Breno Leitao [Mon, 22 Oct 2018 21:16:26 +0000 (18:16 -0300)]
selftests/powerpc: Fix ptrace tm failure
Test ptrace-tm-spd-gpr fails on current kernel (4.19) due to a segmentation
fault that happens on the child process prior to setting cptr[2] = 1. This
causes the parent process to wait forever at 'while (!pptr[2])' and the test to
be killed by the test harness framework by timeout, thus, failing.
The segmentation fault happens because of a inline assembly being
generated as:
0x10000355c <tm_spd_gpr+492> lfs f0, 0(0)
This is reading memory position 0x0 and causing the segmentation fault.
This code is being generated by ASM_LOAD_FPR_SINGLE_PRECISION(flt_4), where
flt_4 is passed to the inline assembly block as:
[flt_4] "r" (&d)
Since the inline assembly 'r' constraint means any GPR, gpr0 is being
chosen, thus causing this issue when issuing a Load Floating-Point Single
instruction.
This patch simply changes the constraint to 'b', which specify that this
register will be used as base, and r0 is not allowed to be used, avoiding
this issue.
Other than that, removing flt_2 register from the input operands, since it
is not used by the inline assembly code at all.
Paul Mackerras [Sat, 20 Oct 2018 09:54:55 +0000 (20:54 +1100)]
KVM: PPC: Use exported tb_to_ns() function in decrementer emulation
This changes the KVM code that emulates the decrementer function to do
the conversion of decrementer values to time intervals in nanoseconds
by calling the tb_to_ns() function exported by the powerpc timer code,
in preference to open-coded arithmetic using values from the
decrementer_clockevent struct. Similarly, the HV-KVM code that did
the same conversion using arithmetic on tb_ticks_per_sec also now
uses tb_to_ns().
Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Christophe Leroy [Fri, 19 Oct 2018 06:55:08 +0000 (06:55 +0000)]
powerpc/8xx: Use patch_site for perf counters setup
The 8xx TLB miss routines are patched when (de)activating
perf counters.
This patch uses the new patch_site functionality in order
to get a better code readability and avoid a label mess when
dumping the code with 'objdump -d'
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Christophe Leroy [Fri, 19 Oct 2018 06:55:06 +0000 (06:55 +0000)]
powerpc/8xx: Use patch_site for memory setup patching
The 8xx TLB miss routines are patched at startup at several places.
This patch uses the new patch_site functionality in order
to get a better code readability and avoid a label mess when
dumping the code with 'objdump -d'
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
That commit was buggy, as it used rlwinm instead of rlwimi.
Instead of fixing that bug, we revert the previous commit in order to
reduce the dependency between L1 entries and L2 entries
Fixes: 4f94b2c7462d9 ("powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Christophe Leroy [Fri, 19 Oct 2018 06:12:50 +0000 (06:12 +0000)]
powerpc/msi: Fix compile error on mpc83xx
mpic_get_primary_version() is not defined when not using MPIC.
The compile error log like:
arch/powerpc/sysdev/built-in.o: In function `fsl_of_msi_probe':
fsl_msi.c:(.text+0x150c): undefined reference to `fsl_mpic_primary_get_version'
Signed-off-by: Jia Hongtao <hongtao.jia@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com> Reported-by: Radu Rendec <radu.rendec@gmail.com> Fixes: 807d38b73b6 ("powerpc/mpic: Add get_version API both for internal and external use") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Fri, 19 Oct 2018 05:19:10 +0000 (16:19 +1100)]
powerpc: Fix stack protector crashes on CPU hotplug
Recently in commit 7241d26e8175 ("powerpc/64: properly initialise
the stackprotector canary on SMP.") we fixed a crash with stack
protector on SMP by initialising the stack canary in
cpu_idle_thread_init().
But this can also causes crashes, when a CPU comes back online after
being offline:
Looking at the stack we see that the canary value in the stack frame
doesn't match the canary in the task/paca. That is because we have
reinitialised the task/paca value, but then the CPU coming online has
returned into a function using the old canary value. That causes the
comparison to fail.
