- 20 Oct, 2018 19 commits
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Michael Ellerman authored
When we have CONFIG_STRICT_KERNEL_RWX enabled, we try to split the kernel linear (1:1) mapping so that the kernel text is in a separate page to kernel data, so we can mark the former read-only. We could achieve that just by always using 64K pages for the linear mapping, but we try to be smarter. Instead we use huge pages when possible, and only switch to smaller pages when necessary. However we have an off-by-one bug in that logic, which causes us to calculate the wrong boundary between text and data. For example with the end of the kernel text at 16M we see: radix-mmu: Mapped 0x0000000000000000-0x0000000001200000 with 64.0 KiB pages radix-mmu: Mapped 0x0000000001200000-0x0000000040000000 with 2.00 MiB pages radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages ie. we mapped from 0 to 18M with 64K pages, even though the boundary between text and data is at 16M. With the fix we see we're correctly hitting the 16M boundary: radix-mmu: Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages radix-mmu: Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages Signed-off-by:Michael Ellerman <mpe@ellerman.id.au>
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Naveen N. Rao authored
Currently, we expect to be able to reach ftrace_caller() from all ftrace-enabled functions through a single relative branch. With large kernel configs, we see functions outside of 32MB of ftrace_caller() causing ftrace_init() to bail. In such configurations, gcc/ld emits two types of trampolines for mcount(): 1. A long_branch, which has a single branch to mcount() for functions that are one hop away from mcount(): c0000000019e8544 <00031b56.long_branch._mcount>: c0000000019e8544: 4a 69 3f ac b c00000000007c4f0 <._mcount> 2. A plt_branch, for functions that are farther away from mcount(): c0000000051f33f8 <0008ba04.plt_branch._mcount>: c0000000051f33f8: 3d 82 ff a4 addis r12,r2,-92 c0000000051f33fc: e9 8c 04 20 ld r12,1056(r12) c0000000051f3400: 7d 89 03 a6 mtctr r12 c0000000051f3404: 4e 80 04 20 bctr We can reuse those trampolines for ftrace if we can have those trampolines go to ftrace_caller() instead. However, with ABIv2, we cannot depend on r2 being valid. As such, we use only the long_branch trampolines by patching those to instead branch to ftrace_caller or ftrace_regs_caller. In addition, we add additional trampolines around .text and .init.text to catch locations that are covered by the plt branches. This allows ftrace to work with most large kernel configurations. For now, we always patch the trampolines to go to ftrace_regs_caller, which is slightly inefficient. This can be optimized further at a later point. Signed-off-by:
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
WARNING: CPU: 12 PID: 4322 at /arch/powerpc/mm/pgtable-book3s64.c:76 set_pmd_at+0x4c/0x2b0 Modules linked in: CPU: 12 PID: 4322 Comm: qemu-system-ppc Tainted: G W 4.19.0-rc3-00758-g8f0c636b0542 #36 NIP: c0000000000872fc LR: c000000000484eec CTR: 0000000000000000 REGS: c000003fba876fe0 TRAP: 0700 Tainted: G W (4.19.0-rc3-00758-g8f0c636b0542) MSR: 900000010282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 24282884 XER: 00000000 CFAR: c000000000484ee8 IRQMASK: 0 GPR00: c000000000484eec c000003fba877268 c000000001f0ec00 c000003fbd229f80 GPR04: 00007c8fe8e00000 c000003f864c5a38 860300853e0000c0 0000000000000080 GPR08: 0000000080000000 0000000000000001 0401000000000080 0000000000000001 GPR12: 0000000000002000 c000003fffff5400 c000003fce292000 00007c9024570000 GPR16: 0000000000000000 0000000000ffffff 0000000000000001 c000000001885950 GPR20: 0000000000000000 001ffffc0004807c 0000000000000008 c000000001f49d05 GPR24: 00007c8fe8e00000 c0000000020f2468 ffffffffffffffff c000003fcd33b090 GPR28: 00007c8fe8e00000 c000003fbd229f80 c000003f864c5a38 860300853e0000c0 NIP [c0000000000872fc] set_pmd_at+0x4c/0x2b0 LR [c000000000484eec] do_huge_pmd_numa_page+0xb1c/0xc20 Call Trace: [c000003fba877268] [c00000000045931c] mpol_misplaced+0x1bc/0x230 (unreliable) [c000003fba8772c8] [c000000000484eec] do_huge_pmd_numa_page+0xb1c/0xc20 [c000003fba877398] [c00000000040d344] __handle_mm_fault+0x5e4/0x2300 [c000003fba8774d8] [c00000000040f400] handle_mm_fault+0x3a0/0x420 [c000003fba877528] [c0000000003ff6f4] __get_user_pages+0x2e4/0x560 [c000003fba877628] [c000000000400314] get_user_pages_unlocked+0x104/0x2a0 [c000003fba8776c8] [c000000000118f44] __gfn_to_pfn_memslot+0x284/0x6a0 [c000003fba877748] [c0000000001463a0] kvmppc_book3s_radix_page_fault+0x360/0x12d0 [c000003fba877838] [c000000000142228] kvmppc_book3s_hv_page_fault+0x48/0x1300 [c000003fba877988] [c00000000013dc08] kvmppc_vcpu_run_hv+0x1808/0x1b50 [c000003fba877af8] [c000000000126b44] kvmppc_vcpu_run+0x34/0x50 [c000003fba877b18] [c000000000123268] kvm_arch_vcpu_ioctl_run+0x288/0x2d0 [c000003fba877b98] [c00000000011253c] kvm_vcpu_ioctl+0x1fc/0x8c0 [c000003fba877d08] [c0000000004e9b24] do_vfs_ioctl+0xa44/0xae0 [c000003fba877db8] [c0000000004e9c44] ksys_ioctl+0x84/0xf0 [c000003fba877e08] [c0000000004e9cd8] sys_ioctl+0x28/0x80 We removed the pte_protnone check earlier with the understanding that we mark the pte invalid before the set_pte/set_pmd usage. But the huge pmd autonuma still use the set_pmd_at directly. This is ok because a protnone pte won't have translation cache in TLB. Fixes: da7ad366 ("powerpc/mm/book3s: Update pmd_present to look at _PAGE_PRESENT bit") Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
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Michael Ellerman authored
Some of our Makefiles don't do the right thing when building the selftests with O=, fix them up. Signed-off-by: -
Christophe Leroy authored
If CONFIG_PPC_SPLPAR is not selected, steal_time will always be NUL, so accounting it is pointless Signed-off-by:
Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by:
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Christophe Leroy authored
scaled cputime is only meaningfull when the processor has SPURR and/or PURR, which means only on PPC64. Removing it on PPC32 significantly reduces the size of vtime_account_system() and vtime_account_idle() on an 8xx: Before: 00000000 l F .text 000000a8 vtime_delta 00000280 g F .text 0000010c vtime_account_system 0000038c g F .text 00000048 vtime_account_idle After: (vtime_delta gets inlined inside the two functions) 000001d8 g F .text 000000a0 vtime_account_system 00000278 g F .text 00000038 vtime_account_idle In terms of performance, we also get approximatly 7% improvement on task switch. The following small benchmark app is run with perf stat: void *thread(void *arg) { int i; for (i = 0; i < atoi((char*)arg); i++) pthread_yield(); } int main(int argc, char **argv) { pthread_t th1, th2; pthread_create(&th1, NULL, thread, argv[1]); pthread_create(&th2, NULL, thread, argv[1]); pthread_join(th1, NULL); pthread_join(th2, NULL); return 0; } Before the patch: Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs): 8228.476465 task-clock (msec) # 0.954 CPUs utilized ( +- 0.23% ) 200004 context-switches # 0.024 M/sec ( +- 0.00% ) After the patch: Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs): 7649.070444 task-clock (msec) # 0.955 CPUs utilized ( +- 0.27% ) 200004 context-switches # 0.026 M/sec ( +- 0.00% ) Signed-off-by: -
Christophe Leroy authored
scaled cputime is only meaningfull when the processor has SPURR and/or PURR, which means only on PPC64. In preparation of the following patch that will remove CONFIG_ARCH_HAS_SCALED_CPUTIME on PPC32, this patch moves all scaled cputing accounting logic into dedicated functions. This patch doesn't change any functionality. It's only code reorganisation. Signed-off-by:
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Christophe Leroy authored
Generic implementation fails to remove breakpoints after init when CONFIG_STRICT_KERNEL_RWX is selected: [ 13.251285] KGDB: BP remove failed: c001c338 [ 13.259587] kgdbts: ERROR PUT: end of test buffer on 'do_fork_test' line 8 expected OK got $E14#aa [ 13.268969] KGDB: re-enter exception: ALL breakpoints killed [ 13.275099] CPU: 0 PID: 1 Comm: init Not tainted 4.18.0-g82bbb913ffd8 #860 [ 13.282836] Call Trace: [ 13.285313] [c60e1ba0] [c0080ef0] kgdb_handle_exception+0x6f4/0x720 (unreliable) [ 13.292618] [c60e1c30] [c000e97c] kgdb_handle_breakpoint+0x3c/0x98 [ 13.298709] [c60e1c40] [c000af54] program_check_exception+0x104/0x700 [ 13.305083] [c60e1c60] [c000e45c] ret_from_except_full+0x0/0x4 [ 13.310845] [c60e1d20] [c02a22ac] run_simple_test+0x2b4/0x2d4 [ 13.316532] [c60e1d30] [c0081698] put_packet+0xb8/0x158 [ 13.321694] [c60e1d60] [c00820b4] gdb_serial_stub+0x230/0xc4c [ 13.327374] [c60e1dc0] [c0080af8] kgdb_handle_exception+0x2fc/0x720 [ 13.333573] [c60e1e50] [c000e928] kgdb_singlestep+0xb4/0xcc [ 13.339068] [c60e1e70] [c000ae1c] single_step_exception+0x90/0xac [ 13.345100] [c60e1e80] [c000e45c] ret_from_except_full+0x0/0x4 [ 13.350865] [c60e1f40] [c000e11c] ret_from_syscall+0x0/0x38 [ 13.356346] Kernel panic - not syncing: Recursive entry to debugger This patch creates powerpc specific version of kgdb_arch_set_breakpoint() and kgdb_arch_remove_breakpoint() using patch_instruction() Fixes: 1e0fc9d1 ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs") Signed-off-by:
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Christophe Leroy authored
ipic_get_mcp_status() is used by targets implementing NMI watchdog in target specific machine check handler in order to known whether a machine check results from a watchdog NMI reset. In case of very early machine check, primary_ipic pointer might not have been set yet, so ipic_get_mcp_status() needs to check it for nullity before using it. Signed-off-by:
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Christophe Leroy authored
This patch fixes the following warnings (obtained with make W=1). arch/powerpc/mm/slice.c: In function 'slice_range_to_mask': arch/powerpc/mm/slice.c:73:12: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (start < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c:81:20: error: comparison is always false due to limited range of data type [-Werror=type-limits] if ((start + len) > SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c: In function 'slice_mask_for_free': arch/powerpc/mm/slice.c:136:17: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (high_limit <= SLICE_LOW_TOP) ^ arch/powerpc/mm/slice.c: In function 'slice_check_range_fits': arch/powerpc/mm/slice.c:185:12: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (start < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c:195:39: error: comparison is always false due to limited range of data type [-Werror=type-limits] if (SLICE_NUM_HIGH && ((start + len) > SLICE_LOW_TOP)) { ^ arch/powerpc/mm/slice.c: In function 'slice_scan_available': arch/powerpc/mm/slice.c:306:11: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (addr < SLICE_LOW_TOP) { ^ arch/powerpc/mm/slice.c: In function 'get_slice_psize': arch/powerpc/mm/slice.c:709:11: error: comparison is always true due to limited range of data type [-Werror=type-limits] if (addr < SLICE_LOW_TOP) { ^ Signed-off-by: -
Christophe Leroy authored
This patch fixes the following warnings (obtained with make W=1). arch/powerpc/mm/slice.c: At top level: arch/powerpc/mm/slice.c:682:15: error: no previous prototype for 'arch_get_unmapped_area' [-Werror=missing-prototypes] unsigned long arch_get_unmapped_area(struct file *filp, ^ arch/powerpc/mm/slice.c:692:15: error: no previous prototype for 'arch_get_unmapped_area_topdown' [-Werror=missing-prototypes] unsigned long arch_get_unmapped_area_topdown(struct file *filp, ^ Signed-off-by: -
Christophe Leroy authored
Add a trace point for tlbia (Translation Lookaside Buffer Invalidate All) instruction. Signed-off-by:
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Christophe Leroy authored
commit 0428491c ("powerpc/mm: Trace tlbie(l) instructions") added tracepoints for tlbie calls, but _tlbil_va() was forgotten Fixes: 0428491c ("powerpc/mm: Trace tlbie(l) instructions") Signed-off-by:
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Christophe Leroy authored
Since commit bd0dbb73 ("powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid."), _PAGE_PRESENT doesn't mean exactly that a page is present. A page is also considered preset when _PAGE_INVALID is set. This patch changes the meaning of "present" and adds a status "valid" associated to the _PAGE_PRESENT flag. Fixes: bd0dbb73 ("powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid.") Signed-off-by:
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Aravinda Prasad authored
This patch exports the raw per-CPU VPA data via debugfs. A per-CPU file is created which exports the VPA data of that CPU to help debug some of the VPA related issues or to analyze the per-CPU VPA related statistics. v3: Removed offline CPU check. v2: Included offline CPU check and other review comments. Signed-off-by:
Aravinda Prasad <aravinda@linux.vnet.ibm.com> Signed-off-by:
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Naveen N. Rao authored
This adds a test to verify proper functioning of the rfi flush capability implemented to mitigate meltdown. The test works by measuring the number of L1d cache misses encountered while loading data from memory. Across a system call, since the L1d cache is flushed when rfi_flush is enabled, the number of cache misses is expected to be relative to the number of cachelines corresponding to the data being loaded. The current system setting is reflected via powerpc/rfi_flush under debugfs (assumed to be /sys/kernel/debug/). This test verifies the expected result with rfi_flush enabled as well as when it is disabled. Signed-off-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
