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commit 1b1f01b653b408ebe58fec78c566d1075d285c64 upstream.
arch/mips/kernel/perf_event_mipsxx.c: In function 'mipsxx_pmu_enable_event':
arch/mips/kernel/perf_event_mipsxx.c:326:21: error: unused variable 'event' [-Werror=unused-variable]
struct perf_event *event = container_of(evt, struct perf_event, hw);
^~~~~
Fix this by making use of IS_ENABLED() to simplify the code and avoid
unnecessary ifdefery.
Fixes: 84002c88599d ("MIPS: perf: Fix perf with MT counting other threads")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit ab8a6d821179ab9bea1a9179f535ccba6330c1ed ]
KGDB_call_nmi_hook is called by other cpu through smp call.
MIPS smp call is processed in ipi irq handler and regs is saved in
handle_int.
So kgdb_call_nmi_hook get regs by get_irq_regs and regs will be passed
to kgdb_cpu_enter.
Signed-off-by: Chong Qiao <qiaochong@loongson.cn>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: QiaoChong <qiaochong@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 79b4a9cf0e2ea8203ce777c8d5cfa86c71eae86e upstream.
Commit 4c21b8fd8f14 (MIPS: seccomp: Handle indirect system calls (o32))
added indirect syscall detection for O32 processes running on MIPS64,
but it did not work correctly for big endian kernel/processes. The
reason is that the syscall number is loaded from ARG1 using the lw
instruction while this is a 64-bit value, so zero is loaded instead of
the syscall number.
Fix the code by using the ld instruction instead. When running a 32-bit
processes on a 64 bit CPU, the values are properly sign-extended, so it
ensures the value passed to syscall_trace_enter is correct.
Recent systemd versions with seccomp enabled whitelist the getpid
syscall for their internal processes (e.g. systemd-journald), but call
it through syscall(SYS_getpid). This fix therefore allows O32 big endian
systems with a 64-bit kernel to run recent systemd versions.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Cc: <stable@vger.kernel.org> # v3.15+
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3f0a53bc6482fb09770982a8447981260ea258dc upstream.
This fixes booting with the combination of CONFIG_RELOCATABLE=y
and CONFIG_MIPS_ELF_APPENDED_DTB=y.
Sections that appear after the relocation table are not relocated
on system boot (except .bss, which has special handling).
With CONFIG_MIPS_ELF_APPENDED_DTB, the dtb is part of the
vmlinux ELF, so it must be relocated together with everything else.
Fixes: 069fd766271d ("MIPS: Reserve space for relocation table")
Signed-off-by: Yasha Cherikovsky <yasha.che3@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 72faa7a773ca59336f3c889e878de81445c5a85c upstream.
The irq_pages is the number of pages for irq stack, but not the
order which is needed by __get_free_pages().
We can use get_order() to calculate the accurate order.
Signed-off-by: Liu Xiang <liu.xiang6@zte.com.cn>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: fe8bd18ffea5 ("MIPS: Introduce irq_stack")
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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For platforms, which use a PHYS_OFFSET != 0, symbol _end also
contains that offset. So when calling memblock_reserve() for
reserving kernel the size argument needs to be adjusted.
Fixes: bcec54bf3118 ("mips: switch to NO_BOOTMEM")
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.20+
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__cmpxchg_small erroneously uses u8 for load comparison which can
be either char or short. This patch changes the local variable to
u32 which is sufficiently sized, as the loaded value is already
masked and shifted appropriately. Using an integer size avoids
any unnecessary canonicalization from use of non native widths.
This patch is part of a series that adapts the MIPS small word
atomics code for xchg and cmpxchg on short and char to RISC-V.
Cc: RISC-V Patches <patches@groups.riscv.org>
Cc: Linux RISC-V <linux-riscv@lists.infradead.org>
Cc: Linux MIPS <linux-mips@linux-mips.org>
Signed-off-by: Michael Clark <michaeljclark@mac.com>
[paul.burton@mips.com:
- Fix varialble typo per Jonas Gorski.