Instead we can call boot_init_stack_canary() from start_secondary()
which never returns. This is essentially what the generic code does in
cpu_startup_entry() under #ifdef X86, we should make that non-x86
specific in a future patch.
Fixes: 7241d26e8175 ("powerpc/64: properly initialise the stackprotector canary on SMP.") Reported-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Christophe Leroy [Sat, 13 Oct 2018 09:16:22 +0000 (09:16 +0000)]
powerpc/traps: restore recoverability of machine_check interrupts
commit b96672dd840f ("powerpc: Machine check interrupt is a non-
maskable interrupt") added a call to nmi_enter() at the beginning of
machine check restart exception handler. Due to that, in_interrupt()
always returns true regardless of the state before entering the
exception, and die() panics even when the system was not already in
interrupt.
This patch calls nmi_exit() before calling die() in order to restore
the interrupt state we had before calling nmi_enter()
Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Wed, 29 Aug 2018 11:56:56 +0000 (21:56 +1000)]
powerpc/64/module: REL32 relocation range check
The recent module relocation overflow crash demonstrated that we
have no range checking on REL32 relative relocations. This patch
implements a basic check, the same kernel that previously oopsed
and rebooted now continues with some of these errors when loading
the module:
Michael Ellerman [Wed, 15 Aug 2018 11:29:45 +0000 (21:29 +1000)]
powerpc/mm: Fix page table dump to work on Radix
When we're running on Book3S with the Radix MMU enabled the page table
dump currently prints the wrong addresses because it uses the wrong
start address.
Fix it to use PAGE_OFFSET rather than KERN_VIRT_START.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Wed, 17 Oct 2018 12:53:38 +0000 (23:53 +1100)]
powerpc/mm/radix: Display if mappings are exec or not
At boot we print the ranges we've mapped for the linear mapping and
what page size we've used. Also track whether the range is mapped
executable or not and display that as well.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Tue, 14 Aug 2018 12:37:32 +0000 (22:37 +1000)]
powerpc/mm/radix: Simplify split mapping logic
If we look closely at the logic in create_physical_mapping(), when
we're doing STRICT_KERNEL_RWX, we do the following steps:
- determine the gap from where we are to the end of the range
- choose an appropriate mapping_size based on the gap
- check if that mapping_size would overlap the __init_begin
boundary, and if not choose an appropriate mapping_size
We can simplify the logic by taking the __init_begin boundary into
account when we calculate the initial gap.
So add a next_boundary() function which tells us what the next
boundary is, either the __init_begin boundary or end. In future we can
add more boundaries.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Tue, 14 Aug 2018 12:01:44 +0000 (22:01 +1000)]
powerpc/mm/radix: Remove the retry in the split mapping logic
When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel
text read only.
The current logic uses a goto inside the for loop, which works, but is
hard to reason about.
When we hit the goto retry case we set max_mapping_size to PMD_SIZE
and go back to the start.
Setting max_mapping_size means we skip the PUD case and go to the PMD
case.
We know we will pass the alignment and gap checks because the only
reason we are there is we hit the goto retry, and that is guarded by
mapping_size == PUD_SIZE, which means addr is PUD aligned and gap is
greater or equal to PUD_SIZE.
So the only part of the check that can fail is the mmu_psize_defs
check for the 2M page size.
If we just duplicate that check we can avoid the goto, and we get the
same result.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Tue, 14 Aug 2018 11:05:20 +0000 (21:05 +1000)]
powerpc/mm/radix: Fix small page at boundary when splitting
When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel
text read only.
Currently we always use a small page at the text/data boundary, even
when that's not necessary:
Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages
Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
This is because the check that the mapping crosses the __init_begin
boundary is too strict, it also returns true when we map exactly up to
the boundary.
So fix it to check that the mapping would actually map past
__init_begin, and with that we see:
Mapped 0x0000000000000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Tue, 14 Aug 2018 10:48:22 +0000 (20:48 +1000)]
powerpc/mm/radix: Fix overuse of small pages in splitting logic
When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel text
read only.
