- 17 Dec, 2015 9 commits
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Michael Ellerman authored
HMT_MEDIUM_PPR_DISCARD is a macro which is present at the start of most of our first level exception handlers. It conditionally executes a HMT_MEDIUM instruction, which sets the processor priority to medium. On on modern systems, ie. Power7 and later, it is nop'ed out at boot. All it does is make the exception vectors more cramped, and consume 4 bytes of icache. On old systems it has the effect of boosting the processor priority at the start of exception processing. If we were previously in the idle loop for example, we may be at low or very low priority. This is desirable as we want to process the exception as fast as possible. However looking closely at the generated code, we see that in all cases we execute another HMT_MEDIUM just four instructions later. With code patching applied, the final code on an old (Power6) system will look like, eg: c000000000000300 <data_access_pSeries>: c000000000000300: 7c 42 13 78 mr r2,r2 <- c000000000000304: 7d b2 43 a6 mtsprg 2,r13 c000000000000308: 7d b1 42 a6 mfsprg r13,1 c00000000000030c: f9 2d 00 80 std r9,128(r13) c000000000000310: 60 00 00 00 nop c000000000000314: 7c 42 13 78 mr r2,r2 <- So I suggest that the added code complexity of HMT_MEDIUM_PPR_DISCARD is not justified by the benefit of boosting the processor priority for the duration of four instructions, and therefore we drop it. Signed-off-by:Michael Ellerman <mpe@ellerman.id.au>
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Michael Ellerman authored
There are no longer any users of enter_rtas() outside of rtas.c, so make it "private", by moving the declaration inside rtas.c. Hopefully this will encourage people to use one of the wrappers which takes the sharp edges off the RTAS calling sequence. Signed-off-by: -
Michael Ellerman authored
Although call_rtas_display_status() does actually want to use the regular RTAS locking, it doesn't want the extra logic that is in rtas_call(), so currently it open codes the logic. Instead we can use rtas_call_unlocked(), after taking the RTAS lock. Signed-off-by: -
Michael Ellerman authored
Avoid open coding the logic by using rtas_call_unlocked(). Signed-off-by: -
Michael Ellerman authored
Avoid open coding the logic by using rtas_call_unlocked(). Signed-off-by: -
Michael Ellerman authored
Most users of RTAS (Run-Time Abstraction Services) use rtas_call(), which deals with locking as well as endian handling. However we have two users outside of rtas.c that can't use rtas_call() because they have different locking requirements. The hotplug CPU code can't take the RTAS lock because the CPU would go offline with the lock held and no other CPUs would be able to call RTAS until the CPU came back online. The xmon code doesn't want to take the lock because it would risk dead locking when we are trying to recover from a crash. Both sites required multiple patches when we added little endian support, proving that programmers can't do endian right. Although that ship has sailed, we can still clean the code up by providing an unlocked version of rtas_call() which avoids the need to open code the logic elsewhere. Signed-off-by: -
Stewart Smith authored
Long ago, only in the lab, there was OPALv1 and OPALv2. Now there is just OPALv3, with nobody ever expecting anything on pre-OPALv3 to be cared about or supported by mainline kernels. So, let's remove FW_FEATURE_OPALv3 and instead use FW_FEATURE_OPAL exclusively. Signed-off-by:
Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by:
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Stewart Smith authored
OPALv2 only ever existed in the lab and didn't escape to the world. All OPAL systems in the wild are OPALv3. The probability of there being an OPALv2 system still powered on anywhere inside IBM is approximately zero, let alone anyone expecting to run mainline kernels. So, start to remove references to OPALv2. Signed-off-by:
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Stewart Smith authored
The OpenPower Abstraction Layer firmware went through a couple of iterations in the lab before being released. What we now know as OPAL advertises itself as OPALv3. OPALv2 and OPALv1 never made it outside the lab, and the possibility of anyone at all ever building a mainline kernel today and expecting it to boot on such hardware is zero. Signed-off-by:
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- 16 Dec, 2015 6 commits
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Daniel Axtens authored
HMIs (Hypervisor Management|Maintenance Interrupts) are a class of interrupt on POWER systems. HMI support has traditionally been exceptionally difficult to test, however Skiboot ships a tool that, with the correct magic numbers, will inject them. This, therefore, is a first pass at a script to inject HMIs and monitor Linux's response. It injects an HMI on each core on every chip in turn It then watches dmesg to see if it's acknowledged by Linux. On a Tuletta, I observed that we see 8 (or sometimes 9 or more) events per injection, regardless of SMT setting, so we wait for 8 before progressing. It sits in a new scripts/ directory in selftests/powerpc, because it's not designed to be run as part of the regular make selftests process. In particular, it is quite possibly going to end up garding lots of your CPUs, so it should only be run if you know how to undo that. CC: Mahesh J Salgaonkar <mahesh.salgaonkar@in.ibm.com> Signed-off-by:
Daniel Axtens <dja@axtens.net> Signed-off-by:
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Michael Ellerman authored
Simply because it touches more code paths that way, and therefore tests more things. Signed-off-by:
Anton Blanchard <anton@samba.org>
