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2022-09-28powerpc/64e: provide an addressing macro for use with TOC in alternate registerNicholas Piggin1-0/+11
The interrupt entry code carefully saves a minimal number of registers, so in some places the TOC is required, it is loaded into a different register, so provide a macro that can supply an alternate TOC register. This continues to use got addressing because TOC-relative results in "got/toc optimization is not supported" messages by the linker. Having r2 be one of the saved registers and using that for TOC addressing may be the best way to avoid that and switch this to TOC addressing. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220926034057.2360083-6-npiggin@gmail.com
2022-09-28powerpc/64: provide a helper macro to load r2 with the kernel TOCNicholas Piggin1-0/+6
A later change stops the kernel using r2 and loads it with a poison value. Provide a PACATOC loading abstraction which can hide this detail. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220926034057.2360083-5-npiggin@gmail.com
2022-09-28powerpc/64: switch asm helpers from GOT to TOC relative addressingNicholas Piggin1-1/+2
There is no need to use GOT addressing within the kernel. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220926034057.2360083-4-npiggin@gmail.com
2022-09-26powerpc: Add ZEROIZE_GPRS macros for register clearsRohan McLure1-0/+22
Provide register zeroing macros, following the same convention as existing register stack save/restore macros, to be used in later change to concisely zero a sequence of consecutive gprs. The resulting macros are called ZEROIZE_GPRS and ZEROIZE_NVGPRS, keeping with the naming of the accompanying restore and save macros, and usage of zeroize to describe this operation elsewhere in the kernel. Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220921065605.1051927-4-rmclure@linux.ibm.com
2022-09-26powerpc: Remove CONFIG_PPC_FSL_BOOK3EChristophe Leroy1-3/+3
CONFIG_PPC_FSL_BOOK3E is redundant with CONFIG_PPC_E500. Remove it. And rename five files accordingly. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Rename include guards to match new file names] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/795cb93b88c9a0279289712e674f39e3b108a1b4.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26powerpc: Remove CONFIG_PPC_BOOK3EChristophe Leroy1-2/+2
CONFIG_PPC_BOOK3E is redundant with CONFIG_PPC_BOOK3E_64. The later is more explicit about the fact that it's a 64 bits target. Remove CONFIG_PPC_BOOK3E. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5d0891490813c19cdcfc04678f512ea68cba3e64.1663606876.git.christophe.leroy@csgroup.eu
2022-05-19powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2}Christophe Leroy1-2/+2
Replace all uses of PPC64_ELF_ABI_v1 and PPC64_ELF_ABI_v2 by resp CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ba13d59e8c50bc9aa6328f1c7f0c0d0278e0a3a7.1652074503.git.christophe.leroy@csgroup.eu
2022-02-23powerpc: Remove remaining stab codesChristophe Leroy1-6/+0
Following commit 12318163737c ("powerpc/32: Remove remaining .stabs annotations"), stabs code are not used anymore. Remove them. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d8b33342d7454f6ca4f368f5206896558dfa06f4.1645538722.git.christophe.leroy@csgroup.eu
2022-02-07powerpc/32: Remove _ENTRY() macroChristophe Leroy1-4/+0
_ENTRY() is now redundant with _GLOBAL(). Remove it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/62a35f8dde2bb74c8d0d7a5430cce07a5a3a6fb6.1638273868.git.christophe.leroy@csgroup.eu
2022-02-07powerpc/32: Remove remaining .stabs annotationsChristophe Leroy1-1/+0
STABS debug format has been superseded long time ago by DWARF. Remove the few remaining .stabs annotations from old 32 bits code. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/68932ec2ba6b868d35006b96e90f0890f3da3c05.1638273868.git.christophe.leroy@csgroup.eu
2021-11-29powerpc: flexible GPR range save/restore macrosNicholas Piggin1-16/+27
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 <npiggin@gmail.com> Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211022061322.2671178-1-npiggin@gmail.com
2021-10-22powerpc/32: Don't use lmw/stmw for saving/restoring non volatile regsChristophe Leroy1-2/+2
