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: NPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This patch exports the maximum possible amount of memory
configured on the system via /proc/powerpc/lparcfg.
Signed-off-by: NAravinda Prasad <aravinda@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This patch adds a helper to get the address of a patch_site.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
[mpe: Call it "patch site" addr]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This reverts commit 4f94b2c7.

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: 4f94b2c7 ("powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAP")
Cc: stable@vger.kernel.org
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This reverts commit d8a2fe29.

That commit, by me, fixed the out of tree build errors by causing some
of the tests not to build at all.

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: NJia Hongtao <hongtao.jia@freescale.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>
Reported-by: NRadu Rendec <radu.rendec@gmail.com>
Fixes: 807d38b7 ("powerpc/mpic: Add get_version API both for internal and external use")
Cc: stable@vger.kernel.org
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Recently in commit 7241d26e ("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:

  Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: pnv_smp_cpu_kill_self+0x2a0/0x2b0
  CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc3-gcc-7.3.1-00168-g4ffe713b #94
  Call Trace:
    dump_stack+0xb0/0xf4 (unreliable)
    panic+0x144/0x328
    __stack_chk_fail+0x2c/0x30
    pnv_smp_cpu_kill_self+0x2a0/0x2b0
    cpu_die+0x48/0x70
    arch_cpu_idle_dead+0x20/0x40
    do_idle+0x274/0x390
    cpu_startup_entry+0x38/0x50
    start_secondary+0x5e4/0x600
    start_secondary_prolog+0x10/0x14

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: 7241d26e ("powerpc/64: properly initialise the stackprotector canary on SMP.")
Reported-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NChristophe Leroy <christophe.leroy@c-s.fr>

commit b96672dd ("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: b96672dd ("powerpc: Machine check interrupt is a non-maskable interrupt")
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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:

  module_64: x_tables: REL32 527703503449812 out of range!

Possibly other relocations (ADDR32, REL16, TOC16, etc.) should also have
overflow checks.
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This tests that a bctr (Branch to counter and link), ie. a function
call, to a wildly out-of-bounds address is handled correctly.

Some old kernel versions didn't handle it correctly, see eg:

  "powerpc/slb: Force a full SLB flush when we insert for a bad EA"
  https://lists.ozlabs.org/pipermail/linuxppc-dev/2017-April/157397.htmlSigned-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NMichael Ellerman <mpe@ellerman.id.au>

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: NMichael Ellerman <mpe@ellerman.id.au>

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: NMichael Ellerman <mpe@ellerman.id.au>

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: NMichael Ellerman <mpe@ellerman.id.au>

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: NMichael Ellerman <mpe@ellerman.id.au>

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: NMichael Ellerman <mpe@ellerman.id.au>

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: NMichael Ellerman <mpe@ellerman.id.au>

Currently, we expect to be able to reach ftrace_caller() from all
ftrace-enabled functions through a single relative branch. With large
kernel configs, we see functions outside of 32MB of ftrace_caller()
causing ftrace_init() to bail.

In such configurations, gcc/ld emits two types of trampolines for mcount():
1. A long_branch, which has a single branch to mcount() for functions that
   are one hop away from mcount():
	c0000000019e8544 <00031b56.long_branch._mcount>:
	c0000000019e8544:	4a 69 3f ac 	b       c00000000007c4f0 <._mcount>

2. A plt_branch, for functions that are farther away from mcount():
	c0000000051f33f8 <0008ba04.plt_branch._mcount>:
	c0000000051f33f8:	3d 82 ff a4 	addis   r12,r2,-92
	c0000000051f33fc:	e9 8c 04 20 	ld      r12,1056(r12)
	c0000000051f3400:	7d 89 03 a6 	mtctr   r12
	c0000000051f3404:	4e 80 04 20 	bctr

We can reuse those trampolines for ftrace if we can have those
trampolines go to ftrace_caller() instead. However, with ABIv2, we
cannot depend on r2 being valid. As such, we use only the long_branch
trampolines by patching those to instead branch to ftrace_caller or
ftrace_regs_caller.

In addition, we add additional trampolines around .text and .init.text
to catch locations that are covered by the plt branches. This allows
ftrace to work with most large kernel configurations.

