- 10 Dec, 2020 4 commits
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Ravi Bangoria authored
Recently added Power10 prefixed VSX instruction are included unconditionally in the kernel. If they are executed on a machine without VSX support, it might create issues. Fix that. Also fix one mnemonics spelling mistake in comment. Fixes: 50b80a12 ("powerpc sstep: Add support for prefixed load/stores") Signed-off-by:
Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201011050908.72173-3-ravi.bangoria@linux.ibm.com
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Balamuruhan S authored
Unconditional emulation of prefixed instructions will allow emulation of them on Power10 predecessors which might cause issues. Restrict that. Fixes: 3920742b ("powerpc sstep: Add support for prefixed fixed-point arithmetic") Fixes: 50b80a12 ("powerpc sstep: Add support for prefixed load/stores") Signed-off-by:
Balamuruhan S <bala24@linux.ibm.com> Signed-off-by:
Sandipan Das <sandipan@linux.ibm.com> Reviewed-by:
Daniel Axtens <dja@axtens.net> Signed-off-by:
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Nicholas Piggin authored
Idle code no longer uses the .cpu_restore CPU operation to restore SPRs, so this workaround is no longer required. Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
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Athira Rajeev authored
Perf event attritube supports exclude_kernel flag to avoid sampling/profiling in supervisor state (kernel). Based on this event attr flag, Monitor Mode Control Register bit is set to freeze on supervisor state. But sometimes (due to hardware limitation), Sampled Instruction Address Register (SIAR) locks on to kernel address even when freeze on supervisor is set. Patch here adds a check to drop those samples. Cc: stable@vger.kernel.org Signed-off-by:
Athira Rajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by:
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- 09 Dec, 2020 36 commits
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Nicholas Piggin authored
This is way to catch some cases of decrementer overflow, when the decrementer has underflowed an odd number of times, while MSR[EE] was disabled. With a typical small decrementer, a timer that fires when MSR[EE] is disabled will be "lost" if MSR[EE] remains disabled for between 4.3 and 8.6 seconds after the timer expires. In any case, the decrementer interrupt would be taken at 8.6 seconds and the timer would be found at that point. So this check is for catching extreme latency events, and it prevents those latencies from being a further few seconds long. It's not obvious this is a good tradeoff. This is already a watchdog magnitude event and that situation is not improved a significantly with this check. For large decrementers, it's useless. Therefore remove this check, which avoids a mftb when enabling hard disabled interrupts (e.g., when enabling after coming from hardware interrupt handlers). Perhaps more importantly, it also removes the clunky MSR[EE] vs PACA_IRQ_HARD_DIS incoherency in soft-interrupt replay which simplifies the code. Signed-off-by:
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Nicholas Piggin authored
No supported processor implements this mode. Setting the bit in MSR values can be a bit confusing (and would prevent the bit from ever being reused). Remove it. Signed-off-by:
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Nicholas Piggin authored
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Christophe Leroy authored
PTE_FLAGS_OFFSET is defined in asm/page_32.h and used only in hash_low.S And PTE_FLAGS_OFFSET nullity depends on CONFIG_PTE_64BIT Instead of tests like #if (PTE_FLAGS_OFFSET != 0), use CONFIG_PTE_64BIT related code. Also move the definition of PTE_FLAGS_OFFSET into hash_low.S directly, that improves readability. Signed-off-by:
Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by:
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Christophe Leroy authored
VSID is only for create_hpte(). When _PAGE_HASHPTE is already set, add_hash_page() bails out without calling create_hpte() and doesn't need the value of VSID. Signed-off-by:
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Christophe Leroy authored
primary_pteg_full and htab_hash_searches are not used. Remove them. Signed-off-by:
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Christophe Leroy authored
All hugetlb range freeing functions have a verification like the following, which only differs by the mask used, depending on the page table level. start &= MASK; if (start < floor) return; if (ceiling) { ceiling &= MASK; if (! ceiling) return; } if (end - 1 > ceiling - 1) return; Refactor that into a helper function which takes the mask as an argument, returning true when [start;end[ is not fully contained inside [floor;ceiling[ Signed-off-by:Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
