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2019-02-23powerpc/kconfig: make _etext and data areas alignment configurable on 8xxChristophe Leroy
On 8xx, large pages (512kb or 8M) are used to map kernel linear memory. Aligning to 8M reduces TLB misses as only 8M pages are used in that case. We make 8M the default for data. This patchs allows the user to do it via Kconfig. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/8xx: don't disable large TLBs with CONFIG_STRICT_KERNEL_RWXChristophe Leroy
This patch implements handling of STRICT_KERNEL_RWX with large TLBs directly in the TLB miss handlers. To do so, etext and sinittext are aligned on 512kB boundaries and the miss handlers use 512kB pages instead of 8Mb pages for addresses close to the boundaries. It sets RO PP flags for addresses under sinittext. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/kconfig: make _etext and data areas alignment configurable on Book3s 32Christophe Leroy
Depending on the number of available BATs for mapping the different kernel areas, it might be needed to increase the alignment of _etext and/or of data areas. This patchs allows the user to do it via Kconfig. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWXChristophe Leroy
Today, STRICT_KERNEL_RWX is based on the use of regular pages to map kernel pages. On Book3s 32, it has three consequences: - Using pages instead of BAT for mapping kernel linear memory severely impacts performance. - Exec protection is not effective because no-execute cannot be set at page level (except on 603 which doesn't have hash tables) - Write protection is not effective because PP bits do not provide RO mode for kernel-only pages (except on 603 which handles it in software via PAGE_DIRTY) On the 603+, we have: - Independent IBAT and DBAT allowing limitation of exec parts. - NX bit can be set in segment registers to forbit execution on memory mapped by pages. - RO mode on DBATs even for kernel-only blocks. On the 601, there is nothing much we can do other than warn the user about it, because: - BATs are common to instructions and data. - BAT do not provide RO mode for kernel-only blocks. - segment registers don't have the NX bit. In order to use IBAT for exec protection, this patch: - Aligns _etext to BAT block sizes (128kb) - Set NX bit in kernel segment register (Except on vmalloc area when CONFIG_MODULES is selected) - Maps kernel text with IBATs. In order to use DBAT for exec protection, this patch: - Aligns RW DATA to BAT block sizes (4M) - Maps kernel RO area with write prohibited DBATs - Maps remaining memory with remaining DBATs Here is what we get with this patch on a 832x when activating STRICT_KERNEL_RWX: Symbols: c0000000 T _stext c0680000 R __start_rodata c0680000 R _etext c0800000 T __init_begin c0800000 T _sinittext ~# cat /sys/kernel/debug/block_address_translation ---[ Instruction Block Address Translation ]--- 0: 0xc0000000-0xc03fffff 0x00000000 Kernel EXEC coherent 1: 0xc0400000-0xc05fffff 0x00400000 Kernel EXEC coherent 2: 0xc0600000-0xc067ffff 0x00600000 Kernel EXEC coherent 3: - 4: - 5: - 6: - 7: - ---[ Data Block Address Translation ]--- 0: 0xc0000000-0xc07fffff 0x00000000 Kernel RO coherent 1: 0xc0800000-0xc0ffffff 0x00800000 Kernel RW coherent 2: 0xc1000000-0xc1ffffff 0x01000000 Kernel RW coherent 3: 0xc2000000-0xc3ffffff 0x02000000 Kernel RW coherent 4: 0xc4000000-0xc7ffffff 0x04000000 Kernel RW coherent 5: 0xc8000000-0xcfffffff 0x08000000 Kernel RW coherent 6: 0xd0000000-0xdfffffff 0x10000000 Kernel RW coherent 7: - ~# cat /sys/kernel/debug/segment_registers ---[ User Segments ]--- 0x00000000-0x0fffffff Kern