- Consolidate load variable with other declarations.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 3ba7f44d2b19 ("MIPS: cmpxchg: Implement 1 byte & 2 byte cmpxchg()")
Cc: stable@vger.kernel.org # v4.13+
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Accordingly to the documentation
---cut---
The GCR_ERROR_CAUSE.ERR_TYPE field and the GCR_ERROR_MULT.ERR_TYPE
fields can be cleared by either a reset or by writing the current
value of GCR_ERROR_CAUSE.ERR_TYPE to the
GCR_ERROR_CAUSE.ERR_TYPE register.
---cut---
Do exactly this. Original value of cm_error may be safely written back;
it clears error cause and keeps other bits untouched.
Fixes: 3885c2b463f6 ("MIPS: CM: Add support for reporting CM cache errors")
Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@linux.intel.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v4.3+
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Patch (b6c7a324df37b "MIPS: Fix get_frame_info() handling of
microMIPS function size.") introduces additional function size
check for microMIPS by only checking insn between ip and ip + func_size.
However, func_size in get_frame_info() is always 0 if KALLSYMS is not
enabled. This causes get_frame_info() to return immediately without
calculating correct frame_size, which in turn causes "Can't analyze
schedule() prologue" warning messages at boot time.
This patch removes func_size check, and let the frame_size check run
up to 128 insns for both MIPS and microMIPS.
Signed-off-by: Jun-Ru Chang <jrjang@realtek.com>
Signed-off-by: Tony Wu <tonywu@realtek.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: b6c7a324df37b ("MIPS: Fix get_frame_info() handling of microMIPS function size.")
Cc: <ralf@linux-mips.org>
Cc: <jhogan@kernel.org>
Cc: <macro@mips.com>
Cc: <yamada.masahiro@socionext.com>
Cc: <peterz@infradead.org>
Cc: <mingo@kernel.org>
Cc: <linux-mips@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
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Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".
The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:
#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
# define HAVE_JUMP_LABEL
#endif
We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.
Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
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Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux
Pull kgdb updates from Daniel Thompson:
"Mostly clean ups although while Doug's was chasing down a odd lockdep
warning he also did some work to improved debugger resilience when
some CPUs fail to respond to the round up request.
The main changes are:
- Fixing a lockdep warning on architectures that cannot use an NMI
for the round up plus related changes to make CPU round up and all
CPU backtrace more resilient.
- Constify the arch ops tables
- A couple of other small clean ups
Two of the three patchsets here include changes that spill over into
arch/. Changes in the arch space are relatively narrow in scope (and
directly related to kgdb). Didn't get comprehensive acks but all
impacted maintainers were Cc:ed in good time"
* tag 'kgdb-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops
mips/kgdb: prepare arch_kgdb_ops for constness
kdb: use bool for binary state indicators
kdb: Don't back trace on a cpu that didn't round up
kgdb: Don't round up a CPU that failed rounding up before
kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function()
kgdb: Remove irq flags from roundup
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checkpatch.pl reports the following:
WARNING: struct kgdb_arch should normally be const
#28: FILE: arch/mips/kernel/kgdb.c:397:
+struct kgdb_arch arch_kgdb_ops = {
This report makes sense, as all other ops struct, this
one should also be const. This patch does the change.
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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MIPS is the only architecture modifying arch_kgdb_ops during init.
This patch makes the init static, so that it can be changed to
const in following patch, as recommended by checkpatch.pl
Suggested-by: Paul Burton <paul.burton@mips.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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When I had lockdep turned on and dropped into kgdb I got a nice splat
on my system. Specifically it hit:
DEBUG_LOCKS_WARN_ON(current->hardirq_context)
Specifically it looked like this:
sysrq: SysRq : DEBUG
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(current->hardirq_context)
WARNING: CPU: 0 PID: 0 at .../kernel/locking/lockdep.c:2875 lockdep_hardirqs_on+0xf0/0x160
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0 #27
pstate: 604003c9 (nZCv DAIF +PAN -UAO)
pc : lockdep_hardirqs_on+0xf0/0x160
...
