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path: root/arch/powerpc/lib/feature-fixups.c
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2017-03-02sched/headers: Prepare to remove the <linux/mm_types.h> dependency from ↵Ingo Molnar1-0/+1
<linux/sched.h> Update code that relied on sched.h including various MM types for them. This will allow us to remove the <linux/mm_types.h> include from <linux/sched.h>. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10powerpc/32: Fix crash during static key initBenjamin Herrenschmidt1-0/+3
We cannot do those initializations from apply_feature_fixups() as this function runs in a very restricted environment on 32-bit where the kernel isn't running at its linked address and the PTRRELOC() macro must be used for any global accesss. Instead, split them into a separtate steup_feature_keys() function which is called in a more suitable spot on ppc32. Fixes: 309b315b6ec6 ("powerpc: Call jump_label_init() in apply_feature_fixups()") Reported-and-tested-by: Christian Kujau <lists@nerdbynature.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-03powerpc/32: Fix early access to cpu_spec relocationBenjamin Herrenschmidt1-1/+1
Commit 9402c6846131 ("powerpc: Factor do_feature_fixup calls") introduced a subtle bug on 32-bit. When reading the cpu spec from the global, we not only need to do a pointer relocation on the global address but also on the pointer we read from it. This fixes crashes reported on MPC5200 based machines. Fixes: 9402c6846131 ("powerpc: Factor do_feature_fixup calls") Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-01powerpc: Add option to use jump label for mmu_has_feature()Kevin Hao1-0/+1
As we just did for CPU features. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-01powerpc: Add option to use jump label for cpu_has_feature()Kevin Hao1-0/+1
We do binary patching of asm code using CPU features, which is a one-time operation, done during early boot. However checks of CPU features in C code are currently done at run time, even though the set of CPU features can never change after boot. We can optimise this by using jump labels to implement cpu_has_feature(), meaning checks in C code are binary patched into a single nop or branch. For a C sequence along the lines of: if (cpu_has_feature(FOO)) return 2; The generated code before is roughly: ld r9,-27640(r2) ld r9,0(r9) lwz r9,32(r9) cmpwi cr7,r9,0 bge cr7, 1f li r3,2 blr 1: ... After (true): nop li r3,2 blr After (false): b 1f li r3,2 blr 1: ... mpe: Rename MAX_CPU_FEATURES as we already have a #define with that name, and define it simply as a constant, rather than doing tricks with sizeof and NULL pointers. Rename the array to cpu_feature_keys. Use the kconfig we added to guard it. Add BUILD_BUG_ON() if the feature is not a compile time constant. Rewrite the change log. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-01powerpc: Call jump_label_init() in apply_feature_fixups()Aneesh Kumar K.V1-0/+8
Call jump_label_init() early so that we can use static keys for CPU and MMU feature checks. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-01powerpc/kernel: Check features don't change after patchingMichael Ellerman1-1/+26
Early in boot we binary patch some sections of code based on the CPU and MMU feature bits. But it is a one-time patching, there is no facility for repatching the code later if the set of features change. It is a major bug if the set of features changes after we've done the code patching - so add a check for it. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-21powerpc: Factor do_feature_fixup callsBenjamin Herrenschmidt1-2/+30
32 and 64-bit do a similar set of calls early on, we move it all to a single common function to make the boot code more readable. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-09-25powerpc: Make a bunch of things staticAnton Blanchard1-1/+1
Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2011-11-16powerpc: Copy down exception vectors after feature fixupsAnton Blanchard1-0/+23
kdump fails because we try to execute an HV only instruction. Feature fixups are being applied after we copy the exception vectors down to 0 so they miss out on any updates. We have always had this issue but it only became critical in v3.0 when we added CFAR support (breaks POWER5) and v3.1 when we added POWERNV (breaks everyone). Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> [v3.0+] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-07-08powerpc: Fix feature-fixup tests for gcc 4.5Stephen Rothwell1-8/+9
The feature-fixup test declare some extern void variables and then take their addresses. Fix this by declaring them as extern u8 instead. Fixes these warnings (treated as errors): CC arch/powerpc/lib/feature-fixups.o cc1: warnings being treated as errors arch/powerpc/lib/feature-fixups.c: In function 'test_cpu_macros': arch/powerpc/lib/feature-fixups.c:293:23: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:294:9: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:297:2: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:297:2: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c: In function 'test_fw_macros': arch/powerpc/lib/feature-fixups.c:306:23: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:307:9: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:310:2: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:310:2: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c: In function 'test_lwsync_macros': arch/powerpc/lib/feature-fixups.c:321:23: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:322:9: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:326:3: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:326:3: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:329:3: error: taking address of expression of type 'void' arch/powerpc/lib/feature-fixups.c:329:3: error: taking address of expression of type 'void' Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-26powerpc: Fix lwsync feature fixup vs. modules on 64-bitBenjamin Herrenschmidt1-1/+2