key 1 User key 1 VSID 0xa085d0 0x10000000-0x1fffffff Kern key 1 User key 1 VSID 0xa086e1 0x20000000-0x2fffffff Kern key 1 User key 1 VSID 0xa087f2 0x30000000-0x3fffffff Kern key 1 User key 1 VSID 0xa08903 0x40000000-0x4fffffff Kern key 1 User key 1 VSID 0xa08a14 0x50000000-0x5fffffff Kern key 1 User key 1 VSID 0xa08b25 0x60000000-0x6fffffff Kern key 1 User key 1 VSID 0xa08c36 0x70000000-0x7fffffff Kern key 1 User key 1 VSID 0xa08d47 0x80000000-0x8fffffff Kern key 1 User key 1 VSID 0xa08e58 0x90000000-0x9fffffff Kern key 1 User key 1 VSID 0xa08f69 0xa0000000-0xafffffff Kern key 1 User key 1 VSID 0xa0907a 0xb0000000-0xbfffffff Kern key 1 User key 1 VSID 0xa0918b ---[ Kernel Segments ]--- 0xc0000000-0xcfffffff Kern key 0 User key 1 No Exec VSID 0x000ccc 0xd0000000-0xdfffffff Kern key 0 User key 1 No Exec VSID 0x000ddd 0xe0000000-0xefffffff Kern key 0 User key 1 No Exec VSID 0x000eee 0xf0000000-0xffffffff Kern key 0 User key 1 No Exec VSID 0x000fff Aligning _etext to 128kb allows to map up to 32Mb text with 8 IBATs: 16Mb + 8Mb + 4Mb + 2Mb + 1Mb + 512kb + 256kb + 128kb (+ 128kb) = 32Mb (A 9th IBAT is unneeded as 32Mb would need only a single 32Mb block) Aligning data to 4M allows to map up to 512Mb data with 8 DBATs: 16Mb + 8Mb + 4Mb + 4Mb + 32Mb + 64Mb + 128Mb + 256Mb = 512Mb Because some processors only have 4 BATs and because some targets need DBATs for mapping other areas, the following patch will allow to modify _etext and data alignment. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/mm/32s: add setibat() clearibat() and update_bats()Christophe Leroy
setibat() and clearibat() allows to manipulate IBATs independently of DBATs. update_bats() allows to update bats after init. This is done with MMU off. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/kconfig: define CONFIG_DATA_SHIFT and CONFIG_ETEXT_SHIFTChristophe Leroy
CONFIG_STRICT_KERNEL_RWX requires a special alignment for DATA for some subarches. Today it is just defined as an #ifdef in vmlinux.lds.S In order to get more flexibility, this patch moves the definition of this alignment in Kconfig On some subarches, CONFIG_STRICT_KERNEL_RWX will require a special alignment of _etext. This patch also adds a configuration item for it in Kconfig Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/kconfig: define PAGE_SHIFT inside KconfigChristophe Leroy
This patch defined CONFIG_PPC_PAGE_SHIFT in order to be able to use PAGE_SHIFT value inside Kconfig. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/mmu: add is_strict_kernel_rwx() helperChristophe Leroy
Add a helper to know whether STRICT_KERNEL_RWX is enabled. This is based on rodata_enabled flag which is defined only when CONFIG_STRICT_KERNEL_RWX is selected. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/32: add helper to write into segment registersChristophe Leroy
This patch add an helper which wraps 'mtsrin' instruction to write into segment registers. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/mm/32s: use _PAGE_EXEC in setbat()Christophe Leroy
Do not set IBAT when setbat() is called without _PAGE_EXEC Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/wii: remove wii_mmu_mapin_mem2()Christophe Leroy
wii_mmu_mapin_mem2() is not used anymore, remove it. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/32: always populate page tables for Abatron BDI.Christophe Leroy
When CONFIG_BDI_SWITCH is set, the page tables have to be populated allthough large TLBs are used, because the BDI switch knows nothing about those large TLBs which are handled directly in TLB miss logic. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/mm/32s: use generic mmu_mapin_ram() for all blocks.Christophe Leroy