Call trace:
lockdep_hardirqs_on+0xf0/0x160
trace_hardirqs_on+0x188/0x1ac
kgdb_roundup_cpus+0x14/0x3c
kgdb_cpu_enter+0x53c/0x5cc
kgdb_handle_exception+0x180/0x1d4
kgdb_compiled_brk_fn+0x30/0x3c
brk_handler+0x134/0x178
do_debug_exception+0xfc/0x178
el1_dbg+0x18/0x78
kgdb_breakpoint+0x34/0x58
sysrq_handle_dbg+0x54/0x5c
__handle_sysrq+0x114/0x21c
handle_sysrq+0x30/0x3c
qcom_geni_serial_isr+0x2dc/0x30c
...
...
irq event stamp: ...45
hardirqs last enabled at (...44): [...] __do_softirq+0xd8/0x4e4
hardirqs last disabled at (...45): [...] el1_irq+0x74/0x130
softirqs last enabled at (...42): [...] _local_bh_enable+0x2c/0x34
softirqs last disabled at (...43): [...] irq_exit+0xa8/0x100
---[ end trace adf21f830c46e638 ]---
Looking closely at it, it seems like a really bad idea to be calling
local_irq_enable() in kgdb_roundup_cpus(). If nothing else that seems
like it could violate spinlock semantics and cause a deadlock.
Instead, let's use a private csd alongside
smp_call_function_single_async() to round up the other CPUs. Using
smp_call_function_single_async() doesn't require interrupts to be
enabled so we can remove the offending bit of code.
In order to avoid duplicating this across all the architectures that
use the default kgdb_roundup_cpus(), we'll add a "weak" implementation
to debug_core.c.
Looking at all the people who previously had copies of this code,
there were a few variants. I've attempted to keep the variants
working like they used to. Specifically:
* For arch/arc we passed NULL to kgdb_nmicallback() instead of
get_irq_regs().
* For arch/mips there was a bit of extra code around
kgdb_nmicallback()
NOTE: In this patch we will still get into trouble if we try to round
up a CPU that failed to round up before. We'll try to round it up
again and potentially hang when we try to grab the csd lock. That's
not new behavior but we'll still try to do better in a future patch.
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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The function kgdb_roundup_cpus() was passed a parameter that was
documented as:
> the flags that will be used when restoring the interrupts. There is
> local_irq_save() call before kgdb_roundup_cpus().
Nobody used those flags. Anyone who wanted to temporarily turn on
interrupts just did local_irq_enable() and local_irq_disable() without
looking at them. So we can definitely remove the flags.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
Pull MIPS updates from Paul Burton:
"Here's the main MIPS pull for Linux 4.21. Core architecture changes
include:
- Syscall tables & definitions for unistd.h are now generated by
scripts, providing greater consistency with other architectures &
making it easier to add new syscalls.
- Support for building kernels with no floating point support, upon
which any userland attempting to use floating point instructions
will receive a SIGILL. Mostly useful to shrink the kernel & as
preparation for nanoMIPS support which does not yet include FP.
- MIPS SIMD Architecture (MSA) vector register context is now exposed
by ptrace via a new NT_MIPS_MSA regset.
- ASIDs are now stored as 64b values even for MIPS32 kernels,
expanding the ASID version field sufficiently that we don't need to
worry about overflow & avoiding rare issues with reused ASIDs that
have been observed in the wild.
- The branch delay slot "emulation" page is now mapped without write
permission for the user, preventing its use as a nice location for
attacks to execute malicious code from.
- Support for ioremap_prot(), primarily to allow gdb or other ptrace
users the ability to view their tracee's memory using the same
cache coherency attribute.
- Optimizations to more cpu_has_* macros, allowing more to be
compile-time constant where possible.
- Enable building the whole kernel with UBSAN instrumentation.
- Enable building the kernel with link-time dead code & data
elimination.
Platform specific changes include:
- The Boston board gains a workaround for DMA prefetching issues with
the EG20T Platform Controller Hub that it uses.
- Cleanups to Cavium Octeon code removing about 20k lines of
redundant code, mostly unused or duplicate register definitions in
headers.
- defconfig updates for the DECstation machines, including new
defconfigs for r4k & 64b machines.
- Further work on Loongson 3 support.
