Commit Graph

781975 Commits

Author SHA1 Message Date
Suzuki K Poulose 8ab66cbe63 arm64: cpufeature: ctr: Fix cpu capability check for late CPUs
The matches() routine for a capability must honor the "scope"
passed to it and return the proper results.
i.e, when passed with SCOPE_LOCAL_CPU, it should check the
status of the capability on the current CPU. This is used by
verify_local_cpu_capabilities() on a late secondary CPU to make
sure that it's compliant with the established system features.
However, ARM64_HAS_CACHE_{IDC/DIC} always checks the system wide
registers and this could mean that a late secondary CPU could return
"true" (since the CPU hasn't updated the system wide registers yet)
and thus lead the system in an inconsistent state, where
the system assumes it has IDC/DIC feature, while the new CPU
doesn't.

Fixes: commit 6ae4b6e057 ("arm64: Add support for new control bits CTR_EL0.DIC and CTR_EL0.IDC")
Cc: Philip Elcan <pelcan@codeaurora.org>
Cc: Shanker Donthineni <shankerd@codeaurora.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-16 11:53:28 +01:00
Punit Agrawal 0c09d48564 Documentation/arm64: HugeTLB page implementation
Arm v8 architecture supports multiple page sizes - 4k, 16k and
64k. Based on the active page size, the Linux port supports
corresponding hugepage sizes at PMD and PUD(4k only) levels.

In addition, the architecture also supports caching larger sized
ranges (composed of multiple entries) at the PTE and PMD level in the
TLBs using the contiguous bit. The Linux port makes use of this
architectural support to enable additional hugepage sizes.

Describe the two different types of hugepages supported by the arm64
kernel and the hugepage sizes enabled by each.

Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-10 18:08:36 +01:00
James Morse 26a6f87ef5 arm64: mm: Use __pa_symbol() for set_swapper_pgd()
commit 2330b7ca78 ("arm64/mm: use fixmap to modify
swapper_pg_dir") modifies the swapper_pg_dir via the fixmap
as the kernel page tables have been moved to a read-only
part of the kernel mapping.

Using __pa() to setup the fixmap causes CONFIG_DEBUG_VIRTUAL
to fire, as this function is used on the kernel-image swapper
address. The in_swapper_pgdir() test before each call of this
function means set_swapper_pgd() will only ever be called when
pgdp points somewhere in the kernel-image mapping of
swapper_pd_dir. Use __pa_symbol().

Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-10 17:57:06 +01:00
Marc Zyngier e03a4e5bb7 arm64: Add silicon-errata.txt entry for ARM erratum 1188873
Document that we actually work around ARM erratum 1188873

Fixes: 95b861a4a6 ("arm64: arch_timer: Add workaround for ARM erratum 1188873")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-10 17:53:29 +01:00
James Morse 3b82a6ea23 Revert "arm64: uaccess: implement unsafe accessors"
This reverts commit a1f33941f7.

The unsafe accessors allow the PAN enable/disable calls to be made
once for a group of accesses. Adding these means we can now have
sequences that look like this:

| user_access_begin();
| unsafe_put_user(static-value, x, err);
| unsafe_put_user(helper-that-sleeps(), x, err);
| user_access_end();

Calling schedule() without taking an exception doesn't switch the
PSTATE or TTBRs. We can switch out of a uaccess-enabled region, and
run other code with uaccess enabled for a different thread.

We can also switch from uaccess-disabled code back into this region,
meaning the unsafe_put_user()s will fault.

For software-PAN, threads that do this will get stuck as
handle_mm_fault() will determine the page has already been mapped in,
but we fault again as the page tables aren't loaded.

To solve this we need code in __switch_to() that save/restores the
PAN state.

Acked-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-10 17:52:08 +01:00
Shaokun Zhang 742fafa50b arm64: mm: Drop the unused cpu parameter
Cpu parameter is never used in flush_context, remove it.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-09 17:17:23 +01:00
James Morse c20c650d91 MAINTAINERS: fix bad sdei paths
The SDEI header files had an 'arm_' namespace added, but the patterns
in the MAINTAINERS files were missed. Oops.

Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-05 17:55:07 +01:00
James Morse e9ed821be4 arm64: mm: Use #ifdef for the __PAGETABLE_P?D_FOLDED defines
__is_defined(__PAGETABLE_P?D_FOLDED) doesn't quite work as intended
as these symbols are internal to asm-generic and aren't defined in the
way kconfig expects. This makes them always evaluate to false.
Switch to #ifdef.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-05 17:19:40 +01:00
Kyrylo Tkachov 0293c8ba80 arm64: Fix typo in a comment in arch/arm64/mm/kasan_init.c
"bellow" -> "below"

The recommendation from kegel.com/kerspell is to only fix the howlers.
"Bellow" is a synonym of "howl" so this should be appropriate.

Signed-off-by: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-05 11:49:32 +01:00
Julien Thierry b0506a8bbb arm64: xen: Use existing helper to check interrupt status
The status of interrupts might depend on more than just pstate. Use
interrupts_disabled() instead of raw_irqs_disabled_flags() to take the full
context into account.

Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-03 16:14:11 +01:00
Julien Thierry 9a0c032825 arm64: Use daifflag_restore after bp_hardening
For EL0 entries requiring bp_hardening, daif status is kept at
DAIF_PROCCTX_NOIRQ until after hardening has been done. Then interrupts
are enabled through local_irq_enable().

Before using local_irq_* functions, daifflags should be properly restored
to a state where IRQs are enabled.

Enable IRQs by restoring DAIF_PROCCTX state after bp hardening.

Acked-by: James Morse <james.morse@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-03 16:12:21 +01:00
Julien Thierry f05692919b arm64: daifflags: Use irqflags functions for daifflags
Some of the work done in daifflags save/restore is already provided
by irqflags functions. Daifflags should always be a superset of irqflags
(it handles irq status + status of other flags). Modifying behaviour of
irqflags should alter the behaviour of daifflags.

Use irqflags_save/restore functions for the corresponding daifflags
operation.

Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-03 16:08:52 +01:00
Arnd Bergmann 040f340134 arm64: arch_timer: avoid unused function warning
arm64_1188873_read_cntvct_el0() is protected by the correct
CONFIG_ARM64_ERRATUM_1188873 #ifdef, but the only reference to it is
also inside of an CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND section,
and causes a warning if that is disabled:

drivers/clocksource/arm_arch_timer.c:323:20: error: 'arm64_1188873_read_cntvct_el0' defined but not used [-Werror=unused-function]

Since the erratum requires that we always apply the workaround
in the timer driver, select that symbol as we do for SoC
specific errata.

Fixes: 95b861a4a6 ("arm64: arch_timer: Add workaround for ARM erratum 1188873")
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-03 11:41:34 +01:00
Marc Zyngier c219bc4e92 arm64: Trap WFI executed in userspace
It recently came to light that userspace can execute WFI, and that
the arm64 kernel doesn't trap this event. This sounds rather benign,
but the kernel should decide when it wants to wait for an interrupt,
and not userspace.

Let's trap WFI and immediately return after having skipped the
instruction. This effectively makes WFI a rather expensive NOP.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 16:52:24 +01:00
Will Deacon ee91176120 arm64: docs: Document SSBS HWCAP
We advertise the MRS/MSR instructions for toggling SSBS at EL0 using an
HWCAP, so document it along with the others.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 16:28:17 +01:00
Giacomo Travaglini 4bfbe5eee3 arm64: docs: Fix typos in ELF hwcaps
Fix some typos in our hwcap documentation, where we refer to the wrong
ID register for some of the capabilities.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
[will: fix amusing binary constants]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 16:28:15 +01:00
zhong jiang 2ba0dacbae arm64/kprobes: remove an extra semicolon in arch_prepare_kprobe
There is an extra semicolon in arch_prepare_kprobe, remove it.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 14:36:49 +01:00
Anshuman Khandual 52338088ef arm64/numa: Unify common error path in numa_init()
At present numa_free_distance() is being called before numa_distance is
even initialized with numa_alloc_distance() which is really pointless.
Instead lets call numa_free_distance() on the common error path inside
numa_init() after numa_alloc_distance() has been successful.