Instructions lmw/stmw are interesting for functions that are rarely used and not in the cache, because only one instruction is to be copied into the instruction cache instead of 19. However those instruction are less performant than 19x raw lwz/stw as they require synchronisation plus one additional cycle. SAVE_NVGPRS / REST_NVGPRS are used in only a few places which are mostly in interrupts entries/exits and in task switch so they are likely already in the cache. Using standard lwz improves null_syscall selftest by: - 10 cycles on mpc832x. - 2 cycles on mpc8xx. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/316c543b8906712c108985c8463eec09c8db577b.1629732542.git.christophe.leroy@csgroup.eu
2021-08-25powerpc/booke: Avoid link stack corruption in several placesChristophe Leroy1-1/+1
Use bcl 20,31,+4 instead of bl in order to preserve link stack. See commit c974809a26a1 ("powerpc/vdso: Avoid link stack corruption in __get_datapage()") for details. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e9fbc285eceb720e6c0e032ef47fe8b05f669b48.1629791751.git.christophe.leroy@csgroup.eu
2021-08-15powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm gotoChristophe Leroy1-10/+1
Using asm goto in __WARN_FLAGS() and WARN_ON() allows more flexibility to GCC. For that add an entry to the exception table so that program_check_exception() knowns where to resume execution after a WARNING. Here are two exemples. The first one is done on PPC32 (which benefits from the previous patch), the second is on PPC64. unsigned long test(struct pt_regs *regs) { int ret; WARN_ON(regs->msr & MSR_PR); return regs->gpr[3]; } unsigned long test9w(unsigned long a, unsigned long b) { if (WARN_ON(!b)) return 0; return a / b; } Before the patch: 000003a8 <test>: 3a8: 81 23 00 84 lwz r9,132(r3) 3ac: 71 29 40 00 andi. r9,r9,16384 3b0: 40 82 00 0c bne 3bc <test+0x14> 3b4: 80 63 00 0c lwz r3,12(r3) 3b8: 4e 80 00 20 blr 3bc: 0f e0 00 00 twui r0,0 3c0: 80 63 00 0c lwz r3,12(r3) 3c4: 4e 80 00 20 blr 0000000000000bf0 <.test9w>: bf0: 7c 89 00 74 cntlzd r9,r4 bf4: 79 29 d1 82 rldicl r9,r9,58,6 bf8: 0b 09 00 00 tdnei r9,0 bfc: 2c 24 00 00 cmpdi r4,0 c00: 41 82 00 0c beq c0c <.test9w+0x1c> c04: 7c 63 23 92 divdu r3,r3,r4 c08: 4e 80 00 20 blr c0c: 38 60 00 00 li r3,0 c10: 4e 80 00 20 blr After the patch: 000003a8 <test>: 3a8: 81 23 00 84 lwz r9,132(r3) 3ac: 71 29 40 00 andi. r9,r9,16384 3b0: 40 82 00 0c bne 3bc <test+0x14> 3b4: 80 63 00 0c lwz r3,12(r3) 3b8: 4e 80 00 20 blr 3bc: 0f e0 00 00 twui r0,0 0000000000000c50 <.test9w>: c50: 7c 89 00 74 cntlzd r9,r4 c54: 79 29 d1 82 rldicl r9,r9,58,6 c58: 0b 09 00 00 tdnei r9,0 c5c: 7c 63 23 92 divdu r3,r3,r4 c60: 4e 80 00 20 blr c70: 38 60 00 00 li r3,0 c74: 4e 80 00 20 blr In the first exemple, we see GCC doesn't need to duplicate what happens after the trap. In the second exemple, we see that GCC doesn't need to emit a test and a branch in the likely path in addition to the trap. We've got some WARN_ON() in .softirqentry.text section so it needs to be added in the OTHER_TEXT_SECTIONS in modpost.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/389962b1b702e3c78d169e59bcfac56282889173.1618331882.git.christophe.leroy@csgroup.eu
2021-06-30powerpc/64s: add a table of implicit soft-masked addressesNicholas Piggin1-0/+7
Commit 9d1988ca87dd ("powerpc/64: treat low kernel text as irqs soft-masked") ends up catching too much code, including ret_from_fork, and parts of interrupt and syscall return that do not expect to be interrupts to be soft-masked. If an interrupt gets marked pending, and then the code proceeds out of the implicit soft-masked region it will fail to deal with the pending interrupt. Fix this by adding a new table of addresses which explicitly marks the regions of code that are soft masked. This table is only checked for interrupts that below __end_soft_masked, so most kernel interrupts will not have the overhead of the table search. Fixes: 9d1988ca87dd ("powerpc/64: treat low kernel text as irqs soft-masked") Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210630074621.2109197-5-npiggin@gmail.com
2021-06-25powerpc/64: allow alternate return locations for soft-masked interruptsNicholas Piggin1-0/+8