Now that mmu_mapin_ram() is able to handle other blocks than the one starting at 0, the WII can use it for all its blocks. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/mm/32s: rework mmu_mapin_ram()Christophe Leroy
This patch reworks mmu_mapin_ram() to be more generic and map as much blocks as possible. It now supports blocks not starting at address 0. It scans DBATs array to find free ones instead of forcing the use of BAT2 and BAT3. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/mm/32: add base address to mmu_mapin_ram()Christophe Leroy
At the time being, mmu_mapin_ram() always maps RAM from the beginning. But some platforms like the WII have to map a second block of RAM. This patch adds to mmu_mapin_ram() the base address of the block. At the moment, only base address 0 is supported. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/wii: properly disable use of BATs when requested.Christophe Leroy
'nobats' kernel parameter or some options like CONFIG_DEBUG_PAGEALLOC deny the use of BATS for mapping memory. This patch makes sure that the specific wii RAM mapping function takes it into account as well. Fixes: de32400dd26e ("wii: use both mem1 and mem2 as ram") Cc: stable@vger.kernel.org Reviewed-by: Jonathan Neuschafer <j.neuschaefer@gmx.net> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/8xx: Map 32Mb of RAM at init.Christophe Leroy
At the time being, initial MMU setup allows 24 Mbytes of DATA and 8 Mbytes of code. Some debug setup like CONFIG_KASAN generate huge kernels with text size over the 8M limit and data over the 24 Mbytes limit. Here is an 8xx kernel compiled with CONFIG_KASAN_INLINE for one of my boards: [root@po16846vm linux-powerpc]# size -x vmlinux text data bss dec hex filename 0x111019c 0x41b0d4 0x490de0 26984528 19bc050 vmlinux This patch maps up to 32 Mbytes code based on _einittext symbol and allows 32 Mbytes of memory instead of 24. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc/8xx: replace most #ifdef by IS_ENABLED() in 8xx_mmu.cChristophe Leroy
This patch replaces most #ifdef mess by IS_ENABLED() in 8xx_mmu.c This has the advantage of allowing syntax verification at compile time regardless of selected options. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc: sstep: Add tests for addc[.] instructionSandipan Das
This adds test cases for the addc[.] instruction. Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc: sstep: Add tests for add[.] instructionSandipan Das
This adds test cases for the add[.] instruction. Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc: sstep: Add tests for compute type instructionsSandipan Das
This enhances the current selftest framework for validating the in-kernel instruction emulation infrastructure by adding support for compute type instructions i.e. integer ALU-based instructions. Originally, this framework was limited to only testing load and store instructions. While most of the GPRs can be validated, support for SPRs is limited to LR, CR and XER for now. When writing the test cases, one must ensure that the Stack Pointer (GPR1) or the Thread Pointer (GPR13) are not touched by any means as these are vital non-volatile registers. Signed-off-by: Sandipan Das <sandipan@linux.ibm.com> [mpe: Use patch_site for the code patching] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23Revert "powerpc/book3s32: Reorder _PAGE_XXX flags to simplify TLB handling"Michael Ellerman
This reverts commit 78ca1108b10927b3d068c8da91352b0f4cd01fc5. It is causing boot failures with qemu mac99 in at least some configurations.