But the current logic uses small pages for the entire text section,
regardless of whether a larger page size would fit. eg. with the
boundary at 16M we could use 2M pages, but instead we use 64K pages up
to the 16M boundary:
Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
This is because the test is checking if addr is < __init_begin
and addr + mapping_size is >= _stext. But that is true for all pages
between _stext and __init_begin.
Instead what we want to check is if we are crossing the text/data
boundary, which is at __init_begin. With that fixed we see:
Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages
Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
ie. we're correctly using 2MB pages below __init_begin, but we still
drop down to 64K pages unnecessarily at the boundary.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Fri, 10 Aug 2018 12:29:26 +0000 (22:29 +1000)]
powerpc/mm/radix: Fix off-by-one in split mapping logic
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>
Naveen N. Rao [Tue, 16 Oct 2018 20:25:00 +0000 (01:55 +0530)]
powerpc/ftrace: Handle large kernel configs
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>
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: Michael Ellerman <mpe@ellerman.id.au>
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: da7ad366b497 ("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: Michael Ellerman <mpe@ellerman.id.au>
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;
powerpc/time: isolate scaled cputime accounting in dedicated functions.
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: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Christophe Leroy [Mon, 27 Aug 2018 08:27:27 +0000 (08:27 +0000)]
powerpc/sysdev/ipic: check primary_ipic NULL pointer before using it
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: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/mm: fix always true/false warning in slice.c
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 <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Christophe Leroy [Fri, 22 Jun 2018 13:49:48 +0000 (13:49 +0000)]
powerpc/mm: fix missing prototypes in slice.c
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 <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Christophe Leroy [Mon, 15 Oct 2018 06:37:41 +0000 (06:37 +0000)]
powerpc/book3s64: fix dump_linuxpagetables "present" flag
Since commit bd0dbb73e013 ("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: bd0dbb73e013 ("powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid.") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Aravinda Prasad [Tue, 16 Oct 2018 11:50:05 +0000 (17:20 +0530)]
powerpc/pseries: Export raw per-CPU VPA data via debugfs
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: Michael Ellerman <mpe@ellerman.id.au>
Naveen N. Rao [Mon, 21 May 2018 15:13:57 +0000 (20:43 +0530)]
selftests/powerpc: Add test to verify rfi flush across a system call
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: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Add SPDX tags, clang format, skip if the debugfs is missing, use
__u64 and SANE_USERSPACE_TYPES to avoid printf() build errors.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Naveen N. Rao [Tue, 29 May 2018 06:51:00 +0000 (12:21 +0530)]
powerpc64/module elfv1: Set opd addresses after module relocation
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: 5633e85b2c313 ("powerpc64: Add .opd based function descriptor dereference") Cc: stable@vger.kernel.org # v4.16 Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Naveen N. Rao [Thu, 7 Jun 2018 09:52:02 +0000 (15:22 +0530)]
powerpc: Add support for function error injection
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: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Wed, 17 Oct 2018 12:39:41 +0000 (23:39 +1100)]
powerpc/time: Fix clockevent_decrementer initalisation for PR KVM
In the recent commit 8b78fdb045de ("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: 8b78fdb045de ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Mon, 15 Oct 2018 12:01:43 +0000 (23:01 +1100)]
powerpc/aout: Fix struct user definition to use user_pt_regs
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: 002af9391bfb ("powerpc: Split user/kernel definitions of struct pt_regs") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Mon, 15 Oct 2018 12:01:42 +0000 (23:01 +1100)]
powerpc/uapi: Fix sigcontext definition to use user_pt_regs
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: 002af9391bfb ("powerpc: Split user/kernel definitions of struct pt_regs") Reported-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Wed, 10 Oct 2018 05:13:06 +0000 (16:13 +1100)]
powerpc: Add -Werror at arch/powerpc level
Back when I added -Werror in commit ba55bd74360e ("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: Michael Ellerman <mpe@ellerman.id.au>
powerpc/prom_init: Generate "phandle" instead of "linux, phandle"
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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Unsplit warning printf()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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: Michael Ellerman <mpe@ellerman.id.au>
powerpc/mm: Increase the max addressable memory to 2PB
Currently we limit the max addressable memory to 128TB. This patch increase the
limit to 2PB. We can have devices like nvdimm which adds memory above 512TB
limit.