The exception table fixup adjusts a failed page fault's interrupt return location if it was taken at an address specified in the exception table, to a corresponding fixup handler address. Introduce a variation of that idea which adds a fixup table for NMIs and soft-masked asynchronous interrupts. This will be used to protect certain critical sections that are sensitive to being clobbered by interrupts coming in (due to using the same SPRs and/or irq soft-mask state). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-10-npiggin@gmail.com
2021-04-14powerpc/64e/interrupt: use new interrupt returnNicholas Piggin1-20/+0
Update the new C and asm interrupt return code to account for 64e specifics, switch over to use it. The now-unused old ret_from_except code, that was moved to 64e after the 64s conversion, is removed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210316104206.407354-5-npiggin@gmail.com
2021-03-29powerpc/32: Entry cpu time accounting in CChristophe Leroy1-10/+0
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> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/daca4c3e05cdfe54d237162a0718b3aaca897662.1615552866.git.christophe.leroy@csgroup.eu
2021-02-09powerpc/64: entry cpu time accounting in CNicholas Piggin1-24/+0
There is no need for this to be in asm, use the new interrupt entry wrapper. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-39-npiggin@gmail.com
2020-12-21powerpc/vdso: Fix DOTSYM for 32-bit LE VDSOMichael Ellerman1-1/+6
Skirmisher reported on IRC that the 32-bit LE VDSO was hanging. This turned out to be due to a branch to self in eg. __kernel_gettimeofday. Looking at the disassembly with objdump -dR shows why: 00000528 <__kernel_gettimeofday>: 528: f0 ff 21 94 stwu r1,-16(r1) 52c: a6 02 08 7c mflr r0 530: f0 ff 21 94 stwu r1,-16(r1) 534: 14 00 01 90 stw r0,20(r1) 538: 05 00 9f 42 bcl 20,4*cr7+so,53c <__kernel_gettimeofday+0x14> 53c: a6 02 a8 7c mflr r5 540: ff ff a5 3c addis r5,r5,-1 544: c4 fa a5 38 addi r5,r5,-1340 548: f0 00 a5 38 addi r5,r5,240 54c: 01 00 00 48 bl 54c <__kernel_gettimeofday+0x24> 54c: R_PPC_REL24 .__c_kernel_gettimeofday Because we don't process relocations for the VDSO, this branch remains a branch from 0x54c to 0x54c. With the preceding patch to prohibit R_PPC_REL24 relocations, we instead get a build failure: 0000054c R_PPC_REL24 .__c_kernel_gettimeofday 00000598 R_PPC_REL24 .__c_kernel_clock_gettime 000005e4 R_PPC_REL24 .__c_kernel_clock_gettime64 00000630 R_PPC_REL24 .__c_kernel_clock_getres 0000067c R_PPC_REL24 .__c_kernel_time arch/powerpc/kernel/vdso32/vdso32.so.dbg: dynamic relocations are not supported The root cause is that we're branching to `.__c_kernel_gettimeofday`. But this is 32-bit LE code, which doesn't use function descriptors, so there are no dot symbols. The reason we're trying to branch to a dot symbol is because we're using the DOTSYM macro, but the ifdefs we use to define the DOTSYM macro do not currently work for 32-bit LE. So like previous commits we need to differentiate if the current compilation unit is 64-bit, rather than the kernel as a whole. ie. switch from CONFIG_PPC64 to __powerpc64__. With that fixed 32-bit LE code gets the empty version of DOTSYM, which just resolves to the original symbol name, leading to a direct branch and no relocations: 000003f8 <__kernel_gettimeofday>: 3f8: f0 ff 21 94 stwu r1,-16(r1) 3fc: a6 02 08 7c mflr r0 400: f0 ff 21 94 stwu r1,-16(r1) 404: 14 00 01 90 stw r0,20(r1) 408: 05 00 9f 42 bcl 20,4*cr7+so,40c <__kernel_gettimeofday+0x14> 40c: a6 02 a8 7c mflr r5 410: ff ff a5 3c addis r5,r5,-1 414: f4 fb a5 38 addi r5,r5,-1036 418: f0 00 a5 38 addi r5,r5,240 41c: 85 06 00 48 bl aa0 <__c_kernel_gettimeofday> Fixes: ab037dd87a2f ("powerpc/vdso: Switch VDSO to generic C implementation.") Reported-by: "Will Springer <skirmisher@protonmail.com>" Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201218111619.1206391-3-mpe@ellerman.id.au
2020-12-04powerpc/vdso: Prepare for switching VDSO to generic C implementation.Christophe Leroy1-0/+2
