powerpc/topology: Get topology for shared processors at boot
On a shared LPAR, Phyp will not update the CPU associativity at boot
time. Just after the boot system does recognize itself as a shared
LPAR and trigger a request for correct CPU associativity. But by then
the scheduler would have already created/destroyed its sched domains.
This causes
- Broken load balance across Nodes causing islands of cores.
- Performance degradation esp if the system is lightly loaded
- dmesg to wrongly report all CPUs to be in Node 0.
- Messages in dmesg saying borken topology.
- With commit 051f3ca02e46 ("sched/topology: Introduce NUMA identity
node sched domain"), can cause rcu stalls at boot up.
The sched_domains_numa_masks table which is used to generate cpumasks
is only created at boot time just before creating sched domains and
never updated. Hence, its better to get the topology correct before
the sched domains are created.
For example on 64 core Power 8 shared LPAR, dmesg reports
Brought up 512 CPUs
Node 0 CPUs: 0-511
Node 1 CPUs:
Node 2 CPUs:
Node 3 CPUs:
Node 4 CPUs:
Node 5 CPUs:
Node 6 CPUs:
Node 7 CPUs:
Node 8 CPUs:
Node 9 CPUs:
Node 10 CPUs:
Node 11 CPUs:
...
BUG: arch topology borken
the DIE domain not a subset of the NUMA domain
BUG: arch topology borken
the DIE domain not a subset of the NUMA domain
numactl/lscpu output will still be correct with cores spreading across
all nodes:
Socket(s): 64
NUMA node(s): 12
Model: 2.0 (pvr 004d 0200)
Model name: POWER8 (architected), altivec supported
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 64K
L1i cache: 32K
NUMA node0 CPU(s): 0-7,32-39,64-71,96-103,176-183,272-279,368-375,464-471
NUMA node1 CPU(s): 8-15,40-47,72-79,104-111,184-191,280-287,376-383,472-479
NUMA node2 CPU(s): 16-23,48-55,80-87,112-119,192-199,288-295,384-391,480-487
NUMA node3 CPU(s): 24-31,56-63,88-95,120-127,200-207,296-303,392-399,488-495
NUMA node4 CPU(s): 208-215,304-311,400-407,496-503
NUMA node5 CPU(s): 168-175,264-271,360-367,456-463
NUMA node6 CPU(s): 128-135,224-231,320-327,416-423
NUMA node7 CPU(s): 136-143,232-239,328-335,424-431
NUMA node8 CPU(s): 216-223,312-319,408-415,504-511
NUMA node9 CPU(s): 144-151,240-247,336-343,432-439
NUMA node10 CPU(s): 152-159,248-255,344-351,440-447
NUMA node11 CPU(s): 160-167,256-263,352-359,448-455
Currently on this LPAR, the scheduler detects 2 levels of Numa and
created numa sched domains for all CPUs, but it finds a single DIE
domain consisting of all CPUs. Hence it deletes all numa sched
domains.
To address this, detect the shared processor and update topology soon
after CPUs are setup so that correct topology is updated just before
scheduler creates sched domain.
Socket(s): 64
NUMA node(s): 12
Model: 2.0 (pvr 004d 0200)
Model name: POWER8 (architected), altivec supported
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 64K
L1i cache: 32K
NUMA node0 CPU(s): 0-7,32-39,64-71,96-103,176-183,272-279,368-375,464-471
NUMA node1 CPU(s): 8-15,40-47,72-79,104-111,184-191,280-287,376-383,472-479
NUMA node2 CPU(s): 16-23,48-55,80-87,112-119,192-199,288-295,384-391,480-487
NUMA node3 CPU(s): 24-31,56-63,88-95,120-127,200-207,296-303,392-399,488-495
NUMA node4 CPU(s): 208-215,304-311,400-407,496-503
NUMA node5 CPU(s): 168-175,264-271,360-367,456-463
NUMA node6 CPU(s): 128-135,224-231,320-327,416-423
NUMA node7 CPU(s): 136-143,232-239,328-335,424-431
NUMA node8 CPU(s): 216-223,312-319,408-415,504-511
NUMA node9 CPU(s): 144-151,240-247,336-343,432-439
NUMA node10 CPU(s): 152-159,248-255,344-351,440-447
NUMA node11 CPU(s): 160-167,256-263,352-359,448-455
Reported-by: Manjunatha H R <manjuhr1@in.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
[mpe: Trim / format change log] Tested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv/pci: Work around races in PCI bridge enabling
The generic code is racy when multiple children of a PCI bridge try to
enable it simultaneously.
This leads to drivers trying to access a device through a
not-yet-enabled bridge, and this EEH errors under various
circumstances when using parallel driver probing.
There is work going on to fix that properly in the PCI core but it
will take some time.
x86 gets away with it because (outside of hotplug), the BIOS enables
all the bridges at boot time.
This patch does the same thing on powernv by enabling all bridges that
have child devices at boot time, thus avoiding subsequent races. It's
suitable for backporting to stable and distros, while the proper PCI
fix will probably be significantly more invasive.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Hari Bathini [Fri, 17 Aug 2018 20:40:56 +0000 (02:10 +0530)]
powerpc/fadump: cleanup crash memory ranges support
Commit 1bd6a1c4b80a ("powerpc/fadump: handle crash memory ranges array
index overflow") changed crash memory ranges to a dynamic array that
is reallocated on-demand with krealloc(). The relevant header for this
call was not included. The kernel compiles though. But be cautious and
add the header anyway.
Also, memory allocation logic in fadump_add_crash_memory() takes care
of memory allocation for crash memory ranges in all scenarios. Drop
unnecessary memory allocation in fadump_setup_crash_memory_ranges().