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Christophe Leroy authored
Exception fixup doesn't require the heady full regs saving, do it from do_page_fault() directly. For that, split bad_page_fault() in two parts. As bad_page_fault() can also be called from other places than handle_page_fault(), it will still perform exception fixup and fallback on __bad_page_fault(). handle_page_fault() directly calls __bad_page_fault() as the exception fixup will now be done by do_page_fault() Signed-off-by:
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Christophe Leroy authored
search_exception_tables() is an heavy operation, we have to avoid it. When KUAP is selected, we'll know the fault has been blocked by KUAP. When it is blocked by KUAP, check whether we are in an expected userspace access place. If so, emit a warning to spot something is going work. Otherwise, just remain silent, it will likely Oops soon. When KUAP is not selected, it behaves just as if the address was already in the TLBs and no fault was generated. Signed-off-by:
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Christophe Leroy authored
In order to prepare the removal of calls to search_exception_tables() on the fast path, move the WARN() out of bad_kuap_fault(). Signed-off-by:
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Christophe Leroy authored
To make it more readable, separate page_fault_is_write() and page_fault_is_bad() to avoir several levels of #ifdefs Signed-off-by:
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Christophe Leroy authored
The verification and message introduced by commit 374f3f59 ("powerpc/mm/hash: Handle user access of kernel address gracefully") applies to all platforms, it should not be limited to BOOK3S. Make the BOOK3S version of sanity_check_fault() the one for all, and bail out earlier if not BOOK3S. Fixes: 374f3f59 ("powerpc/mm/hash: Handle user access of kernel address gracefully") Signed-off-by:
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Christophe Leroy authored
Add PPC_RAW_MFSPR() to replace open coding done in 8xx-pmu.c Signed-off-by:
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Christophe Leroy authored
Use SPRN_SPRG_SCRATCH2 in DTLB miss exception instead of DAR in order to be similar to ITLB miss exception. This also simplifies mpc8xx_pmu_del() Signed-off-by:
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Christophe Leroy authored
In order to re-enable MMU earlier, ensure ITLB miss exception cannot clobber SPRN_SPRG_SCRATCH0 and SPRN_SPRG_SCRATCH1. Do so by using SPRN_SPRG_SCRATCH2 and SPRN_M_TW instead, like the DTLB miss exception. Signed-off-by:
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Christophe Leroy authored
We now have r11 available as a scratch register so INVALIDATE_ADJACENT_PAGES_CPU15() can be simplified. Signed-off-by:
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Christophe Leroy authored
There is no big poing in not pinning kernel text anymore, as now we can keep pinned TLB even with things like DEBUG_PAGEALLOC. Remove CONFIG_PIN_TLB_TEXT, making it always right. Signed-off-by:
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Christophe Leroy authored
Since commit e611939f ("powerpc/mm: Ensure change_page_attr() doesn't invalidate pinned TLBs"), pinned TLBs are not anymore invalidated by __kernel_map_pages() when CONFIG_DEBUG_PAGEALLOC is selected. Remove the dependency on CONFIG_DEBUG_PAGEALLOC. Signed-off-by:
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Christophe Leroy authored
__set_dabr() are simple functions that can be inline directly inside set_dabr() and using IS_ENABLED() instead of #ifdef Signed-off-by:
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Christophe Leroy authored
When SMC1 is relocated and early debug is selected, the board hangs is ppc_md.setup_arch(). This is because ones the microcode has been loaded and SMC1 relocated, early debug writes in the weed. To allow smooth continuation, the SMC1 parameter RAM set up by the bootloader have to be copied into the new location. Fixes: 43db76f4 ("powerpc/8xx: Add microcode patch to move SMC parameter RAM.") Cc: stable@vger.kernel.org Signed-off-by:
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Christophe Leroy authored
On hash 32 bits, handling minor protection faults like unsetting dirty flag is heavy if done from the normal page_fault processing, because it implies hash table software lookup for flushing the entry and then a DSI is taken anyway to add the entry back. When KUAP was implemented, as explained in commit a68c31fc ("powerpc/32s: Implement Kernel Userspace Access Protection"), protection faults has been diverted from hash_page() because hash_page() was not able to identify a KUAP fault. Implement KUAP verification in hash_page(), by clearing write permission when the access is a kernel access and Ks is 1. This works regardless of the address because kernel segments always have Ks set to 0 while user segments have Ks set to 0 only when kernel write to userspace is granted. Then protection faults can be handled by hash_page() even for KUAP. Signed-off-by:
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Christophe Leroy authored
book3s/32 has two main families: - CPU with 603 cores that don't have HASH PTE table and perform SW TLB loading. - Other CPUs based on 604+ cores that have HASH PTE table. This leads to some complex logic and additionnal code to support both. This makes sense for distribution kernels that aim at running on any CPU, but when you are fine tuning a kernel for an embedded 603 based board you don't need all the HASH logic. Allow selection of support for each family, in order to opt out unneeded parts of code. At least one must be selected. Note that some of the CPU supporting HASH also support SW TLB loading, however it is not supported by Linux kernel at the time being, because they do not have alternate registers in the TLB miss exception handlers. Signed-off-by:
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Christophe Leroy authored
In order to selectively build the kernel for 603 SW TLB handling, regroup all 603 based CPUs together. Signed-off-by:
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Christophe Leroy authored
As 601 is gone, CONFIG_PPC_BOO3S_6xx and CONFIG_PPC_BOOK3S_32 are dedundant. Remove CONFIG_PPC_BOOK3S_6xx. Signed-off-by:
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Christophe Leroy authored
early_mmu_init() is independent of MMU type and not directly linked to tlb handling. In a following patch, tlb.c will be restricted to HASH mmu. Move early_mmu_init() into mmu.c which is common. Signed-off-by:
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Christophe Leroy authored
flush_hash_entry() is a simple function calling flush_hash_pages() if it's a hash MMU or doing nothing otherwise. Inline it. And use it also in __ptep_test_and_clear_young(). Signed-off-by:
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Christophe Leroy authored
On book3s/32, tlb_flush() does nothing when the CPU has a hash table, it calls _tlbia() otherwise. Inline it. Signed-off-by:
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Christophe Leroy authored
flush_range() handle both the MMU_FTR_HPTE_TABLE case and the other case. The non MMU_FTR_HPTE_TABLE case is trivial as it is only a call to _tlbie()/_tlbia() which is not worth a dedicated function. Make flush_range() a hash specific and call it from tlbflush.h based on mmu_has_feature(MMU_FTR_HPTE_TABLE). Signed-off-by:
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Christophe Leroy authored
flush_tlb_range() and flush_tlb_kernel_range() are trivial calls to flush_range(). Make flush_range() global and inline flush_tlb_range() and flush_tlb_kernel_range(). Signed-off-by:
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Christophe Leroy authored
flush_tlb_mm() and flush_tlb_page() handle both the MMU_FTR_HPTE_TABLE case and the other case. The non MMU_FTR_HPTE_TABLE case is trivial as it is only a call to _tlbie()/_tlbia() which is not worth a dedicated function. Make flush_tlb_mm() and flush_tlb_page() hash specific and call them from tlbflush.h based on mmu_has_feature(MMU_FTR_HPTE_TABLE). Signed-off-by:
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Christophe Leroy authored
_tlbie() and _tlbia() are used only on 603 cores while the other functions are used only on cores having a hash table. Move them into a new file named nohash_low.S Add mmu_hash_lock var is used by both, it needs to go in a common file. Signed-off-by:
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Christophe Leroy authored
On non SMP, _tlbie() is just a tlbie plus a sync instruction. Make it static inline. Signed-off-by:
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Christophe Leroy authored
In order to use _tlbie() and _tlbia() directly from asm/book3s/32/tlbflush.h, move their prototypes from mm/mm_decl.h to there. Signed-off-by:
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Christophe Leroy authored
Hash related vars are used at init only. Declare them in __initdata. Signed-off-by:
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Christophe Leroy authored
Hash var is used only locally in mmu.c now. No need to set it in head_32.S anymore. Make it static and initialises it to the early hash table. Signed-off-by:
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Christophe Leroy authored
We now have an early hash table on hash MMU, so no need to check Hash var to know if the Hash table is set of not. Use mmu_has_feature(MMU_FTR_HPTE_TABLE) instead. This will allow optimisation via jump_label. Signed-off-by:
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