- DMA fixes for SiByte machines"
* tag 'mips_4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (95 commits)
MIPS: math-emu: Write-protect delay slot emulation pages
MIPS: Remove struct mm_context_t fp_mode_switching field
mips: generate uapi header and system call table files
mips: add system call table generation support
mips: remove syscall table entries
mips: add +1 to __NR_syscalls in uapi header
mips: rename scall64-64.S to scall64-n64.S
mips: remove unused macros
mips: add __NR_syscalls along with __NR_Linux_syscalls
MIPS: Expand MIPS32 ASIDs to 64 bits
MIPS: OCTEON: delete redundant register definitions
MIPS: OCTEON: cvmx_gmxx_inf_mode: use oldest forward compatible definition
MIPS: OCTEON: cvmx_mio_fus_dat3: use oldest forward compatible definition
MIPS: OCTEON: cvmx_pko_mem_debug8: use oldest forward compatible definition
MIPS: OCTEON: octeon-usb: use common gpio_bit definition
MIPS: OCTEON: enable all OCTEON drivers in defconfig
mips: annotate implicit fall throughs
MIPS: Hardcode cpu_has_mips* where target ISA allows
MIPS: MT: Remove norps command line parameter
MIPS: Only include mmzone.h when CONFIG_NEED_MULTIPLE_NODES=y
...
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Mapping the delay slot emulation page as both writeable & executable
presents a security risk, in that if an exploit can write to & jump into
the page then it can be used as an easy way to execute arbitrary code.
Prevent this by mapping the page read-only for userland, and using
access_process_vm() with the FOLL_FORCE flag to write to it from
mips_dsemul().
This will likely be less efficient due to copy_to_user_page() performing
cache maintenance on a whole page, rather than a single line as in the
previous use of flush_cache_sigtramp(). However this delay slot
emulation code ought not to be running in any performance critical paths
anyway so this isn't really a problem, and we can probably do better in
copy_to_user_page() anyway in future.
A major advantage of this approach is that the fix is small & simple to
backport to stable kernels.
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 432c6bacbd0c ("MIPS: Use per-mm page to execute branch delay slot instructions")
Cc: stable@vger.kernel.org # v4.8+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Rich Felker <dalias@libc.org>
Cc: David Daney <david.daney@cavium.com>
|
|
The fp_mode_switching field in struct mm_context_t was left unused by
commit 8c8d953c2800 ("MIPS: Schedule on CPUs we need to lose FPU for a
mode switch") in v4.19, with nothing modifying its value & nothing
waiting on it having any particular value after that commit. Remove the
unused field & the one remaining reference to it.
Signed-off-by: Paul Burton <paul.burton@mips.com>
|
|
System call table generation script must be run to gener-
ate unistd_(nr_)n64/n32/o32.h and syscall_table_32_o32/
64_n64/64_n32/64-o32.h files. This patch will have changes
which will invokes the script.
This patch will generate unistd_(nr_)n64/n32/o32.h and
syscall_table_32_o32/64_n64/64-n32/64-o32.h files by the
syscall table generation script invoked by parisc/Make-
file and the generated files against the removed files
must be identical.
The generated uapi header file will be included in uapi/-
asm/unistd.h and generated system call table header file
will be included by kernel/scall32-o32/64-n64/64-n32/-
64-o32.Sfile.
Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: y2038@lists.linaro.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: arnd@arndb.de
Cc: deepa.kernel@gmail.com
Cc: marcin.juszkiewicz@linaro.org
|
|
The system call tables are in different format in all
architecture and it will be difficult to manually add,
modify or delete the syscall table entries in the res-
pective files. To make it easy by keeping a script and
which will generate the uapi header and syscall table
file. This change will also help to unify the implemen-
tation across all architectures.
The system call table generation script is added in
kernel/syscalls directory which contain the scripts to
generate both uapi header file and system call table
files. The syscall.tbl will be input for the scripts.
syscall.tbl contains the list of available system calls
along with system call number and corresponding entry
point. Add a new system call in this architecture will
be possible by adding new entry in the syscall.tbl file.
Adding a new table entry consisting of:
- System call number.
- ABI.
- System call name.
- Entry point name.