2019-02-22powerpc: Move page table dump files in a dedicated subdirectoryChristophe Leroy
This patch moves the files related to page table dump in a dedicated subdirectory. The purpose is to clean a bit arch/powerpc/mm by regrouping multiple files handling a dedicated function. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Shorten the file names while we're at it] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc: dump as a single line areas mapping a single physical page.Christophe Leroy
When using KASAN, there are parts of the shadow area where all pages are mapped to the kasan_early_shadow_page. It is pointless to dump one line for each of those pages (in the example below there are 7168 entries pointing to the same physical page). ~# cat /sys/kernel/debug/kernel_page_tables ... ---[ kasan shadow mem start ]--- 0xf7c00000-0xf8bfffff 0x06fac000 16M rw present dirty accessed 0xf8c00000-0xf8c03fff 0x00cd0000 16K r present dirty accessed 0xf8c04000-0xf8c07fff 0x00cd0000 16K r present dirty accessed 0xf8c08000-0xf8c0bfff 0x00cd0000 16K r present dirty accessed 0xf8c0c000-0xf8c0ffff 0x00cd0000 16K r present dirty accessed 0xf8c10000-0xf8c13fff 0x00cd0000 16K r present dirty accessed ... 7168 identical lines 0xffbfc000-0xffbfffff 0x00cd0000 16K r present dirty accessed ---[ kasan shadow mem end ]--- ... This patch modifies linux table dump to dump as a single line areas where all addresses points to the same physical page. That physical address is put inside [] to show that all virt pages points to the same phys page. ~# cat /sys/kernel/debug/kernel_page_tables ... ---[ kasan shadow mem start ]--- 0xf7c00000-0xf8bfffff 0x06fac000 16M rw present dirty accessed 0xf8c00000-0xffbfffff [0x00cd0000] 16K r present dirty accessed ---[ kasan shadow mem end ]--- ... Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/32: Fix CONFIG_VIRT_CPU_ACCOUNTING_NATIVE for 40x/bookeChristophe Leroy
40x/booke have another path to reach 3f from transfer_to_handler, make sure it also calls ACCOUNT_CPU_USER_ENTRY() when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is selected. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/book3s32: Reorder _PAGE_XXX flags to simplify TLB handlingChristophe Leroy
For pages without _PAGE_USER, PP field is 00 For pages with _PAGE_USER, PP field is 10 for RW and 11 for RO. This patch sets _PAGE_USER to 0x002 and _PAGE_RW to 0x001 is order to simplify TLB handling by reducing amount of shifts. The location of _PAGE_PRESENT and _PAGE_HASHPTE doesn't matter as they are only SW related flags. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/603: don't handle PAGE_ACCESSED in TLB miss handlers.Christophe Leroy
PAGE_ACCESSED is only needed for CONFIG_SWAP. When CONFIG_SWAP is not set, just ignore it. If CONFIG_SWAP is set and PAGE_ACCESSED is not, let's take a minor fault. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/603: Don't worry about _PAGE_USER in TLB miss handlersChristophe Leroy
PP bits take user access into account, so no need to check _PAGE_USER here. A DSI or ISI will be generated if needed. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/603: let's handle PAGE_DIRTY directlyChristophe Leroy
PAGE_DIRTY corresponds to the C bit. If writing on a page for which the C bit is not set, a DataStoreTLBMiss is generated. No need to check it in DataLoadTLBMiss. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/603: Don't handle _PAGE_RW and _PAGE_DIRTY on ITLB missesChristophe Leroy
_PAGE_RW and _PAGE_DIRTY do not matter for ITLB misses. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/603: Don't handle kernel page TLB misses when not needChristophe Leroy
ITLB miss on kernel pages only occur with CONFIG_MODULES and CONFIG_DEBUG_PAGEALLOC. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/hash32: use physical address directly in hash handlers.Christophe Leroy
Since commit c62ce9ef97ba ("powerpc: remove remaining bits from CONFIG_APUS"), tophys() has become a pure constant operation. PAGE_OFFSET is known at compile time so the physical address can be builtin directly. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/603: use physical address directly in TLB miss handlers.Christophe Leroy
Since commit c62ce9ef97ba ("powerpc: remove remaining bits from CONFIG_APUS"), tophys() has become a pure constant operation. PAGE_OFFSET is known at compile time so the physical address can be builtin directly. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/6xx: Store PGDIR physical address in a SPRGChristophe Leroy
