                 randconfig-a002-20210311
i386                 randconfig-a004-20210311
i386                 randconfig-a006-20210311
i386                 randconfig-a013-20210311
i386                 randconfig-a016-20210311
i386                 randconfig-a011-20210311
i386                 randconfig-a014-20210311
i386                 randconfig-a015-20210311
i386                 randconfig-a012-20210311
riscv                    nommu_k210_defconfig
riscv                            allyesconfig
riscv                    nommu_virt_defconfig
riscv                             allnoconfig
riscv                               defconfig
riscv                          rv32_defconfig
riscv                            allmodconfig
x86_64                    rhel-7.6-kselftests
x86_64                              defconfig
x86_64                               rhel-8.3
x86_64                      rhel-8.3-kbuiltin
x86_64                                  kexec

clang tested configs:
x86_64               randconfig-a006-20210312
x86_64               randconfig-a001-20210312
x86_64               randconfig-a005-20210312
x86_64               randconfig-a003-20210312
x86_64               randconfig-a002-20210312
x86_64               randconfig-a004-20210312

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

^ permalink raw reply

* [PATCH v3 04/41] powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

In order to be able to switch MMU on in exception prolog, save
SRR0 and SRR1 earlier.

Also save r10 and r11 into stack earlier to better match with the
normal exception prolog.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/entry_32.S | 9 ---------
 arch/powerpc/kernel/head_40x.S | 8 ++++++++
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 78c430b7f9d9..8528b4c7f9d3 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -107,15 +107,6 @@ _ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
 #ifdef CONFIG_40x
 	.globl	crit_transfer_to_handler
 crit_transfer_to_handler:
-	lwz	r0,crit_r10@l(0)
-	stw	r0,GPR10(r11)
-	lwz	r0,crit_r11@l(0)
-	stw	r0,GPR11(r11)
-	mfspr	r0,SPRN_SRR0
-	stw	r0,crit_srr0@l(0)
-	mfspr	r0,SPRN_SRR1
-	stw	r0,crit_srr1@l(0)
-
 	/* set the stack limit to the current stack */
 	mfspr	r8,SPRN_SPRG_THREAD
 	lwz	r0,KSP_LIMIT(r8)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 9cef423d574b..067ae1302c1c 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -103,6 +103,10 @@ _ENTRY(saved_ksp_limit)
 .macro CRITICAL_EXCEPTION_PROLOG
 	stw	r10,crit_r10@l(0)	/* save two registers to work with */
 	stw	r11,crit_r11@l(0)
+	mfspr	r10,SPRN_SRR0
+	mfspr	r11,SPRN_SRR1
+	stw	r10,crit_srr0@l(0)
+	stw	r11,crit_srr1@l(0)
 	mfcr	r10			/* save CR in r10 for now	   */
 	mfspr	r11,SPRN_SRR3		/* check whether user or kernel    */
 	andi.	r11,r11,MSR_PR
@@ -120,6 +124,10 @@ _ENTRY(saved_ksp_limit)
 	stw	r9,GPR9(r11)
 	mflr	r10
 	stw	r10,_LINK(r11)
+	lwz	r10,crit_r10@l(0)
+	lwz	r12,crit_r11@l(0)
+	stw	r10,GPR10(r11)
+	stw	r12,GPR11(r11)
 	mfspr	r12,SPRN_DEAR		/* save DEAR and ESR in the frame  */
 	stw	r12,_DEAR(r11)		/* since they may have had stuff   */
 	mfspr	r9,SPRN_ESR		/* in them at the point where the  */
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 02/41] powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlers
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

SPRN_SPRG_SCRATCH5 is used to save SPRN_PID.
SPRN_SPRG_SCRATCH6 is already available.

SPRN_PID is only 8 bits. We have r12 that contains CR.
We only need to preserve CR0, so we have space available in r12
to save PID.

Keep PID in r12 and free up SPRN_SPRG_SCRATCH5.

Then In TLB miss handlers, instead of using SPRN_SPRG_SCRATCH0 and
SPRN_SPRG_SCRATCH1, use SPRN_SPRG_SCRATCH5 and SPRN_SPRG_SCRATCH6
to avoid future conflicts with normal exception prologs.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_40x.S | 39 ++++++++++++++++------------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 24724a7dad49..383238a98f77 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -249,13 +249,13 @@ _ENTRY(saved_ksp_limit)
  * load TLB entries from the page table if they exist.
  */
 	START_EXCEPTION(0x1100,	DTLBMiss)
-	mtspr	SPRN_SPRG_SCRATCH0, r10 /* Save some working registers */
-	mtspr	SPRN_SPRG_SCRATCH1, r11
+	mtspr	SPRN_SPRG_SCRATCH5, r10 /* Save some working registers */
+	mtspr	SPRN_SPRG_SCRATCH6, r11
 	mtspr	SPRN_SPRG_SCRATCH3, r12
 	mtspr	SPRN_SPRG_SCRATCH4, r9
 	mfcr	r12
 	mfspr	r9, SPRN_PID
-	mtspr	SPRN_SPRG_SCRATCH5, r9
+	rlwimi	r12, r9, 0, 0xff
 	mfspr	r10, SPRN_DEAR		/* Get faulting address */
 
 	/* If we are faulting a kernel address, we have to use the
@@ -316,13 +316,12 @@ _ENTRY(saved_ksp_limit)
 	/* The bailout.  Restore registers to pre-exception conditions
 	 * and call the heavyweights to help us out.
 	 */
-	mfspr	r9, SPRN_SPRG_SCRATCH5
-	mtspr	SPRN_PID, r9
-	mtcr	r12
+	mtspr	SPRN_PID, r12
+	mtcrf	0x80, r12
 	mfspr	r9, SPRN_SPRG_SCRATCH4
 	mfspr	r12, SPRN_SPRG_SCRATCH3
-	mfspr	r11, SPRN_SPRG_SCRATCH1
-	mfspr	r10, SPRN_SPRG_SCRATCH0
+	mfspr	r11, SPRN_SPRG_SCRATCH6
+	mfspr	r10, SPRN_SPRG_SCRATCH5
 	b	DataStorage
 
 /* 0x1200 - Instruction TLB Miss Exception
@@ -330,13 +329,13 @@ _ENTRY(saved_ksp_limit)
  * registers and bailout to a different point.
  */
 	START_EXCEPTION(0x1200,	ITLBMiss)
-	mtspr	SPRN_SPRG_SCRATCH0, r10	 /* Save some working registers */
-	mtspr	SPRN_SPRG_SCRATCH1, r11
+	mtspr	SPRN_SPRG_SCRATCH5, r10	 /* Save some working registers */
+	mtspr	SPRN_SPRG_SCRATCH6, r11
 	mtspr	SPRN_SPRG_SCRATCH3, r12
 	mtspr	SPRN_SPRG_SCRATCH4, r9
 	mfcr	r12
 	mfspr	r9, SPRN_PID
-	mtspr	SPRN_SPRG_SCRATCH5, r9
+	rlwimi	r12, r9, 0, 0xff
 	mfspr	r10, SPRN_SRR0		/* Get faulting address */
 
 	/* If we are faulting a kernel address, we have to use the
@@ -397,13 +396,12 @@ _ENTRY(saved_ksp_limit)
 	/* The bailout.  Restore registers to pre-exception conditions
 	 * and call the heavyweights to help us out.
 	 */
-	mfspr	r9, SPRN_SPRG_SCRATCH5
-	mtspr	SPRN_PID, r9
-	mtcr	r12
+	mtspr	SPRN_PID, r12
+	mtcrf	0x80, r12
 	mfspr	r9, SPRN_SPRG_SCRATCH4
 	mfspr	r12, SPRN_SPRG_SCRATCH3
-	mfspr	r11, SPRN_SPRG_SCRATCH1
-	mfspr	r10, SPRN_SPRG_SCRATCH0
+	mfspr	r11, SPRN_SPRG_SCRATCH6
+	mfspr	r10, SPRN_SPRG_SCRATCH5
 	b	InstructionAccess
 
 	EXCEPTION(0x1300, Trap_13, unknown_exception, EXC_XFER_STD)
@@ -543,13 +541,12 @@ finish_tlb_load:
 
 	/* Done...restore registers and get out of here.
 	*/
-	mfspr	r9, SPRN_SPRG_SCRATCH5
-	mtspr	SPRN_PID, r9
-	mtcr	r12
+	mtspr	SPRN_PID, r12
+	mtcrf	0x80, r12
 	mfspr	r9, SPRN_SPRG_SCRATCH4
 	mfspr	r12, SPRN_SPRG_SCRATCH3
-	mfspr	r11, SPRN_SPRG_SCRATCH1
-	mfspr	r10, SPRN_SPRG_SCRATCH0
+	mfspr	r11, SPRN_SPRG_SCRATCH6
+	mfspr	r10, SPRN_SPRG_SCRATCH5
 	rfi			/* Should sync shadow TLBs */
 	b	.		/* prevent prefetch past rfi */
 
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 03/41] powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro to
remove the ugly ; and \ on each line.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_40x.S | 71 +++++++++++++++++-----------------
 1 file changed, 36 insertions(+), 35 deletions(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 383238a98f77..9cef423d574b 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -100,42 +100,43 @@ _ENTRY(saved_ksp_limit)
  * Instead we use a couple of words of memory at low physical addresses.
  * This is OK since we don't support SMP on these processors.
  */
-#define CRITICAL_EXCEPTION_PROLOG					     \
-	stw	r10,crit_r10@l(0);	/* save two registers to work with */\
-	stw	r11,crit_r11@l(0);					     \
-	mfcr	r10;			/* save CR in r10 for now	   */\
-	mfspr	r11,SPRN_SRR3;		/* check whether user or kernel    */\
-	andi.	r11,r11,MSR_PR;						     \
-	lis	r11,critirq_ctx@ha;					     \
-	tophys(r11,r11);						     \
-	lwz	r11,critirq_ctx@l(r11);					     \
-	beq	1f;							     \
-	/* COMING FROM USER MODE */					     \
-	mfspr	r11,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
-	lwz	r11,TASK_STACK-THREAD(r11); /* this thread's kernel stack */\
-1:	addi	r11,r11,THREAD_SIZE-INT_FRAME_SIZE; /* Alloc an excpt frm  */\
-	tophys(r11,r11);						     \
-	stw	r10,_CCR(r11);          /* save various registers	   */\
-	stw	r12,GPR12(r11);						     \
-	stw	r9,GPR9(r11);						     \
-	mflr	r10;							     \
-	stw	r10,_LINK(r11);						     \
-	mfspr	r12,SPRN_DEAR;		/* save DEAR and ESR in the frame  */\
-	stw	r12,_DEAR(r11);		/* since they may have had stuff   */\
-	mfspr	r9,SPRN_ESR;		/* in them at the point where the  */\
-	stw	r9,_ESR(r11);		/* exception was taken		   */\
-	mfspr	r12,SPRN_SRR2;						     \
-	stw	r1,GPR1(r11);						     \
-	mfspr	r9,SPRN_SRR3;						     \
-	stw	r1,0(r11);						     \
-	tovirt(r1,r11);							     \
-	rlwinm	r9,r9,0,14,12;		/* clear MSR_WE (necessary?)	   */\
-	stw	r0,GPR0(r11);						     \
-	lis	r10, STACK_FRAME_REGS_MARKER@ha; /* exception frame marker */\
-	addi	r10, r10, STACK_FRAME_REGS_MARKER@l;			     \
-	stw	r10, 8(r11);						     \
-	SAVE_4GPRS(3, r11);						     \
+.macro CRITICAL_EXCEPTION_PROLOG
+	stw	r10,crit_r10@l(0)	/* save two registers to work with */
+	stw	r11,crit_r11@l(0)
+	mfcr	r10			/* save CR in r10 for now	   */
+	mfspr	r11,SPRN_SRR3		/* check whether user or kernel    */
+	andi.	r11,r11,MSR_PR
+	lis	r11,critirq_ctx@ha
+	tophys(r11,r11)
+	lwz	r11,critirq_ctx@l(r11)
+	beq	1f
+	/* COMING FROM USER MODE */
+	mfspr	r11,SPRN_SPRG_THREAD	/* if from user, start at top of   */
+	lwz	r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
+1:	addi	r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm  */
+	tophys(r11,r11)
+	stw	r10,_CCR(r11)		/* save various registers	   */
+	stw	r12,GPR12(r11)
+	stw	r9,GPR9(r11)
+	mflr	r10
+	stw	r10,_LINK(r11)
+	mfspr	r12,SPRN_DEAR		/* save DEAR and ESR in the frame  */
+	stw	r12,_DEAR(r11)		/* since they may have had stuff   */
+	mfspr	r9,SPRN_ESR		/* in them at the point where the  */
+	stw	r9,_ESR(r11)		/* exception was taken		   */
+	mfspr	r12,SPRN_SRR2
+	stw	r1,GPR1(r11)
+	mfspr	r9,SPRN_SRR3
+	stw	r1,0(r11)
+	tovirt(r1,r11)
+	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?)	   */
+	stw	r0,GPR0(r11)
+	lis	r10, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
+	addi	r10, r10, STACK_FRAME_REGS_MARKER@l
+	stw	r10, 8(r11)
+	SAVE_4GPRS(3, r11)
 	SAVE_2GPRS(7, r11)
+.endm
 
 	/*
 	 * State at this point:
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 00/41] powerpc/32: Switch to interrupt entry/exit in C
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel

This series aims at porting interrupt entry/exit in C on PPC32, using
the work already merged for PPC64.

First patch is an optimisation around unrecoverable_exception() function.

Six following patches do minimal changes in 40x in order to be able to enable MMU
earlier in exception entry.

Second part of the series prepares and switches interrupt exit in C.

Third part moves more and more things in C, ending with KUAP management.

v3 is tested on 8xx and 83xx and qemu mac99 and qemu bamboo.

Changes in v3:
- Remove the WARN in first patch
- Fix oopses due fast_interrupt_return clobering registers after FPunavailable expection.
- Only call restore_math if PPC64
- Rename C version of kuap_{get_and_}check() into kuap_{get_and_}assert_locked().
- Drop the patch to call bad_page_fault() from do_page_fault() on book3e/64
- Remove the unneeded setting of current->thread.regs on every interrupt entry from user.