Fixes: 1a2db30034 ("arm64, numa: Add NUMA support for arm64 platforms")
Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:49:52 +01:00
Anshuman Khandual 77cfe95090 arm64/numa: Report correct memblock range for the dummy node
The dummy node ID is marked into all memory ranges on the system. So the
dummy node really extends the entire memblock.memory. Hence report correct
extent information for the dummy node using memblock range helper functions
instead of the range [0LLU, PFN_PHYS(max_pfn) - 1)].

Fixes: 1a2db30034 ("arm64, numa: Add NUMA support for arm64 platforms")
Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:48:54 +01:00
Anshuman Khandual 359048f91d arm64/mm: Define esr_to_debug_fault_info()
fault_info[] and debug_fault_info[] are static arrays defining memory abort
exception handling functions looking into ESR fault status code encodings.
As esr_to_fault_info() is already available providing fault_info[] array
lookup, it really makes sense to have a corresponding debug_fault_info[]
array lookup function as well. This just adds an equivalent helper function
esr_to_debug_fault_info().

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:48:23 +01:00
Anshuman Khandual dbfe3828a6 arm64/mm: Reorganize arguments for is_el1_permission_fault()
Most memory abort exception handling related functions have the arguments
in the order (addr, esr, regs) except is_el1_permission_fault(). This
changes the argument order in this function as (addr, esr, regs) like
others.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:47:31 +01:00
Anshuman Khandual 00bbd5d901 arm64/mm: Use ESR_ELx_FSC macro while decoding fault exception
Just replace hard code value of 63 (0x111111) with an existing macro
ESR_ELx_FSC when parsing for the status code during fault exception.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:47:12 +01:00
Marc Zyngier 95b861a4a6 arm64: arch_timer: Add workaround for ARM erratum 1188873
When running on Cortex-A76, a timer access from an AArch32 EL0
task may end up with a corrupted value or register. The workaround for
this is to trap these accesses at EL1/EL2 and execute them there.

This only affects versions r0p0, r1p0 and r2p0 of the CPU.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:38:47 +01:00
Marc Zyngier 32a3e635fb arm64: compat: Add CNTFRQ trap handler
Just like CNTVCT, we need to handle userspace trapping into the
kernel if we're decided that the timer wasn't fit for purpose...
64bit userspace is already dealt with, but we're missing the
equivalent compat handling.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:36:03 +01:00
Marc Zyngier 50de013d22 arm64: compat: Add CNTVCT trap handler
Since people seem to make a point in breaking the userspace visible
counter, we have no choice but to trap the access. We already do this
for 64bit userspace, but this is lacking for compat. Let's provide
the required handler.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:36:01 +01:00
Marc Zyngier 2a8905e18c arm64: compat: Add cp15_32 and cp15_64 handler arrays
We're now ready to start handling CP15 access. Let's add (empty)
arrays for both 32 and 64bit accessors, and the code that deals
with them.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:35:59 +01:00
Marc Zyngier 1f1c014035 arm64: compat: Add condition code checks and IT advance
Here's a /really nice/ part of the architecture: a CP15 access is
allowed to trap even if it fails its condition check, and SW must
handle it. This includes decoding the IT state if this happens in
am IT block. As a consequence, SW must also deal with advancing
the IT state machine.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:35:56 +01:00
Marc Zyngier 70c63cdfd6 arm64: compat: Add separate CP15 trapping hook
Instead of directly generating an UNDEF when trapping a CP15 access,
let's add a new entry point to that effect (which only generates an
UNDEF for now).

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:35:53 +01:00
Marc Zyngier bd7ac140b8 arm64: Add decoding macros for CP15_32 and CP15_64 traps
So far, we don't have anything to help decoding ESR_ELx when dealing
with ESR_ELx_EC_CP15_{32,64}. As we're about to handle some of those,
let's add some useful macros.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 13:35:50 +01:00
Ard Biesheuvel 9376b1e7b6 arm64: remove unused asm/compiler.h header file
arm64 does not define CONFIG_HAVE_ARCH_COMPILER_H, nor does it keep
anything useful in its copy of asm/compiler.h, so let's remove it
before anybody starts using it.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 11:57:04 +01:00
Will Deacon 24951465cb arm64: compat: Provide definition for COMPAT_SIGMINSTKSZ
arch/arm/ defines a SIGMINSTKSZ of 2k, so we should use the same value
for compat tasks.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Reported-by: Steve McIntyre <steve.mcintyre@arm.com>
Tested-by: Steve McIntyre <93sam@debian.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 11:44:02 +01:00
Will Deacon 22839869f2 signal: Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack
The sigaltstack(2) system call fails with -ENOMEM if the new alternative
signal stack is found to be smaller than SIGMINSTKSZ. On architectures
such as arm64, where the native value for SIGMINSTKSZ is larger than
the compat value, this can result in an unexpected error being reported
to a compat task. See, for example:

  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=904385

This patch fixes the problem by extending do_sigaltstack to take the
minimum signal stack size as an additional parameter, allowing the
native and compat system call entry code to pass in their respective
values. COMPAT_SIGMINSTKSZ is just defined as SIGMINSTKSZ if it has not
been defined by the architecture.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Reported-by: Steve McIntyre <steve.mcintyre@arm.com>
Tested-by: Steve McIntyre <93sam@debian.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 11:43:55 +01:00
Rob Herring 03630b3b76 perf: Convert to using %pOFn instead of device_node.name
In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01 11:33:17 +01:00
Jun Yao 8eb7e28d4c arm64/mm: move runtime pgds to rodata
Now that deliberate writes to swapper_pg_dir are made via the fixmap, we
can defend against errant writes by moving it into the rodata section.
Since tramp_pg_dir and reserved_ttbr0 must be at a fixed offset from
swapper_pg_dir, and are not modified at runtime, these are also moved
into the rodata section. Likewise, idmap_pg_dir is not modified at
runtime, and is moved into rodata.

Signed-off-by: Jun Yao <yaojun8558363@gmail.com>
Reviewed-by: James Morse <james.morse@arm.com>
[Mark: simplify linker script, commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-25 15:10:55 +01:00
Jun Yao 2330b7ca78 arm64/mm: use fixmap to modify swapper_pg_dir
Once swapper_pg_dir is in the rodata section, it will not be possible to
modify it directly, but we will need to modify it in some cases.

To enable this, we can use the fixmap when deliberately modifying
swapper_pg_dir. As the pgd is only transiently mapped, this provides
some resilience against illicit modification of the pgd, e.g. for
Kernel Space Mirror Attack (KSMA).

Signed-off-by: Jun Yao <yaojun8558363@gmail.com>
Reviewed-by: James Morse <james.morse@arm.com>
[Mark: simplify ifdeffery, commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-25 15:10:55 +01:00
Jun Yao 2b5548b681 arm64/mm: Separate boot-time page tables from swapper_pg_dir
Since the address of swapper_pg_dir is fixed for a given kernel image,
it is an attractive target for manipulation via an arbitrary write. To
mitigate this we'd like to make it read-only by moving it into the
rodata section.

We require that swapper_pg_dir is at a fixed offset from tramp_pg_dir
and reserved_ttbr0, so these will also need to move into rodata.
However, swapper_pg_dir is allocated along with some transient page
tables used for boot which we do not want to move into rodata.

As a step towards this, this patch separates the boot-time page tables
into a new init_pg_dir, and reduces swapper_pg_dir to the single page it
needs to be. This allows us to retain the relationship between
swapper_pg_dir, tramp_pg_dir, and swapper_pg_dir, while cleanly
separating these from the boot-time page tables.

The init_pg_dir holds all of the pgd/pud/pmd/pte levels needed during
boot, and all of these levels will be freed when we switch to the
swapper_pg_dir, which is initialized by the existing code in
paging_init(). Since we start off on the init_pg_dir, we no longer need
to allocate a transient page table in paging_init() in order to ensure
that swapper_pg_dir isn't live while we initialize it.

There should be no functional change as a result of this patch.