- Compat entry name, if required.
syscallhdr.sh, syscallnr.sh and syscalltbl.sh will gene-
rate uapi header unistd_n64/n32/o32.h, unistd_nr_n64/n32/-
o32.h and syscall_table_32_o32/64_n64/64-n32/64-o32.h files
respectively. All *.sh files will parse the content sys-
call.tbl to generate the header and table files. unistd-
_n64/n32/o32.h and unistd_nr_n64/n32/o32.h will be included
by uapi/asm/unistd.h and syscall_table_32_o32/64_n64/64-n32-
/64-o32.h is included by kernel/syscall_table32_o32/64-
_n64/64-n32/64-o32.S - the real system call table.
ARM, s390 and x86 architecuture does have similar support.
I leverage their implementation to come up with a generic
solution.
Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
[paul.burton@mips.com:
- Change sysnr_pfx_unistd_nr_n64 to 64.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: y2038@lists.linaro.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: arnd@arndb.de
Cc: deepa.kernel@gmail.com
Cc: marcin.juszkiewicz@linaro.org
|
|
The config flag - CONFIG_MIPS_MT_FPAFF uses to check whether which
syscall entries need to be used in scall32-o32.S file.
One of the patch in this patch series will generate syscall table
file. But CONFIG_MIPS_MT_FPAFF flag will add more complexity in the
script to generate the syscall table file.
In order to come up with a common implementation across all archit-
ecture, we need to remove mipsmt_sys_sched_setaffinity and mipsmt-
_sys_sched_getaffinity from the table and define it in other way.
Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: y2038@lists.linaro.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: arnd@arndb.de
Cc: deepa.kernel@gmail.com
Cc: marcin.juszkiewicz@linaro.org
|
|
All other architectures are hold a value for __NR_syscalls will
be equal to the last system call number +1.
But in mips architecture, __NR_syscalls hold the value equal to
total number of system exits in the architecture. One of the
patch in this patch series will genarate uapi header files.
In order to make the implementation common across all architect-
ures, add +1 to __NR_syscalls, which will be equal to the last
system call number +1.
Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: y2038@lists.linaro.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: arnd@arndb.de
Cc: deepa.kernel@gmail.com
Cc: marcin.juszkiewicz@linaro.org
|
|
When we get nanoMIPS support we'll be introducing the p32
ABI, and there's a reasonable chance that the equivalent
p64 ABI may come along in the future. Using 'n64' now would
avoid confusion in that case where we may have 2 different
64-bit ABIs.
Suggested-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
[paul.burton@mips.com:
- Remove UAPI macro renaming, github code search shows at least the
chromium project uses __NR_64_Linux & __NR_64_Linux_syscalls.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: y2038@lists.linaro.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: arnd@arndb.de
Cc: deepa.kernel@gmail.com
Cc: marcin.juszkiewicz@linaro.org
|
|
Remove __NR_Linux_syscalls from uapi/asm/unistd.h as
there is no users to use NR_syscalls macro in mips
kernel.
MAX_SYSCALL_NO can also remove as there is commit
2957c9e61ee9 ("[MIPS] IRIX: Goodbye and thanks for
all the fish"), eight years ago.
Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
[paul.burton@mips.com:
- Drop the removal of NR_syscalls which is used by
kernel/trace/trace.h.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: y2038@lists.linaro.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: arnd@arndb.de
Cc: deepa.kernel@gmail.com
Cc: marcin.juszkiewicz@linaro.org
|
|
There is a plan to build the kernel with -Wimplicit-fallthrough and
these places in the code produced warnings. Fix them up.
This patch produces no change in behaviour, but should be reviewed in
case these are actually bugs not intentional fallthoughs.
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Kees Cook <keescook@google.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"While rewriting the function graph tracer, I discovered a design flaw
that was introduced by a patch that tried to fix one bug, but by doing
so created another bug.
As both bugs corrupt the output (but they do not crash the kernel), I
decided to fix the design such that it could have both bugs fixed. The
original fix, fixed time reporting of the function graph tracer when
doing a max_depth of one. This was code that can test how much the
kernel interferes with userspace. But in doing so, it could corrupt
the time keeping of the function profiler.
The issue is that the curr_ret_stack variable was being used for two
different meanings. One was to keep track of the stack pointer on the
ret_stack (shadow stack used by the function graph tracer), and the
other use case was the graph call depth. Although, the two may be
closely related, where they got updated was the issue that lead to the
two different bugs that required the two use cases to be updated
differently.