Changes in v2:
- Two first patches are new.
- Mainly build fixes, nothing much new.

Christophe Leroy (41):
  powerpc/traps: Declare unrecoverable_exception() as __noreturn
  powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlers
  powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro
  powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception
  powerpc/40x: Reorder a few instructions in critical exception prolog
  powerpc/40x: Prepare for enabling MMU in critical exception prolog
  powerpc/40x: Prepare normal exception handler for enabling MMU early
  powerpc/32: Reconcile interrupts in C
  powerpc/32: Entry cpu time accounting in C
  powerpc/32: Handle bookE debugging in C in exception entry
  powerpc/32: Use fast instruction to set MSR RI in exception prolog on
    8xx
  powerpc/32: Remove ksp_limit
  powerpc/32: Always enable data translation in exception prolog
  powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx
  powerpc/32: Enable instruction translation at the same time as data
    translation
  powerpc/32: Statically initialise first emergency context
  powerpc/32: Add vmap_stack_overflow label inside the macro
  powerpc/32: Use START_EXCEPTION() as much as possible
  powerpc/32: Move exception prolog code into .text once MMU is back on
  powerpc/32: Provide a name to exception prolog continuation in virtual
    mode
  powerpc/32: Refactor booke critical registers saving
  powerpc/32: Perform normal function call in exception entry
  powerpc/32: Always save non volatile registers on exception entry
  powerpc/32: Replace ASM exception exit by C exception exit from ppc64
  powerpc/32: Don't save thread.regs on interrupt entry
  powerpc/32: Set regs parameter in r3 in transfer_to_handler
  powerpc/32: Call bad_page_fault() from do_page_fault()
  powerpc/32: Save trap number on stack in exception prolog
  powerpc/32: Add a prepare_transfer_to_handler macro for exception
    prologs
  powerpc/32: Only restore non volatile registers when required
  powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE
  powerpc/32: Remove the xfer parameter in EXCEPTION() macro
  powerpc/32: Refactor saving of volatile registers in exception prologs
  powerpc/32: Save remaining registers in exception prolog
  powerpc/32: Return directly from power_save_ppc32_restore()
  powerpc/32: Only use prepare_transfer_to_handler function on book3s/32
    and e500
  powerpc/32s: Move KUEP locking/unlocking in C
  powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr()
    generic
  powerpc/32s: Create C version of kuap save/restore/check helpers
  powerpc/8xx: Create C version of kuap save/restore/check helpers
  powerpc/32: Manage KUAP in C

 arch/powerpc/include/asm/book3s/32/kup.h     | 126 ++-
 arch/powerpc/include/asm/book3s/64/kup.h     |  24 +-
 arch/powerpc/include/asm/interrupt.h         |  17 +-
 arch/powerpc/include/asm/kup.h               |  27 +-
 arch/powerpc/include/asm/nohash/32/kup-8xx.h |  56 +-
 arch/powerpc/include/asm/ppc_asm.h           |  10 -
 arch/powerpc/include/asm/processor.h         |   6 +-
 arch/powerpc/include/asm/ptrace.h            |   6 +-
 arch/powerpc/kernel/asm-offsets.c            |   4 -
 arch/powerpc/kernel/entry_32.S               | 796 ++++---------------
 arch/powerpc/kernel/fpu.S                    |   2 -
 arch/powerpc/kernel/head_32.h                | 198 ++---
 arch/powerpc/kernel/head_40x.S               | 271 ++++---
 arch/powerpc/kernel/head_44x.S               |  10 +-
 arch/powerpc/kernel/head_8xx.S               | 151 ++--
 arch/powerpc/kernel/head_book3s_32.S         | 233 +++---
 arch/powerpc/kernel/head_booke.h             | 203 +++--
 arch/powerpc/kernel/head_fsl_booke.S         |  64 +-
 arch/powerpc/kernel/idle_6xx.S               |  14 +-
 arch/powerpc/kernel/idle_e500.S              |  14 +-
 arch/powerpc/kernel/interrupt.c              |  41 +-
 arch/powerpc/kernel/irq.c                    |   2 +-
 arch/powerpc/kernel/misc_32.S                |  14 -
 arch/powerpc/kernel/process.c                |   6 +-
 arch/powerpc/kernel/setup_32.c               |   2 +-
 arch/powerpc/kernel/traps.c                  |  14 +-
 arch/powerpc/kernel/vector.S                 |   2 -
 arch/powerpc/lib/sstep.c                     |   9 -
 arch/powerpc/mm/book3s32/Makefile            |   1 +
 arch/powerpc/mm/book3s32/hash_low.S          |  14 -
 arch/powerpc/mm/book3s32/kuep.c              |  38 +
 arch/powerpc/mm/fault.c                      |   2 +-
 32 files changed, 887 insertions(+), 1490 deletions(-)
 create mode 100644 arch/powerpc/mm/book3s32/kuep.c

-- 
2.25.0


^ permalink raw reply

* [PATCH v3 01/41] powerpc/traps: Declare unrecoverable_exception() as __noreturn
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

unrecoverable_exception() is never expected to return, most callers
have an infiniteloop in case it returns.

Ensure it really never returns by terminating it with a BUG(), and
declare it __no_return.

It always GCC to really simplify functions calling it. In the exemple
below, it avoids the stack frame in the likely fast path and avoids
code duplication for the exit.

With this patch:

	00000348 <interrupt_exit_kernel_prepare>:
	 348:	81 43 00 84 	lwz     r10,132(r3)
	 34c:	71 48 00 02 	andi.   r8,r10,2
	 350:	41 82 00 2c 	beq     37c <interrupt_exit_kernel_prepare+0x34>
	 354:	71 4a 40 00 	andi.   r10,r10,16384
	 358:	40 82 00 20 	bne     378 <interrupt_exit_kernel_prepare+0x30>
	 35c:	80 62 00 70 	lwz     r3,112(r2)
	 360:	74 63 00 01 	andis.  r3,r3,1
	 364:	40 82 00 28 	bne     38c <interrupt_exit_kernel_prepare+0x44>
	 368:	7d 40 00 a6 	mfmsr   r10
	 36c:	7c 11 13 a6 	mtspr   81,r0
	 370:	7c 12 13 a6 	mtspr   82,r0
	 374:	4e 80 00 20 	blr
	 378:	48 00 00 00 	b       378 <interrupt_exit_kernel_prepare+0x30>
	 37c:	94 21 ff f0 	stwu    r1,-16(r1)
	 380:	7c 08 02 a6 	mflr    r0
	 384:	90 01 00 14 	stw     r0,20(r1)
	 388:	48 00 00 01 	bl      388 <interrupt_exit_kernel_prepare+0x40>
				388: R_PPC_REL24	unrecoverable_exception
	 38c:	38 e2 00 70 	addi    r7,r2,112
	 390:	3d 00 00 01 	lis     r8,1
	 394:	7c c0 38 28 	lwarx   r6,0,r7
	 398:	7c c6 40 78 	andc    r6,r6,r8
	 39c:	7c c0 39 2d 	stwcx.  r6,0,r7
	 3a0:	40 a2 ff f4 	bne     394 <interrupt_exit_kernel_prepare+0x4c>
	 3a4:	38 60 00 01 	li      r3,1
	 3a8:	4b ff ff c0 	b       368 <interrupt_exit_kernel_prepare+0x20>

Without this patch:

	00000348 <interrupt_exit_kernel_prepare>:
	 348:	94 21 ff f0 	stwu    r1,-16(r1)
	 34c:	93 e1 00 0c 	stw     r31,12(r1)
	 350:	7c 7f 1b 78 	mr      r31,r3
	 354:	81 23 00 84 	lwz     r9,132(r3)
	 358:	71 2a 00 02 	andi.   r10,r9,2
	 35c:	41 82 00 34 	beq     390 <interrupt_exit_kernel_prepare+0x48>
	 360:	71 29 40 00 	andi.   r9,r9,16384
	 364:	40 82 00 28 	bne     38c <interrupt_exit_kernel_prepare+0x44>
	 368:	80 62 00 70 	lwz     r3,112(r2)
	 36c:	74 63 00 01 	andis.  r3,r3,1
	 370:	40 82 00 3c 	bne     3ac <interrupt_exit_kernel_prepare+0x64>
	 374:	7d 20 00 a6 	mfmsr   r9
	 378:	7c 11 13 a6 	mtspr   81,r0
	 37c:	7c 12 13 a6 	mtspr   82,r0
	 380:	83 e1 00 0c 	lwz     r31,12(r1)
	 384:	38 21 00 10 	addi    r1,r1,16
	 388:	4e 80 00 20 	blr
	 38c:	48 00 00 00 	b       38c <interrupt_exit_kernel_prepare+0x44>
	 390:	7c 08 02 a6 	mflr    r0
	 394:	90 01 00 14 	stw     r0,20(r1)
	 398:	48 00 00 01 	bl      398 <interrupt_exit_kernel_prepare+0x50>
				398: R_PPC_REL24	unrecoverable_exception
	 39c:	80 01 00 14 	lwz     r0,20(r1)
	 3a0:	81 3f 00 84 	lwz     r9,132(r31)
	 3a4:	7c 08 03 a6 	mtlr    r0
	 3a8:	4b ff ff b8 	b       360 <interrupt_exit_kernel_prepare+0x18>
	 3ac:	39 02 00 70 	addi    r8,r2,112
	 3b0:	3d 40 00 01 	lis     r10,1
	 3b4:	7c e0 40 28 	lwarx   r7,0,r8
	 3b8:	7c e7 50 78 	andc    r7,r7,r10
	 3bc:	7c e0 41 2d 	stwcx.  r7,0,r8
	 3c0:	40 a2 ff f4 	bne     3b4 <interrupt_exit_kernel_prepare+0x6c>
	 3c4:	38 60 00 01 	li      r3,1
	 3c8:	4b ff ff ac 	b       374 <interrupt_exit_kernel_prepare+0x2c>

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/interrupt.h | 2 +-
 arch/powerpc/kernel/traps.c          | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index e8d09a841373..232a4847f596 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -436,7 +436,7 @@ DECLARE_INTERRUPT_HANDLER_NMI(hmi_exception_realmode);
 
 DECLARE_INTERRUPT_HANDLER_ASYNC(TAUException);
 
-void unrecoverable_exception(struct pt_regs *regs);
+void __noreturn unrecoverable_exception(struct pt_regs *regs);
 
 void replay_system_reset(void);
 void replay_soft_interrupts(void);
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index a44a30b0688c..a1c14680ed5a 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -2170,11 +2170,14 @@ DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundException)
  * in the MSR is 0.  This indicates that SRR0/1 are live, and that
  * we therefore lost state by taking this exception.
  */
-void unrecoverable_exception(struct pt_regs *regs)
+void __noreturn unrecoverable_exception(struct pt_regs *regs)
 {
 	pr_emerg("Unrecoverable exception %lx at %lx (msr=%lx)\n",
 		 regs->trap, regs->nip, regs->msr);
 	die("Unrecoverable exception", regs, SIGABRT);
+	/* die() should not return */
+	for (;;)
+		;
 }
 
 #if defined(CONFIG_BOOKE_WDT) || defined(CONFIG_40x)
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 07/41] powerpc/40x: Prepare normal exception handler for enabling MMU early
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

Ensure normal exception handler are able to manage stuff with
MMU enabled. For that we use CONFIG_VMAP_STACK related code
allthough there is no intention to really activate CONFIG_VMAP_STACK
on powerpc 40x for the moment.

40x uses SPRN_DEAR instead of SPRN_DAR and SPRN_ESR instead of
SPRN_DSISR. Take it into account in common macros.

40x MSR value doesn't fit on 15 bits, use LOAD_REG_IMMEDIATE() in
common macros that will be used also with 40x.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/entry_32.S |  2 +-
 arch/powerpc/kernel/head_32.h  | 15 ++++++++++++++-
 arch/powerpc/kernel/head_40x.S | 17 ++++++-----------
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 8528b4c7f9d3..535c55f4393a 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -162,7 +162,7 @@ transfer_to_handler:
 	li	r12,-1			/* clear all pending debug events */
 	mtspr	SPRN_DBSR,r12
 	lis	r11,global_dbcr0@ha
-	tophys(r11,r11)
+	tophys_novmstack r11,r11
 	addi	r11,r11,global_dbcr0@l
 #ifdef CONFIG_SMP
 	lwz	r9,TASK_CPU(r2)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 5d4706c14572..ac6b391f1493 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -22,9 +22,17 @@
 #ifdef CONFIG_VMAP_STACK
 	mfspr	r10, SPRN_SPRG_THREAD
 	.if	\handle_dar_dsisr
+#ifdef CONFIG_40x
+	mfspr	r11, SPRN_DEAR
+#else
 	mfspr	r11, SPRN_DAR
+#endif
 	stw	r11, DAR(r10)
+#ifdef CONFIG_40x
+	mfspr	r11, SPRN_ESR
+#else
 	mfspr	r11, SPRN_DSISR
+#endif
 	stw	r11, DSISR(r10)
 	.endif
 	mfspr	r11, SPRN_SRR0
@@ -61,7 +69,7 @@
 
 .macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
 #ifdef CONFIG_VMAP_STACK
-	li	r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
+	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
 	mtmsr	r11
 	isync
 	mfspr	r11, SPRN_SPRG_SCRATCH2
@@ -158,8 +166,13 @@
 
 .macro save_dar_dsisr_on_stack reg1, reg2, sp
 #ifndef CONFIG_VMAP_STACK
+#ifdef CONFIG_40x
+	mfspr	\reg1, SPRN_DEAR
+	mfspr	\reg2, SPRN_ESR
+#else
 	mfspr	\reg1, SPRN_DAR
 	mfspr	\reg2, SPRN_DSISR
+#endif
 	stw	\reg1, _DAR(\sp)
 	stw	\reg2, _DSISR(\sp)
 #endif
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 1468f38c3860..4bf0aee858eb 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -221,11 +221,8 @@ _ENTRY(saved_ksp_limit)
  * if they can't resolve the lightweight TLB fault.
  */
 	START_EXCEPTION(0x0300,	DataStorage)
-	EXCEPTION_PROLOG
-	mfspr	r5, SPRN_ESR		/* Grab the ESR, save it */
-	stw	r5, _ESR(r11)
-	mfspr	r4, SPRN_DEAR		/* Grab the DEAR, save it */
-	stw	r4, _DEAR(r11)
+	EXCEPTION_PROLOG handle_dar_dsisr=1
+	save_dar_dsisr_on_stack	r4, r5, r11
 	EXC_XFER_LITE(0x300, handle_page_fault)
 