Use SPRN_SPRG2 to store the current thread PGDIR and avoid reading thread_struct.pgdir at every TLB miss. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/6xx: Don't use SPRN_SPRG2 for storing stack pointer while in RTASChristophe Leroy
When calling RTAS, the stack pointer is stored in SPRN_SPRG2 in order to be able to restore it in case of machine check in RTAS. As machine check is not a perfomance critical path, this patch frees SPRN_SPRG2 by using a field in thread struct instead. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc: simplify BDI switchChristophe Leroy
There is no reason to re-read each time the pointer at location 0xf0 as it is fixed and known. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/83xx: Also save/restore SPRG4-7 during suspendChristophe Leroy
The 83xx has 8 SPRG registers and uses at least SPRG4 for DTLB handling LRU. Fixes: 2319f1239592 ("powerpc/mm: e300c2/c3/c4 TLB errata workaround") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/traps: fix recoverability of machine check handling on book3s/32Christophe Leroy
Looks like book3s/32 doesn't set RI on machine check, so checking RI before calling die() will always be fatal allthought this is not an issue in most cases. Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt") Fixes: daf00ae71dad ("powerpc/traps: restore recoverability of machine_check interrupts") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/32: Remove unneccessary MSR[RI] clearing for 8xxChristophe Leroy
MSR[RI] has already been cleared a few lines above. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/setup: display reason for not bootingChristophe Leroy
When no machine description matches, display it clearly before looping forever. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/8xx: hide itlbie and dtlbie symbolsChristophe Leroy
When disassembling InstructionTLBError we get the following messy code: c000138c: 7d 84 63 78 mr r4,r12 c0001390: 75 25 58 00 andis. r5,r9,22528 c0001394: 75 2a 40 00 andis. r10,r9,16384 c0001398: 41 a2 00 08 beq c00013a0 <itlbie> c000139c: 7c 00 22 64 tlbie r4,r0 c00013a0 <itlbie>: c00013a0: 39 40 04 01 li r10,1025 c00013a4: 91 4b 00 b0 stw r10,176(r11) c00013a8: 39 40 10 32 li r10,4146 c00013ac: 48 00 cc 59 bl c000e004 <transfer_to_handler> For a cleaner code dump, this patch replaces itlbie and dtlbie symbols by local symbols. c000138c: 7d 84 63 78 mr r4,r12 c0001390: 75 25 58 00 andis. r5,r9,22528 c0001394: 75 2a 40 00 andis. r10,r9,16384 c0001398: 41 a2 00 08 beq c00013a0 <InstructionTLBError+0xa0> c000139c: 7c 00 22 64 tlbie r4,r0 c00013a0: 39 40 04 01 li r10,1025 c00013a4: 91 4b 00 b0 stw r10,176(r11) c00013a8: 39 40 10 32 li r10,4146 c00013ac: 48 00 cc 59 bl c000e004 <transfer_to_handler> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/powernv: Don't reprogram SLW image on every KVM guest entry/exitPaul Mackerras
Commit 24be85a23d1f ("powerpc/powernv: Clear PECE1 in LPCR via stop-api only on Hotplug", 2017-07-21) added two calls to opal_slw_set_reg() inside pnv_cpu_offline(), with the aim of changing the LPCR value in the SLW image to disable wakeups from the decrementer while a CPU is offline. However, pnv_cpu_offline() gets called each time a secondary CPU thread is woken up to participate in running a KVM guest, that is, not just when a CPU is offlined. Since opal_slw_set_reg() is a very slow operation (with observed execution times around 20 milliseconds), this means that an offline secondary CPU can often be busy doing the opal_slw_set_reg() call when the primary CPU wants to grab all the secondary threads so that it can run a KVM guest. This leads to messages like "KVM: couldn't grab CPU n" being printed and guest execution failing. There is no need to reprogram the SLW image on every KVM guest entry and exit. So that we do it only when a CPU is really transitioning between online and offline, this moves the calls to pnv_program_cpu_hotplug_lpcr() into pnv_smp_cpu_kill_self(). Fixes: 24be85a23d1f ("powerpc/powernv: Clear PECE1 in LPCR via stop-api only on Hotplug") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/64s: Fix logic when handling unknown CPU featuresMichael Ellerman