We still don't support regular system ram above 512TB. One of the challenge with
that is the percpu allocator, that allocates per node memory and use the max
distance between them as the percpu offsets. This means with large gap in
address space ( system ram above 1PB) we will run out of vmalloc space to map
the percpu allocation.
In order to support addressable memory above 512TB, kernel should be able to
linear map this range. To do that with hash translation we now add 4 context
to kernel linear map region. Our per context addressable range is 512TB. We
still keep VMALLOC and VMEMMAP region to old size. SLB miss handlers is updated
to validate these limit.
We also limit this update to SPARSEMEM_VMEMMAP and SPARSEMEM_EXTREME
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Tue, 2 Oct 2018 14:27:59 +0000 (00:27 +1000)]
powerpc/64s/hash: Add some SLB debugging tests
This adds CONFIG_DEBUG_VM checks to ensure:
- The kernel stack is in the SLB after it's flushed and bolted.
- We don't insert an SLB for an address that is aleady in the SLB.
- The kernel SLB miss handler does not take an SLB miss.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Tue, 2 Oct 2018 14:27:58 +0000 (00:27 +1000)]
powerpc/64s/hash: Simplify slb_flush_and_rebolt()
slb_flush_and_rebolt() is misleading, it is called in virtual mode, so
it can not possibly change the stack, so it should not be touching the
shadow area. And since vmalloc is no longer bolted, it should not
change any bolted mappings at all.
Change the name to slb_flush_and_restore_bolted(), and have it just
load the kernel stack from what's currently in the shadow SLB area.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Fri, 14 Sep 2018 15:30:56 +0000 (01:30 +1000)]
powerpc/64s/hash: Add a SLB preload cache
When switching processes, currently all user SLBEs are cleared, and a
few (exec_base, pc, and stack) are preloaded. In trivial testing with
small apps, this tends to miss the heap and low 256MB segments, and it
will also miss commonly accessed segments on large memory workloads.
Add a simple round-robin preload cache that just inserts the last SLB
miss into the head of the cache and preloads those at context switch
time. Every 256 context switches, the oldest entry is removed from the
cache to shrink the cache and require fewer slbmte if they are unused.
Much more could go into this, including into the SLB entry reclaim
side to track some LRU information etc, which would require a study of
large memory workloads. But this is a simple thing we can do now that
is an obvious win for common workloads.
With the full series, process switching speed on the context_switch
benchmark on POWER9/hash (with kernel speculation security masures
disabled) increases from 140K/s to 178K/s (27%).
POWER8 does not change much (within 1%), it's unclear why it does not
see a big gain like POWER9.
Booting to busybox init with 256MB segments has SLB misses go down
from 945 to 69, and with 1T segments 900 to 21. These could almost all
be eliminated by preloading a bit more carefully with ELF binary
loading.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Fri, 14 Sep 2018 15:30:53 +0000 (01:30 +1000)]
powerpc/64s/hash: Add SLB allocation status bitmaps
Add 32-entry bitmaps to track the allocation status of the first 32
SLB entries, and whether they are user or kernel entries. These are
used to allocate free SLB entries first, before resorting to the round
robin allocator.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Fri, 14 Sep 2018 15:30:51 +0000 (01:30 +1000)]
powerpc/64s/hash: Convert SLB miss handlers to C
This patch moves SLB miss handlers completely to C, using the standard
exception handler macros to set up the stack and branch to C.
This can be done because the segment containing the kernel stack is
always bolted, so accessing it with relocation on will not cause an
SLB exception.
Arbitrary kernel memory must not be accessed when handling kernel
space SLB misses, so care should be taken there. However user SLB
misses can access any kernel memory, which can be used to move some
fields out of the paca (in later patches).
User SLB misses could quite easily reconcile IRQs and set up a first
class kernel environment and exit via ret_from_except, however that
doesn't seem to be necessary at the moment, so we only do that if a
bad fault is encountered.