Fixes: 1bd6a1c4b80a ("powerpc/fadump: handle crash memory ranges array index overflow") Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Mon, 30 Apr 2018 14:55:58 +0000 (00:55 +1000)]
powerpc/powernv: provide a console flush operation for opal hvc driver
Provide the flush hv_op for the opal hvc driver. This will flush the
firmware console buffers without spinning with interrupts disabled.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Thu, 16 Aug 2018 05:27:47 +0000 (15:27 +1000)]
powerpc/traps: Avoid rate limit messages from show unhandled signals
In the recent commit to add an explicit ratelimit state when showing
unhandled signals, commit 35a52a10c3ac ("powerpc/traps: Use an
explicit ratelimit state for show_signal_msg()"), I put the check of
show_unhandled_signals and the ratelimit state before the call to
unhandled_signal() so as to avoid unnecessarily calling the latter
when show_unhandled_signals is false.
However that causes us to check the ratelimit state on every call, so
if we take a lot of *handled* signals that has the effect of making
the ratelimit code print warnings that callbacks have been suppressed
when they haven't.
So rearrange the code so that we check show_unhandled_signals first,
then call unhandled_signal() and finally check the ratelimit state.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Nicholas Piggin [Tue, 7 Aug 2018 13:21:56 +0000 (23:21 +1000)]
powerpc/64s: Fix PACA_IRQ_HARD_DIS accounting in idle_power4()
When idle_power4() hard disables interrupts then finds a soft pending
interrupt, it returns with interrupts hard disabled but without
PACA_IRQ_HARD_DIS set. Commit 9b81c0211c ("powerpc/64s: make
PACA_IRQ_HARD_DIS track MSR[EE] closely") added a warning for that
condition (since disabled).
Fix this by adding the PACA_IRQ_HARD_DIS for that case.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add statistics that show how memory is mapped within the kernel linear mapping.
This is similar to commit 37cd944c8d8f ("s390/pgtable: add mapping statistics")
We don't do this with Hash translation mode. Hash uses one size (mmu_linear_psize)
to map the kernel linear mapping and we print the linear psize during boot as
below.
Michael Ellerman [Tue, 10 Jul 2018 06:20:56 +0000 (16:20 +1000)]
powerpc/uaccess: Enable get_user(u64, *p) on 32-bit
Currently if you build a 32-bit powerpc kernel and use get_user() to
load a u64 value it will fail to build with eg:
kernel/rseq.o: In function `rseq_get_rseq_cs':
kernel/rseq.c:123: undefined reference to `__get_user_bad'
This is hitting the check in __get_user_size() that makes sure the
size we're copying doesn't exceed the size of the destination:
#define __get_user_size(x, ptr, size, retval)
do {
retval = 0;
__chk_user_ptr(ptr);
if (size > sizeof(x))
(x) = __get_user_bad();
Which doesn't immediately make sense because the size of the
destination is u64, but it's not really, because __get_user_check()
etc. internally create an unsigned long and copy into that:
#define __get_user_check(x, ptr, size)
({
long __gu_err = -EFAULT;
unsigned long __gu_val = 0;
The problem being that on 32-bit unsigned long is not big enough to
hold a u64. We can fix this with a trick from hpa in the x86 code, we
statically check the type of x and set the type of __gu_val to either
unsigned long or unsigned long long.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Fri, 10 Aug 2018 06:42:48 +0000 (16:42 +1000)]
powerpc/64s: move machine check SLB flushing to mm/slb.c
The machine check code that flushes and restores bolted segments in
real mode belongs in mm/slb.c. This will also be used by pseries
machine check and idle code in future changes.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix the below build error using strlcpy instead of strncpy
In function 'pnv_parse_cpuidle_dt',
inlined from 'pnv_init_idle_states' at arch/powerpc/platforms/powernv/idle.c:840:7,
inlined from '__machine_initcall_powernv_pnv_init_idle_states' at arch/powerpc/platforms/powernv/idle.c:870:1:
arch/powerpc/platforms/powernv/idle.c:820:3: error: 'strncpy' specified bound 16 equals destination size [-Werror=stringop-truncation]
strncpy(pnv_idle_states[i].name, temp_string[i],
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PNV_IDLE_NAME_LEN);
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range
This patch makes sure we update the mmu_gather page size even if we are
requesting for a fullmm flush. This avoids triggering VM_WARN_ON in code
paths like __tlb_remove_page_size that explicitly check for removing range page
size to be same as mmu gather page size.
Fixes: 5a6099346c41 ("powerpc/64s/radix: tlb do not flush on page size when fullmm") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Acked-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix the following warnings (treated as error in W=1):
arch/powerpc/kernel/setup_32.c:198:13: error: no previous prototype for ‘irqstack_early_init’
arch/powerpc/kernel/setup_32.c:238:13: error: no previous prototype for ‘setup_power_save’
arch/powerpc/kernel/setup_32.c:253:13: error: no previous prototype for ‘initialize_cache_info’
Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These functions can all be static, make it so. Fix warnings treated as
errors with W=1:
arch/powerpc/platforms/powermac/pci.c:1022:6: error: no previous prototype for ‘pmac_pci_fixup_ohci’
arch/powerpc/platforms/powermac/pci.c:1057:6: error: no previous prototype for ‘pmac_pci_fixup_cardbus’
arch/powerpc/platforms/powermac/pci.c:1094:6: error: no previous prototype for ‘pmac_pci_fixup_pciata’
Remove has_address declaration and assignment since it's not used.