 /*
@@ -244,17 +241,15 @@ _ENTRY(saved_ksp_limit)
 
 /* 0x0600 - Alignment Exception */
 	START_EXCEPTION(0x0600, Alignment)
-	EXCEPTION_PROLOG
-	mfspr	r4,SPRN_DEAR		/* Grab the DEAR and save it */
-	stw	r4,_DEAR(r11)
+	EXCEPTION_PROLOG handle_dar_dsisr=1
+	save_dar_dsisr_on_stack r4, r5, r11
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0x600, alignment_exception)
 
 /* 0x0700 - Program Exception */
 	START_EXCEPTION(0x0700, ProgramCheck)
-	EXCEPTION_PROLOG
-	mfspr	r4,SPRN_ESR		/* Grab the ESR and save it */
-	stw	r4,_ESR(r11)
+	EXCEPTION_PROLOG handle_dar_dsisr=1
+	save_dar_dsisr_on_stack r4, r5, r11
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0x700, program_check_exception)
 
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 05/41] powerpc/40x: Reorder a few instructions in critical exception prolog
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

In order to ease preparation for CONFIG_VMAP_STACK, reorder
a few instruction, especially save r1 into stack frame earlier.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_40x.S | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 067ae1302c1c..5b337bf49bcb 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -119,6 +119,9 @@ _ENTRY(saved_ksp_limit)
 	lwz	r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
 1:	addi	r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm  */
 	tophys(r11,r11)
+	stw	r1,GPR1(r11)
+	stw	r1,0(r11)
+	tovirt(r1,r11)
 	stw	r10,_CCR(r11)		/* save various registers	   */
 	stw	r12,GPR12(r11)
 	stw	r9,GPR9(r11)
@@ -129,14 +132,11 @@ _ENTRY(saved_ksp_limit)
 	stw	r10,GPR10(r11)
 	stw	r12,GPR11(r11)
 	mfspr	r12,SPRN_DEAR		/* save DEAR and ESR in the frame  */
-	stw	r12,_DEAR(r11)		/* since they may have had stuff   */
 	mfspr	r9,SPRN_ESR		/* in them at the point where the  */
+	stw	r12,_DEAR(r11)		/* since they may have had stuff   */
 	stw	r9,_ESR(r11)		/* exception was taken		   */
 	mfspr	r12,SPRN_SRR2
-	stw	r1,GPR1(r11)
 	mfspr	r9,SPRN_SRR3
-	stw	r1,0(r11)
-	tovirt(r1,r11)
 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?)	   */
 	stw	r0,GPR0(r11)
 	lis	r10, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 09/41] powerpc/32: Entry cpu time accounting in C
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

There is no need for this to be in asm,
use the new interrupt entry wrapper.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/interrupt.h |  3 +++
 arch/powerpc/include/asm/ppc_asm.h   | 10 ----------
 arch/powerpc/kernel/entry_32.S       |  1 -
 3 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index b2f69e5dcb50..c35368adbe71 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -32,6 +32,9 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
 #ifdef CONFIG_PPC32
 	if (!arch_irq_disabled_regs(regs))
 		trace_hardirqs_off();
+
+	if (user_mode(regs))
+		account_cpu_user_entry();
 #endif
 	/*
 	 * Book3E reconciles irq soft mask in asm
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 3dceb64fc9af..8998122fc7e2 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -23,18 +23,8 @@
  */
 
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-#define ACCOUNT_CPU_USER_ENTRY(ptr, ra, rb)
 #define ACCOUNT_CPU_USER_EXIT(ptr, ra, rb)
 #else
-#define ACCOUNT_CPU_USER_ENTRY(ptr, ra, rb)				\
-	MFTB(ra);			/* get timebase */		\
-	PPC_LL	rb, ACCOUNT_STARTTIME_USER(ptr);			\
-	PPC_STL	ra, ACCOUNT_STARTTIME(ptr);				\
-	subf	rb,rb,ra;		/* subtract start value */	\
-	PPC_LL	ra, ACCOUNT_USER_TIME(ptr);				\
-	add	ra,ra,rb;		/* add on to user time */	\
-	PPC_STL	ra, ACCOUNT_USER_TIME(ptr);				\
-
 #define ACCOUNT_CPU_USER_EXIT(ptr, ra, rb)				\
 	MFTB(ra);			/* get timebase */		\
 	PPC_LL	rb, ACCOUNT_STARTTIME(ptr);				\
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0f18fe14649c..0f3f1bdd909e 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -152,7 +152,6 @@ transfer_to_handler:
 	lwz	r12,THREAD_DBCR0(r12)
 	andis.	r12,r12,DBCR0_IDM@h
 #endif
-	ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
 #ifdef CONFIG_PPC_BOOK3S_32
 	kuep_lock r11, r12
 #endif
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 08/41] powerpc/32: Reconcile interrupts in C
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

There is no need for this to be in asm anymore,
use the new interrupt entry wrapper.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/interrupt.h |  4 ++
 arch/powerpc/kernel/entry_32.S       | 58 ----------------------------
 2 files changed, 4 insertions(+), 58 deletions(-)

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 232a4847f596..b2f69e5dcb50 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -29,6 +29,10 @@ static inline void booke_restore_dbcr0(void)
 
 static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrupt_state *state)
 {
+#ifdef CONFIG_PPC32
+	if (!arch_irq_disabled_regs(regs))
+		trace_hardirqs_off();
+#endif
 	/*
 	 * Book3E reconciles irq soft mask in asm
 	 */
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 535c55f4393a..0f18fe14649c 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -202,22 +202,6 @@ transfer_to_handler_cont:
 	lwz	r9,4(r9)		/* where to go when done */
 #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
 	mtspr	SPRN_NRI, r0
-#endif
-#ifdef CONFIG_TRACE_IRQFLAGS
-	/*
-	 * When tracing IRQ state (lockdep) we enable the MMU before we call
-	 * the IRQ tracing functions as they might access vmalloc space or
-	 * perform IOs for console output.
-	 *
-	 * To speed up the syscall path where interrupts stay on, let's check
-	 * first if we are changing the MSR value at all.
-	 */
-	tophys_novmstack r12, r1
-	lwz	r12,_MSR(r12)
-	andi.	r12,r12,MSR_EE
-	bne	1f
-
-	/* MSR isn't changing, just transition directly */
 #endif
 	mtspr	SPRN_SRR0,r11
 	mtspr	SPRN_SRR1,r10
@@ -244,48 +228,6 @@ transfer_to_handler_cont:
 _ASM_NOKPROBE_SYMBOL(transfer_to_handler)
 _ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont)
 
-#ifdef CONFIG_TRACE_IRQFLAGS
-1:	/* MSR is changing, re-enable MMU so we can notify lockdep. We need to
-	 * keep interrupts disabled at this point otherwise we might risk
-	 * taking an interrupt before we tell lockdep they are enabled.
-	 */
-	lis	r12,reenable_mmu@h
-	ori	r12,r12,reenable_mmu@l
-	LOAD_REG_IMMEDIATE(r0, MSR_KERNEL)
-	mtspr	SPRN_SRR0,r12
-	mtspr	SPRN_SRR1,r0
-	rfi
-#ifdef CONFIG_40x
-	b .	/* Prevent prefetch past rfi */
-#endif
-
-reenable_mmu:
-	/*
-	 * We save a bunch of GPRs,
-	 * r3 can be different from GPR3(r1) at this point, r9 and r11
-	 * contains the old MSR and handler address respectively,
-	 * r0, r4-r8, r12, CCR, CTR, XER etc... are left
-	 * clobbered as they aren't useful past this point.
-	 */
-
-	stwu	r1,-32(r1)
-	stw	r9,8(r1)
-	stw	r11,12(r1)
-	stw	r3,16(r1)
-
-	/* If we are disabling interrupts (normal case), simply log it with
-	 * lockdep
-	 */
-1:	bl	trace_hardirqs_off
-	lwz	r3,16(r1)
-	lwz	r11,12(r1)
-	lwz	r9,8(r1)
-	addi	r1,r1,32
-	mtctr	r11
-	mtlr	r9
-	bctr				/* jump to handler */
-#endif /* CONFIG_TRACE_IRQFLAGS */
-
 #ifndef CONFIG_VMAP_STACK
 /*
  * On kernel stack overflow, load up an initial stack pointer
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 06/41] powerpc/40x: Prepare for enabling MMU in critical exception prolog
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

In order the enable MMU early in exception prolog, implement
CONFIG_VMAP_STACK principles in critical exception prolog.

There is no intention to use CONFIG_VMAP_STACK on 40x,
but related code will be used to enable MMU early in exception
in a later patch.

Also address (critirq_ctx - PAGE_OFFSET) directly instead of
using tophys() in order to win one instruction.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_40x.S | 40 +++++++++++++++++++++++++++++++---
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 5b337bf49bcb..1468f38c3860 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -89,6 +89,12 @@ _ENTRY(crit_srr0)
 	.space	4
 _ENTRY(crit_srr1)
 	.space	4
+_ENTRY(crit_r1)
+	.space	4
+_ENTRY(crit_dear)
+	.space	4
+_ENTRY(crit_esr)
+	.space	4
 _ENTRY(saved_ksp_limit)
 	.space	4
 
@@ -107,32 +113,60 @@ _ENTRY(saved_ksp_limit)
 	mfspr	r11,SPRN_SRR1
 	stw	r10,crit_srr0@l(0)
 	stw	r11,crit_srr1@l(0)
+#ifdef CONFIG_VMAP_STACK
+	mfspr	r10,SPRN_DEAR
+	mfspr	r11,SPRN_ESR
+	stw	r10,crit_dear@l(0)
+	stw	r11,crit_esr@l(0)
+#endif
 	mfcr	r10			/* save CR in r10 for now	   */
 	mfspr	r11,SPRN_SRR3		/* check whether user or kernel    */
 	andi.	r11,r11,MSR_PR
-	lis	r11,critirq_ctx@ha
-	tophys(r11,r11)
-	lwz	r11,critirq_ctx@l(r11)
+	lis	r11,(critirq_ctx-PAGE_OFFSET)@ha
+	lwz	r11,(critirq_ctx-PAGE_OFFSET)@l(r11)
 	beq	1f
 	/* COMING FROM USER MODE */
 	mfspr	r11,SPRN_SPRG_THREAD	/* if from user, start at top of   */
 	lwz	r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
+#ifdef CONFIG_VMAP_STACK
+1:	stw	r1,crit_r1@l(0)
+	addi	r1,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm  */
+	LOAD_REG_IMMEDIATE(r11,MSR_KERNEL & ~(MSR_IR | MSR_RI))
+	mtmsr	r11
+	isync
+	lwz	r11,crit_r1@l(0)
+	stw	r11,GPR1(r1)
+	stw	r11,0(r1)
+	mr	r11,r1
+#else
 1:	addi	r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm  */
 	tophys(r11,r11)
 	stw	r1,GPR1(r11)
 	stw	r1,0(r11)
 	tovirt(r1,r11)
+#endif
 	stw	r10,_CCR(r11)		/* save various registers	   */
 	stw	r12,GPR12(r11)
 	stw	r9,GPR9(r11)
 	mflr	r10
 	stw	r10,_LINK(r11)
+#ifdef CONFIG_VMAP_STACK
+	lis	r9,PAGE_OFFSET@ha
+	lwz	r10,crit_r10@l(r9)
+	lwz	r12,crit_r11@l(r9)
+#else
 	lwz	r10,crit_r10@l(0)
 	lwz	r12,crit_r11@l(0)
+#endif
 	stw	r10,GPR10(r11)
 	stw	r12,GPR11(r11)
+#ifdef CONFIG_VMAP_STACK
+	lwz	r12,crit_dear@l(r9)
+	lwz	r9,crit_esr@l(r9)
+#else
 	mfspr	r12,SPRN_DEAR		/* save DEAR and ESR in the frame  */
 	mfspr	r9,SPRN_ESR		/* in them at the point where the  */
+#endif
 	stw	r12,_DEAR(r11)		/* since they may have had stuff   */
 	stw	r9,_ESR(r11)		/* exception was taken		   */
 	mfspr	r12,SPRN_SRR2
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 11/41] powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xx
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

8xx has registers SPRN_NRI, SPRN_EID and SPRN_EIE for changing
MSR EE and RI.

Use SPRN_EID in exception prolog to set RI.

On an 8xx, it reduces the null_syscall test by 3 cycles.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index ac6b391f1493..25ee6b26ef5a 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -107,6 +107,8 @@
 #endif
 #ifdef CONFIG_40x
 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
+#elif defined(CONFIG_PPC_8xx)
+	mtspr	SPRN_EID, r2		/* Set MSR_RI */
 #else
 #ifdef CONFIG_VMAP_STACK
 	li	r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 10/41] powerpc/32: Handle bookE debugging in C in exception entry
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

The handling of SPRN_DBCR0 and other registers can easily
be done in C instead of ASM.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/interrupt.h |  2 ++
 arch/powerpc/kernel/entry_32.S       | 23 -----------------------
 2 files changed, 2 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index c35368adbe71..861e6eadc98c 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -65,6 +65,8 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
 	if (user_mode(regs))
 		account_cpu_user_entry();
 #endif
+
+	booke_restore_dbcr0();
 }
 
 /*
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0f3f1bdd909e..4ffbcf3df72e 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -146,32 +146,9 @@ transfer_to_handler:
 	addi	r2, r12, -THREAD
 	addi	r11,r1,STACK_FRAME_OVERHEAD
 	stw	r11,PT_REGS(r12)
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
-	/* Check to see if the dbcr0 register is set up to debug.  Use the
-	   internal debug mode bit to do this. */
-	lwz	r12,THREAD_DBCR0(r12)
-	andis.	r12,r12,DBCR0_IDM@h
-#endif
 #ifdef CONFIG_PPC_BOOK3S_32
 	kuep_lock r11, r12
 #endif
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
-	beq+	3f
-	/* From user and task is ptraced - load up global dbcr0 */
-	li	r12,-1			/* clear all pending debug events */
-	mtspr	SPRN_DBSR,r12
-	lis	r11,global_dbcr0@ha
-	tophys_novmstack r11,r11
-	addi	r11,r11,global_dbcr0@l
-#ifdef CONFIG_SMP
-	lwz	r9,TASK_CPU(r2)
-	slwi	r9,r9,2
-	add	r11,r11,r9
-#endif
-	lwz	r12,0(r11)
-	mtspr	SPRN_DBCR0,r12
-#endif
-
 	b	3f
 
 2:	/* if from kernel, check interrupted DOZE/NAP mode and
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 12/41] powerpc/32: Remove ksp_limit
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

ksp_limit is there to help detect stack overflows.
That is specific to ppc32 as it was removed from ppc64 in
commit cbc9565ee826 ("powerpc: Remove ksp_limit on ppc64").