In cpufeatures_process_feature(), if a provided CPU feature is unknown and enable_unknown is false, we erroneously print that the feature is being enabled and return true, even though no feature has been enabled, and may also set feature bits based on the last entry in the match table. Fix this so that we only set feature bits from the match table if we have actually enabled a feature from that table, and when failing to enable an unknown feature, always print the "not enabling" message and return false. Coincidentally, some older gccs (<GCC 7), when invoked with -fsanitize-coverage=trace-pc, cause a spurious uninitialised variable warning in this function: arch/powerpc/kernel/dt_cpu_ftrs.c: In function ‘cpufeatures_process_feature’: arch/powerpc/kernel/dt_cpu_ftrs.c:686:7: warning: ‘m’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (m->cpu_ftr_bit_mask) An upcoming patch will enable support for kcov, which requires this option. This patch avoids the warning. Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features") Reported-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> [ajd: add commit message] Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
2019-02-22powerpc/smp: Make __smp_send_nmi_ipi() staticNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/smp: Fix NMI IPI xmon timeoutNicholas Piggin
The xmon debugger IPI handler waits in the callback function while xmon is still active. This means they don't complete the IPI, and the initiator always times out waiting for them. Things manage to work after the timeout because there is some fallback logic to keep NMI IPI state sane in case of the timeout, but this is a bit ugly. This patch changes NMI IPI back to half-asynchronous (i.e., wait for everyone to call in, do not wait for IPI function to complete), but the complexity is avoided by going one step further and allowing new IPIs to be issued before the IPI functions to all complete. If synchronization against that is required, it is left up to the caller, but current callers don't require that. In fact with the timeout handling, callers must be able to cope with this already. Fixes: 5b73151fff63 ("powerpc: NMI IPI make NMI IPIs fully sychronous") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/smp: Fix NMI IPI timeoutNicholas Piggin
The NMI IPI timeout logic is broken, if __smp_send_nmi_ipi() times out on the first condition, delay_us will be zero which will send it into the second spin loop with no timeout so it will spin forever. Fixes: 5b73151fff63 ("powerpc: NMI IPI make NMI IPIs fully sychronous") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc: Make PPC_64K_PAGES depend on only 44x or PPC_BOOK3S_64Michael Ellerman
In commit 7820856a4fcd ("powerpc/mm/book3e/64: Remove unsupported 64Kpage size from 64bit booke") we dropped the 64K page size support from the 64-bit nohash (Book3E) code. But we didn't update the dependencies of the PPC_64K_PAGES option, meaning a randconfig can still trigger this code and cause a build breakage, eg: arch/powerpc/include/asm/nohash/64/pgtable.h:14:2: error: #error "Page size not supported" arch/powerpc/include/asm/nohash/mmu-book3e.h:275:2: error: #error Unsupported page size So remove PPC_BOOK3E_64 from the dependencies. This also means we don't need to worry about PPC_FSL_BOOK3E, because that was just trying to prevent the PPC_BOOK3E_64=y && PPC_FSL_BOOK3E=y case. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/64: Make sys_switch_endian() traceableMichael Ellerman
We weren't using SYSCALL_DEFINE for sys_switch_endian(), which means it wasn't able to be traced by CONFIG_FTRACE_SYSCALLS. By using the macro we create the right metadata and the syscall is visible. eg: # cd /sys/kernel/debug/tracing # echo 1 | tee events/syscalls/sys_*_switch_endian/enable # ~/switch_endian_test # cat trace ... switch_endian_t-3604 [009] .... 315.175164: sys_switch_endian() switch_endian_t-3604 [009] .... 315.175167: sys_switch_endian -> 0x5555aaaa5555aaaa switch_endian_t-3604 [009] .... 315.175169: sys_switch_endian() switch_endian_t-3604 [009] .... 315.175169: sys_switch_endian -> 0x5555aaaa5555aaaa Fixes: 529d235a0e19 ("powerpc: Add a proper syscall for switching endianness") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/dts: Standardize DTS status assignments from "ok" to "okay"Robert P. J. Day
While the current kernel drivers/of/ code allows developers to be sloppy and use a DTS status value of "ok", the current DTSpec 0.1 makes it clear that the proper spelling is "okay", so fix the small number of PowerPC .dts files that do this. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-22powerpc/book3s: Remove pgd/pud/pmd_set() interfacesAneesh Kumar K.V
When updating page tables, we need to make sure we fill the page table entry valid bits. We do this by or'ing in one of PGD/PUD/PMD_VAL_BITS. The page table 'set' interfaces allow updating the raw value of page table entries without setting the valid bits, so remove those interfaces to avoid incorrect usage in future. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Reword commit message based on mailing list discussion] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>