Prepare for switching VDSO to generic C implementation in following patch. Here, we: - Prepare the helpers to call the C VDSO functions - Prepare the required callbacks for the C VDSO functions - Prepare the clocksource.h files to define VDSO_ARCH_CLOCKMODES - Add the C trampolines to the generic C VDSO functions powerpc is a bit special for VDSO as well as system calls in the way that it requires setting CR SO bit which cannot be done in C. Therefore, entry/exit needs to be performed in ASM. Implementing __arch_get_vdso_data() would clobber the link register, requiring the caller to save it. As the ASM calling function already has to set a stack frame and saves the link register before calling the C vdso function, retriving the vdso data pointer there is lighter. Implement __arch_vdso_capable() and always return true. Provide vdso_shift_ns(), as the generic x >> s gives the following bad result: 18: 35 25 ff e0 addic. r9,r5,-32 1c: 41 80 00 10 blt 2c <shift+0x14> 20: 7c 64 4c 30 srw r4,r3,r9 24: 38 60 00 00 li r3,0 ... 2c: 54 69 08 3c rlwinm r9,r3,1,0,30 30: 21 45 00 1f subfic r10,r5,31 34: 7c 84 2c 30 srw r4,r4,r5 38: 7d 29 50 30 slw r9,r9,r10 3c: 7c 63 2c 30 srw r3,r3,r5 40: 7d 24 23 78 or r4,r9,r4 In our case the shift is always <= 32. In addition, the upper 32 bits of the result are likely nul. Lets GCC know it, it also optimises the following calculations. With the patch, we get: 0: 21 25 00 20 subfic r9,r5,32 4: 7c 69 48 30 slw r9,r3,r9 8: 7c 84 2c 30 srw r4,r4,r5 c: 7d 24 23 78 or r4,r9,r4 10: 7c 63 2c 30 srw r3,r3,r5 Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201126131006.2431205-6-mpe@ellerman.id.au
2020-11-19powerpc: Remove RFI macroChristophe Leroy1-5/+0
RFI macro is just there to add an infinite loop past rfi in order to avoid prefetch on 40x in half a dozen of places in entry_32 and head_32. Those places are already full of #ifdefs, so just add a few more to explicitely show those loops and remove RFI. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f7e9cb9e9240feec63cb330abf40b67d1aad852f.1604854583.git.christophe.leroy@csgroup.eu
2020-11-19powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFIChristophe Leroy1-1/+0
In head_64.S, we have two places using RFI to return to kernel. Use RFI_TO_KERNEL instead. They are the two only places using RFI on book3s/64, so the RFI macro can go away. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7719261b0a0d2787772339484c33eb809723bca7.1604854583.git.christophe.leroy@csgroup.eu
2020-10-08powerpc: Remove support for PowerPC 601Christophe Leroy1-2/+1
PowerPC 601 has been retired. Remove all associated specific code. CPU_FTRS_PPC601 has CPU_FTR_COHERENT_ICACHE and CPU_FTR_COMMON. CPU_FTR_COMMON is already present via other CPU_FTRS. None of the remaining CPU selects CPU_FTR_COHERENT_ICACHE. So CPU_FTRS_PPC601 can be removed from the possible features, hence can be removed completely. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/60b725d55e21beec3335175c20b77903ff98284f.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08powerpc: Drop SYNC_601() ISYNC_601() and SYNC()Christophe Leroy1-4/+0
Those macros are now empty at all time. Drop them. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7990bb63fc53e460bfa94f8040184881d9e6fbc3.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08powerpc: Remove CONFIG_PPC601_SYNC_FIXChristophe Leroy1-6/+0
This config option isn't in any defconfig. The very first versions of Powerpc 601 have a bug which requires additional sync before and/or after some instructions. This was more than 25 years ago and time has come to retire those buggy versions of the 601 from the kernel. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/55b46bff16705b1ae7bf0a60ccd522b1010ebf75.1601362098.git.christophe.leroy@csgroup.eu
2020-07-27powerpc/ppc_asm.h: delete duplicated wordRandy Dunlap1-1/+1
Drop the repeated word "in". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726003809.20454-7-rdunlap@infradead.org
2020-07-22powerpc/64s: system call support for scv/rfscv instructionsNicholas Piggin1-0/+2
Add support for the scv instruction on POWER9 and later CPUs. For now this implements the zeroth scv vector 'scv 0', as identical to 'sc' system calls, with the exception that LR is not preserved, nor are volatile CR registers, and error is not indicated with CR0[SO], but by returning a negative errno. rfscv is implemented to return from scv type system calls. It can not be used to return from sc system calls because those are defined to preserve LR. getpid syscall throughput on POWER9 is improved by 26% (428 to 318 cycles), largely due to reducing mtmsr and mtspr. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix ppc64e build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200611081203.995112-3-npiggin@gmail.com
2019-08-28powerpc/32s: get rid of CPU_FTR_601 featureChristophe Leroy1-21/+7