There are other means for detecting stack overflows.

As ppc64 has proven to not need it, ppc32 should be able to do
without it too.

Lets remove it and simplify exception handling.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/processor.h |  2 -
 arch/powerpc/kernel/asm-offsets.c    |  2 -
 arch/powerpc/kernel/entry_32.S       | 68 +---------------------------
 arch/powerpc/kernel/head_40x.S       |  2 -
 arch/powerpc/kernel/head_booke.h     |  1 -
 arch/powerpc/kernel/misc_32.S        | 14 ------
 arch/powerpc/kernel/process.c        |  3 --
 arch/powerpc/kernel/traps.c          |  9 ----
 arch/powerpc/lib/sstep.c             |  9 ----
 9 files changed, 2 insertions(+), 108 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 8acc3590c971..43cbd9281055 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -144,7 +144,6 @@ struct thread_struct {
 #endif
 #ifdef CONFIG_PPC32
 	void		*pgdir;		/* root of page-table tree */
-	unsigned long	ksp_limit;	/* if ksp <= ksp_limit stack overflow */
 #ifdef CONFIG_PPC_RTAS
 	unsigned long	rtas_sp;	/* stack pointer for when in RTAS */
 #endif
@@ -282,7 +281,6 @@ struct thread_struct {
 #ifdef CONFIG_PPC32
 #define INIT_THREAD { \
 	.ksp = INIT_SP, \
-	.ksp_limit = INIT_SP_LIMIT, \
 	.pgdir = swapper_pg_dir, \
 	.fpexc_mode = MSR_FE0 | MSR_FE1, \
 	SPEFSCR_INIT \
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index f3a662201a9f..73620536c801 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -91,7 +91,6 @@ int main(void)
 	DEFINE(SIGSEGV, SIGSEGV);
 	DEFINE(NMI_MASK, NMI_MASK);
 #else
-	OFFSET(KSP_LIMIT, thread_struct, ksp_limit);
 #ifdef CONFIG_PPC_RTAS
 	OFFSET(RTAS_SP, thread_struct, rtas_sp);
 #endif
@@ -381,7 +380,6 @@ int main(void)
 	DEFINE(_CSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, csrr1));
 	DEFINE(_DSRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr0));
 	DEFINE(_DSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr1));
-	DEFINE(SAVED_KSP_LIMIT, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, saved_ksp_limit));
 #endif
 #endif
 
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 4ffbcf3df72e..66198e6e25e7 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -94,12 +94,6 @@ crit_transfer_to_handler:
 	mfspr	r0,SPRN_SRR1
 	stw	r0,_SRR1(r11)
 
-	/* set the stack limit to the current stack */
-	mfspr	r8,SPRN_SPRG_THREAD
-	lwz	r0,KSP_LIMIT(r8)
-	stw	r0,SAVED_KSP_LIMIT(r11)
-	rlwinm	r0,r1,0,0,(31 - THREAD_SHIFT)
-	stw	r0,KSP_LIMIT(r8)
 	/* fall through */
 _ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
 #endif
@@ -107,12 +101,6 @@ _ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
 #ifdef CONFIG_40x
 	.globl	crit_transfer_to_handler
 crit_transfer_to_handler:
-	/* set the stack limit to the current stack */
-	mfspr	r8,SPRN_SPRG_THREAD
-	lwz	r0,KSP_LIMIT(r8)
-	stw	r0,saved_ksp_limit@l(0)
-	rlwinm	r0,r1,0,0,(31 - THREAD_SHIFT)
-	stw	r0,KSP_LIMIT(r8)
 	/* fall through */
 _ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
 #endif
@@ -151,17 +139,10 @@ transfer_to_handler:
 #endif
 	b	3f
 
-2:	/* if from kernel, check interrupted DOZE/NAP mode and
-         * check for stack overflow
-         */
+	/* if from kernel, check interrupted DOZE/NAP mode */
+2:
 	kuap_save_and_lock r11, r12, r9, r2, r6
 	addi	r2, r12, -THREAD
-#ifndef CONFIG_VMAP_STACK
-	lwz	r9,KSP_LIMIT(r12)
-	cmplw	r1,r9			/* if r1 <= ksp_limit */
-	ble-	stack_ovf		/* then the kernel stack overflowed */
-#endif
-5:
 #if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
 	lwz	r12,TI_LOCAL_FLAGS(r2)
 	mtcrf	0x01,r12
@@ -204,37 +185,6 @@ transfer_to_handler_cont:
 _ASM_NOKPROBE_SYMBOL(transfer_to_handler)
 _ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont)
 
-#ifndef CONFIG_VMAP_STACK
-/*
- * On kernel stack overflow, load up an initial stack pointer
- * and call StackOverflow(regs), which should not return.
- */
-stack_ovf:
-	/* sometimes we use a statically-allocated stack, which is OK. */
-	lis	r12,_end@h
-	ori	r12,r12,_end@l
-	cmplw	r1,r12
-	ble	5b			/* r1 <= &_end is OK */
-	SAVE_NVGPRS(r11)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	lis	r1,init_thread_union@ha
-	addi	r1,r1,init_thread_union@l
-	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
-	lis	r9,StackOverflow@ha
-	addi	r9,r9,StackOverflow@l
-	LOAD_REG_IMMEDIATE(r10,MSR_KERNEL)
-#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(stack_ovf)
-#endif
-
 	.globl	transfer_to_syscall
 transfer_to_syscall:
 	SAVE_NVGPRS(r1)
@@ -815,11 +765,6 @@ _ASM_NOKPROBE_SYMBOL(exc_exit_restart)
 #ifdef CONFIG_40x
 	.globl	ret_from_crit_exc
 ret_from_crit_exc:
-	mfspr	r9,SPRN_SPRG_THREAD
-	lis	r10,saved_ksp_limit@ha;
-	lwz	r10,saved_ksp_limit@l(r10);
-	tovirt(r9,r9);
-	stw	r10,KSP_LIMIT(r9)
 	lis	r9,crit_srr0@ha;
 	lwz	r9,crit_srr0@l(r9);
 	lis	r10,crit_srr1@ha;
@@ -833,9 +778,6 @@ _ASM_NOKPROBE_SYMBOL(ret_from_crit_exc)
 #ifdef CONFIG_BOOKE
 	.globl	ret_from_crit_exc
 ret_from_crit_exc:
-	mfspr	r9,SPRN_SPRG_THREAD
-	lwz	r10,SAVED_KSP_LIMIT(r1)
-	stw	r10,KSP_LIMIT(r9)
 	RESTORE_xSRR(SRR0,SRR1);
 	RESTORE_MMU_REGS;
 	RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
@@ -843,9 +785,6 @@ _ASM_NOKPROBE_SYMBOL(ret_from_crit_exc)
 
 	.globl	ret_from_debug_exc
 ret_from_debug_exc:
-	mfspr	r9,SPRN_SPRG_THREAD
-	lwz	r10,SAVED_KSP_LIMIT(r1)
-	stw	r10,KSP_LIMIT(r9)
 	RESTORE_xSRR(SRR0,SRR1);
 	RESTORE_xSRR(CSRR0,CSRR1);
 	RESTORE_MMU_REGS;
@@ -854,9 +793,6 @@ _ASM_NOKPROBE_SYMBOL(ret_from_debug_exc)
 
 	.globl	ret_from_mcheck_exc
 ret_from_mcheck_exc:
-	mfspr	r9,SPRN_SPRG_THREAD
-	lwz	r10,SAVED_KSP_LIMIT(r1)
-	stw	r10,KSP_LIMIT(r9)
 	RESTORE_xSRR(SRR0,SRR1);
 	RESTORE_xSRR(CSRR0,CSRR1);
 	RESTORE_xSRR(DSRR0,DSRR1);
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 4bf0aee858eb..72e4962902de 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -95,8 +95,6 @@ _ENTRY(crit_dear)
 	.space	4
 _ENTRY(crit_esr)
 	.space	4
-_ENTRY(saved_ksp_limit)
-	.space	4
 
 /*
  * Exception prolog for critical exceptions.  This is a little different
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 47857795f50a..4a5f0c9b652b 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -481,7 +481,6 @@ struct exception_regs {
 	unsigned long csrr1;
 	unsigned long dsrr0;
 	unsigned long dsrr1;
-	unsigned long saved_ksp_limit;
 };
 
 /* ensure this structure is always sized to a multiple of the stack alignment */
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 717e658b90fd..acc410043b96 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -27,23 +27,14 @@
 
 	.text
 
-/*
- * We store the saved ksp_limit in the unused part
- * of the STACK_FRAME_OVERHEAD
- */
 _GLOBAL(call_do_softirq)
 	mflr	r0
 	stw	r0,4(r1)
-	lwz	r10,THREAD+KSP_LIMIT(r2)
-	stw	r3, THREAD+KSP_LIMIT(r2)
 	stwu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
 	mr	r1,r3
-	stw	r10,8(r1)
 	bl	__do_softirq
-	lwz	r10,8(r1)
 	lwz	r1,0(r1)
 	lwz	r0,4(r1)
-	stw	r10,THREAD+KSP_LIMIT(r2)
 	mtlr	r0
 	blr
 
@@ -53,16 +44,11 @@ _GLOBAL(call_do_softirq)
 _GLOBAL(call_do_irq)
 	mflr	r0
 	stw	r0,4(r1)
-	lwz	r10,THREAD+KSP_LIMIT(r2)
-	stw	r4, THREAD+KSP_LIMIT(r2)
 	stwu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r4)
 	mr	r1,r4
-	stw	r10,8(r1)
 	bl	__do_irq
-	lwz	r10,8(r1)
 	lwz	r1,0(r1)
 	lwz	r0,4(r1)
-	stw	r10,THREAD+KSP_LIMIT(r2)
 	mtlr	r0
 	blr
 
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 3231c2df9e26..5d5d64be2679 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1724,9 +1724,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	kregs = (struct pt_regs *) sp;
 	sp -= STACK_FRAME_OVERHEAD;
 	p->thread.ksp = sp;
-#ifdef CONFIG_PPC32
-	p->thread.ksp_limit = (unsigned long)end_of_stack(p);
-#endif
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	for (i = 0; i < nr_wp_slots(); i++)
 		p->thread.ptrace_bps[i] = NULL;
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index a1c14680ed5a..c74e7727860a 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1606,15 +1606,6 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception)
 		bad_page_fault(regs, sig);
 }
 
-DEFINE_INTERRUPT_HANDLER(StackOverflow)
-{
-	pr_crit("Kernel stack overflow in process %s[%d], r1=%lx\n",
-		current->comm, task_pid_nr(current), regs->gpr[1]);
-	debugger(regs);
-	show_regs(regs);
-	panic("kernel stack overflow");
-}
-
 DEFINE_INTERRUPT_HANDLER(stack_overflow_exception)
 {
 	die("Kernel stack overflow", regs, SIGSEGV);
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index c6aebc149d14..739ea6dc461c 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -3086,15 +3086,6 @@ NOKPROBE_SYMBOL(analyse_instr);
  */
 static nokprobe_inline int handle_stack_update(unsigned long ea, struct pt_regs *regs)
 {
-#ifdef CONFIG_PPC32
-	/*
-	 * Check if we will touch kernel stack overflow
-	 */
-	if (ea - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) {
-		printk(KERN_CRIT "Can't kprobe this since kernel stack would overflow.\n");
-		return -EINVAL;
-	}
-#endif /* CONFIG_PPC32 */
 	/*
 	 * Check if we already set since that means we'll
 	 * lose the previous value.
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 13/41] powerpc/32: Always enable data translation in exception prolog
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.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.

That means the data translation is now re-enabled early in
exception prolog in all cases, not only when using VMAP stacks.

