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path: root/arch/powerpc/kernel/exceptions-64s.S
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2016-10-11powerpc/64s: Fix power4_fixup_nap placementNicholas Piggin
power4_fixup_nap is called from the "common" handlers, not the virt/real handlers, therefore it should itself be a common handler. Placing it down in the trampoline space caused it to go out of reach of its callers, requiring a trampoline inserted at the start of the text section, which breaks the fixed section address calculations. Fixes: da2bc4644c75 ("powerpc/64s: Add new exception vector macros") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Remove unused exception code, small cleanupsNicholas Piggin
This was not done before the big patches because I only noticed them afterwards. It has become much easier to see which handlers are branched to from which exception vectors now, and to see exactly what vector space is being used for what. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Use a single macro for both parts of OOL exceptionNicholas Piggin
Simple substitution. This is possible now that both parts of the OOL initial handler get linked into their correct location. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Move __replay_interrupt function below handlersNicholas Piggin
This is not an exception handler as such, it's called from local_irq_enable(), not exception entry. Also clean up some now redundant comments at the end of the consolidation series. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate CBE Thermal 0x1800 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Altivec 0x1700 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Debug 0x1600 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Softpatch 0x1500 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Instruction Breakpoint 0x1300 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate CBE System Error 0x1200 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Reserved 0xfa0-0x1200 interruptsNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Hypervisor Facility Unavailable 0xf80 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Facility Unavailable 0xf60 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate VSX Unavailable 0xf40 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Vector Unavailable 0xf20 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Performance Monitor 0xf00 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Reserved 0xec0, 0xee0 interruptsNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Hypervisor Virtualization 0xea0 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Directed Hypervisor Doorbell 0xe80 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Hypervisor Maintenance 0xe60 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Hypervisor Emulation Assistance 0xe40 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Hypervisor Instruction Storage 0xe20 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Hypervisor Data Storage 0xe00 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Trace 0xd00 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate System Call 0xc00 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Reserved 0xb00 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Directed Privileged Doorbell 0xa00 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Hypervisor Decrementer 0x980 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Decrementer 0x900 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate FP Unavailable 0x800 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Program 0x700 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Alignment 0x600 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate External 0x500 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Instruction Segment 0x480 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Instruction Storage 0x400 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Data Segment 0x380 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Data Storage 0x300 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate Machine Check 0x200 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate System Reset 0x100 interruptNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc: Use gas sections for arranging exception vectorsNicholas Piggin
Use assembler sections of fixed size and location to arrange the 64-bit Book3S exception vector code (64-bit Book3E also uses it in head_64.S for 0x0..0x100). This allows better flexibility in arranging exception code and hiding unimportant details behind macros. Gas sections can be a bit painful to use this way, mainly because the assembler does not know where they will be finally linked. Taking absolute addresses requires a bit of trickery for example, but it can be hidden behind macros for the most part. Generated code is mostly the same except locations, offsets, alignments. The "+ 0x2" is only required for the trap number / kvm exit number, which gets loaded as a constant into a register. Previously, code also used + 0x2 for label names, but we changed to using "H" to distinguish HV case for that. Remove the last vestiges of that. __after_prom_start is taking absolute address of a label in another fixed section. Newer toolchains seemed to compile this okay, but older ones do not. FIXED_SYMBOL_ABS_ADDR is more foolproof, it just takes an additional line to define. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Consolidate exception handler alignmentNicholas Piggin
Move exception handler alignment directives into the head-64.h macros, beause they will no longer work in-place after the next patch. This slightly changes functions that have alignments applied and therefore code generation, which is why it was not done initially (see earlier patch). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-04powerpc/64s: Add new exception vector macrosMichael Ellerman
Create arch/powerpc/include/asm/head-64.h with macros that specify an exception vector (name, type, location), which will be used to label and lay out exceptions into the object file. Naming is moved out of exception-64s.h, which is used to specify the implementation of exception handlers. objdump of generated code in exception vectors is unchanged except for names. Alignment directives scattered around are annoying, but done this way so that disassembly can verify identical instruction generation before and after patch. These get cleaned up in future patch. We change the way KVMTEST works, explicitly passing EXC_HV or EXC_STD rather than overloading the trap number. This removes the need to have SOFTEN values for the overloaded trap numbers, eg. 0x502. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23powerpc/pseries: Remove unnecessary syscall trampolineNicholas Piggin