Also add gcc attribute unused to fix a warning treated as error with
W=1:
arch/powerpc/platforms/powermac/pci.c:784:19: error: variable ‘has_address’ set but not used
arch/powerpc/platforms/powermac/pci.c:907:22: error: variable ‘ht’ set but not used
In commit 14baf4d9c739 ("cxl: Add guest-specific code") the following code
was added:
if (afu->crs_len < 0) {
dev_err(&afu->dev, "Unexpected configuration record size value\n");
return -EINVAL;
}
However the variable `crs_len` is of type u64 and cannot be compared < 0.
Remove the dead code section. Fix the following warning treated as error
with W=1:
../drivers/misc/cxl/guest.c:919:19: error: comparison of unsigned expression < 0 is always false [-Werror=type-limits]
Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powermac: Add missing include of header pmac.h
The header `pmac.h` was not included, leading to the following warnings,
treated as error with W=1:
arch/powerpc/platforms/powermac/time.c:69:13: error: no previous prototype for ‘pmac_time_init’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:207:15: error: no previous prototype for ‘pmac_get_boot_time’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:222:6: error: no previous prototype for ‘pmac_get_rtc_time’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:240:5: error: no previous prototype for ‘pmac_set_rtc_time’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:259:12: error: no previous prototype for ‘via_calibrate_decr’ [-Werror=missing-prototypes]
arch/powerpc/platforms/powermac/time.c:311:13: error: no previous prototype for ‘pmac_calibrate_decr’ [-Werror=missing-prototypes]
The function `via_calibrate_decr` was made static to silence a warning.
Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Boqun Feng [Tue, 22 Nov 2016 09:20:09 +0000 (17:20 +0800)]
powerpc/xmon: Add address lookup for percpu symbols
Currently, in xmon, there is no obvious way to get an address for a
percpu symbol for a particular cpu. Having such an ability would be
good for debugging the system when percpu variables got involved.
Therefore, this patch introduces a new xmon command "lp" to lookup the
address for percpu symbols. Usage of "lp" is similar to "ls", except
that we could add a cpu number to choose the variable of which cpu we
want to lookup. If no cpu number is given, lookup for current cpu.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/pseries: Fix endianness while restoring of r3 in MCE handler.
During Machine Check interrupt on pseries platform, register r3 points
RTAS extended event log passed by hypervisor. Since hypervisor uses r3
to pass pointer to rtas log, it stores the original r3 value at the
start of the memory (first 8 bytes) pointed by r3. Since hypervisor
stores this info and rtas log is in BE format, linux should make
sure to restore r3 value in correct endian format.
Without this patch when MCE handler, after recovery, returns to code that
that caused the MCE may end up with Data SLB access interrupt for invalid
address followed by kernel panic or hang.
Severe Machine check interrupt [Recovered]
NIP [d00000000ca301b8]: init_module+0x1b8/0x338 [bork_kernel]
Initiator: CPU
Error type: SLB [Multihit]
Effective address: d00000000ca70000
cpu 0xa: Vector: 380 (Data SLB Access) at [c0000000fc7775b0]
pc: c0000000009694c0: vsnprintf+0x80/0x480
lr: c0000000009698e0: vscnprintf+0x20/0x60
sp: c0000000fc777830
msr: 8000000002009033
dar: a803a30c000000d0
current = 0xc00000000bc9ef00
paca = 0xc00000001eca5c00 softe: 3 irq_happened: 0x01
pid = 8860, comm = insmod
vscnprintf+0x20/0x60
vprintk_emit+0xb4/0x4b0
vprintk_func+0x5c/0xd0
printk+0x38/0x4c
init_module+0x1c0/0x338 [bork_kernel]
do_one_initcall+0x54/0x230
do_init_module+0x8c/0x248
load_module+0x12b8/0x15b0
sys_finit_module+0xa8/0x110
system_call+0x58/0x6c
--- Exception: c00 (System Call) at 00007fff8bda0644
SP (7fffdfbfe980) is in userspace
Hari Bathini [Mon, 6 Aug 2018 20:42:54 +0000 (02:12 +0530)]
powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements
With dynamic memory allocation support for crash memory ranges array,
there is no hard limit on the no. of crash memory ranges kernel could
export, but program headers count could overflow in the /proc/vmcore
ELF file while exporting each memory range as PT_LOAD segment. Reduce
the likelihood of a such scenario, by folding adjacent crash memory
ranges which minimizes the total number of PT_LOAD segments.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Hari Bathini [Mon, 6 Aug 2018 20:42:45 +0000 (02:12 +0530)]
powerpc/fadump: handle crash memory ranges array index overflow
Crash memory ranges is an array of memory ranges of the crashing kernel
to be exported as a dump via /proc/vmcore file. The size of the array
is set based on INIT_MEMBLOCK_REGIONS, which works alright in most cases
where memblock memory regions count is less than INIT_MEMBLOCK_REGIONS
value. But this count can grow beyond INIT_MEMBLOCK_REGIONS value since
commit 142b45a72e22 ("memblock: Add array resizing support").
On large memory systems with a few DLPAR operations, the memblock memory
regions count could be larger than INIT_MEMBLOCK_REGIONS value. On such
systems, registering fadump results in crash or other system failures
like below:
as array index overflow is not checked for while setting up crash memory
ranges causing memory corruption. To resolve this issue, dynamically
allocate memory for crash memory ranges and resize it incrementally,
in units of pagesize, on hitting array size limit.