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Naveen N. Rao authored
... so that it can be used by others. Signed-off-by:
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Naveen N. Rao authored
module_frob_arch_sections() is called before the module is moved to its final location. The function descriptor section addresses we are setting here are thus invalid. Fix this by processing opd section during module_finalize() Fixes: 5633e85b ("powerpc64: Add .opd based function descriptor dereference") Cc: stable@vger.kernel.org # v4.16 Signed-off-by:
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Naveen N. Rao authored
We implement regs_set_return_value() and override_function_with_return() for this purpose. On powerpc, a return from a function (blr) just branches to the location contained in the link register. So, we can just update pt_regs rather than redirecting execution to a dummy function that returns. Signed-off-by:
Samuel Mendoza-Jonas <sam@mendozajonas.com> Signed-off-by:
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- 19 Oct, 2018 3 commits
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Michael Ellerman authored
In the recent commit 8b78fdb0 ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer") we changed the way we initialise the decrementer clockevent(s). We no longer initialise the mult & shift values of decrementer_clockevent itself. This has the effect of breaking PR KVM, because it uses those values in kvmppc_emulate_dec(). The symptom is guest kernels spin forever mid-way through boot. For now fix it by assigning back to decrementer_clockevent the mult and shift values. Fixes: 8b78fdb0 ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer") Signed-off-by:
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Michael Ellerman authored
I'm pretty sure this is dead code, it's only used by the a.out core dump code, and we don't support a.out. We should remove it. But while it's in the tree it should be using the ABI version of pt_regs which is called user_pt_regs in the kernel, because the whole struct is written to the core dump and so its size shouldn't change. Note this isn't a uapi header so we don't need an ifdef. Fixes: 002af939 ("powerpc: Split user/kernel definitions of struct pt_regs") Signed-off-by:
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Michael Ellerman authored
My recent patch to split pt_regs between user and kernel missed the usage in struct sigcontext. Because this is a user visible struct it should be using the user visible definition, which when we're building for the kernel is called struct user_pt_regs. As far as I can see this hasn't actually caused a bug (yet), because we don't use the sizeof() the sigcontext->regs anywhere. But we should still fix it to avoid confusion and future bugs. Fixes: 002af939 ("powerpc: Split user/kernel definitions of struct pt_regs") Reported-by:
Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by:
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- 18 Oct, 2018 18 commits
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Christophe Leroy authored
GCC 4.6 is the minimum supported now. Signed-off-by:
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Michael Ellerman authored
Back when I added -Werror in commit ba55bd74 ("powerpc: Add configurable -Werror for arch/powerpc") I did it by adding it to most of the arch Makefiles. At the time we excluded math-emu, because apparently it didn't build cleanly. But that seems to have been fixed somewhere in the interim. So move the -Werror addition to the top-level of the arch, this saves us from repeating it in every Makefile and means we won't forget to add it to any new sub-dirs. Signed-off-by:
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Michael Ellerman authored
This is a nice cleanup, arch/powerpc/Makefile is long and messy so moving this out helps a little. It also allows us to do: $ make arch/powerpc Which can be helpful if you just want to compile test some changes to arch code and not link everything. Finally it also gives us a single place to do subdir-cc-flags assignments which affect the whole of arch/powerpc, which we will do in a future patch. Signed-off-by: -