Now that 601 is exclusive from other 6xx, CPU_FTR_601 and associated fixups are useless. Drop this feature and use #ifdefs instead. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ecdb7194a17dbfa01865df6a82979533adc2c70b.1566834712.git.christophe.leroy@c-s.fr
2019-08-27powerpc/64: optimise LOAD_REG_IMMEDIATE_SYM()Christophe Leroy1-6/+6
Optimise LOAD_REG_IMMEDIATE_SYM() using a temporary register to parallelise operations. It reduces the path from 5 to 3 instructions. Suggested-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bad41ed02531bb0382420cbab50a0d7153b71767.1566311636.git.christophe.leroy@c-s.fr
2019-08-27powerpc: rewrite LOAD_REG_IMMEDIATE() as an intelligent macroChristophe Leroy1-5/+37
Today LOAD_REG_IMMEDIATE() is a basic #define which loads all parts on a value into a register, including the parts that are NUL. This means always 2 instructions on PPC32 and always 5 instructions on PPC64. And those instructions cannot run in parallele as they are updating the same register. Ex: LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) in head_64.S results in: 3c 20 00 00 lis r1,0 60 21 00 00 ori r1,r1,0 78 21 07 c6 rldicr r1,r1,32,31 64 21 00 00 oris r1,r1,0 60 21 40 00 ori r1,r1,16384 Rewrite LOAD_REG_IMMEDIATE() with GAS macro in order to skip the parts that are NUL. Rename existing LOAD_REG_IMMEDIATE() as LOAD_REG_IMMEDIATE_SYM() and use that one for loading value of symbols which are not known at compile time. Now LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) in head_64.S results in: 38 20 40 00 li r1,16384 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d60ce8dd3a383c7adbfc322bf1d53d81724a6000.1566311636.git.christophe.leroy@c-s.fr
2018-12-20powerpc/fsl: Add macro to flush the branch predictorDiana Craciun1-0/+10
The BUCSR register can be used to invalidate the entries in the branch prediction mechanisms. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-19powerpc: remove remaining bits from CONFIG_APUSChristophe Leroy1-17/+2
commit f21f49ea639a ("[POWERPC] Remove the dregs of APUS support from arch/powerpc") removed CONFIG_APUS, but forgot to remove the logic which adapts tophys() and tovirt() for it. This patch removes the last stale pieces. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-30powerpc: clean inclusions of asm/feature-fixups.hChristophe Leroy1-0/+1
files not using feature fixup don't need asm/feature-fixups.h files using feature fixup need asm/feature-fixups.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-18powerpc/32: Use stmw/lmw for registers save/restore in asmChristophe Leroy1-4/+2
arch/powerpc/Makefile activates -mmultiple on BE PPC32 configs in order to use multiple word instructions in functions entry/exit. The patch does the same for the asm parts, for consistency. On processors like the 8xx on which insn fetching is pretty slow, this speeds up registers save/restore. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: PPC32 is BE only, so drop the endian checks] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01powerpc/64s: Set assembler machine type to POWER4Nicholas Piggin1-7/+4
Rather than override the machine type in .S code (which can hide wrong or ambiguous code generation for the target), set the type to power4 for all assembly. This also means we need to be careful not to build power4-only code when we're not building for Book3S, such as the "power7" versions of copyuser/page/memcpy. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix Book3E build, don't build the "power7" variants for non-Book3S] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06powerpc/book3s: Add an HV variant of FIXUP_ENDIAN that is recoverableNicholas Piggin1-0/+22
Add an HV variant of FIXUP_ENDIAN which uses HSRR[01] and does not clear MSR[RI], which improves recoverability. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-11-06powerpc/book3s: Use label for FIXUP_ENDIAN macro branchNicholas Piggin1-2/+3
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-10powerpc/8xx: Getting rid of remaining use of CONFIG_8xxChristophe Leroy1-1/+1
Two config options exist to define powerpc MPC8xx: * CONFIG_PPC_8xx * CONFIG_8xx arch/powerpc/platforms/Kconfig.cputype has contained the following comment about CONFIG_8xx item for some years: "# this is temp to handle compat with arch=ppc" arch/powerpc is now the only place with remaining use of CONFIG_8xx: get rid of them. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-10powerpc/time: refactor MFTB() to limit number of ifdefsChristophe Leroy1-3/+9