Fixes: 2df173d9e85d ("fadump: Initialize elfcore header and add PT_LOAD program headers.") Cc: stable@vger.kernel.org # v3.4+ Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
[mpe: Just use PAGE_SIZE directly, fixup variable placement] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/cpm1: fix compilation error with CONFIG_PPC_EARLY_DEBUG_CPM
commit e8cb7a55eb8dc ("powerpc: remove superflous inclusions of
asm/fixmap.h") removed inclusion of asm/fixmap.h from files not
including objects from that file.
However, asm/mmu-8xx.h includes call to __fix_to_virt(). The proper
way would be to include asm/fixmap.h in asm/mmu-8xx.h but it creates
an inclusion loop.
So we have to leave asm/fixmap.h in sysdep/cpm_common.c for
CONFIG_PPC_EARLY_DEBUG_CPM
CC arch/powerpc/sysdev/cpm_common.o
In file included from ./arch/powerpc/include/asm/mmu.h:340:0,
from ./arch/powerpc/include/asm/reg_8xx.h:8,
from ./arch/powerpc/include/asm/reg.h:29,
from ./arch/powerpc/include/asm/processor.h:13,
from ./arch/powerpc/include/asm/thread_info.h:28,
from ./include/linux/thread_info.h:38,
from ./arch/powerpc/include/asm/ptrace.h:159,
from ./arch/powerpc/include/asm/hw_irq.h:12,
from ./arch/powerpc/include/asm/irqflags.h:12,
from ./include/linux/irqflags.h:16,
from ./include/asm-generic/cmpxchg-local.h:6,
from ./arch/powerpc/include/asm/cmpxchg.h:537,
from ./arch/powerpc/include/asm/atomic.h:11,
from ./include/linux/atomic.h:5,
from ./include/linux/mutex.h:18,
from ./include/linux/kernfs.h:13,
from ./include/linux/sysfs.h:16,
from ./include/linux/kobject.h:20,
from ./include/linux/device.h:16,
from ./include/linux/node.h:18,
from ./include/linux/cpu.h:17,
from ./include/linux/of_device.h:5,
from arch/powerpc/sysdev/cpm_common.c:21:
arch/powerpc/sysdev/cpm_common.c: In function ‘udbg_init_cpm’:
./arch/powerpc/include/asm/mmu-8xx.h:218:25: error: implicit declaration of function ‘__fix_to_virt’ [-Werror=implicit-function-declaration]
#define VIRT_IMMR_BASE (__fix_to_virt(FIX_IMMR_BASE))
^
arch/powerpc/sysdev/cpm_common.c:75:7: note: in expansion of macro ‘VIRT_IMMR_BASE’
VIRT_IMMR_BASE);
^
./arch/powerpc/include/asm/mmu-8xx.h:218:39: error: ‘FIX_IMMR_BASE’ undeclared (first use in this function)
#define VIRT_IMMR_BASE (__fix_to_virt(FIX_IMMR_BASE))
^
arch/powerpc/sysdev/cpm_common.c:75:7: note: in expansion of macro ‘VIRT_IMMR_BASE’
VIRT_IMMR_BASE);
^
./arch/powerpc/include/asm/mmu-8xx.h:218:39: note: each undeclared identifier is reported only once for each function it appears in
#define VIRT_IMMR_BASE (__fix_to_virt(FIX_IMMR_BASE))
^
arch/powerpc/sysdev/cpm_common.c:75:7: note: in expansion of macro ‘VIRT_IMMR_BASE’
VIRT_IMMR_BASE);
^
cc1: all warnings being treated as errors
make[1]: *** [arch/powerpc/sysdev/cpm_common.o] Error 1
Fixes: e8cb7a55eb8dc ("powerpc: remove superflous inclusions of asm/fixmap.h") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Rashmica Gupta [Fri, 3 Aug 2018 06:06:00 +0000 (16:06 +1000)]
powerpc/powernv: Allow memory that has been hot-removed to be hot-added
This patch allows the memory removed by memtrace to be readded to the
kernel. So now you don't have to reboot your system to add the memory
back to the kernel or to have a different amount of memory removed.
Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com> Tested-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/dts/fsl: t2080rdb: use the Cortina PHY driver compatible
The Cortina PHY is not compatible with IEEE 802.3 clause 45.
Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
[scottwood: made commit message about compatibility, not driver choice] Signed-off-by: Scott Wood <oss@buserror.net>
powerpc/dts/fsl: t4240rdb: use the Cortina PHY driver compatible
The Cortina PHY is not compatible with IEEE 802.3 clause 45.
Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
[scottwood: made commit message about compatibility, not driver choice] Signed-off-by: Scott Wood <oss@buserror.net>
powerpc/cpm1: fix compilation error with CONFIG_PPC_EARLY_DEBUG_CPM
commit e8cb7a55eb8dc ("powerpc: remove superflous inclusions of
asm/fixmap.h") removed inclusion of asm/fixmap.h from files not
including objects from that file.
However, asm/mmu-8xx.h includes call to __fix_to_virt(). The proper
way would be to include asm/fixmap.h in asm/mmu-8xx.h but it creates
an inclusion loop.
