kernel.git/arch/powerpc/kernel/entry_64.S, branch linux-5.13.y

powerpc/64e/interrupt: reconcile irq soft-mask state in C

2021-04-14T13:04:43Z

Use existing 64s interrupt entry wrapper code to reconcile irqs in C. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210316104206.407354-7-npiggin@gmail.com

powerpc/interrupt: update common interrupt code for

2021-04-14T13:04:20Z

This makes adjustments to 64-bit asm and common C interrupt return code to be usable by the 64e subarchitecture. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210316104206.407354-4-npiggin@gmail.com

powerpc/64e/interrupt: always save nvgprs on interrupt

2021-04-14T13:04:19Z

In order to use the C interrupt return, nvgprs must always be saved. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210316104206.407354-3-npiggin@gmail.com

Merge tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2021-02-22T22:34:00Z

Pull powerpc updates from Michael Ellerman: - A large series adding wrappers for our interrupt handlers, so that irq/nmi/user tracking can be isolated in the wrappers rather than spread in each handler. - Conversion of the 32-bit syscall handling into C. - A series from Nick to streamline our TLB flushing when using the Radix MMU. - Switch to using queued spinlocks by default for 64-bit server CPUs. - A rework of our PCI probing so that it happens later in boot, when more generic infrastructure is available. - Two small fixes to allow 32-bit little-endian processes to run on 64-bit kernels. - Other smaller features, fixes & cleanups. Thanks to: Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang Fan, Christophe Leroy, Christopher M. Riedl, Fabiano Rosas, Florian Fainelli, Frederic Barrat, Ganesh Goudar, Hari Bathini, Jiapeng Chong, Joseph J Allen, Kajol Jain, Markus Elfring, Michal Suchanek, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pingfan Liu, Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan Das, Stephen Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, and Zheng Yongjun. * tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (188 commits) powerpc/perf: Adds support for programming of Thresholding in P10 powerpc/pci: Remove unimplemented prototypes powerpc/uaccess: Merge raw_copy_to_user_allowed() into raw_copy_to_user() powerpc/uaccess: Merge __put_user_size_allowed() into __put_user_size() powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user() powerpc/64: Fix stack trace not displaying final frame powerpc/time: Remove get_tbl() powerpc/time: Avoid using get_tbl() spi: mpc52xx: Avoid using get_tbl() powerpc/syscall: Avoid storing 'current' in another pointer powerpc/32: Handle bookE debugging in C in syscall entry/exit powerpc/syscall: Do not check unsupported scv vector on PPC32 powerpc/32: Remove the counter in global_dbcr0 powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry powerpc/syscall: implement system call entry/exit logic in C for PPC32 powerpc/32: Always save non volatile GPRs at syscall entry powerpc/syscall: Change condition to check MSR_RI powerpc/syscall: Save r3 in regs->orig_r3 powerpc/syscall: Use is_compat_task() powerpc/syscall: Make interrupt.c buildable on PPC32 ...

powerpc/syscall: Save r3 in regs->orig_r3

2021-02-11T12:35:10Z

Save r3 in regs->orig_r3 in system_call_exception() Signed-off-by: Christophe Leroy Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/9a90805ab6b9101b46daf56470f457a57acd86fc.1612796617.git.christophe.leroy@csgroup.eu

powerpc/64s: syscall real mode entry use mtmsrd rather than rfid

2021-02-11T12:35:05Z

Have the real mode system call entry handler branch to the kernel 0xc000... address and then use mtmsrd to enable the MMU, rather than use SRRs and rfid. Commit 8729c26e675c ("powerpc/64s/exception: Move real to virt switch into the common handler") implemented this style of real mode entry for other interrupt handlers, so this brings system calls into line with them, which is the main motivcation for the change. This tends to be slightly faster due to avoiding the mtsprs, and it also does not clobber the SRR registers, which becomes important in a subsequent change. The real mode entry points don't tend to be too important for performance these days, but it is possible for a hypervisor to run guests in AIL=0 mode for certian reasons. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210208063326.331502-1-npiggin@gmail.com

powerpc/64s: fix scv entry fallback flush vs interrupt

2021-01-20T04:58:19Z

The L1D flush fallback functions are not recoverable vs interrupts, yet the scv entry flush runs with MSR[EE]=1. This can result in a timer (soft-NMI) or MCE or SRESET interrupt hitting here and overwriting the EXRFI save area, which ends up corrupting userspace registers for scv return. Fix this by disabling RI and EE for the scv entry fallback flush. Fixes: f79643787e0a0 ("powerpc/64s: flush L1D on kernel entry") Cc: stable@vger.kernel.org # 5.9+ which also have flush L1D patch backport Reported-by: Tulio Magno Quites Machado Filho Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210111062408.287092-1-npiggin@gmail.com

powerpc/64s: Remove MSR[ISF] bit

2020-12-09T12:48:14Z

No supported processor implements this mode. Setting the bit in MSR values can be a bit confusing (and would prevent the bit from ever being reused). Remove it. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201106045340.1935841-1-npiggin@gmail.com

powerpc/book3s64/pkeys: Optimize KUAP and KUEP feature disabled case

2020-12-03T14:01:28Z

If FTR_BOOK3S_KUAP is disabled, kernel will continue to run with the same AMR value with which it was entered. Hence there is a high chance that we can return without restoring the AMR value. This also helps the case when applications are not using the pkey feature. In this case, different applications will have the same AMR values and hence we can avoid restoring AMR in this case too. Also avoid isync() if not really needed. Do the same for IAMR. null-syscall benchmark results: With smap/smep disabled: Without patch: 957.95 ns 2778.17 cycles With patch: 858.38 ns 2489.30 cycles With smap/smep enabled: Without patch: 1017.26 ns 2950.36 cycles With patch: 1021.51 ns 2962.44 cycles Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201127044424.40686-23-aneesh.kumar@linux.ibm.com

powerpc/book3s64/pkeys: Store/restore userspace AMR/IAMR correctly on entry and exit from kernel

2020-12-03T14:01:25Z

This prepare kernel to operate with a different value than userspace AMR/IAMR. For this, AMR/IAMR need to be saved and restored on entry and return from the kernel. With KUAP we modify kernel AMR when accessing user address from the kernel via copy_to/from_user interfaces. We don't need to modify IAMR value in similar fashion. If MMU_FTR_PKEY is enabled we need to save AMR/IAMR in pt_regs on entering kernel from userspace. If not we can assume that AMR/IAMR is not modified from userspace. We need to save AMR if we have MMU_FTR_BOOK3S_KUAP feature enabled and we are interrupted within kernel. This is required so that if we get interrupted within copy_to/from_user we continue with the right AMR value. If we hae MMU_FTR_BOOK3S_KUEP enabled we need to restore IAMR on return to userspace beause kernel will be running with a different IAMR value. Signed-off-by: Aneesh Kumar K.V Reviewed-by: Sandipan Das Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201127044424.40686-11-aneesh.kumar@linux.ibm.com