The big issue with this fix is that it requires changing each
architecture. The good news is, I was able to remove a lot of code
that was duplicated within the architectures and place it into a
single location. Then I could make the fix in one place.
I pushed this code into linux-next to let it settle over a week, and
before doing so, I cross compiled all the affected architectures to
make sure that they built fine.
In the mean time, I also pulled in a patch that fixes the sched_switch
previous tasks state output, that was not actually correct"
* tag 'trace-v4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
sched, trace: Fix prev_state output in sched_switch tracepoint
function_graph: Have profiler use curr_ret_stack and not depth
function_graph: Reverse the order of pushing the ret_stack and the callback
function_graph: Move return callback before update of curr_ret_stack
function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack
function_graph: Make ftrace_push_return_trace() static
sparc/function_graph: Simplify with function_graph_enter()
sh/function_graph: Simplify with function_graph_enter()
s390/function_graph: Simplify with function_graph_enter()
riscv/function_graph: Simplify with function_graph_enter()
powerpc/function_graph: Simplify with function_graph_enter()
parisc: function_graph: Simplify with function_graph_enter()
nds32: function_graph: Simplify with function_graph_enter()
MIPS: function_graph: Simplify with function_graph_enter()
microblaze: function_graph: Simplify with function_graph_enter()
arm64: function_graph: Simplify with function_graph_enter()
ARM: function_graph: Simplify with function_graph_enter()
x86/function_graph: Simplify with function_graph_enter()
function_graph: Create function_graph_enter() to consolidate architecture code
|
|
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have MIPS use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: stable@kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
|
|
The "norps" kernel command line parameter has apparently been deprecated
ever since it was added to the kernel back in 2006 - all it does is
print a message telling the user to use something else.
Remove the long dead "norps" parameter.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21244/
Cc: linux-mips@linux-mips.org
|
|
Select CONFIG_HAVE_LD_DEAD_CODE_DATA_ELIMINATION for MIPS, allowing the
user to enable dead code elimination. In order for this to work, ensure
that we keep the data bus exception table & the machine list by
annotating them with KEEP.
This shrinks both 32r2el_defconfig & 64r6el_defconfig builds by ~6%, as
shown by numbers from scripts/bloat-o-meter:
| 32r2el_defconfig | 64r6el_defconfig
--------|------------------|------------------
No DCE | 8919864 | 8286307
DCE | 8338988 (-6.51%) | 7741808 (-6.57%)
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21187/
Cc: linux-mips@linux-mips.org
|
|
The current methods for obtaining FP context via ptrace only provide
either 32 or 64 bits per data register. With MSA, where vector registers
are aliased with scalar FP data registers, those registers are 128 bits
wide. Thus a new mechanism is required for userland to access those
registers via ptrace. This patch introduces an NT_MIPS_MSA regset which
provides, in this order:
- The full 128 bits value of each vector register, in native
endianness saved as though elements are doubles. That is, the format
of each vector register is as would be obtained by saving it to
memory using an st.d instruction.
- The 32 bit scalar FP implementation register (FIR).
- The 32 bit scalar FP control & status register (FCSR).
- The 32 bit MSA implementation register (MSAIR).
- The 32 bit MSA control & status register (MSACSR).
The provision of the FIR & FCSR registers in addition to the MSA
equivalents allows scalar FP context to be retrieved as a subset of
the context available via this regset. Along with the MSA equivalents
they also nicely form the final 128 bit "register" of the regset.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21180/
Cc: linux-mips@linux-mips.org
|
|
Loongson-3A R2.1 is the bugfix revision of Loongson-3A R2.