[ Credit to Aneesh for bug fixes, error checks, and improvements to
bad address handling, etc ]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Disallow tracing for all of slb.c for now.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nicholas Piggin [Fri, 12 Oct 2018 13:15:16 +0000 (00:15 +1100)]
powerpc/64: Interrupts save PPR on stack rather than thread_struct
PPR is the odd register out when it comes to interrupt handling, it is
saved in current->thread.ppr while all others are saved on the stack.
The difficulty with this is that accessing thread.ppr can cause a SLB
fault, but the SLB fault handler implementation in C change had
assumed the normal exception entry handlers would not cause an SLB
fault.
Fix this by allocating room in the interrupt stack to save PPR.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Michael Ellerman [Fri, 12 Oct 2018 12:13:17 +0000 (23:13 +1100)]
powerpc: Split user/kernel definitions of struct pt_regs
We use a shared definition for struct pt_regs in uapi/asm/ptrace.h.
That means the layout of the structure is ABI, ie. we can't change it.
That would be fine if it was only used to describe the user-visible
register state of a process, but it's also the struct we use in the
kernel to describe the registers saved in an interrupt frame.
We'd like more flexibility in the content (and possibly layout) of the
kernel version of the struct, but currently that's not possible.
So split the definition into a user-visible definition which remains
unchanged, and a kernel internal one.
At the moment they're still identical, and we check that at build
time. That's because we have code (in ptrace etc.) that assumes that
they are the same. We will fix that code in future patches, and then
we can break the strict symmetry between the two structs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/book3s64: Avoid multiple endian conversion in pte helpers
In the same spirit as already done in pte query helpers,
this patch changes pte setting helpers to perform endian
conversions on the constants rather than on the pte value.
In the meantime, it changes pte_access_permitted() to use
pte helpers for the same reason.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/8xx: change name of a few page flags to avoid confusion
_PAGE_PRIVILEGED corresponds to the SH bit which doesn't protect
against user access but only disables ASID verification on kernel
accesses. User access is controlled with _PMD_USER flag.
Name it _PAGE_SH instead of _PAGE_PRIVILEGED
_PAGE_HUGE corresponds to the SPS bit which doesn't really tells
that's it is a huge page but only that it is not a 4k page.
powerpc/mm: Define platform default caches related flags
Cache related flags like _PAGE_COHERENT and _PAGE_WRITETHRU
are defined on most platforms. The platforms not defining
them don't define any alternative. So we can give them a NUL
value directly for those platforms directly.
powerpc/mm: Allow platforms to redefine some helpers
The 40xx defines _PAGE_HWWRITE while others don't.
The 8xx defines _PAGE_RO instead of _PAGE_RW.
The 8xx defines _PAGE_PRIVILEGED instead of _PAGE_USER.
The 8xx defines _PAGE_HUGE and _PAGE_NA while others don't.
Lets those platforms redefine pte_write(), pte_wrprotect() and
pte_mkwrite() and get _PAGE_RO and _PAGE_HWWRITE off the common
helpers.
Lets the 8xx redefine pte_user(), pte_mkprivileged() and pte_mkuser()
and get rid of _PAGE_PRIVILEGED and _PAGE_USER default values.
Lets the 8xx redefine pte_mkhuge() and get rid of
_PAGE_HUGE default value.
powerpc/mm: Distribute platform specific PAGE and PMD flags and definitions
The base kernel PAGE_XXXX definition sets are more or less platform
specific. Lets distribute them close to platform _PAGE_XXX flags
definition, and customise them to their exact platform flags.
Also defines _PAGE_PSIZE and _PTE_NONE_MASK for each platform
allthough they are defined as 0.
Do the same with _PMD flags like _PMD_USER and _PMD_PRESENT_MASK
As done for book3s/64, add necessary flags/defines in
book3s/32/pgtable.h and do not include pte-common.h
It allows in the meantime to remove all related hash
definitions from pte-common.h and to also remove
_PAGE_EXEC default as _PAGE_EXEC is defined on all
platforms except book3s/32.