When we originally added the ability to split the exception vectors from the kernel (commit 1f6a93e4c35e ("powerpc: Make it possible to move the interrupt handlers away from the kernel" 2008-09-15)), the LOAD_HANDLER() macro used an addi instruction to compute the offset of the common handler from the kernel base address. Using addi meant the handler had to be within 32K of the kernel base address, due to the addi instruction taking a signed immediate value. That necessitated creating a trampoline for the system call handler, because system_call_common (in entry64.S) is not linked within 32K of the kernel base address. Later in commit 61e2390ede3c ("powerpc: Make load_hander handle upto 64k offset" 2012-11-15) we changed LOAD_HANDLER to take a 64K offset, by changing it to use ori. Although system_call_common is not in head_64.S or exceptions-64s.S, it is included in head-y, which causes it to be linked early in the kernel text, so in practice it ends up below 64K. Additionally if it can't be placed below 64K the linker will fail to build with a "relocation truncated to fit" error. So remove the trampoline. Newer toolchains are able to work out that the ori in LOAD_HANDLER only takes a 16 bit offset, and so they generate a 16 bit relocation. Older toolchains (binutils 2.22 at least) are not so smart, so we have to add the @l annotation to tell the assembler to generate a 16 bit relocation. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-23powerpc/pseries: Fix HV facility unavailable to use correct handlerNicholas Piggin
The 0xf80 hv_facility_unavailable trampoline branches to the 0xf60 handler. This works because they both do the same thing, but it should be fixed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-20powerpc/64: Optimise syscall entry for virtual, relocatable caseNicholas Piggin
The mflr r10 instruction was left over from when the code used LR to branch to system_call_entry from the exception handler. That was changed by commit 6a404806dfce ("powerpc: Avoid link stack corruption in MMU on syscall entry path") to use the count register. The value is never used now, so mflr can be removed, and r10 can be used for storage rather than spilling to the SPR scratch register. The scratch register spill causes a long pipeline stall due to the SPR read after write. This change brings getppid syscall cost from 406 to 376 cycles on POWER8. getppid for non-relocatable case is 371 cycles. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-13powerpc/64: Do load of PACAKBASE in LOAD_HANDLERMichael Ellerman
The LOAD_HANDLER macro requires that you have previously loaded "reg" with PACAKBASE. Although that gives callers flexibility to get PACAKBASE in some interesting way, none of the callers actually do that. So fold the load of PACAKBASE into the macro, making it simpler for callers to use correctly. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nick Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-13powerpc/mm: Preserve CFAR value on SLB miss caused by access to bogus addressPaul Mackerras
Currently, if userspace or the kernel accesses a completely bogus address, for example with any of bits 46-59 set, we first take an SLB miss interrupt, install a corresponding SLB entry with VSID 0, retry the instruction, then take a DSI/ISI interrupt because there is no HPT entry mapping the address. However, by the time of the second interrupt, the Come-From Address Register (CFAR) has been overwritten by the rfid instruction at the end of the SLB miss interrupt handler. Since bogus accesses can often be caused by a function return after the stack has been overwritten, the CFAR value would be very useful as it could indicate which function it was whose return had led to the bogus address. This patch adds code to create a full exception frame in the SLB miss handler in the case of a bogus address, rather than inserting an SLB entry with a zero VSID field. Then we call a new slb_miss_bad_addr() function in C code, which delivers a signal for a user access or creates an oops for a kernel access. In the latter case the oops message will show the CFAR value at the time of the access. In the case of the radix MMU, a segment miss interrupt indicates an access outside the ranges mapped by the page tables. Previously this was handled by the code for an unrecoverable SLB miss (one with MSR[RI] = 0), which is not really correct. With this patch, we now handle these interrupts with slb_miss_bad_addr(), which is much more consistent. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-22powerpc/pseries: PACA save area fix for MCE vs MCENicholas Piggin
MCE must not enable MSR_RI until PACA_EXMC is no longer being used. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2016-08-22powerpc/pseries: PACA save area fix for general exception vs MCENicholas Piggin
MCE must not use PACA_EXGEN. When a general exception enables MSR_RI, that means SPRN_SRR[01] and SPRN_SPRG are no longer used. However the PACA save area is still in use. Acked-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2016-08-09powerpc/powernv: Fix MCE handler to avoid trashing CR0/CR1 registers.Mahesh Salgaonkar
The current implementation of MCE early handling modifies CR0/1 registers without saving its old values. Fix this by moving early check for powersaving mode to machine_check_handle_early(). The power architecture 2.06 or later allows the possibility of getting machine check while in nap/sleep/winkle. The last bit of HSPRG0 is set to 1, if thread is woken up from winkle. Hence, clear the last bit of HSPRG0 (r13) before MCE handler starts using it as paca pointer. Also, the current code always puts the thread into nap state irrespective of whatever idle state it woke up from. Fix that by looking at paca->thread_idle_state and put the thread back into same state where it came from. Fixes: 1c51089f777b ("powerpc/book3s: Return from interrupt if coming from evil context.") Reported-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>