All Loongson-3 CPU family:
Code-name Brand-name PRId
Loongson-3A R1 Loongson-3A1000 0x6305
Loongson-3A R2 Loongson-3A2000 0x6308
Loongson-3A R2.1 Loongson-3A2000 0x630c
Loongson-3A R3 Loongson-3A3000 0x6309
Loongson-3A R3.1 Loongson-3A3000 0x630d
Loongson-3B R1 Loongson-3B1000 0x6306
Loongson-3B R2 Loongson-3B1500 0x6307
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21128/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
|
|
After switched to NO_BOOTMEM, there are several boot failures. Some of
them have been fixed and some of them haven't. I find that many of them
are because of memory allocations are top-down, while the old behavior
is bottom-up. This patch let early memblock_alloc*() allocate memories
bottom-up to avoid some potential problems.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: bcec54bf3118 ("mips: switch to NO_BOOTMEM")
Patchwork: https://patchwork.linux-mips.org/patch/21069/
References: https://patchwork.linux-mips.org/patch/21031/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
|
|
MIPSr6 removed the Hi & Lo registers, so displaying their values on
MIPSr6 systems is pointless. Avoid doing so.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21067/
Cc: linux-mips@linux-mips.org
|
|
A closing brace in do_ade() has misleading indentation; fix it.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21066/
Cc: linux-mips@linux-mips.org
|
|
We currently have 2 commonly used methods for switching ISA within
assembly code, then restoring the original ISA.
1) Using a pair of .set push & .set pop directives. For example:
.set push
.set mips32r2
<some_insn>
.set pop
2) Using .set mips0 to restore the ISA originally specified on the
command line. For example:
.set mips32r2
<some_insn>
.set mips0
Unfortunately method 2 does not work with nanoMIPS toolchains, where the
assembler rejects the .set mips0 directive like so:
Error: cannot change ISA from nanoMIPS to mips0
In preparation for supporting nanoMIPS builds, switch all instances of
method 2 in generic non-platform-specific code to use push & pop as in
method 1 instead. The .set push & .set pop is arguably cleaner anyway,
and if nothing else it's good to consistently use one method.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21037/
Cc: linux-mips@linux-mips.org
|
|
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point & so don't
need to preserve floating point context for tasks. Remove that context
from struct task_struct.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21013/
Cc: linux-mips@linux-mips.org
|
|
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so we can
avoid needless checks of ELF headers specifying the FP ABI or NaN
encoding to use. Deselect CONFIG_ARCH_BINFMT_ELF_STATE in this case to
avoid the need for our arch_elf_pt_proc() & arch_check_elf() functions,
and stub out the mips_set_personality_nan() & mips_set_personality_fp()
functions such that SET_PERSONALITY() doesn't need to worry about any of
this.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21011/
Cc: linux-mips@linux-mips.org
|
|
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so
there's no need to save & restore floating point context around signals.
This prepares us for the removal of FP context from struct task_struct
later.
Since MSA context is a superset of FP context support for it similarly
needs to be removed when MSA/FP support is disabled.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21009/
Cc: linux-mips@linux-mips.org
|
|
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so remove
the related ptrace support. Besides removing code which should not be
needed, this prepares us for the removal of FPU state in struct
task_struct which this code requires.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21008/
Cc: linux-mips@linux-mips.org
|
|
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so remove
support for floating point instructions from emulate_load_store_insn() &
emulate_load_store_microMIPS(). This code should not be needed & relies
upon access to FPU state in struct task_struct which will later be
removed.
Similarly & for the same reasons, when CONFIG_CPU_HAS_MSA=n remove
support for MSA instructions. Since MSA support depends upon FP support
this is implied when CONFIG_MIPS_FP_SUPPORT=n.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21020/
Cc: linux-mips@linux-mips.org
|
|
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so remove
the floating point branch support from __compute_return_epc_for_insn() &
__mm_isBranchInstr(). This code should never be needed & more
importantly relies upon FPU state in struct task_struct which will later
be removed.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21017/
Cc: linux-mips@linux-mips.org
|
|
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so we'll
never need to enable the FPU. Avoid doing so on a Co-Processor Unusable
exception (do_cpu), and remove the Floating Point Exception handler
(do_fpe) which should never be executed when the FPU is disabled.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21007/
Cc: linux-mips@linux-mips.org
|
|
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point so there's
no point in attempting to detect an FPU. Avoid doing so.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21021/
Cc: linux-mips@linux-mips.org
|
|
Introduce a CONFIG_CPU_R2300_FPU Kconfig symbol mirroring the existing
CONFIG_CPU_R4K_FPU, and use it to determine whether to build r4k_fpu.S.
