linux-dev/arch/powerpc/kernel/head_32.h, branch linus/master

Merge tag 'powerpc-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2022-01-14T14:17:26Z

Pull powerpc updates from Michael Ellerman: - Optimise radix KVM guest entry/exit by 2x on Power9/Power10. - Allow firmware to tell us whether to disable the entry and uaccess flushes on Power10 or later CPUs. - Add BPF_PROBE_MEM support for 32 and 64-bit BPF jits. - Several fixes and improvements to our hard lockup watchdog. - Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on 32-bit. - Allow building the 64-bit Book3S kernel without hash MMU support, ie. Radix only. - Add KUAP (SMAP) support for 40x, 44x, 8xx, Book3E (64-bit). - Add new encodings for perf_mem_data_src.mem_hops field, and use them on Power10. - A series of small performance improvements to 64-bit interrupt entry. - Several commits fixing issues when building with the clang integrated assembler. - Many other small features and fixes. Thanks to Alan Modra, Alexey Kardashevskiy, Ammar Faizi, Anders Roxell, Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christophe JAILLET, Christophe Leroy, Christoph Hellwig, Daniel Axtens, David Yang, Erhard Furtner, Fabiano Rosas, Greg Kroah-Hartman, Guo Ren, Hari Bathini, Jason Wang, Joel Stanley, Julia Lawall, Kajol Jain, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mark Brown, Minghao Chi, Nageswara R Sastry, Naresh Kamboju, Nathan Chancellor, Nathan Lynch, Nicholas Piggin, Nick Child, Oliver O'Halloran, Peiwei Hu, Randy Dunlap, Ravi Bangoria, Rob Herring, Russell Currey, Sachin Sant, Sean Christopherson, Segher Boessenkool, Thadeu Lima de Souza Cascardo, Tyrel Datwyler, Xiang wangx, and Yang Guang. * tag 'powerpc-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (240 commits) powerpc/xmon: Dump XIVE information for online-only processors. powerpc/opal: use default_groups in kobj_type powerpc/cacheinfo: use default_groups in kobj_type powerpc/sched: Remove unused TASK_SIZE_OF powerpc/xive: Add missing null check after calling kmalloc powerpc/floppy: Remove usage of the deprecated "pci-dma-compat.h" API selftests/powerpc: Add a test of sigreturning to an unaligned address powerpc/64s: Use EMIT_WARN_ENTRY for SRR debug warnings powerpc/64s: Mask NIP before checking against SRR0 powerpc/perf: Fix spelling of "its" powerpc/32: Fix boot failure with GCC latent entropy plugin powerpc/code-patching: Replace patch_instruction() by ppc_inst_write() in selftests powerpc/code-patching: Move code patching selftests in its own file powerpc/code-patching: Move instr_is_branch_{i/b}form() in code-patching.h powerpc/code-patching: Move patch_exception() outside code-patching.c powerpc/code-patching: Use test_trampoline for prefixed patch test powerpc/code-patching: Fix patch_branch() return on out-of-range failure powerpc/code-patching: Reorganise do_patch_instruction() to ease error handling powerpc/code-patching: Fix unmap_patch_area() error handling powerpc/code-patching: Fix error handling in do_patch_instruction() ...

powerpc/32s: Do kuep_lock() and kuep_unlock() in assembly

2021-12-09T11:41:17Z

When interrupt and syscall entries where converted to C, KUEP locking and unlocking was also converted. It improved performance by unrolling the loop, and allowed easily implementing boot time deactivation of KUEP. However, null_syscall selftest shows that KUEP is still heavy (361 cycles with KUEP, 212 cycles without). A way to improve more is to group 'mtsr's together, instead of repeating 'addi' + 'mtsr' several times. In order to do that, more registers need to be available. In C, GCC will always be able to provide the requested number of registers, but at the cost of saving some data on the stack, which is counter performant here. So let's do it in assembly, when we have full control of which register can be used. It also has the advantage of locking earlier and unlocking later and it helps GCC generating less tricky code. The only drawback is to make boot time deactivation less straight forward and require 'hand' instruction patching. Group 'mtsr's by 4. With this change, null_syscall selftest reports 336 cycles. Without the change it was 361 cycles, that's a 7% reduction. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/115cb279e9b9948dfd93a065e047081c59e3a2a6.1634627931.git.christophe.leroy@csgroup.eu

powerpc: flexible GPR range save/restore macros

2021-11-29T12:15:20Z

Introduce macros that operate on a (start, end) range of GPRs, which reduces lines of code and need to do mental arithmetic while reading the code. Signed-off-by: Nicholas Piggin Reviewed-by: Segher Boessenkool Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211022061322.2671178-1-npiggin@gmail.com

powerpc/32: Fix hardlockup on vmap stack overflow

2021-11-24T10:00:51Z

Since the commit c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") a vmap stack overflow results in a hard lockup. This is because emergency_ctx is still addressed with its virtual address allthough data MMU is not active anymore at that time. Fix it by using a physical address instead. Fixes: c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/ce30364fb7ccda489272af4a1612b6aa147e1d23.1637227521.git.christophe.leroy@csgroup.eu

powerpc/32: Reduce code duplication of system call entry

2021-06-24T14:07:10Z

booke and non booke do pretty similar things in SYSCALL_ENTRY macro just before calling jumping to transfer_to_syscall(). Do them in transfer_to_syscall() instead. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/552e27fa09394a6bc70585fcdfa237f99a5d1267.1622818435.git.christophe.leroy@csgroup.eu

powerpc/32: Interchange r1 and r11 in SYSCALL_ENTRY on booke

2021-06-24T14:07:10Z

To better match non booke version of SYSCALL_ENTRY macro, interchange r1 and r11 in the booke version. While at it, in both versions use r1 instead of r11 to save _NIP and _CCR. All other uses of r11 will go away in next patch, so don't bother changing them for now. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1684c39724a069b0ce1aa82eaee6ec194e354e4e.1622818435.git.christophe.leroy@csgroup.eu

powerpc/32: Interchange r10 and r12 in SYSCALL_ENTRY on non booke

2021-06-24T14:07:10Z

To better match booke version of SYSCALL_ENTRY macro, interchange r10 and r12 in the non booke version. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/5ab3a517bc883a2fc905fb2cb5ee9344f37b2cfa.1622818435.git.christophe.leroy@csgroup.eu

powerpc/32s: Move KUEP locking/unlocking in C

2021-03-29T02:22:10Z

This can be done in C, do it. Unrolling the loop gains approx. 15% performance. From now on, prepare_transfer_to_handler() is only for interrupts from kernel. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4eadd873927e9a73c3d1dfe2f9497353465514cf.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500

2021-03-29T02:22:10Z

Only book3s/32 and e500 have significative work to do in prepare_transfer_to_handler. Other 32 bit have nothing to do at all. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b5e29ca0e557c11340415a13fe8b107189d315e1.1615552867.git.christophe.leroy@csgroup.eu

powerpc/32: Save remaining registers in exception prolog

2021-03-29T02:22:10Z

Save non volatile registers, XER, CTR, MSR and NIP in exception prolog. Also assign proper value to r2 and r3 there. For now, recalculate thread pointer in prepare_transfer_to_handler. It will disappear once KUAP is ported to C. And remove the comment which is now completely wrong. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/56f0cde9dd0362edf2ddba4d887552013eee7329.1615552867.git.christophe.leroy@csgroup.eu