Benjamin Herrenschmidt authored
There's some antiquated debug output that's trying to do a hand-made hexdump and turning into horrible 1-byte-per-line output these days. Use print_hex_dump() instead Signed-off-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
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Christophe Leroy authored
do_exit() already includes a test to panic() is in_interrupt() This patch removes powerpc one which is redundant. Signed-off-by:
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Benjamin Herrenschmidt authored
When creating the boot-time FDT from an actual Open Firmware live tree, let's generate "phandle" properties for the phandles instead of the old deprecated "linux,phandle". Signed-off-by:
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Benjamin Herrenschmidt authored
prom_init.c must not modify the kernel image outside of the .bss.prominit section. Thus make sure that prom_init.o doesn't have anything in any of these: .data .bss .init.data Signed-off-by:
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Benjamin Herrenschmidt authored
This makes __prombss its own section, and for now store it in .bss. This will give us the ability later to store it elsewhere and/or free it after boot (it's about 8KB). Signed-off-by:
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Benjamin Herrenschmidt authored
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Benjamin Herrenschmidt authored
As they are no longer used past the end of prom_init Signed-off-by:
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Benjamin Herrenschmidt authored
Make the existing initialized definition constant and copy it to a __prombss copy Signed-off-by:
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Benjamin Herrenschmidt authored
Initialize it dynamically instead of statically Signed-off-by:
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Benjamin Herrenschmidt authored
We removed support for running under any OPAL version earlier than v3 in 2015 (they never saw the light of day anyway), but we kept some leftovers of this support in prom_init.c, so let's take it out. Signed-off-by:
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Benjamin Herrenschmidt authored
This replaces all occurrences of __initdata for uninitialized data with a new __prombss Currently __promdata is defined to be __initdata but we'll eventually change that. Signed-off-by:
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Oliver O'Halloran authored
Adds a driver that implements support for enabling and accessing PAPR SCM regions. Unfortunately due to how the PAPR interface works we can't use the existing of_pmem driver (yet) because: a) The guest is required to use the H_SCM_BIND_MEM h-call to add add the SCM region to it's physical address space, and b) There is currently no mechanism for relating a bare of_pmem region to the backing DIMM (or not-a-DIMM for our case). Both of these are easily handled by rolling the functionality into a seperate driver so here we are... Acked-by:Dan Williams <dan.j.williams@intel.com> Signed-off-by:
Oliver O'Halloran <oohall@gmail.com> Signed-off-by:
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Oliver O'Halloran authored
This patch implements support for discovering storage class memory devices at boot and for handling hotplug of new regions via RTAS hotplug events. Signed-off-by:
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Christophe Leroy authored
When printing the machine check cause, the cause appears on the following line due to bad use of printk without \n: [ 33.663993] Machine check in kernel mode. [ 33.664011] Caused by (from SRR1=9032): [ 33.664036] Data access error at address c90c8000 This patch fixes it by using pr_cont() for the second part: [ 133.258131] Machine check in kernel mode. [ 133.258146] Caused by (from SRR1=9032): Data access error at address c90c8000 Signed-off-by:
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Christophe Leroy authored
Book3e defines both _PAGE_USER and _PAGE_PRIVILEGED, so the nohash default pte_mkprivileged() and pte_mkuser() are not usable. This patch redefines them for book3e. In theorie, only pte_mkprivileged() needs to be redefined because _PAGE_USER includes _PAGE_PRIVILEGED, but it is less confusing to redefine both. Fixes: a0da4bc1 ("powerpc/mm: Allow platforms to redefine some helpers") Signed-off-by:
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