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Michael Ellerman authored
For ease of use make the context_switch test do something useful when called with no arguments. Default to a 30 second run, using threads, doing yield, and use any online cpu. Make it print out what it's doing to avoid confusion. Signed-off-by:
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Michael Ellerman authored
This gets referred to a lot in commit messages, so let's pull it into the selftests. Almost vanilla from: http://ozlabs.org/~anton/junkcode/context_switch2.cSigned-off-by:
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Michael Ellerman authored
We want to use this in another test, so make it available at the top of the powerpc selftests tree. Signed-off-by: -
Daniel Axtens authored
GregorianDay() is supposed to calculate the day of the week (tm->tm_wday) for a given day/month/year. In that calcuation it indexed into an array called MonthOffset using tm->tm_mon-1. However tm_mon is zero-based, not one-based, so this is off-by-one. It also means that every January, GregoiranDay() will access element -1 of the MonthOffset array. It also doesn't appear to be a correct algorithm either: see in contrast kernel/time/timeconv.c's time_to_tm function. It's been broken forever, which suggests no-one in userland uses this. It looks like no-one in the kernel uses tm->tm_wday either (see e.g. drivers/rtc/rtc-ds1305.c:319). tm->tm_wday is conventionally set to -1 when not available in hardware so we can simply set it to -1 and drop the function. (There are over a dozen other drivers in drivers/rtc that do this.) Found using UBSAN. Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrew Morton <akpm@linux-foundation.org> # as an example of what UBSan finds. Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: rtc-linux@googlegroups.com Signed-off-by:
Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by:
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- 14 Dec, 2015 25 commits
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Rashmica Gupta authored
When a transaction is aborted, VSR values should rollback to the checkpointed values before the transaction began. VSRs used elsewhere in the kernel during a transaction, or while the transaction is suspended should not affect the checkpointed values. Prior to the bug fix in commit d31626f7 ("powerpc: Don't corrupt transactional state when using FP/VMX in kernel") when VMX was requested by the kernel the .vr_state (which held the checkpointed state of VSRs before the transaction) was overwritten with the current state from outside the transation. Thus if the transaction did not complete, the VSR values would be "rolled back" to potentially incorrect values. Signed-off-by:
Rashmica Gupta <rashmicy@gmail.com> Signed-off-by:
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Rashmica Gupta authored
Currently if you are in xmon without an oops etc. to view the kernel version you have to type "d $linux_banner" - not necessarily obvious. As this is useful information, append to the output of "e" command. Example output: $mon> e cpu 0x1: Vector: 0 at [c0000000f879ba80] pc: c000000000081718: sysrq_handle_xmon+0x68/0x80 lr: c000000000081718: sysrq_handle_xmon+0x68/0x80 sp: c0000000f879bbe0 msr: 8000000000009033 current = 0xc0000000f604d5c0 paca = 0xc00000000fdc0480 softe: 0 irq_happened: 0x01 pid = 2467, comm = bash Linux version 4.4.0-rc2-00008-gc51af91c3ab3-dirty (rashmica@circle) (gcc version 5.1.1 20150629 (GCC) ) #45 SMP Wed Nov 25 10:25:12 AEDT 2015 Signed-off-by: -
Rashmica Gupta authored
All users of QPACE have upgraded to QPACE2 so remove the Cell QPACE code. Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Vipin K Parashar authored
Kernel prints respective warnings about various EPOW events for user information/action after parsing EPOW interrupts. At times below EPOW reset event warning is seen to be flooding kernel log over a period of time. May 25 03:46:34 alp kernel: Non critical power or cooling issue cleared May 25 03:46:52 alp kernel: Non critical power or cooling issue cleared May 25 03:53:48 alp kernel: Non critical power or cooling issue cleared May 25 03:55:46 alp kernel: Non critical power or cooling issue cleared May 25 03:56:34 alp kernel: Non critical power or cooling issue cleared May 25 03:59:04 alp kernel: Non critical power or cooling issue cleared May 25 04:02:01 alp kernel: Non critical power or cooling issue cleared These EPOW reset events are spurious in nature and are triggered by firmware without an actual EPOW event being reset. This patch avoids these multiple EPOW reset warnings by using a counter variable. This variable is incremented every time an EPOW event is reported. Upon receiving a EPOW reset event the same variable is checked to filter out spurious events and decremented accordingly. This patch also improves log messages to better describe EPOW event being reported. Merged adjacent log messages into single one to reduce number of lines printed per event. Signed-off-by:
Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by:
Vipin K Parashar <vipin@linux.vnet.ibm.com> Signed-off-by:
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Michael Neuling authored
Test the kernels signal generation code to ensure it can handle an invalid stack pointer when transactional. Signed-off-by:
Michael Neuling <mikey@neuling.org> Tested-by:
Anshuman Khandual <khandual@linux.vnet.ibm.com> [mpe: Skip if we don't have TM] Signed-off-by:
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Michael Neuling authored
Test the kernel's signal return code to ensure that it doesn't crash when both the transactional and suspend MSR bits are set in the signal context. Signed-off-by:
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Michael Ellerman authored
Signed-off-by: -
Michael Ellerman authored
Move have_htm_nosc() into a new tm.h, and add a new helper, have_htm() which we'll use in the next patch. Signed-off-by: -
Michael Ellerman authored
We already do this twice and want to add another so add a helper. Signed-off-by: -
Michael Ellerman authored
This doesn't really belong in harness.c, it's a helper function. So move it into utils.c. Signed-off-by: -
Michael Ellerman authored
Merge the two TM fixes we merged in 4.4. We are about to merge selftests for these, and without the fixes the selftests will oops. powerpc fixes for 4.4 #2 - tm: Block signal return from setting invalid MSR state from Michael Neuling - tm: Check for already reclaimed tasks from Michael Neuling
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Michael Neuling authored
Print MSR TM bits in oops messages. This appends them to the end like this: MSR: 8000000502823031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[TE]> You get the TM[] only if at least one TM MSR bit is set. Inside the TM[], E means Enabled (bit 32), S means Suspended (bit 33), and T means Transactional (bit 34) If no bits are set, you get no TM[] output. Include rework of printbits() to handle this case. Signed-off-by: -
Boqun Feng authored
According to memory-barriers.txt, xchg*, cmpxchg* and their atomic_ versions all need to be fully ordered, however they are now just RELEASE+ACQUIRE, which are not fully ordered. So also replace PPC_RELEASE_BARRIER and PPC_ACQUIRE_BARRIER with PPC_ATOMIC_ENTRY_BARRIER and PPC_ATOMIC_EXIT_BARRIER in __{cmp,}xchg_{u32,u64} respectively to guarantee fully ordered semantics of atomic{,64}_{cmp,}xchg() and {cmp,}xchg(), as a complement of commit b97021f8 ("powerpc: Fix atomic_xxx_return barrier semantics") This patch depends on patch "powerpc: Make value-returning atomics fully ordered" for PPC_ATOMIC_ENTRY_BARRIER definition. Cc: stable@vger.kernel.org # 3.2+ Signed-off-by:Boqun Feng <boqun.feng@gmail.com> Reviewed-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:
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Boqun Feng authored
According to memory-barriers.txt: > Any atomic operation that modifies some state in memory and returns > information about the state (old or new) implies an SMP-conditional > general memory barrier (smp_mb()) on each side of the actual > operation ... Which mean these operations should be fully ordered. However on PPC, PPC_ATOMIC_ENTRY_BARRIER is the barrier before the actual operation, which is currently "lwsync" if SMP=y. The leading "lwsync" can not guarantee fully ordered atomics, according to Paul Mckenney: https://lkml.org/lkml/2015/10/14/970 To fix this, we define PPC_ATOMIC_ENTRY_BARRIER as "sync" to guarantee the fully-ordered semantics. This also makes futex atomics fully ordered, which can avoid possible memory ordering problems if userspace code relies on futex system call for fully ordered semantics. Fixes: b97021f8 ("powerpc: Fix atomic_xxx_return barrier semantics") Cc: stable@vger.kernel.org # 3.2+ Signed-off-by:
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Aneesh Kumar K.V authored
The slot information of base page size hash pte is stored in the pgtable_t w.r.t transparent hugepage. We need to make sure we don't index beyond pgtable_t size. Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
This will bulk read 4 hash pte slot entries and should reduce the loop Signed-off-by:
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Aneesh Kumar K.V authored
Remove the related functions and #defines Signed-off-by:
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Aneesh Kumar K.V authored
They don't need to track 4k subpage slot details and hence don't need second half of pgtable_t. Signed-off-by:
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Aneesh Kumar K.V authored
Use the #define instead of open-coding the same Signed-off-by:
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Aneesh Kumar K.V authored
pte and pmd table size are dependent on config items. Don't hard code the same. This make sure we use the right value when masking pmd entries and also while checking pmd_bad Signed-off-by:
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Aneesh Kumar K.V authored
For a pte entry we will have _PAGE_PTE set. Our pte page address have a minimum alignment requirement of HUGEPD_SHIFT_MASK + 1. We use the lower 7 bits to indicate hugepd. ie. For pmd and pgd we can find: 1) _PAGE_PTE set pte -> indicate PTE 2) bits [2..6] non zero -> indicate hugepd. They also encode the size. We skip bit 1 (_PAGE_PRESENT). 3) othewise pointer to next table. Acked-by:
Scott Wood <scottwood@freescale.com> Signed-off-by:
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Aneesh Kumar K.V authored
We support THP only with book3s_64 and 64K page size. Move THP details to hash64-64k.h to clarify the same. Acked-by:
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Aneesh Kumar K.V authored
W.r.t hugetlb, we support two format for pmd. With book3s_64 and 64K linux page size, we can have pte at the pmd level. Hence we don't need to support hugepd there. For everything else hugepd is supported and pmd_huge is (0). Acked-by:
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Aneesh Kumar K.V authored
Only difference here is, we apply the WIMG mapping early, so rflags passed to updatepp will also be changed. Acked-by:
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Aneesh Kumar K.V authored
Instead of open coding it in multiple code paths, export the helper and add more documentation. Also make sure we don't make assumption regarding pte bit position Acked-by:
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