While we are touching EXCEPTION_PROLOG macros, remove the
unused for_rtas parameter in EXCEPTION_PROLOG_1.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/processor.h |  4 +-
 arch/powerpc/kernel/asm-offsets.c    |  2 -
 arch/powerpc/kernel/entry_32.S       | 19 +++----
 arch/powerpc/kernel/fpu.S            |  2 -
 arch/powerpc/kernel/head_32.h        | 85 +---------------------------
 arch/powerpc/kernel/head_40x.S       | 23 --------
 arch/powerpc/kernel/head_8xx.S       | 19 +------
 arch/powerpc/kernel/head_book3s_32.S | 47 +--------------
 arch/powerpc/kernel/idle_6xx.S       | 12 +---
 arch/powerpc/kernel/idle_e500.S      |  4 +-
 arch/powerpc/kernel/vector.S         |  2 -
 arch/powerpc/mm/book3s32/hash_low.S  | 14 -----
 12 files changed, 17 insertions(+), 216 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 43cbd9281055..eae16facc390 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -147,11 +147,9 @@ struct thread_struct {
 #ifdef CONFIG_PPC_RTAS
 	unsigned long	rtas_sp;	/* stack pointer for when in RTAS */
 #endif
-#endif
 #if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
 	unsigned long	kuap;		/* opened segments for user access */
 #endif
-#ifdef CONFIG_VMAP_STACK
 	unsigned long	srr0;
 	unsigned long	srr1;
 	unsigned long	dar;
@@ -160,7 +158,7 @@ struct thread_struct {
 	unsigned long	r0, r3, r4, r5, r6, r8, r9, r11;
 	unsigned long	lr, ctr;
 #endif
-#endif
+#endif /* CONFIG_PPC32 */
 	/* Debug Registers */
 	struct debug_reg debug;
 #ifdef CONFIG_PPC_FPU_REGS
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 73620536c801..85ba2b0bc8d8 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -131,7 +131,6 @@ int main(void)
 	OFFSET(KSP_VSID, thread_struct, ksp_vsid);
 #else /* CONFIG_PPC64 */
 	OFFSET(PGDIR, thread_struct, pgdir);
-#ifdef CONFIG_VMAP_STACK
 	OFFSET(SRR0, thread_struct, srr0);
 	OFFSET(SRR1, thread_struct, srr1);
 	OFFSET(DAR, thread_struct, dar);
@@ -148,7 +147,6 @@ int main(void)
 	OFFSET(THLR, thread_struct, lr);
 	OFFSET(THCTR, thread_struct, ctr);
 #endif
-#endif
 #ifdef CONFIG_SPE
 	OFFSET(THREAD_EVR0, thread_struct, evr[0]);
 	OFFSET(THREAD_ACC, thread_struct, acc);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 66198e6e25e7..33e97032ca25 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -129,7 +129,7 @@ transfer_to_handler:
 	stw	r12,_CTR(r11)
 	stw	r2,_XER(r11)
 	mfspr	r12,SPRN_SPRG_THREAD
-	tovirt_vmstack r12, r12
+	tovirt(r12, r12)
 	beq	2f			/* if from user, fix up THREAD.regs */
 	addi	r2, r12, -THREAD
 	addi	r11,r1,STACK_FRAME_OVERHEAD
@@ -153,8 +153,7 @@ transfer_to_handler:
 transfer_to_handler_cont:
 3:
 	mflr	r9
-	tovirt_novmstack r2, r2 	/* set r2 to current */
-	tovirt_vmstack r9, r9
+	tovirt(r9, r9)
 	lwz	r11,0(r9)		/* virtual address of handler */
 	lwz	r9,4(r9)		/* where to go when done */
 #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
@@ -933,7 +932,6 @@ _GLOBAL(enter_rtas)
 	lis	r6,1f@ha	/* physical return address for rtas */
 	addi	r6,r6,1f@l
 	tophys(r6,r6)
-	tophys_novmstack r7, r1
 	lwz	r8,RTASENTRY(r4)
 	lwz	r4,RTASBASE(r4)
 	mfmsr	r9
@@ -942,22 +940,19 @@ _GLOBAL(enter_rtas)
 	mtmsr	r0	/* disable interrupts so SRR0/1 don't get trashed */
 	li	r9,MSR_KERNEL & ~(MSR_IR|MSR_DR)
 	mtlr	r6
-	stw	r7, THREAD + RTAS_SP(r2)
+	stw	r1, THREAD + RTAS_SP(r2)
 	mtspr	SPRN_SRR0,r8
 	mtspr	SPRN_SRR1,r9
 	rfi
-1:	tophys_novmstack r9, r1
-#ifdef CONFIG_VMAP_STACK
+1:
 	li	r0, MSR_KERNEL & ~MSR_IR	/* can take DTLB miss */
 	mtmsr	r0
 	isync
-#endif
-	lwz	r8,INT_FRAME_SIZE+4(r9)	/* get return address */
-	lwz	r9,8(r9)	/* original msr value */
+	lwz	r8,INT_FRAME_SIZE+4(r1)	/* get return address */
+	lwz	r9,8(r1)	/* original msr value */
 	addi	r1,r1,INT_FRAME_SIZE
 	li	r0,0
-	tophys_novmstack r7, r2
-	stw	r0, THREAD + RTAS_SP(r7)
+	stw	r0, THREAD + RTAS_SP(r2)
 	mtspr	SPRN_SRR0,r8
 	mtspr	SPRN_SRR1,r9
 	rfi			/* return to caller */
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 3ff9a8fafa46..2c57ece6671c 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -92,9 +92,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 	/* enable use of FP after return */
 #ifdef CONFIG_PPC32
 	mfspr	r5,SPRN_SPRG_THREAD	/* current task's THREAD (phys) */
-#ifdef CONFIG_VMAP_STACK
 	tovirt(r5, r5)
-#endif
 	lwz	r4,THREAD_FPEXC_MODE(r5)
 	ori	r9,r9,MSR_FP		/* enable FP for current */
 	or	r9,r9,r4
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 25ee6b26ef5a..1b707755c68e 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -19,7 +19,6 @@
 .macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0
 	mtspr	SPRN_SPRG_SCRATCH0,r10
 	mtspr	SPRN_SPRG_SCRATCH1,r11
-#ifdef CONFIG_VMAP_STACK
 	mfspr	r10, SPRN_SPRG_THREAD
 	.if	\handle_dar_dsisr
 #ifdef CONFIG_40x
@@ -37,17 +36,13 @@
 	.endif
 	mfspr	r11, SPRN_SRR0
 	stw	r11, SRR0(r10)
-#endif
 	mfspr	r11, SPRN_SRR1		/* check whether user or kernel */
-#ifdef CONFIG_VMAP_STACK
 	stw	r11, SRR1(r10)
-#endif
 	mfcr	r10
 	andi.	r11, r11, MSR_PR
 .endm
 
-.macro EXCEPTION_PROLOG_1 for_rtas=0
-#ifdef CONFIG_VMAP_STACK
+.macro EXCEPTION_PROLOG_1
 	mtspr	SPRN_SPRG_SCRATCH2,r1
 	subi	r1, r1, INT_FRAME_SIZE		/* use r1 if kernel */
 	beq	1f
@@ -55,20 +50,13 @@
 	lwz	r1,TASK_STACK-THREAD(r1)
 	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
 1:
+#ifdef CONFIG_VMAP_STACK
 	mtcrf	0x3f, r1
 	bt	32 - THREAD_ALIGN_SHIFT, stack_overflow
-#else
-	subi	r11, r1, INT_FRAME_SIZE		/* use r1 if kernel */
-	beq	1f
-	mfspr	r11,SPRN_SPRG_THREAD
-	lwz	r11,TASK_STACK-THREAD(r11)
-	addi	r11, r11, THREAD_SIZE - INT_FRAME_SIZE
-1:	tophys(r11, r11)
 #endif
 .endm
 
 .macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
-#ifdef CONFIG_VMAP_STACK
 	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
 	mtmsr	r11
 	isync
@@ -76,11 +64,6 @@
 	stw	r11,GPR1(r1)
 	stw	r11,0(r1)
 	mr	r11, r1
-#else
-	stw	r1,GPR1(r11)
-	stw	r1,0(r11)
-	tovirt(r1, r11)		/* set new kernel sp */
-#endif
 	stw	r10,_CCR(r11)		/* save registers */
 	stw	r12,GPR12(r11)
 	stw	r9,GPR9(r11)
@@ -90,7 +73,6 @@
 	stw	r12,GPR11(r11)
 	mflr	r10
 	stw	r10,_LINK(r11)
-#ifdef CONFIG_VMAP_STACK
 	mfspr	r12, SPRN_SPRG_THREAD
 	tovirt(r12, r12)
 	.if	\handle_dar_dsisr
@@ -101,20 +83,12 @@
 	.endif
 	lwz	r9, SRR1(r12)
 	lwz	r12, SRR0(r12)
-#else
-	mfspr	r12,SPRN_SRR0
-	mfspr	r9,SPRN_SRR1
-#endif
 #ifdef CONFIG_40x
 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
 #elif defined(CONFIG_PPC_8xx)
 	mtspr	SPRN_EID, r2		/* Set MSR_RI */
 #else
-#ifdef CONFIG_VMAP_STACK
 	li	r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
-#else
-	li	r10,MSR_KERNEL & ~(MSR_IR|MSR_DR) /* can take exceptions */
-#endif
 	mtmsr	r10			/* (except for mach check in rtas) */
 #endif
 	stw	r0,GPR0(r11)
@@ -166,59 +140,6 @@
 	b	transfer_to_syscall		/* jump to handler */
 .endm
 
-.macro save_dar_dsisr_on_stack reg1, reg2, sp
-#ifndef CONFIG_VMAP_STACK
-#ifdef CONFIG_40x
-	mfspr	\reg1, SPRN_DEAR
-	mfspr	\reg2, SPRN_ESR
-#else
-	mfspr	\reg1, SPRN_DAR
-	mfspr	\reg2, SPRN_DSISR
-#endif
-	stw	\reg1, _DAR(\sp)
-	stw	\reg2, _DSISR(\sp)
-#endif
-.endm
-
-.macro get_and_save_dar_dsisr_on_stack reg1, reg2, sp
-#ifdef CONFIG_VMAP_STACK
-	lwz	\reg1, _DAR(\sp)
-	lwz	\reg2, _DSISR(\sp)
-#else
-	save_dar_dsisr_on_stack \reg1, \reg2, \sp
-#endif
-.endm
-
-.macro tovirt_vmstack dst, src
-#ifdef CONFIG_VMAP_STACK
-	tovirt(\dst, \src)
-#else
-	.ifnc	\dst, \src
-	mr	\dst, \src
-	.endif
-#endif
-.endm
-
-.macro tovirt_novmstack dst, src
-#ifndef CONFIG_VMAP_STACK
-	tovirt(\dst, \src)
-#else
-	.ifnc	\dst, \src
-	mr	\dst, \src
-	.endif
-#endif
-.endm
-
-.macro tophys_novmstack dst, src
-#ifndef CONFIG_VMAP_STACK
-	tophys(\dst, \src)
-#else
-	.ifnc	\dst, \src
-	mr	\dst, \src
-	.endif
-#endif
-.endm
-
 /*
  * Note: code which follows this uses cr0.eq (set if from kernel),
  * r11, r12 (SRR0), and r9 (SRR1).
@@ -266,7 +187,6 @@
 			  ret_from_except)
 
 .macro vmap_stack_overflow_exception
-#ifdef CONFIG_VMAP_STACK
 #ifdef CONFIG_SMP
 	mfspr	r1, SPRN_SPRG_THREAD
 	lwz	r1, TASK_CPU - THREAD(r1)
@@ -285,7 +205,6 @@
 	SAVE_NVGPRS(r11)
 	addi	r3, r1, STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0, stack_overflow_exception)
-#endif
 .endm
 
 #endif /* __HEAD_32_H__ */
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 72e4962902de..7da673ec63ef 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -111,12 +111,10 @@ _ENTRY(crit_esr)
 	mfspr	r11,SPRN_SRR1
 	stw	r10,crit_srr0@l(0)
 	stw	r11,crit_srr1@l(0)
-#ifdef CONFIG_VMAP_STACK
 	mfspr	r10,SPRN_DEAR
 	mfspr	r11,SPRN_ESR
 	stw	r10,crit_dear@l(0)
 	stw	r11,crit_esr@l(0)
-#endif
 	mfcr	r10			/* save CR in r10 for now	   */
 	mfspr	r11,SPRN_SRR3		/* check whether user or kernel    */
 	andi.	r11,r11,MSR_PR
@@ -126,7 +124,6 @@ _ENTRY(crit_esr)
 	/* COMING FROM USER MODE */
 	mfspr	r11,SPRN_SPRG_THREAD	/* if from user, start at top of   */
 	lwz	r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
-#ifdef CONFIG_VMAP_STACK
 1:	stw	r1,crit_r1@l(0)
 	addi	r1,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm  */
 	LOAD_REG_IMMEDIATE(r11,MSR_KERNEL & ~(MSR_IR | MSR_RI))
@@ -136,35 +133,18 @@ _ENTRY(crit_esr)
 	stw	r11,GPR1(r1)
 	stw	r11,0(r1)
 	mr	r11,r1
-#else
-1:	addi	r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm  */
-	tophys(r11,r11)
-	stw	r1,GPR1(r11)
-	stw	r1,0(r11)
-	tovirt(r1,r11)
-#endif
 	stw	r10,_CCR(r11)		/* save various registers	   */
 	stw	r12,GPR12(r11)
 	stw	r9,GPR9(r11)
 	mflr	r10
 	stw	r10,_LINK(r11)
-#ifdef CONFIG_VMAP_STACK
 	lis	r9,PAGE_OFFSET@ha
 	lwz	r10,crit_r10@l(r9)
 	lwz	r12,crit_r11@l(r9)
-#else
-	lwz	r10,crit_r10@l(0)
-	lwz	r12,crit_r11@l(0)
-#endif
 	stw	r10,GPR10(r11)
 	stw	r12,GPR11(r11)
-#ifdef CONFIG_VMAP_STACK
 	lwz	r12,crit_dear@l(r9)
 	lwz	r9,crit_esr@l(r9)
-#else
-	mfspr	r12,SPRN_DEAR		/* save DEAR and ESR in the frame  */
-	mfspr	r9,SPRN_ESR		/* in them at the point where the  */
-#endif
 	stw	r12,_DEAR(r11)		/* since they may have had stuff   */
 	stw	r9,_ESR(r11)		/* exception was taken		   */
 	mfspr	r12,SPRN_SRR2
@@ -220,7 +200,6 @@ _ENTRY(crit_esr)
  */
 	START_EXCEPTION(0x0300,	DataStorage)
 	EXCEPTION_PROLOG handle_dar_dsisr=1
-	save_dar_dsisr_on_stack	r4, r5, r11
 	EXC_XFER_LITE(0x300, handle_page_fault)
 
 /*
@@ -240,14 +219,12 @@ _ENTRY(crit_esr)
 /* 0x0600 - Alignment Exception */
 	START_EXCEPTION(0x0600, Alignment)
 	EXCEPTION_PROLOG handle_dar_dsisr=1
-	save_dar_dsisr_on_stack r4, r5, r11
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0x600, alignment_exception)
 