For now, we always patch the trampolines to go to ftrace_regs_caller,
which is slightly inefficient. This can be optimized further at a later
point.
Signed-off-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

WARNING: CPU: 12 PID: 4322 at /arch/powerpc/mm/pgtable-book3s64.c:76 set_pmd_at+0x4c/0x2b0
 Modules linked in:
 CPU: 12 PID: 4322 Comm: qemu-system-ppc Tainted: G        W         4.19.0-rc3-00758-g8f0c636b0542 #36
 NIP:  c0000000000872fc LR: c000000000484eec CTR: 0000000000000000
 REGS: c000003fba876fe0 TRAP: 0700   Tainted: G        W          (4.19.0-rc3-00758-g8f0c636b0542)
 MSR:  900000010282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]>  CR: 24282884  XER: 00000000
 CFAR: c000000000484ee8 IRQMASK: 0
 GPR00: c000000000484eec c000003fba877268 c000000001f0ec00 c000003fbd229f80
 GPR04: 00007c8fe8e00000 c000003f864c5a38 860300853e0000c0 0000000000000080
 GPR08: 0000000080000000 0000000000000001 0401000000000080 0000000000000001
 GPR12: 0000000000002000 c000003fffff5400 c000003fce292000 00007c9024570000
 GPR16: 0000000000000000 0000000000ffffff 0000000000000001 c000000001885950
 GPR20: 0000000000000000 001ffffc0004807c 0000000000000008 c000000001f49d05
 GPR24: 00007c8fe8e00000 c0000000020f2468 ffffffffffffffff c000003fcd33b090
 GPR28: 00007c8fe8e00000 c000003fbd229f80 c000003f864c5a38 860300853e0000c0
 NIP [c0000000000872fc] set_pmd_at+0x4c/0x2b0
 LR [c000000000484eec] do_huge_pmd_numa_page+0xb1c/0xc20
 Call Trace:
 [c000003fba877268] [c00000000045931c] mpol_misplaced+0x1bc/0x230 (unreliable)
 [c000003fba8772c8] [c000000000484eec] do_huge_pmd_numa_page+0xb1c/0xc20
 [c000003fba877398] [c00000000040d344] __handle_mm_fault+0x5e4/0x2300
 [c000003fba8774d8] [c00000000040f400] handle_mm_fault+0x3a0/0x420
 [c000003fba877528] [c0000000003ff6f4] __get_user_pages+0x2e4/0x560
 [c000003fba877628] [c000000000400314] get_user_pages_unlocked+0x104/0x2a0
 [c000003fba8776c8] [c000000000118f44] __gfn_to_pfn_memslot+0x284/0x6a0
 [c000003fba877748] [c0000000001463a0] kvmppc_book3s_radix_page_fault+0x360/0x12d0
 [c000003fba877838] [c000000000142228] kvmppc_book3s_hv_page_fault+0x48/0x1300
 [c000003fba877988] [c00000000013dc08] kvmppc_vcpu_run_hv+0x1808/0x1b50
 [c000003fba877af8] [c000000000126b44] kvmppc_vcpu_run+0x34/0x50
 [c000003fba877b18] [c000000000123268] kvm_arch_vcpu_ioctl_run+0x288/0x2d0
 [c000003fba877b98] [c00000000011253c] kvm_vcpu_ioctl+0x1fc/0x8c0
 [c000003fba877d08] [c0000000004e9b24] do_vfs_ioctl+0xa44/0xae0
 [c000003fba877db8] [c0000000004e9c44] ksys_ioctl+0x84/0xf0
 [c000003fba877e08] [c0000000004e9cd8] sys_ioctl+0x28/0x80

We removed the pte_protnone check earlier with the understanding that we
mark the pte invalid before the set_pte/set_pmd usage. But the huge pmd
autonuma still use the set_pmd_at directly. This is ok because a protnone pte
won't have translation cache in TLB.

Fixes: da7ad366 ("powerpc/mm/book3s: Update pmd_present to look at _PAGE_PRESENT bit")
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Some of our Makefiles don't do the right thing when building the
selftests with O=, fix them up.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

If CONFIG_PPC_SPLPAR is not selected, steal_time will always
be NUL, so accounting it is pointless
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

scaled cputime is only meaningfull when the processor has
SPURR and/or PURR, which means only on PPC64.

Removing it on PPC32 significantly reduces the size of
vtime_account_system() and vtime_account_idle() on an 8xx:

Before:
00000000 l     F .text	000000a8 vtime_delta
00000280 g     F .text	0000010c vtime_account_system
0000038c g     F .text	00000048 vtime_account_idle

After:
(vtime_delta gets inlined inside the two functions)
000001d8 g     F .text	000000a0 vtime_account_system
00000278 g     F .text	00000038 vtime_account_idle

In terms of performance, we also get approximatly 7% improvement on
task switch. The following small benchmark app is run with perf stat:

void *thread(void *arg)
{
	int i;

	for (i = 0; i < atoi((char*)arg); i++)
		pthread_yield();
}

int main(int argc, char **argv)
{
	pthread_t th1, th2;

	pthread_create(&th1, NULL, thread, argv[1]);
	pthread_create(&th2, NULL, thread, argv[1]);
	pthread_join(th1, NULL);
	pthread_join(th2, NULL);

	return 0;
}

Before the patch:

 Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs):

       8228.476465      task-clock (msec)         #    0.954 CPUs utilized            ( +-  0.23% )
            200004      context-switches          #    0.024 M/sec                    ( +-  0.00% )

After the patch:

 Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs):

       7649.070444      task-clock (msec)         #    0.955 CPUs utilized            ( +-  0.27% )
            200004      context-switches          #    0.026 M/sec                    ( +-  0.00% )
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Generic implementation fails to remove breakpoints after init
when CONFIG_STRICT_KERNEL_RWX is selected:

[   13.251285] KGDB: BP remove failed: c001c338
[   13.259587] kgdbts: ERROR PUT: end of test buffer on 'do_fork_test' line 8 expected OK got $E14#aa
[   13.268969] KGDB: re-enter exception: ALL breakpoints killed
[   13.275099] CPU: 0 PID: 1 Comm: init Not tainted 4.18.0-g82bbb913ffd8 #860
[   13.282836] Call Trace:
[   13.285313] [c60e1ba0] [c0080ef0] kgdb_handle_exception+0x6f4/0x720 (unreliable)
[   13.292618] [c60e1c30] [c000e97c] kgdb_handle_breakpoint+0x3c/0x98
[   13.298709] [c60e1c40] [c000af54] program_check_exception+0x104/0x700
[   13.305083] [c60e1c60] [c000e45c] ret_from_except_full+0x0/0x4
[   13.310845] [c60e1d20] [c02a22ac] run_simple_test+0x2b4/0x2d4
[   13.316532] [c60e1d30] [c0081698] put_packet+0xb8/0x158
[   13.321694] [c60e1d60] [c00820b4] gdb_serial_stub+0x230/0xc4c
[   13.327374] [c60e1dc0] [c0080af8] kgdb_handle_exception+0x2fc/0x720
[   13.333573] [c60e1e50] [c000e928] kgdb_singlestep+0xb4/0xcc
[   13.339068] [c60e1e70] [c000ae1c] single_step_exception+0x90/0xac
[   13.345100] [c60e1e80] [c000e45c] ret_from_except_full+0x0/0x4
[   13.350865] [c60e1f40] [c000e11c] ret_from_syscall+0x0/0x38
[   13.356346] Kernel panic - not syncing: Recursive entry to debugger

This patch creates powerpc specific version of
kgdb_arch_set_breakpoint() and kgdb_arch_remove_breakpoint()
using patch_instruction()

Fixes: 1e0fc9d1 ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Add a trace point for tlbia (Translation Lookaside Buffer Invalidate
All) instruction.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

commit 0428491c ("powerpc/mm: Trace tlbie(l) instructions")
added tracepoints for tlbie calls, but _tlbil_va() was forgotten

Fixes: 0428491c ("powerpc/mm: Trace tlbie(l) instructions")
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Since commit bd0dbb73 ("powerpc/mm/books3s: Add new pte bit to
mark pte temporarily invalid."), _PAGE_PRESENT doesn't mean exactly
that a page is present. A page is also considered preset when
_PAGE_INVALID is set.

This patch changes the meaning of "present" and adds a status "valid"
associated to the _PAGE_PRESENT flag.

Fixes: bd0dbb73 ("powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid.")
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NAravinda Prasad <aravinda@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NAnton Blanchard <anton@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NNaveen 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: NMichael Ellerman <mpe@ellerman.id.au>

... so that it can be used by others.
Signed-off-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

module_frob_arch_sections() is called before the module is moved to its
final location. The function descriptor section addresses we are setting
here are thus invalid. Fix this by processing opd section during
module_finalize()

Fixes: 5633e85b ("powerpc64: Add .opd based function descriptor dereference")
Cc: stable@vger.kernel.org # v4.16
Signed-off-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: NSamuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

In the recent commit 8b78fdb0 ("powerpc/time: Use
clockevents_register_device(), fixing an issue with large
decrementer") we changed the way we initialise the decrementer
clockevent(s).

We no longer initialise the mult & shift values of
decrementer_clockevent itself.

This has the effect of breaking PR KVM, because it uses those values
in kvmppc_emulate_dec(). The symptom is guest kernels spin forever
mid-way through boot.

For now fix it by assigning back to decrementer_clockevent the mult
and shift values.

Fixes: 8b78fdb0 ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

I'm pretty sure this is dead code, it's only used by the a.out core
dump code, and we don't support a.out. We should remove it.

But while it's in the tree it should be using the ABI version of
pt_regs which is called user_pt_regs in the kernel, because the whole
struct is written to the core dump and so its size shouldn't change.

Note this isn't a uapi header so we don't need an ifdef.

Fixes: 002af939 ("powerpc: Split user/kernel definitions of struct pt_regs")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>