The 8xx cannot access the TBL and TBU registers using mfspr/mtspr It must be accessed using mftb/mftbu Due to this, there is a number of places with #ifdef CONFIG_8xx This patch defines new macros MFTBL(x) and MFTBU(x) on the same model as MFTB(x) and tries to make use of them as much as possible. In arch/powerpc/include/asm/timex.h, we also remove the ifdef for the asm() operands as the compiler doesn't mind unused operands Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-10powerpc: Fix invalid use of register expressionsAndreas Schwab1-1/+1
binutils >= 2.26 now warns about misuse of register expressions in assembler operands that are actually literals, for example: arch/powerpc/kernel/entry_64.S:535: Warning: invalid register expression In practice these are almost all uses of r0 that should just be a literal 0. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> [mpe: Mention r0 is almost always the culprit, fold in purgatory change] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-05-30powerpc/64s: Fix FIXUP_ENDIAN non-maskable interrupt reentrancyNicholas Piggin1-4/+7
FIXUP_ENDIAN uses SRR[01] with MSR_RI=1, which gets corrupted if there is an interleaving system reset or machine check interrupt. Set MSR_RI=0 before setting SRRs. The rfid will restore MSR. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-26powerpc/32: Remove FIX_SRR1Christophe Leroy1-1/+0
FIX_SRR1() is defined as blank. Last useful instance of FIX_SRR1() was removed by commit 40ef8cbc6d360 ("powerpc: Get 64-bit configs to compile with ARCH=powerpc") in 2005. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net>
2016-11-14powerpc: Make _ASM_NOKPROBE_SYMBOL a noop when KPROBES not definedNicholas Piggin1-0/+4
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-14powerpc: Add support for relative exception tablesNicholas Piggin1-3/+3
This halves the exception table size on 64-bit builds, and it allows build-time sorting of exception tables to work on relocated kernels. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Minor asm fixups and bits to keep the selftests working] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-14powerpc: EX_TABLE macro for exception tablesNicholas Piggin1-0/+10
This macro is taken from s390, and allows more flexibility in changing exception table format. mpe: Put it in ppc_asm.h and only define one version using stringinfy_in_c(). Add some empty definitions and headers to keep the selftests happy. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-14powerpc/asm: Allow including ppc_asm.h in asm filesMichael Ellerman1-3/+3
There's no reason to #error if we include ppc_asm.h in asm files, the ifdef already prevents any problems. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23powerpc/32: Remove CLR_TOP32Christophe Leroy1-1/+0
CLR_TOP32() is defined as blank. Last useful instance of CLR_TOP32() was removed by commit 40ef8cbc6d360 ("powerpc: Get 64-bit configs to compile with ARCH=powerpc") in 2005. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-19powerpc: Don't change the section in _GLOBAL()Michael Ellerman1-6/+2
Currently the _GLOBAL() macro unilaterally sets the assembler section to ".text" at the start of the macro. This is rude as the caller may be using a different section. So let the caller decide which section to emit the code into. On big endian we do need to switch to the ".opd" section to emit the OPD, but do that with pushsection/popsection, thereby leaving the original section intact. I verified that the order of all entries in System.map is unchanged after this patch. The actual addresses shift around slightly so you can't just diff the System.map. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-19powerpc/kernel: Use kprobe blacklist for asm functionsNicholas Piggin1-26/+14
Rather than forcing the whole function into the ".kprobes.text" section, just add the symbol's address to the kprobe blacklist. This also lets us drop the three versions of the_KPROBE macro, in exchange for just one version of _ASM_NOKPROBE_SYMBOL - which is a good cleanup. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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