This removes the duplicate R3000 & TX39XX cases in
arch/mips/kernel/Makefile and prepares us for the possibility of
disabling FP support later.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21004/
Cc: linux-mips@linux-mips.org
|
|
Emulated floating point instructions don't ensure that the PF_USED_MATH
flag is set for the task. This results in a couple of inconsistencies:
- ptrace will return the default initial state of FP registers rather
than the values actually stored in struct thread_struct, hiding
state that has been updated by emulated floating point instructions.
- If a task migrates to a CPU with an FPU after having emulated
floating point instructions then its floating point register state
will be reset to the default ~0 bit pattern, losing state from the
emulated instructions.
Fix this by calling init_fp_ctx() from fpu_emulator_cop1Handler() to
consistently initialize FP state if it was previously uninitialized,
setting the PF_USED_MATH flag in the process.
All callers of fpu_emulator_cop1Handler() either call lose_fpu(1) before
it in order to save any live FPU registers to struct thread_struct, or
in the case of do_cpu() already know that the task does not own an FPU
so lose_fpu(1) would be a no-op. Since we know that saving FP context
will be unnecessary in the case where FP context was just initialized we
move this call into fpu_emulator_cop1Handler() too, providing
consistency & avoiding needless duplication.
Calls to own_fpu(1) are common after return from
fpu_emulator_cop1Handler() too, but this would not be a no-op in the
do_cpu() case so these are left as-is. A potential future improvement
could be to have fpu_emulator_cop1Handler() restore FPU state
automatically only if it saved it, though this may not be optimal if
some callers are better off without their current calls to own_fpu(1).
One potential example of this could be mipsr2_decoder() which as-is
could end up saving & restoring FP context repeatedly & unnecessarily if
emulating multiple FP instructions.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21003/
Cc: linux-mips@linux-mips.org
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MIPS has up until now had 3 different ways for a task's floating point
context to be initialized:
- If the task's first use of FP involves it gaining ownership of an
FPU then _init_fpu() is used to initialize the FPU's registers such
that they all contain ~0, and the FPU registers will be stored to
struct thread_info later (eg. when context switching).
- If the task first uses FP on a CPU without an associated FPU then
fpu_emulator_init_fpu() initializes the task's floating point
register state in struct thread_info such that all floating point
register contain the bit pattern 0x7ff800007ff80000, different to
the _init_fpu() behaviour.
- If a task's floating point context is first accessed via ptrace then
init_fp_ctx() initializes the floating point register state in
struct thread_info to ~0, giving equivalent state to _init_fpu().
The _init_fpu() path has 2 separate implementations - one for r2k/r3k
style systems & one for r4k style systems. The _init_fpu() path also
requires that we be careful to clear & restore the value of the
Config5.FRE bit on modern systems in order to avoid inadvertently
triggering floating point exceptions.
None of this code is in a performance critical hot path - it runs only
the first time a task uses floating point. As such it doesn't seem to
warrant the complications of maintaining the _init_fpu() path.
Remove _init_fpu() & fpu_emulator_init_fpu(), instead using
init_fp_ctx() consistently to initialize floating point register state
in struct thread_info. Upon a task's first use of floating point this
will typically mean that we initialize state in memory & then load it
into FPU registers using _restore_fp() just as we would on a context
switch. For other paths such as __compute_return_epc_for_insn() or
mipsr2_decoder() this results in a significant simplification of the
work to be done.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21002/
Cc: linux-mips@linux-mips.org
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The BMIPS5xxx core_init function contains a call to an init_fpu function
inside an #ifdef whose condition never evaluates true. Remove the dead
code. FPU initialization happens later, primarily when a userland
program attempts to use it.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21018/
Cc: linux-mips@linux-mips.org
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asm/compiler.h defined GCC_IMM_ASM & GCC_REG_ACCUM macros, both of which
are defined differently for GCC pre-3.4 or GCC 3.4 & higher. We only
support building with GCC 4.6 & higher since commit cafa0010cd51 ("Raise
the minimum required gcc version to 4.6"), which makes the pre-3.4
definition dead code.
Rather than leave the macro definitions around, inline the GCC 3.4 &
higher definitions into the single file that uses them & remove the
macros entirely.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21000/
Cc: linux-mips@linux-mips.org
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Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20991/
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
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