So we have to leave asm/fixmap.h in sysdep/cpm_common.c for
CONFIG_PPC_EARLY_DEBUG_CPM
CC arch/powerpc/sysdev/cpm_common.o
In file included from ./arch/powerpc/include/asm/mmu.h:340:0,
from ./arch/powerpc/include/asm/reg_8xx.h:8,
from ./arch/powerpc/include/asm/reg.h:29,
from ./arch/powerpc/include/asm/processor.h:13,
from ./arch/powerpc/include/asm/thread_info.h:28,
from ./include/linux/thread_info.h:38,
from ./arch/powerpc/include/asm/ptrace.h:159,
from ./arch/powerpc/include/asm/hw_irq.h:12,
from ./arch/powerpc/include/asm/irqflags.h:12,
from ./include/linux/irqflags.h:16,
from ./include/asm-generic/cmpxchg-local.h:6,
from ./arch/powerpc/include/asm/cmpxchg.h:537,
from ./arch/powerpc/include/asm/atomic.h:11,
from ./include/linux/atomic.h:5,
from ./include/linux/mutex.h:18,
from ./include/linux/kernfs.h:13,
from ./include/linux/sysfs.h:16,
from ./include/linux/kobject.h:20,
from ./include/linux/device.h:16,
from ./include/linux/node.h:18,
from ./include/linux/cpu.h:17,
from ./include/linux/of_device.h:5,
from arch/powerpc/sysdev/cpm_common.c:21:
arch/powerpc/sysdev/cpm_common.c: In function ‘udbg_init_cpm’:
./arch/powerpc/include/asm/mmu-8xx.h:218:25: error: implicit declaration of function ‘__fix_to_virt’ [-Werror=implicit-function-declaration]
#define VIRT_IMMR_BASE (__fix_to_virt(FIX_IMMR_BASE))
^
arch/powerpc/sysdev/cpm_common.c:75:7: note: in expansion of macro ‘VIRT_IMMR_BASE’
VIRT_IMMR_BASE);
^
./arch/powerpc/include/asm/mmu-8xx.h:218:39: error: ‘FIX_IMMR_BASE’ undeclared (first use in this function)
#define VIRT_IMMR_BASE (__fix_to_virt(FIX_IMMR_BASE))
^
arch/powerpc/sysdev/cpm_common.c:75:7: note: in expansion of macro ‘VIRT_IMMR_BASE’
VIRT_IMMR_BASE);
^
./arch/powerpc/include/asm/mmu-8xx.h:218:39: note: each undeclared identifier is reported only once for each function it appears in
#define VIRT_IMMR_BASE (__fix_to_virt(FIX_IMMR_BASE))
^
arch/powerpc/sysdev/cpm_common.c:75:7: note: in expansion of macro ‘VIRT_IMMR_BASE’
VIRT_IMMR_BASE);
^
cc1: all warnings being treated as errors
make[1]: *** [arch/powerpc/sysdev/cpm_common.o] Error 1
Fixes: e8cb7a55eb8dc ("powerpc: remove superflous inclusions of asm/fixmap.h") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net>
Breno Leitao [Tue, 7 Aug 2018 14:15:39 +0000 (11:15 -0300)]
selftests/powerpc: Kill child processes on SIGINT
There are some powerpc selftests, as tm/tm-unavailable, that run for a long
period (>120 seconds), and if it is interrupted, as pressing CRTL-C
(SIGINT), the foreground process (harness) dies but the child process and
threads continue to execute (with PPID = 1 now) in background.
In this case, you'd think the whole test exited, but there are remaining
threads and processes being executed in background. Sometimes these
zombies processes are doing annoying things, as consuming the whole CPU or
dumping things to STDOUT.
This patch fixes this problem by attaching an empty signal handler to
SIGINT in the harness process. This handler will interrupt (EINTR) the
parent process waitpid() call, letting the code to follow through the
normal flow, which will kill all the processes in the child process group.
powerpc/powernv/opal: Use standard interrupts property when available
For (bad) historical reasons, OPAL used to create a non-standard pair
of properties "opal-interrupts" and "opal-interrupts-names" for
representing the list of interrupts it wants Linux to request on its
behalf.
Among other issues, the opal-interrupts doesn't have a way to carry
the type of interrupts, and they were assumed to be all level
sensitive.
This is wrong on some recent systems where some of them are edge
sensitive causing warnings in the XIVE code and possible misbehaviours
if they need to be retriggered (typically the NPU2 TCE error
interrupts).
This makes Linux switch to using the standard "interrupts" and
"interrupt-names" properties instead when they are available, using
standard of_irq helpers, which can carry all the desired type
information.
Newer versions of OPAL will generate those properties in addition to
the legacy ones.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Fixup prefix logic to check strlen(r->name). Reinstate setting
of start = 0 in opal_event_shutdown() to avoid double free warnings] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc: Make CPU selection logic generic in Makefile
At the time being, when adding a new CPU for selection, both
Kconfig.cputype and Makefile have to be modified.
This patch moves into Kconfig.cputype the name of the CPU to me
passed to the -mcpu= argument.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Rename the option to TARGET_CPU to echo the gcc documentation] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/Makefiles: Convert ifeq to ifdef where possible
In Makefiles if we're testing a CONFIG_FOO symbol for equality with 'y'
we can instead just use ifdef. The latter reads easily, so convert to
it where possible.
Signed-off-by: Rodrigo R. Galvao <rosattig@linux.vnet.ibm.com> Reviewed-by: Mauro S. M. Rodrigues <maurosr@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Paul Mackerras [Fri, 3 Aug 2018 10:13:06 +0000 (20:13 +1000)]
powerpc/64: Copy as much as possible in __copy_tofrom_user
In __copy_tofrom_user, if we encounter an exception on a store, we
stop copying and return the number of bytes not copied. However,
if the store is wider than one byte and is to an unaligned address,
it is possible that the store operand overlaps a page boundary
and the exception occurred on the latter part of the store operand,
meaning that it would be possible to copy a few more bytes. Since
copy_to_user is generally expected to copy as much as possible,
it would be better to copy those extra few bytes. This adds code
to do that. Since this edge case is not performance-critical,
the code has been written to be compact rather than as fast as
possible.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
selftests/powerpc/64: Test exception cases in copy_tofrom_user
This adds a set of test cases to test the behaviour of
copy_tofrom_user when exceptions are encountered accessing the
source or destination. Currently, copy_tofrom_user does not always
copy as many bytes as possible when an exception occurs on a store
to the destination, and that is reflected in failures in these tests.