Signed-off-by: Jun Yao <yaojun8558363@gmail.com>
Reviewed-by: James Morse <james.morse@arm.com>
[Mark: place init_pg_dir after BSS, fold mm changes, commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-25 15:10:54 +01:00
Jun Yao 693d5639b4 arm64/mm: Pass ttbr1 as a parameter to __enable_mmu()
In subsequent patches we'll use a transient pgd during the primary cpu's
boot process. To make this work while allowing secondary cpus to use the
swapper_pg_dir, we need to pass the relevant TTBR1 pgd as a parameter
to __enable_mmu().

This patch updates __enable__mmu() to take this as a parameter, updating
callsites to pass swapper_pg_dir for now.

There should be no functional change as a result of this patch.

Signed-off-by: Jun Yao <yaojun8558363@gmail.com>
Reviewed-by: James Morse <james.morse@arm.com>
[Mark: simplify assembly, clarify commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-25 15:10:54 +01:00
Tri Vo 2a6c7c367d arm64: lse: remove -fcall-used-x0 flag
x0 is not callee-saved in the PCS. So there is no need to specify
-fcall-used-x0.

Clang doesn't currently support -fcall-used flags. This patch will help
building the kernel with clang.

Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Tri Vo <trong@android.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-24 10:56:24 +01:00
Andrew Murray 0b8af74549 arm64: Remove unused VGA console support
Support for VGA_CONSOLE is not allowable due to commit ee23794b86
("video: vgacon: Don't build on arm64"), thus remove the associated
unused code.

Whilst PCI on arm64 would support VGA a valid screen_info structure
is missing.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-21 12:12:24 +01:00
James Morse 8a695a5873 arm64: Kconfig: Remove ARCH_HAS_HOLES_MEMORYMODEL
include/linux/mmzone.h describes ARCH_HAS_HOLES_MEMORYMODEL as
relevant when parts the memmap have been free()d. This would
happen on systems where memory is smaller than a sparsemem-section,
and the extra struct pages are expensive. pfn_valid() on these
systems returns true for the whole sparsemem-section, so an extra
memmap_valid_within() check is needed.

On arm64 we have nomap memory, so always provide pfn_valid() to test
for nomap pages. This means ARCH_HAS_HOLES_MEMORYMODEL's extra checks
are already rolled up into pfn_valid().

Remove it.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-21 12:02:45 +01:00
Anshuman Khandual 21f8479617 arm64/cpufeatures: Emulate MRS instructions by parsing ESR_ELx.ISS
Armv8.4-A extension enables MRS instruction encodings inside ESR_ELx.ISS
during exception class ESR_ELx_EC_SYS64 (0x18). This encoding can be used
to emulate MRS instructions which can avoid fetch/decode from user space
thus improving performance. This adds a new sys64_hook structure element
with applicable ESR mask/value pair for MRS instructions on various system
registers but constrained by sysreg encodings which is currently allowed
to be emulated.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-21 11:06:18 +01:00
Anshuman Khandual 520ad98871 arm64/cpufeatures: Factorize emulate_mrs()
MRS emulation gets triggered with exception class (0x00 or 0x18) eventually
calling the function emulate_mrs() which fetches the user space instruction
and analyses it's encodings (OP0, OP1, OP2, CRN, CRM, RT). The kernel tries
to emulate the given instruction looking into the encoding details. Going
forward these encodings can also be parsed from ESR_ELx.ISS fields without
requiring to fetch/decode faulting userspace instruction which can improve
performance. This factorizes emulate_mrs() function in a way that it can be
called directly with MRS encodings (OP0, OP1, OP2, CRN, CRM) for any given
target register which can then be used directly from 0x18 exception class.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-21 11:05:58 +01:00
Anshuman Khandual 1c8391412d arm64/cpufeatures: Introduce ESR_ELx_SYS64_ISS_RT()
Extracting target register from ESR.ISS encoding has already been required
at multiple instances. Just make it a macro definition and replace all the
existing use cases.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-21 11:05:25 +01:00
Will Deacon 880f7cc472 arm64: cpu_errata: Remove ARM64_MISMATCHED_CACHE_LINE_SIZE
There's no need to treat mismatched cache-line sizes reported by CTR_EL0
differently to any other mismatched fields that we treat as "STRICT" in
the cpufeature code. In both cases we need to trap and emulate EL0
accesses to the register, so drop ARM64_MISMATCHED_CACHE_LINE_SIZE and
rely on ARM64_MISMATCHED_CACHE_TYPE instead.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
[catalin.marinas@arm.com: move ARM64_HAS_CNP in the empty cpucaps.h slot]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-19 18:21:49 +01:00
Vladimir Murzin ab510027dc arm64: KVM: Enable Common Not Private translations
We rely on cpufeature framework to detect and enable CNP so for KVM we
need to patch hyp to set CNP bit just before TTBR0_EL2 gets written.