Anton's commit enabling the use of the lwsync fixup mechanism on 64-bit breaks modules. The lwsync fixup section uses .long instead of the FTR_ENTRY_OFFSET macro used by other fixups sections, and thus will generate 32-bit relocations that our module loader cannot resolve. This changes it to use the same type as other feature sections. Note however that we might want to consider using 32-bit for all the feature fixup offsets and add support for R_PPC_REL32 to module_64.c instead as that would reduce the size of the kernel image. I'll leave that as an exercise for the reader for now... Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-17powerpc: Fix lwsync patching code on 64bitAnton Blanchard1-1/+1
do_lwsync_fixups doesn't work on 64bit, we end up writing lwsyncs to the wrong addresses: 0:mon> di c0000001000bfacc c0000001000bfacc 7c2004ac lwsync Since the lwsync section has negative offsets we need to use a signed int pointer so we sign extend the value. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23powerpc: Unify opcode definitions and supportKumar Gala1-2/+2
Create a new header that becomes a single location for defining PowerPC opcodes used by code that is either generationg instructions at runtime (fixups, debug, etc.), emulating instructions, or just compiling instructions old assemblers don't know about. We currently don't handle the floating point emulation or alignment decode as both are better handled by the specific decode support they already have. Added support for the new dcbzl, dcbal, msgsnd, tlbilx, & wait instructions since older assemblers don't know about them. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-22powerpc: Use WARN_ON(1) instead of __WARN()Michael Ellerman1-1/+1
__WARN() is not defined for all configs, use WARN_ON(1) instead. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-03powerpc: Fixup lwsync at runtimeKumar Gala1-0/+36
To allow for a single kernel image on e500 v1/v2/mc we need to fixup lwsync at runtime. On e500v1/v2 lwsync causes an illop so we need to patch up the code. We default to 'sync' since that is always safe and if the cpu is capable we will replace 'sync' with 'lwsync'. We introduce CPU_FTR_LWSYNC as a way to determine at runtime if this is needed. This flag could be moved elsewhere since we dont really use it for the normal CPU_FTR purpose. Finally we only store the relative offset in the fixup section to keep it as small as possible rather than using a full fixup_entry. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Add self-tests of the feature fixup codeMichael Ellerman1-0/+206
This commit adds tests of the feature fixup code, they are run during boot if CONFIG_FTR_FIXUP_SELFTEST=y. Some of the tests manually invoke the patching routines to check their behaviour, and others use the macros and so are patched during the normal patching done during boot. Because we have two sets of macros with different names, we use a macro to generate the test of the macros, very niiiice. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Add logic to patch alternative feature sectionsMichael Ellerman1-14/+65
This commit adds the logic to patch alternative sections. This is fairly straightforward, except for branches. Relative branches that jump from inside the else section to outside of it need to be translated as they're moved, otherwise they will jump to the wrong location. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Introduce infrastructure for feature sections with alternativesMichael Ellerman1-0/+2
The current feature section logic only supports nop'ing out code, this means if you want to choose at runtime between instruction sequences, one or both cases will have to execute the nop'ed out contents of the other section, eg: BEGIN_FTR_SECTION or 1,1,1 END_FTR_SECTION_IFSET(FOO) BEGIN_FTR_SECTION or 2,2,2 END_FTR_SECTION_IFCLR(FOO) and the resulting code will be either, or 1,1,1 nop or, nop or 2,2,2 For small code segments this is fine, but for larger code blocks and in performance criticial code segments, it would be nice to avoid the nops. This commit starts to implement logic to allow the following: BEGIN_FTR_SECTION or 1,1,1 FTR_SECTION_ELSE or 2,2,2 ALT_FTR_SECTION_END_IFSET(FOO) and the resulting code will be: or 1,1,1 or, or 2,2,2 We achieve this by extending the existing FTR macros. The current feature section semantic just becomes a special case, ie. if the else case is empty we nop out the default case. The key limitation is that the size of the else case must be less than or equal to the size of the default case. If the else case is smaller the remainder of the section is nop'ed. We let the linker put the else case code in with the rest of the text, so that relative branches from the else case are more likley to link, this has the disadvantage that we can't free the unused else cases. This commit introduces the required macro and linker script changes, but does not enable the patching of the alternative sections. We also need to update two hand-made section entries in reg.h and timex.h Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01powerpc: Split out do_feature_fixups() from cputable.cMichael Ellerman1-0/+56
The logic to patch CPU feature sections lives in cputable.c, but these days it's used for CPU features as well as firmware features. Move it into it's own file for neatness and as preparation for some additions. While we're moving the code, we pull the loop body logic into a separate routine, and remove a comment which doesn't apply anymore. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>