Based on a test program from Anton Blanchard.
[paulus@ozlabs.org - test all three paths, wrote commit description,
made EX_TABLE create an exception table.]
Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Paul Mackerras [Fri, 3 Aug 2018 10:13:04 +0000 (20:13 +1000)]
selftests/powerpc/64: Test all paths through copy routines
The hand-coded assembler 64-bit copy routines include feature sections
that select one code path or another depending on which CPU we are
executing on. The self-tests for these copy routines end up testing
just one path. This adds a mechanism for selecting any desired code
path at compile time, and makes 2 or 3 versions of each test, each
using a different code path, so as to cover all the possible paths.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
[mpe: Add -mcpu=power4 to CFLAGS for older compilers] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Paul Mackerras [Fri, 3 Aug 2018 10:13:03 +0000 (20:13 +1000)]
powerpc/64: Make exception table clearer in __copy_tofrom_user_base
This aims to make the generation of exception table entries for the
loads and stores in __copy_tofrom_user_base clearer and easier to
verify. Instead of having a series of local labels on the loads and
stores, with a series of corresponding labels later for the exception
handlers, we now use macros to generate exception table entries at the
point of each load and store that could potentially trap. We do this
with the macros lex (load exception) and stex (store exception).
These macros are used right before the load or store to which they
apply.
Some complexity is introduced by the fact that we have some more work
to do after hitting an exception, because we need to calculate and
return the number of bytes not copied. The code uses r3 as the
current pointer into the destination buffer, that is, the address of
the first byte of the destination that has not been modified.
However, at various points in the copy loops, r3 can be 4, 8, 16 or 24
bytes behind that point.
To express this offset in an understandable way, we define a symbol
r3_offset which is updated at various points so that it equal to the
difference between the address of the first unmodified byte of the
destination and the value in r3. (In fact it only needs to be
accurate at the point of each lex or stex macro invocation.)
The rules for updating r3_offset are as follows:
* It starts out at 0
* An addi r3,r3,N instruction decreases r3_offset by N
* A store instruction (stb, sth, stw, std) to N(r3)
increases r3_offset by the width of the store (1, 2, 4, 8)
* A store with update instruction (stbu, sthu, stwu, stdu) to N(r3)
sets r3_offset to the width of the store.
There is some trickiness to the way that the lex and stex macros and
the associated exception handlers work. I would have liked to use
the current value of r3_offset in the name of the symbol used as
the exception handler, as in ".Lld_exc_$(r3_offset)" and then
have symbols .Lld_exc_0, .Lld_exc_8, .Lld_exc_16 etc. corresponding
to the offsets that needed to be added to r3. However, I couldn't
see a way to do that with gas.
Instead, the exception handler address is .Lld_exc - r3_offset or
.Lst_exc - r3_offset, that is, the distance ahead of .Lld_exc/.Lst_exc
that we start executing is equal to the amount that we need to add to
r3. This works because r3_offset is always a small multiple of 4,
and our instructions are 4 bytes long. This means that before
.Lld_exc and .Lst_exc, we have a sequence of instructions that
increments r3 by 4, 8, 16 or 24 depending on where we start. The
sequence increments r3 by 4 per instruction (on average).
We also replace the exception table for the 4k copy loop by a
macro per load or store. These loads and stores all use exactly
the same exception handler, which simply resets the argument registers
r3, r4 and r5 to there original values and re-does the whole copy
using the slower loop.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Haren Myneni [Wed, 13 Jun 2018 07:32:40 +0000 (00:32 -0700)]
crypto/nx: Initialize 842 high and normal RxFIFO control registers
NX increments readOffset by FIFO size in receive FIFO control register
when CRB is read. But the index in RxFIFO has to match with the
corresponding entry in FIFO maintained by VAS in kernel. Otherwise NX
may be processing incorrect CRBs and can cause CRB timeout.
VAS FIFO offset is 0 when the receive window is opened during
initialization. When the module is reloaded or in kexec boot, readOffset
in FIFO control register may not match with VAS entry. This patch adds
nx_coproc_init OPAL call to reset readOffset and queued entries in FIFO
control register for both high and normal FIFOs.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
[mpe: Fixup uninitialized variable warning] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix build errors and warnings in t1042rdb_diu.c by adding header files
and MODULE_LICENSE().
../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: warning: data definition has no type or storage class
early_initcall(t1042rdb_diu_init);
../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: error: type defaults to 'int' in declaration of 'early_initcall' [-Werror=implicit-int]
../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: warning: parameter names (without types) in function declaration
and
WARNING: modpost: missing MODULE_LICENSE() in arch/powerpc/platforms/85xx/t1042rdb_diu.o
Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Scott Wood <oss@buserror.net> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The context switch call-backs for thread-imc are defined in sched_task function.
So when thread-imc events are grouped with software pmu events,
perf_pmu_sched_task hits the WARN_ON_ONCE condition, since software PMUs are
assumed not to have a sched_task defined.
Patch to move the thread_imc enable/disable opal call back from sched_task to
event_[add/del] function
Fixes: f74c89bd80fb ("powerpc/perf: Add thread IMC PMU support") Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Tested-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Fri, 27 Jul 2018 11:48:17 +0000 (21:48 +1000)]
powerpc/64s: Fix page table fragment refcount race vs speculative references
The page table fragment allocator uses the main page refcount racily
with respect to speculative references. A customer observed a BUG due
to page table page refcount underflow in the fragment allocator. This
can be caused by the fragment allocator set_page_count stomping on a
speculative reference, and then the speculative failure handler
decrements the new reference, and the underflow eventually pops when
the page tables are freed.