 /* 0x0700 - Program Exception */
 	START_EXCEPTION(0x0700, ProgramCheck)
 	EXCEPTION_PROLOG handle_dar_dsisr=1
-	save_dar_dsisr_on_stack r4, r5, r11
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0x700, program_check_exception)
 
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 46dff3f9c31f..792e2fd86479 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -124,7 +124,6 @@ instruction_counter:
 	. = 0x200
 MachineCheck:
 	EXCEPTION_PROLOG handle_dar_dsisr=1
-	save_dar_dsisr_on_stack r4, r5, r11
 	li	r6, RPN_PATTERN
 	mtspr	SPRN_DAR, r6	/* Tag DAR, to be used in DTLB Error */
 	addi r3,r1,STACK_FRAME_OVERHEAD
@@ -137,7 +136,6 @@ MachineCheck:
 	. = 0x600
 Alignment:
 	EXCEPTION_PROLOG handle_dar_dsisr=1
-	save_dar_dsisr_on_stack r4, r5, r11
 	li	r6, RPN_PATTERN
 	mtspr	SPRN_DAR, r6	/* Tag DAR, to be used in DTLB Error */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
@@ -333,21 +331,16 @@ DataTLBError:
 	cmpwi	cr1, r11, RPN_PATTERN
 	beq-	cr1, FixupDAR	/* must be a buggy dcbX, icbi insn. */
 DARFixed:/* Return from dcbx instruction bug workaround */
-#ifdef CONFIG_VMAP_STACK
 	li	r11, RPN_PATTERN
 	mtspr	SPRN_DAR, r11	/* Tag DAR, to be used in DTLB Error */
-#endif
 	EXCEPTION_PROLOG_1
 	EXCEPTION_PROLOG_2 handle_dar_dsisr=1
-	get_and_save_dar_dsisr_on_stack r4, r5, r11
+	lwz	r4, _DAR(r11)
+	lwz	r5, _DSISR(r11)
 	andis.	r10,r5,DSISR_NOHPTE@h
 	beq+	.Ldtlbie
 	tlbie	r4
 .Ldtlbie:
-#ifndef CONFIG_VMAP_STACK
-	li	r10,RPN_PATTERN
-	mtspr	SPRN_DAR,r10	/* Tag DAR, to be used in DTLB Error */
-#endif
 	/* 0x300 is DataAccess exception, needed by bad_page_fault() */
 	EXC_XFER_LITE(0x300, handle_page_fault)
 
@@ -364,10 +357,6 @@ do_databreakpoint:
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	mfspr	r4,SPRN_BAR
 	stw	r4,_DAR(r11)
-#ifndef CONFIG_VMAP_STACK
-	mfspr	r5,SPRN_DSISR
-	stw	r5,_DSISR(r11)
-#endif
 	EXC_XFER_STD(0x1c00, do_break)
 
 	. = 0x1c00
@@ -510,14 +499,10 @@ FixupDAR:/* Entry point for dcbx workaround. */
 152:
 	mfdar	r11
 	mtctr	r11			/* restore ctr reg from DAR */
-#ifdef CONFIG_VMAP_STACK
 	mfspr	r11, SPRN_SPRG_THREAD
 	stw	r10, DAR(r11)
 	mfspr	r10, SPRN_DSISR
 	stw	r10, DSISR(r11)
-#else
-	mtdar	r10			/* save fault EA to DAR */
-#endif
 	mfspr	r10,SPRN_M_TW
 	b	DARFixed		/* Go back to normal TLB handling */
 
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 565e84e20a72..1cf7bd5d5ec1 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -260,21 +260,14 @@ __secondary_hold_acknowledge:
 MachineCheck:
 	EXCEPTION_PROLOG_0
 #ifdef CONFIG_PPC_CHRP
-#ifdef CONFIG_VMAP_STACK
 	mtspr	SPRN_SPRG_SCRATCH2,r1
 	mfspr	r1, SPRN_SPRG_THREAD
 	lwz	r1, RTAS_SP(r1)
 	cmpwi	cr1, r1, 0
 	bne	cr1, 7f
 	mfspr	r1, SPRN_SPRG_SCRATCH2
-#else
-	mfspr	r11, SPRN_SPRG_THREAD
-	lwz	r11, RTAS_SP(r11)
-	cmpwi	cr1, r11, 0
-	bne	cr1, 7f
-#endif
 #endif /* CONFIG_PPC_CHRP */
-	EXCEPTION_PROLOG_1 for_rtas=1
+	EXCEPTION_PROLOG_1
 7:	EXCEPTION_PROLOG_2
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 #ifdef CONFIG_PPC_CHRP
@@ -288,7 +281,6 @@ MachineCheck:
 	. = 0x300
 	DO_KVM  0x300
 DataAccess:
-#ifdef CONFIG_VMAP_STACK
 #ifdef CONFIG_PPC_BOOK3S_604
 BEGIN_MMU_FTR_SECTION
 	mtspr	SPRN_SPRG_SCRATCH2,r10
@@ -310,29 +302,11 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
 1:	EXCEPTION_PROLOG_0 handle_dar_dsisr=1
 	EXCEPTION_PROLOG_1
 	b	handle_page_fault_tramp_1
-#else	/* CONFIG_VMAP_STACK */
-	EXCEPTION_PROLOG handle_dar_dsisr=1
-	get_and_save_dar_dsisr_on_stack	r4, r5, r11
-#ifdef CONFIG_PPC_BOOK3S_604
-BEGIN_MMU_FTR_SECTION
-	andis.	r0, r5, (DSISR_BAD_FAULT_32S | DSISR_DABRMATCH)@h
-	bne	handle_page_fault_tramp_2	/* if not, try to put a PTE */
-	rlwinm	r3, r5, 32 - 15, 21, 21		/* DSISR_STORE -> _PAGE_RW */
-	bl	hash_page
-	b	handle_page_fault_tramp_1
-MMU_FTR_SECTION_ELSE
-#endif
-	b	handle_page_fault_tramp_2
-#ifdef CONFIG_PPC_BOOK3S_604
-ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
-#endif
-#endif	/* CONFIG_VMAP_STACK */
 
 /* Instruction access exception. */
 	. = 0x400
 	DO_KVM  0x400
 InstructionAccess:
-#ifdef CONFIG_VMAP_STACK
 	mtspr	SPRN_SPRG_SCRATCH0,r10
 	mtspr	SPRN_SPRG_SCRATCH1,r11
 	mfspr	r10, SPRN_SPRG_THREAD
@@ -353,18 +327,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
 
 	EXCEPTION_PROLOG_1
 	EXCEPTION_PROLOG_2
-#else	/* CONFIG_VMAP_STACK */
-	EXCEPTION_PROLOG
-	andis.	r0,r9,SRR1_ISI_NOPT@h	/* no pte found? */
-	beq	1f			/* if so, try to put a PTE */
-	li	r3,0			/* into the hash table */
-	mr	r4,r12			/* SRR0 is fault address */
-#ifdef CONFIG_PPC_BOOK3S_604
-BEGIN_MMU_FTR_SECTION
-	bl	hash_page
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
-#endif
-#endif	/* CONFIG_VMAP_STACK */
 	andis.	r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
 	stw	r5, _DSISR(r11)
 	stw	r12, _DAR(r11)
@@ -378,7 +340,6 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
 	DO_KVM  0x600
 Alignment:
 	EXCEPTION_PROLOG handle_dar_dsisr=1
-	save_dar_dsisr_on_stack r4, r5, r11
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	b	alignment_exception_tramp
 
@@ -689,18 +650,13 @@ alignment_exception_tramp:
 	EXC_XFER_STD(0x600, alignment_exception)
 
 handle_page_fault_tramp_1:
-#ifdef CONFIG_VMAP_STACK
 	EXCEPTION_PROLOG_2 handle_dar_dsisr=1
-#endif
 	lwz	r5, _DSISR(r11)
-	/* fall through */
-handle_page_fault_tramp_2:
 	andis.	r0, r5, DSISR_DABRMATCH@h
 	bne-	1f
 	EXC_XFER_LITE(0x300, handle_page_fault)
 1:	EXC_XFER_STD(0x300, do_break)
 
-#ifdef CONFIG_VMAP_STACK
 #ifdef CONFIG_PPC_BOOK3S_604
 .macro save_regs_thread		thread
 	stw	r0, THR0(\thread)
@@ -775,6 +731,7 @@ fast_hash_page_return:
 	rfi
 #endif /* CONFIG_PPC_BOOK3S_604 */
 
+#ifdef CONFIG_VMAP_STACK
 stack_overflow:
 	vmap_stack_overflow_exception
 #endif
diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 69df840f7253..153366e178c4 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -145,9 +145,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 
 /*
  * Return from NAP/DOZE mode, restore some CPU specific registers,
- * we are called with DR/IR still off and r2 containing physical
- * address of current.  R11 points to the exception frame (physical
- * address).  We have to preserve r10.
+ * R11 points to the exception frame. We have to preserve r10.
  */
 _GLOBAL(power_save_ppc32_restore)
 	lwz	r9,_LINK(r11)		/* interrupted in ppc6xx_idle: */
@@ -166,11 +164,7 @@ BEGIN_FTR_SECTION
 	mfspr	r9,SPRN_HID0
 	andis.	r9,r9,HID0_NAP@h
 	beq	1f
-#ifdef CONFIG_VMAP_STACK
 	addis	r9, r11, nap_save_msscr0@ha
-#else
-	addis	r9,r11,(nap_save_msscr0-KERNELBASE)@ha
-#endif
 	lwz	r9,nap_save_msscr0@l(r9)
 	mtspr	SPRN_MSSCR0, r9
 	sync
@@ -178,11 +172,7 @@ BEGIN_FTR_SECTION
 1:
 END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR)
 BEGIN_FTR_SECTION
-#ifdef CONFIG_VMAP_STACK
 	addis	r9, r11, nap_save_hid1@ha
-#else
-	addis	r9,r11,(nap_save_hid1-KERNELBASE)@ha
-#endif
 	lwz	r9,nap_save_hid1@l(r9)
 	mtspr	SPRN_HID1, r9
 END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX)
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 72c85b6f3898..7795727e7f08 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -74,8 +74,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
 
 /*
  * Return from NAP/DOZE mode, restore some CPU specific registers,
- * r2 containing physical address of current.
- * r11 points to the exception frame (physical address).
+ * r2 containing address of current.
+ * r11 points to the exception frame.
  * We have to preserve r10.
  */
 _GLOBAL(power_save_ppc32_restore)
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index 801dc28fdcca..f5a52f444e36 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -67,9 +67,7 @@ _GLOBAL(load_up_altivec)
 #ifdef CONFIG_PPC32
 	mfspr	r5,SPRN_SPRG_THREAD		/* current task's THREAD (phys) */
 	oris	r9,r9,MSR_VEC@h
-#ifdef CONFIG_VMAP_STACK
 	tovirt(r5, r5)
-#endif
 #else
 	ld	r4,PACACURRENT(r13)
 	addi	r5,r4,THREAD		/* Get THREAD */
diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index 0e6dc830c38b..fb4233a5bdf7 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -140,10 +140,6 @@ _GLOBAL(hash_page)
 	bne-	.Lretry			/* retry if someone got there first */
 
 	mfsrin	r3,r4			/* get segment reg for segment */
-#ifndef CONFIG_VMAP_STACK
-	mfctr	r0
-	stw	r0,_CTR(r11)
-#endif
 	bl	create_hpte		/* add the hash table entry */
 
 #ifdef CONFIG_SMP
@@ -152,17 +148,7 @@ _GLOBAL(hash_page)
 	li	r0,0
 	stw	r0, (mmu_hash_lock - PAGE_OFFSET)@l(r8)
 #endif
-
-#ifdef CONFIG_VMAP_STACK
 	b	fast_hash_page_return
-#else
-	/* Return from the exception */
-	lwz	r5,_CTR(r11)
-	mtctr	r5
-	lwz	r0,GPR0(r11)
-	lwz	r8,GPR8(r11)
-	b	fast_exception_return
-#endif
 
 #ifdef CONFIG_SMP
 .Lhash_page_out:
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 14/41] powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

8xx requires to tag the DAR with a magic value in order to
fixup DAR on faults generated by 'dcbX', as the 8xx
forgets to update the DAR for those faults.

Do the tagging as early as possible, that is before enabling MMU.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h  |  6 ++++++
 arch/powerpc/kernel/head_8xx.S | 18 ++++++------------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 1b707755c68e..910f86642eec 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -57,6 +57,12 @@
 .endm
 
 .macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
+#ifdef CONFIG_PPC_8xx
+	.if	\handle_dar_dsisr
+	li	r11, RPN_PATTERN
+	mtspr	SPRN_DAR, r11	/* Tag DAR, to be used in DTLB Error */
+	.endif
+#endif
 	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
 	mtmsr	r11
 	isync
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 792e2fd86479..cdbfa9d41353 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -30,6 +30,12 @@
 #include <asm/export.h>
 #include <asm/code-patching-asm.h>
 
+/*
+ * Value for the bits that have fixed value in RPN entries.
+ * Also used for tagging DAR for DTLBerror.
+ */
+#define RPN_PATTERN	0x00f0
+
 #include "head_32.h"
 
 .macro compare_to_kernel_boundary scratch, addr
@@ -42,12 +48,6 @@
 #endif
 .endm
 
-/*
- * Value for the bits that have fixed value in RPN entries.
- * Also used for tagging DAR for DTLBerror.
- */
-#define RPN_PATTERN	0x00f0
-
 #define PAGE_SHIFT_512K		19
 #define PAGE_SHIFT_8M		23
 
@@ -124,8 +124,6 @@ instruction_counter:
 	. = 0x200
 MachineCheck:
 	EXCEPTION_PROLOG handle_dar_dsisr=1
-	li	r6, RPN_PATTERN
-	mtspr	SPRN_DAR, r6	/* Tag DAR, to be used in DTLB Error */
 	addi r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0x200, machine_check_exception)
 
@@ -136,8 +134,6 @@ MachineCheck:
 	. = 0x600
 Alignment:
 	EXCEPTION_PROLOG handle_dar_dsisr=1
-	li	r6, RPN_PATTERN
-	mtspr	SPRN_DAR, r6	/* Tag DAR, to be used in DTLB Error */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	b	.Lalignment_exception_ool
 
@@ -331,8 +327,6 @@ DataTLBError:
 	cmpwi	cr1, r11, RPN_PATTERN
 	beq-	cr1, FixupDAR	/* must be a buggy dcbX, icbi insn. */
 DARFixed:/* Return from dcbx instruction bug workaround */
-	li	r11, RPN_PATTERN
-	mtspr	SPRN_DAR, r11	/* Tag DAR, to be used in DTLB Error */
 	EXCEPTION_PROLOG_1
 	EXCEPTION_PROLOG_2 handle_dar_dsisr=1
 	lwz	r4, _DAR(r11)
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 15/41] powerpc/32: Enable instruction translation at the same time as data translation
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.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.