For the guest we encode CNP bit while building vttbr, so we don't need
to bother with that in a world switch.

Reviewed-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-18 12:03:34 +01:00
Vladimir Murzin 5ffdfaedfa arm64: mm: Support Common Not Private translations
Common Not Private (CNP) is a feature of ARMv8.2 extension which
allows translation table entries to be shared between different PEs in
the same inner shareable domain, so the hardware can use this fact to
optimise the caching of such entries in the TLB.

CNP occupies one bit in TTBRx_ELy and VTTBR_EL2, which advertises to
the hardware that the translation table entries pointed to by this
TTBR are the same as every PE in the same inner shareable domain for
which the equivalent TTBR also has CNP bit set. In case CNP bit is set
but TTBR does not point at the same translation table entries for a
given ASID and VMID, then the system is mis-configured, so the results
of translations are UNPREDICTABLE.

For kernel we postpone setting CNP till all cpus are up and rely on
cpufeature framework to 1) patch the code which is sensitive to CNP
and 2) update TTBR1_EL1 with CNP bit set. TTBR1_EL1 can be
reprogrammed as result of hibernation or cpuidle (via __enable_mmu).
For these two cases we restore CnP bit via __cpu_suspend_exit().

There are a few cases we need to care of changes in TTBR0_EL1:
  - a switch to idmap
  - software emulated PAN

we rule out latter via Kconfig options and for the former we make
sure that CNP is set for non-zero ASIDs only.

Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
[catalin.marinas@arm.com: default y for CONFIG_ARM64_CNP]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-18 12:02:27 +01:00
Suzuki K Poulose 74e248286e arm64: sysreg: Clean up instructions for modifying PSTATE fields
Instructions for modifying the PSTATE fields which were not supported
in the older toolchains (e.g, PAN, UAO) are generated using macros.
We have so far used the normal sys_reg() helper for defining the PSTATE
fields. While this works fine, it is really difficult to correlate the
code with the Arm ARM definition.

As per Arm ARM, the PSTATE fields are defined only using Op1, Op2 fields,
with fixed values for Op0, CRn. Also the CRm field has been reserved
for the Immediate value for the instruction. So using the sys_reg()
looks quite confusing.

This patch cleans up the instruction helpers by bringing them
in line with the Arm ARM definitions to make it easier to correlate
code with the document. No functional changes.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-17 14:56:01 +01:00
Hari Vyas e4ba15debc arm64: fix for bad_mode() handler to always result in panic
The bad_mode() handler is called if we encounter an uunknown exception,
with the expectation that the subsequent call to panic() will halt the
system. Unfortunately, if the exception calling bad_mode() is taken from
EL0, then the call to die() can end up killing the current user task and
calling schedule() instead of falling through to panic().

Remove the die() call altogether, since we really want to bring down the
machine in this "impossible" case.

Signed-off-by: Hari Vyas <hari.vyas@broadcom.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-14 17:46:25 +01:00
Will Deacon 8a60419d36 arm64: force_signal_inject: WARN if called from kernel context
force_signal_inject() is designed to send a fatal signal to userspace,
so WARN if the current pt_regs indicates a kernel context. This can
currently happen for the undefined instruction trap, so patch that up so
we always BUG() if we didn't have a handler.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-14 17:46:24 +01:00
Will Deacon b8925ee2e1 arm64: cpu: Move errata and feature enable callbacks closer to callers
The cpu errata and feature enable callbacks are only called via their
respective arm64_cpu_capabilities structure and therefore shouldn't
exist in the global namespace.

Move the PAN, RAS and cache maintenance emulation enable callbacks into
the same files as their corresponding arm64_cpu_capabilities structures,
making them static in the process.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-09-14 17:46:22 +01:00