Fix this by using a dedicated field in the struct page for the page
table fragment allocator.
Darren Stevens [Fri, 3 Aug 2018 11:15:10 +0000 (21:15 +1000)]
powerpc/pasemi: Use pr_err/pr_warn... for kernel messages
Pasemi code still uses printk(KERN_ERR/KERN_WARN ... change these to
pr_err(, pr_warn(... to match other powerpc arch code.
No functional changes.
Signed-off-by: Darren Stevens <darren@stevens-zone.net>
[mpe: Unsplit some strings while we're at it] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The current->comm and current->pid printed can serve as a glue that
links the instructions dump to its originator, allowing messages to be
interleaved in the logs.
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/traps: Use %lx format in show_signal_msg()
Use %lx format to print registers. This avoids having two different
formats and avoids checking for MSR_64BIT, improving readability of the
function.
Even though we could have used %px, which is functionally equivalent to %lx
as per Documentation/core-api/printk-formats.rst, it is not semantically
correct because the data printed are not pointers. And using %px requires
casting data to (void *).
Besides that, %lx matches the format used in show_regs().
Michael Ellerman [Tue, 31 Jul 2018 12:08:42 +0000 (22:08 +1000)]
selftests/powerpc: Add more version checks to alignment_handler test
The alignment_handler is documented to only work on Power8/Power9, but
we can make it run on older CPUs by guarding more of the tests with
feature checks.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Michael Ellerman [Tue, 31 Jul 2018 12:08:41 +0000 (22:08 +1000)]
selftests/powerpc: Skip earlier in alignment_handler test
Currently the alignment_handler test prints "Can't open /dev/fb0"
about 80 times per run, which is a little annoying.
Refactor it to check earlier if it can open /dev/fb0 and skip if not,
this results in each test printing something like:
test: test_alignment_handler_vsx_206
tags: git_version:v4.18-rc3-134-gfb21a48904aa
[SKIP] Test skipped on line 291
skip: test_alignment_handler_vsx_206
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Michael Ellerman [Thu, 26 Jul 2018 12:42:44 +0000 (22:42 +1000)]
powerpc/64s: Make rfi_flush_fallback a little more robust
Because rfi_flush_fallback runs immediately before the return to
userspace it currently runs with the user r1 (stack pointer). This
means if we oops in there we will report a bad kernel stack pointer in
the exception entry path, eg:
Although the NIP tells us where we were, and the TRAP number tells us
what happened, it would still be nicer if we could report the actual
exception rather than barfing about the stack pointer.
We an do that fairly simply by loading the kernel stack pointer on
entry and restoring the user value before returning. That way we see a
regular oops such as:
Note this shouldn't make the kernel stack pointer vulnerable to a
meltdown attack, because it should be flushed from the cache before we
return to userspace. The user r1 value will be in the cache, because
we load it in the return path, but that is harmless.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Michael Ellerman [Mon, 23 Jul 2018 15:07:56 +0000 (01:07 +1000)]
powerpc/powernv: Query firmware for count cache flush settings
Look for fw-features properties to determine the appropriate settings
for the count cache flush, and then call the generic powerpc code to
set it up based on the security feature flags.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Mon, 23 Jul 2018 15:07:55 +0000 (01:07 +1000)]
powerpc/pseries: Query hypervisor for count cache flush settings
Use the existing hypercall to determine the appropriate settings for
the count cache flush, and then call the generic powerpc code to set
it up based on the security feature flags.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Mon, 23 Jul 2018 15:07:54 +0000 (01:07 +1000)]
powerpc/64s: Add support for software count cache flush
Some CPU revisions support a mode where the count cache needs to be
flushed by software on context switch. Additionally some revisions may
have a hardware accelerated flush, in which case the software flush
sequence can be shortened.
If we detect the appropriate flag from firmware we patch a branch
into _switch() which takes us to a count cache flush sequence.
That sequence in turn may be patched to return early if we detect that
the CPU supports accelerating the flush sequence in hardware.
Add debugfs support for reporting the state of the flush, as well as
runtime disabling it.
And modify the spectre_v2 sysfs file to report the state of the
software flush.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Mon, 23 Jul 2018 15:07:53 +0000 (01:07 +1000)]
powerpc/64s: Add new security feature flags for count cache flush
Add security feature flags to indicate the need for software to flush
the count cache on context switch, and for the presence of a hardware
assisted count cache flush.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Mon, 23 Jul 2018 15:07:52 +0000 (01:07 +1000)]
powerpc/asm: Add a patch_site macro & helpers for patching instructions
Add a macro and some helper C functions for patching single asm
instructions.
The gas macro means we can do something like:
1: nop
patch_site 1b, patch__foo
Which is less visually distracting than defining a GLOBAL symbol at 1,
and also doesn't pollute the symbol table which can confuse eg. perf.
These are obviously similar to our existing feature sections, but are
not automatically patched based on CPU/MMU features, rather they are
designed to be manually patched by C code at some arbitrary point.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/64: Make meltdown reporting Book3S 64 specific
In a subsequent patch we will enable building security.c for Book3E.
However the NXP platforms are not vulnerable to Meltdown, so make the
Meltdown vulnerability reporting PPC_BOOK3S_64 specific.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
[mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Fri, 27 Jul 2018 23:06:35 +0000 (09:06 +1000)]
powerpc/64: Call setup_barrier_nospec() from setup_arch()
Currently we require platform code to call setup_barrier_nospec(). But
if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case
then we can call it in setup_arch().
Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Fri, 27 Jul 2018 23:06:34 +0000 (09:06 +1000)]
powerpc/64: Add CONFIG_PPC_BARRIER_NOSPEC
Add a config symbol to encode which platforms support the
barrier_nospec speculation barrier. Currently this is just Book3S 64
but we will add Book3E in a future patch.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The EXCEPTION_RELON_PROLOG_PSERIES_1() macro does the same job as
EXCEPTION_PROLOG_2 (which we just recently created), except for
"RELON" (relocation on) exceptions.
So rename it as such.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Thu, 26 Jul 2018 13:07:04 +0000 (23:07 +1000)]
powerpc/64s: Rename STD_EXCEPTION_PSERIES to STD_EXCEPTION
The "PSERIES" in STD_EXCEPTION_PSERIES is to differentiate the macros
from the legacy iSeries versions, which are called
STD_EXCEPTION_ISERIES. It is not anything to do with pseries vs
powernv or powermac etc.
We removed the legacy iSeries code in 2012, in commit 8ee3e0d69623x
("powerpc: Remove the main legacy iSerie platform code").
So remove "PSERIES" from the macros.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Thu, 26 Jul 2018 13:07:03 +0000 (23:07 +1000)]
powerpc/64s: Move SET_SCRATCH0() into EXCEPTION_RELON_PROLOG_PSERIES()
EXCEPTION_RELON_PROLOG_PSERIES() only has two users,
STD_RELON_EXCEPTION_PSERIES() and STD_RELON_EXCEPTION_HV() both of
which "call" SET_SCRATCH0(), so just move SET_SCRATCH0() into
EXCEPTION_RELON_PROLOG_PSERIES().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Thu, 26 Jul 2018 13:07:02 +0000 (23:07 +1000)]
powerpc/64s: Move SET_SCRATCH0() into EXCEPTION_PROLOG_PSERIES()
EXCEPTION_PROLOG_PSERIES() only has two users, STD_EXCEPTION_PSERIES()
and STD_EXCEPTION_HV() both of which "call" SET_SCRATCH0(), so just
move SET_SCRATCH0() into EXCEPTION_PROLOG_PSERIES().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Darren Stevens [Wed, 25 Jul 2018 20:55:18 +0000 (21:55 +0100)]
powerpc/pasemi: Search for PCI root bus by compatible property
Pasemi arch code finds the root of the PCI-e bus by searching the
device-tree for a node called 'pxp'. But the root bus has a compatible
property of 'pasemi,rootbus' so search for that instead.
Signed-off-by: Darren Stevens <darren@stevens-zone.net> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/lib: Implement strlen() in assembly for PPC32
The generic implementation of strlen() reads strings byte per byte.
This patch implements strlen() in assembly based on a read of entire
words, in the same spirit as what some other arches and glibc do.
On a 8xx the time spent in strlen is reduced by 3/4 for long strings.
strlen() selftest on an 8xx provides the following values:
Before the patch (ie with the generic strlen() in lib/string.c):
len 256 : time = 1.195055
len 016 : time = 0.083745
len 008 : time = 0.046828
len 004 : time = 0.028390
After the patch:
len 256 : time = 0.272185 ==> 78% improvment
len 016 : time = 0.040632 ==> 51% improvment
len 008 : time = 0.033060 ==> 29% improvment
len 004 : time = 0.029149 ==> 2% degradation
On a 832x:
Before the patch:
len 256 : time = 0.236125
len 016 : time = 0.018136
len 008 : time = 0.011000
len 004 : time = 0.007229
After the patch:
len 256 : time = 0.094950 ==> 60% improvment
len 016 : time = 0.013357 ==> 26% improvment
len 008 : time = 0.010586 ==> 4% improvment
len 004 : time = 0.008784
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
string.c contains a copy of strlen() from lib/string.c
The test first tests the correctness of strlen() by comparing
the result with libc strlen(). It tests all cases of alignment.
It them tests the duration of an aligned strlen() on a 4 bytes string,
on a 16 bytes string and on a 256 bytes string.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Drop change log from copy of string.c] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/pseries: Defer the logging of rtas error to irq work queue.
rtas_log_buf is a buffer to hold RTAS event data that are communicated
to kernel by hypervisor. This buffer is then used to pass RTAS event
data to user through proc fs. This buffer is allocated from
vmalloc (non-linear mapping) area.
On Machine check interrupt, register r3 points to RTAS extended event
log passed by hypervisor that contains the MCE event. The pseries
machine check handler then logs this error into rtas_log_buf. The
rtas_log_buf is a vmalloc-ed (non-linear) buffer we end up taking up a
page fault (vector 0x300) while accessing it. Since machine check
interrupt handler runs in NMI context we can not afford to take any
page fault. Page faults are not honored in NMI context and causes
kernel panic. Apart from that, as Nick pointed out,
pSeries_log_error() also takes a spin_lock while logging error which
is not safe in NMI context. It may endup in deadlock if we get another
MCE before releasing the lock. Fix this by deferring the logging of
rtas error to irq work queue.
Current implementation uses two different buffers to hold rtas error
log depending on whether extended log is provided or not. This makes
bit difficult to identify which buffer has valid data that needs to
logged later in irq work. Simplify this using single buffer, one per
paca, and copy rtas log to it irrespective of whether extended log is
provided or not. Allocate this buffer below RMA region so that it can
be accessed in real mode mce handler.
Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt") Cc: stable@vger.kernel.org # v4.14+ Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>