In syscall handler, 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. Just update msr.

Also update comment in power_save_ppc32_restore().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/entry_32.S   | 30 ++++++++++++------------------
 arch/powerpc/kernel/head_32.h    | 13 ++++++++-----
 arch/powerpc/kernel/head_40x.S   | 10 +++++++---
 arch/powerpc/kernel/head_booke.h |  6 ++++--
 4 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 33e97032ca25..01a064c8a96a 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -153,19 +153,11 @@ transfer_to_handler:
 transfer_to_handler_cont:
 3:
 	mflr	r9
-	tovirt(r9, r9)
 	lwz	r11,0(r9)		/* virtual address of handler */
 	lwz	r9,4(r9)		/* where to go when done */
-#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
-	mtspr	SPRN_NRI, r0
-#endif
-	mtspr	SPRN_SRR0,r11
-	mtspr	SPRN_SRR1,r10
+	mtctr	r11
 	mtlr	r9
-	rfi				/* jump to handler, enable MMU */
-#ifdef CONFIG_40x
-	b .	/* Prevent prefetch past rfi */
-#endif
+	bctr				/* jump to handler */
 
 #if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
 4:	rlwinm	r12,r12,0,~_TLF_NAPPING
@@ -444,8 +436,6 @@ fee_restarts:
 	li	r10,-1
 	stw	r10,_TRAP(r11)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	lis	r10,MSR_KERNEL@h
-	ori	r10,r10,MSR_KERNEL@l
 	bl	transfer_to_handler_full
 	.long	unrecoverable_exception
 	.long	ret_from_except
@@ -945,16 +935,20 @@ _GLOBAL(enter_rtas)
 	mtspr	SPRN_SRR1,r9
 	rfi
 1:
-	li	r0, MSR_KERNEL & ~MSR_IR	/* can take DTLB miss */
-	mtmsr	r0
-	isync
+	lis	r8, 1f@h
+	ori	r8, r8, 1f@l
+	LOAD_REG_IMMEDIATE(r9,MSR_KERNEL)
+	mtspr	SPRN_SRR0,r8
+	mtspr	SPRN_SRR1,r9
+	rfi			/* Reactivate MMU translation */
+1:
 	lwz	r8,INT_FRAME_SIZE+4(r1)	/* get return address */
 	lwz	r9,8(r1)	/* original msr value */
 	addi	r1,r1,INT_FRAME_SIZE
 	li	r0,0
 	stw	r0, THREAD + RTAS_SP(r2)
-	mtspr	SPRN_SRR0,r8
-	mtspr	SPRN_SRR1,r9
-	rfi			/* return to caller */
+	mtlr	r8
+	mtmsr	r9
+	blr			/* return to caller */
 _ASM_NOKPROBE_SYMBOL(enter_rtas)
 #endif /* CONFIG_PPC_RTAS */
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 910f86642eec..88b02bd91e8e 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -63,10 +63,14 @@
 	mtspr	SPRN_DAR, r11	/* Tag DAR, to be used in DTLB Error */
 	.endif
 #endif
-	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
-	mtmsr	r11
-	isync
+	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~MSR_RI) /* re-enable MMU */
+	mtspr	SPRN_SRR1, r11
+	lis	r11, 1f@h
+	ori	r11, r11, 1f@l
+	mtspr	SPRN_SRR0, r11
 	mfspr	r11, SPRN_SPRG_SCRATCH2
+	rfi
+1:
 	stw	r11,GPR1(r1)
 	stw	r11,0(r1)
 	mr	r11, r1
@@ -94,7 +98,7 @@
 #elif defined(CONFIG_PPC_8xx)
 	mtspr	SPRN_EID, r2		/* Set MSR_RI */
 #else
-	li	r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
+	li	r10, MSR_KERNEL		/* can take exceptions */
 	mtmsr	r10			/* (except for mach check in rtas) */
 #endif
 	stw	r0,GPR0(r11)
@@ -179,7 +183,6 @@
 #define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret)		\
 	li	r10,trap;					\
 	stw	r10,_TRAP(r11);					\
-	LOAD_REG_IMMEDIATE(r10, msr);				\
 	bl	tfer;						\
 	.long	hdlr;						\
 	.long	ret
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 7da673ec63ef..55fa99c5085c 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -126,9 +126,13 @@ _ENTRY(crit_esr)
 	lwz	r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
 1:	stw	r1,crit_r1@l(0)
 	addi	r1,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm  */
-	LOAD_REG_IMMEDIATE(r11,MSR_KERNEL & ~(MSR_IR | MSR_RI))
-	mtmsr	r11
-	isync
+	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)) /* re-enable MMU */
+	mtspr	SPRN_SRR1, r11
+	lis	r11, 1f@h
+	ori	r11, r11, 1f@l
+	mtspr	SPRN_SRR0, r11
+	rfi
+1:
 	lwz	r11,crit_r1@l(0)
 	stw	r11,GPR1(r1)
 	stw	r11,0(r1)
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 4a5f0c9b652b..f712b9bc6d62 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -53,6 +53,8 @@ END_BTB_FLUSH_SECTION
 	mfspr	r11, SPRN_SRR1;		                                     \
 	DO_KVM	BOOKE_INTERRUPT_##intno SPRN_SRR1;			     \
 	andi.	r11, r11, MSR_PR;	/* check whether user or kernel    */\
+	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL);				\
+	mtmsr	r11;							\
 	mr	r11, r1;						     \
 	beq	1f;							     \
 	BOOKE_CLEAR_BTB(r11)						\
@@ -192,6 +194,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
 	DO_KVM	BOOKE_INTERRUPT_##intno exc_level_srr1;		             \
 	BOOKE_CLEAR_BTB(r10)						\
 	andi.	r11,r11,MSR_PR;						     \
+	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE));	\
+	mtmsr	r11;							\
 	mfspr	r11,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
 	lwz	r11, TASK_STACK - THREAD(r11); /* this thread's kernel stack */\
 	addi	r11,r11,EXC_LVL_FRAME_OVERHEAD;	/* allocate stack frame    */\
@@ -282,8 +286,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
 #define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret)	\
 	li	r10,trap;					\
 	stw	r10,_TRAP(r11);					\
-	lis	r10,msr@h;					\
-	ori	r10,r10,msr@l;					\
 	bl	tfer;		 				\
 	.long	hdlr;						\
 	.long	ret
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 16/41] powerpc/32: Statically initialise first emergency context
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

The check of the emergency context initialisation in
vmap_stack_overflow is buggy for the SMP case, as it
compares r1 with 0 while in the SMP case r1 is offseted
by the CPU id.

Instead of fixing it, just perform static initialisation
of the first emergency context.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h  | 6 +-----
 arch/powerpc/kernel/setup_32.c | 2 +-
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 88b02bd91e8e..15c6fc7cbbf5 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -205,11 +205,7 @@
 	lis	r1, emergency_ctx@ha
 #endif
 	lwz	r1, emergency_ctx@l(r1)
-	cmpwi	cr1, r1, 0
-	bne	cr1, 1f
-	lis	r1, init_thread_union@ha
-	addi	r1, r1, init_thread_union@l
-1:	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
+	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
 	EXCEPTION_PROLOG_2
 	SAVE_NVGPRS(r11)
 	addi	r3, r1, STACK_FRAME_OVERHEAD
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 8ba49a6bf515..d7c1f92152af 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -164,7 +164,7 @@ void __init irqstack_early_init(void)
 }
 
 #ifdef CONFIG_VMAP_STACK
-void *emergency_ctx[NR_CPUS] __ro_after_init;
+void *emergency_ctx[NR_CPUS] __ro_after_init = {[0] = &init_stack};
 
 void __init emergency_stack_init(void)
 {
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 17/41] powerpc/32: Add vmap_stack_overflow label inside the macro
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

For consistency, add in the macro the label used by exception prolog
to branch to stack overflow processing.

While at it, enclose the macro in #ifdef CONFIG_VMAP_STACK on the 8xx
as already done on book3s/32.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h        | 3 ++-
 arch/powerpc/kernel/head_8xx.S       | 3 ++-
 arch/powerpc/kernel/head_book3s_32.S | 1 -
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 15c6fc7cbbf5..d97ec94b34da 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -52,7 +52,7 @@
 1:
 #ifdef CONFIG_VMAP_STACK
 	mtcrf	0x3f, r1
-	bt	32 - THREAD_ALIGN_SHIFT, stack_overflow
+	bt	32 - THREAD_ALIGN_SHIFT, vmap_stack_overflow
 #endif
 .endm
 
@@ -196,6 +196,7 @@
 			  ret_from_except)
 
 .macro vmap_stack_overflow_exception
+vmap_stack_overflow:
 #ifdef CONFIG_SMP
 	mfspr	r1, SPRN_SPRG_THREAD
 	lwz	r1, TASK_CPU - THREAD(r1)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index cdbfa9d41353..b63445c55f4d 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -338,8 +338,9 @@ DARFixed:/* Return from dcbx instruction bug workaround */
 	/* 0x300 is DataAccess exception, needed by bad_page_fault() */
 	EXC_XFER_LITE(0x300, handle_page_fault)
 
-stack_overflow:
+#ifdef CONFIG_VMAP_STACK
 	vmap_stack_overflow_exception
+#endif
 
 /* On the MPC8xx, these next four traps are used for development
  * support of breakpoints and such.  Someday I will get around to
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 1cf7bd5d5ec1..79a7715fadde 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -732,7 +732,6 @@ fast_hash_page_return:
 #endif /* CONFIG_PPC_BOOK3S_604 */
 
 #ifdef CONFIG_VMAP_STACK
-stack_overflow:
 	vmap_stack_overflow_exception
 #endif
 
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 18/41] powerpc/32: Use START_EXCEPTION() as much as possible
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

Everywhere where it is possible, use START_EXCEPTION().

This will help for proper exception init in future patches.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_40x.S       | 12 +++++------
 arch/powerpc/kernel/head_8xx.S       | 27 +++++++++----------------
 arch/powerpc/kernel/head_book3s_32.S | 30 ++++++++--------------------
 3 files changed, 22 insertions(+), 47 deletions(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 55fa99c5085c..c14a71e0d6d3 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -247,17 +247,15 @@ _ENTRY(crit_esr)
 	EXCEPTION(0x0F00, Trap_0F, unknown_exception, EXC_XFER_STD)
 
 /* 0x1000 - Programmable Interval Timer (PIT) Exception */
-	. = 0x1000
+	START_EXCEPTION(0x1000, DecrementerTrap)
 	b Decrementer
 
-/* 0x1010 - Fixed Interval Timer (FIT) Exception
-*/
-	. = 0x1010
+/* 0x1010 - Fixed Interval Timer (FIT) Exception */
+	START_EXCEPTION(0x1010, FITExceptionTrap)
 	b FITException
 
-/* 0x1020 - Watchdog Timer (WDT) Exception
-*/
-	. = 0x1020
+/* 0x1020 - Watchdog Timer (WDT) Exception */
+	START_EXCEPTION(0x1020, WDTExceptionTrap)
 	b WDTException
 
 /* 0x1100 - Data TLB Miss Exception
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index b63445c55f4d..11789a077d76 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -121,8 +121,7 @@ instruction_counter:
 	EXCEPTION(0x100, Reset, system_reset_exception, EXC_XFER_STD)
 
 /* Machine check */
-	. = 0x200
-MachineCheck:
+	START_EXCEPTION(0x200, MachineCheck)
 	EXCEPTION_PROLOG handle_dar_dsisr=1
 	addi r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0x200, machine_check_exception)
@@ -131,8 +130,7 @@ MachineCheck:
 	EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
 
 /* Alignment exception */
-	. = 0x600
-Alignment:
+	START_EXCEPTION(0x600, Alignment)
 	EXCEPTION_PROLOG handle_dar_dsisr=1
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	b	.Lalignment_exception_ool
@@ -149,8 +147,7 @@ Alignment:
 	EXC_XFER_STD(0x600, alignment_exception)
 
 /* System call */
-	. = 0xc00
-SystemCall:
+	START_EXCEPTION(0xc00, SystemCall)
 	SYSCALL_ENTRY	0xc00
 
 /* Single step - not used on 601 */
@@ -161,7 +158,6 @@ SystemCall:
  */
 	EXCEPTION(0x1000, SoftEmu, emulation_assist_interrupt, EXC_XFER_STD)
 
-	. = 0x1100
 /*
  * For the MPC8xx, this is a software tablewalk to load the instruction
  * TLB.  The task switch loads the M_TWB register with the pointer to the first
@@ -183,7 +179,7 @@ SystemCall:
 #define INVALIDATE_ADJACENT_PAGES_CPU15(addr, tmp)
 #endif
 
-InstructionTLBMiss:
+	START_EXCEPTION(0x1100, InstructionTLBMiss)
 	mtspr	SPRN_SPRG_SCRATCH2, r10
 	mtspr	SPRN_M_TW, r11
 