To reduce the complexity of flag_array, and allow the removal of
default 0 value of non existing flags, lets have one flag_array
table for each platform family with only the really existing flags.
powerpc/mm: don't use _PAGE_EXEC for calling hash_preload()
The 'access' parameter of hash_preload() is either 0 or _PAGE_EXEC.
Among the two versions of hash_preload(), only the PPC64 one is
doing something with this 'access' parameter.
In order to remove the use of _PAGE_EXEC outside platform code,
'access' parameter is replaced by 'is_exec' which will be either
true of false, and the PPC64 version of hash_preload() creates
the access flag based on 'is_exec'.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/mm: add pte helpers to query and change pte flags
In order to avoid using generic _PAGE_XXX flags in powerpc
core functions, define helpers for all needed flags:
- pte_mkuser() and pte_mkprivileged() to set/unset and/or
unset/set _PAGE_USER and/or _PAGE_PRIVILEGED
- pte_hashpte() to check if _PAGE_HASHPTE is set.
- pte_ci() check if cache is inhibited (already existing on book3s/64)
- pte_exprotect() to protect against execution
- pte_exec() and pte_mkexec() to query and set page execution
- pte_mkpte() to set _PAGE_PTE flag.
- pte_hw_valid() to check _PAGE_PRESENT since pte_present does
something different on book3s/64.
On book3s/32 there is no exec protection, so pte_mkexec() and
pte_exprotect() are nops and pte_exec() returns always true.
powerpc/mm: move some nohash pte helpers in nohash/[32:64]/pgtable.h
In order to allow their use in nohash/32/pgtable.h, we have to move the
following helpers in nohash/[32:64]/pgtable.h:
- pte_mkwrite()
- pte_mkdirty()
- pte_mkyoung()
- pte_wrprotect()
powerpc: don't use ioremap_prot() nor __ioremap() unless really needed.
In many places, ioremap_prot() and __ioremap() can be replaced with
higher level functions like ioremap(), ioremap_coherent(),
ioremap_cache(), ioremap_wc() ...
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
soc/fsl/qbman: use ioremap_cache() instead of ioremap_prot(0)
ioremap_prot() with flag set to 0 relies on a hack in
__ioremap_caller() which adds PAGE_KERNEL flags when the
handed flags don't look like a valid set of flags
(ie don't include _PAGE_PRESENT)
The intention being to map cached memory, use ioremap_cache() instead.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
drivers/video/fbdev: use ioremap_wc/wt() instead of __ioremap()
_PAGE_NO_CACHE is a platform specific flag. In addition, this flag
is misleading because one would think it requests a noncached page
whereas a noncached page is _PAGE_NO_CACHE | _PAGE_GUARDED
_PAGE_NO_CACHE alone means write combined noncached page, so lets
use ioremap_wc() instead.
_PAGE_WRITETHRU is also platform specific flag. Use ioremap_wt()
instead.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/rtas: Fix a potential race between CPU-Offline & Migration
Live Partition Migrations require all the present CPUs to execute the
H_JOIN call, and hence rtas_ibm_suspend_me() onlines any offline CPUs
before initiating the migration for this purpose.
The commit 85a88cabad57
("powerpc/pseries: Disable CPU hotplug across migrations")
disables any CPU-hotplug operations once all the offline CPUs are
brought online to prevent any further state change. Once the
CPU-Hotplug operation is disabled, the code assumes that all the CPUs
are online.
However, there is a minor window in rtas_ibm_suspend_me() between
onlining the offline CPUs and disabling CPU-Hotplug when a concurrent
CPU-offline operations initiated by the userspace can succeed thereby
nullifying the the aformentioned assumption. In this unlikely case
these offlined CPUs will not call H_JOIN, resulting in a system hang.
Fix this by verifying that all the present CPUs are actually online
after CPU-Hotplug has been disabled, failing which we restore the
state of the offline CPUs in rtas_ibm_suspend_me() and return an
-EBUSY.
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
projects / mirror_ubuntu-jammy-kernel.git / log