@@ -239,8 +235,7 @@ InstructionTLBMiss:
 	rfi
 #endif
 
-	. = 0x1200
-DataStoreTLBMiss:
+	START_EXCEPTION(0x1200, DataStoreTLBMiss)
 	mtspr	SPRN_SPRG_SCRATCH2, r10
 	mtspr	SPRN_M_TW, r11
 	mfcr	r11
@@ -303,8 +298,7 @@ DataStoreTLBMiss:
  * to many reasons, such as executing guarded memory or illegal instruction
  * addresses.  There is nothing to do but handle a big time error fault.
  */
-	. = 0x1300
-InstructionTLBError:
+	START_EXCEPTION(0x1300, InstructionTLBError)
 	EXCEPTION_PROLOG
 	andis.	r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
 	andis.	r10,r9,SRR1_ISI_NOPT@h
@@ -320,8 +314,7 @@ InstructionTLBError:
  * many reasons, including a dirty update to a pte.  We bail out to
  * a higher level function that can handle it.
  */
-	. = 0x1400
-DataTLBError:
+	START_EXCEPTION(0x1400, DataTLBError)
 	EXCEPTION_PROLOG_0 handle_dar_dsisr=1
 	mfspr	r11, SPRN_DAR
 	cmpwi	cr1, r11, RPN_PATTERN
@@ -354,8 +347,7 @@ do_databreakpoint:
 	stw	r4,_DAR(r11)
 	EXC_XFER_STD(0x1c00, do_break)
 
-	. = 0x1c00
-DataBreakpoint:
+	START_EXCEPTION(0x1c00, DataBreakpoint)
 	EXCEPTION_PROLOG_0 handle_dar_dsisr=1
 	mfspr	r11, SPRN_SRR0
 	cmplwi	cr1, r11, (.Ldtlbie - PAGE_OFFSET)@l
@@ -368,8 +360,7 @@ DataBreakpoint:
 	rfi
 
 #ifdef CONFIG_PERF_EVENTS
-	. = 0x1d00
-InstructionBreakpoint:
+	START_EXCEPTION(0x1d00, InstructionBreakpoint)
 	mtspr	SPRN_SPRG_SCRATCH0, r10
 	lwz	r10, (instruction_counter - PAGE_OFFSET)@l(0)
 	addi	r10, r10, -1
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 79a7715fadde..17510c99802d 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -255,9 +255,7 @@ __secondary_hold_acknowledge:
  * pointer when we take an exception from supervisor mode.)
  *	-- paulus.
  */
-	. = 0x200
-	DO_KVM  0x200
-MachineCheck:
+	START_EXCEPTION(0x200, MachineCheck)
 	EXCEPTION_PROLOG_0
 #ifdef CONFIG_PPC_CHRP
 	mtspr	SPRN_SPRG_SCRATCH2,r1
@@ -278,9 +276,7 @@ MachineCheck:
 #endif
 
 /* Data access exception. */
-	. = 0x300
-	DO_KVM  0x300
-DataAccess:
+	START_EXCEPTION(0x300, DataAccess)
 #ifdef CONFIG_PPC_BOOK3S_604
 BEGIN_MMU_FTR_SECTION
 	mtspr	SPRN_SPRG_SCRATCH2,r10
@@ -304,9 +300,7 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
 	b	handle_page_fault_tramp_1
 
 /* Instruction access exception. */
-	. = 0x400
-	DO_KVM  0x400
-InstructionAccess:
+	START_EXCEPTION(0x400, InstructionAccess)
 	mtspr	SPRN_SPRG_SCRATCH0,r10
 	mtspr	SPRN_SPRG_SCRATCH1,r11
 	mfspr	r10, SPRN_SPRG_THREAD
@@ -336,9 +330,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
 	EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
 
 /* Alignment exception */
-	. = 0x600
-	DO_KVM  0x600
-Alignment:
+	START_EXCEPTION(0x600, Alignment)
 	EXCEPTION_PROLOG handle_dar_dsisr=1
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	b	alignment_exception_tramp
@@ -347,9 +339,7 @@ Alignment:
 	EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
 
 /* Floating-point unavailable */
-	. = 0x800
-	DO_KVM  0x800
-FPUnavailable:
+	START_EXCEPTION(0x800, FPUnavailable)
 #ifdef CONFIG_PPC_FPU
 BEGIN_FTR_SECTION
 /*
@@ -375,9 +365,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
 	EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_STD)
 
 /* System call */
-	. = 0xc00
-	DO_KVM  0xc00
-SystemCall:
+	START_EXCEPTION(0xc00, SystemCall)
 	SYSCALL_ENTRY	0xc00
 
 	EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
@@ -391,12 +379,10 @@ SystemCall:
  * non-altivec kernel running on a machine with altivec just
  * by executing an altivec instruction.
  */
-	. = 0xf00
-	DO_KVM  0xf00
+	START_EXCEPTION(0xf00, PerformanceMonitorTrap)
 	b	PerformanceMonitor
 
-	. = 0xf20
-	DO_KVM  0xf20
+	START_EXCEPTION(0xf20, AltiVecUnavailableTrap)
 	b	AltiVecUnavailable
 
 /*
-- 
2.25.0


^ permalink raw reply related

* [PATCH v3 19/41] powerpc/32: Move exception prolog code into .text once MMU is back on
From: Christophe Leroy @ 2021-03-12 12:50 UTC (permalink / raw)
  To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, npiggin
  Cc: linuxppc-dev, linux-kernel
In-Reply-To: <cover.1615552866.git.christophe.leroy@csgroup.eu>

The space in the head section is rather constrained by the fact that
exception vectors are spread every 0x100 bytes and sometimes we
need to have "out of line" code because it doesn't fit.

Now that we are enabling MMU early in the prolog, take that opportunity
to jump somewhere else in the .text section where we don't have any
space constraint.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/head_32.h        |  5 ++++
 arch/powerpc/kernel/head_40x.S       |  6 +++++
 arch/powerpc/kernel/head_8xx.S       | 25 ++++++++------------
 arch/powerpc/kernel/head_book3s_32.S | 34 ++++++++++++----------------
 4 files changed, 36 insertions(+), 34 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index d97ec94b34da..3c0aa4538514 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -70,6 +70,8 @@
 	mtspr	SPRN_SRR0, r11
 	mfspr	r11, SPRN_SPRG_SCRATCH2
 	rfi
+
+	.text
 1:
 	stw	r11,GPR1(r1)
 	stw	r11,0(r1)
@@ -163,12 +165,14 @@
  */
 #ifdef CONFIG_PPC_BOOK3S
 #define	START_EXCEPTION(n, label)		\
+	__HEAD;					\
 	. = n;					\
 	DO_KVM n;				\
 label:
 
 #else
 #define	START_EXCEPTION(n, label)		\
+	__HEAD;					\
 	. = n;					\
 label:
 
@@ -196,6 +200,7 @@
 			  ret_from_except)
 
 .macro vmap_stack_overflow_exception
+	__HEAD
 vmap_stack_overflow:
 #ifdef CONFIG_SMP
 	mfspr	r1, SPRN_SPRG_THREAD
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index c14a71e0d6d3..e7d8856714d3 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -132,6 +132,8 @@ _ENTRY(crit_esr)
 	ori	r11, r11, 1f@l
 	mtspr	SPRN_SRR0, r11
 	rfi
+
+	.text
 1:
 	lwz	r11,crit_r1@l(0)
 	stw	r11,GPR1(r1)
@@ -496,6 +498,7 @@ _ENTRY(crit_esr)
 		crit_transfer_to_handler, ret_from_crit_exc)
 
 	/* Programmable Interval Timer (PIT) Exception. (from 0x1000) */
+	__HEAD
 Decrementer:
 	EXCEPTION_PROLOG
 	lis	r0,TSR_PIS@h
@@ -504,12 +507,14 @@ Decrementer:
 	EXC_XFER_LITE(0x1000, timer_interrupt)
 
 	/* Fixed Interval Timer (FIT) Exception. (from 0x1010) */
+	__HEAD
 FITException:
 	EXCEPTION_PROLOG
 	addi	r3,r1,STACK_FRAME_OVERHEAD;
 	EXC_XFER_STD(0x1010, unknown_exception)
 
 	/* Watchdog Timer (WDT) Exception. (from 0x1020) */
+	__HEAD
 WDTException:
 	CRITICAL_EXCEPTION_PROLOG;
 	addi	r3,r1,STACK_FRAME_OVERHEAD;
@@ -523,6 +528,7 @@ WDTException:
  * reserved.
  */
 
+	__HEAD
 	/* Damn, I came up one instruction too many to fit into the
 	 * exception space :-).  Both the instruction and data TLB
 	 * miss get to this point to load the TLB.
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 11789a077d76..d16d0ec71bb2 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -133,7 +133,7 @@ instruction_counter:
 	START_EXCEPTION(0x600, Alignment)
 	EXCEPTION_PROLOG handle_dar_dsisr=1
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	b	.Lalignment_exception_ool
+	EXC_XFER_STD(0x600, alignment_exception)
 
 /* Program check exception */
 	EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
@@ -141,11 +141,6 @@ instruction_counter:
 /* Decrementer */
 	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
 
-	/* With VMAP_STACK there's not enough room for this at 0x600 */
-	. = 0xa00
-.Lalignment_exception_ool:
-	EXC_XFER_STD(0x600, alignment_exception)
-
 /* System call */
 	START_EXCEPTION(0xc00, SystemCall)
 	SYSCALL_ENTRY	0xc00
@@ -339,26 +334,25 @@ DARFixed:/* Return from dcbx instruction bug workaround */
  * support of breakpoints and such.  Someday I will get around to
  * using them.
  */
-do_databreakpoint:
-	EXCEPTION_PROLOG_1
-	EXCEPTION_PROLOG_2 handle_dar_dsisr=1
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	mfspr	r4,SPRN_BAR
-	stw	r4,_DAR(r11)
-	EXC_XFER_STD(0x1c00, do_break)
-
 	START_EXCEPTION(0x1c00, DataBreakpoint)
 	EXCEPTION_PROLOG_0 handle_dar_dsisr=1
 	mfspr	r11, SPRN_SRR0
 	cmplwi	cr1, r11, (.Ldtlbie - PAGE_OFFSET)@l
 	cmplwi	cr7, r11, (.Litlbie - PAGE_OFFSET)@l
 	cror	4*cr1+eq, 4*cr1+eq, 4*cr7+eq
-	bne	cr1, do_databreakpoint
+	bne	cr1, 1f
 	mtcr	r10
 	mfspr	r10, SPRN_SPRG_SCRATCH0
 	mfspr	r11, SPRN_SPRG_SCRATCH1
 	rfi
 
+1:	EXCEPTION_PROLOG_1
+	EXCEPTION_PROLOG_2 handle_dar_dsisr=1
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	mfspr	r4,SPRN_BAR
+	stw	r4,_DAR(r11)
+	EXC_XFER_STD(0x1c00, do_break)
+
 #ifdef CONFIG_PERF_EVENTS
 	START_EXCEPTION(0x1d00, InstructionBreakpoint)
 	mtspr	SPRN_SPRG_SCRATCH0, r10
@@ -376,6 +370,7 @@ do_databreakpoint:
 	EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_STD)
 	EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_STD)
 
+	__HEAD
 	. = 0x2000
 
 /* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 17510c99802d..4a74bbe7462b 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -269,11 +269,10 @@ __secondary_hold_acknowledge:
 7:	EXCEPTION_PROLOG_2
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 #ifdef CONFIG_PPC_CHRP
-	beq	cr1, machine_check_tramp
+	beq	cr1, 1f
 	twi	31, 0, 0
-#else
-	b	machine_check_tramp
 #endif
+1:	EXC_XFER_STD(0x200, machine_check_exception)
 
 /* Data access exception. */
 	START_EXCEPTION(0x300, DataAccess)
@@ -297,7 +296,13 @@ ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE)
 #endif
 1:	EXCEPTION_PROLOG_0 handle_dar_dsisr=1
 	EXCEPTION_PROLOG_1
-	b	handle_page_fault_tramp_1
+	EXCEPTION_PROLOG_2 handle_dar_dsisr=1
+	lwz	r5, _DSISR(r11)
+	andis.	r0, r5, DSISR_DABRMATCH@h
+	bne-	1f
+	EXC_XFER_LITE(0x300, handle_page_fault)
+1:	EXC_XFER_STD(0x300, do_break)
+
 
 /* Instruction access exception. */
 	START_EXCEPTION(0x400, InstructionAccess)
@@ -333,7 +338,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
 	START_EXCEPTION(0x600, Alignment)
 	EXCEPTION_PROLOG handle_dar_dsisr=1
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	b	alignment_exception_tramp
+	EXC_XFER_STD(0x600, alignment_exception)
 
 /* Program check exception */
 	EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
@@ -385,6 +390,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
 	START_EXCEPTION(0xf20, AltiVecUnavailableTrap)
 	b	AltiVecUnavailable
 
+	__HEAD
 /*
  * Handle TLB miss for instruction on 603/603e.
  * Note: we get an alternate set of r0 - r3 to use automatically.
@@ -627,22 +633,9 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
 	EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_STD)
 	EXCEPTION(0x2f00, Trap_2f, unknown_exception, EXC_XFER_STD)
 
+	__HEAD
 	. = 0x3000
 
-machine_check_tramp:
-	EXC_XFER_STD(0x200, machine_check_exception)
-
-alignment_exception_tramp:
-	EXC_XFER_STD(0x600, alignment_exception)
-
-handle_page_fault_tramp_1:
-	EXCEPTION_PROLOG_2 handle_dar_dsisr=1
-	lwz	r5, _DSISR(r11)
-	andis.	r0, r5, DSISR_DABRMATCH@h
-	bne-	1f
-	EXC_XFER_LITE(0x300, handle_page_fault)
-1:	EXC_XFER_STD(0x300, do_break)
-
 #ifdef CONFIG_PPC_BOOK3S_604
 .macro save_regs_thread		thread
 	stw	r0, THR0(\thread)
@@ -721,6 +714,7 @@ fast_hash_page_return:
 	vmap_stack_overflow_exception
 #endif
 
+	__HEAD
 AltiVecUnavailable:
 	EXCEPTION_PROLOG
 #ifdef CONFIG_ALTIVEC
@@ -731,12 +725,14 @@ AltiVecUnavailable:
 1:	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_LITE(0xf20, altivec_unavailable_exception)
 
+	__HEAD
 PerformanceMonitor:
 	EXCEPTION_PROLOG
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_STD(0xf00, performance_monitor_exception)
 
 
+	__HEAD
 /*
  * This code is jumped to from the startup code to copy
  * the kernel image to physical address PHYSICAL_START.
-- 
2.25.0


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