[ Upstream commit c82dd6d078a2bb29d41eda032bb96d05699a524d ]

When the handle_exception function addresses an exception, the interrupts
will be unconditionally enabled after finishing the context save. However,
It may erroneously enable the interrupts if the interrupts are disabled
before entering the handle_exception.

For example, one of the WARN_ON() condition is satisfied in the scheduling
where the interrupt is disabled and rq.lock is locked. The WARN_ON will
trigger a break exception and the handle_exception function will enable the
interrupts before entering do_trap_break function. During the procedure, if
a timer interrupt is pending, it will be taken when interrupts are enabled.
In this case, it may cause a deadlock problem if the rq.lock is locked
again in the timer ISR.

Hence, the handle_exception() can only enable interrupts when the state of
sstatus.SPIE is 1.

This patch is tested on HiFive Unleashed board.
Signed-off-by: NVincent Chen <vincent.chen@sifive.com>
Reviewed-by: NPalmer Dabbelt <palmer@sifive.com>
[paul.walmsley@sifive.com: updated to apply]
Fixes: bcae803a ("RISC-V: Enable IRQ during exception handling")
Cc: David Abdurachmanov <david.abdurachmanov@sifive.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 397182e0db56b8894a43631ce72de14d90a29834 ]

Noticed while building kernel-4.20.0-0.rc5.git2.1.fc30 for
Fedora 30/RISCV.

[..]
BUILDSTDERR: arch/riscv/kernel/ftrace.c: In function 'prepare_ftrace_return':
BUILDSTDERR: arch/riscv/kernel/ftrace.c:135:6: warning: unused variable 'err' [-Wunused-variable]
BUILDSTDERR:   int err;
BUILDSTDERR:       ^~~
[..]
Signed-off-by: NDavid Abdurachmanov <david.abdurachmanov@gmail.com>
Fixes: e949b6db51dc1 ("riscv/function_graph: Simplify with function_graph_enter()")
Reviewed-by: NOlof Johansson <olof@lixom.net>
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 69703eb9a8ae28a46cd5bce7d69ceeef6273a104 upstream.

Make the __fstate_clean() function correctly set the
state of sstatus.FS in pt_regs to SR_FS_CLEAN.

Fixes: 7db91e57 ("RISC-V: Task implementation")
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NVincent Chen <vincent.chen@sifive.com>
Reviewed-by: NAnup Patel <anup@brainfault.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
[paul.walmsley@sifive.com: expanded "Fixes" commit ID]
Signed-off-by: NPaul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit d0e1f2110a5eeb6e410b2dd37d98bc5b30da7bc7 ]

In RV32, udelay would delay the wrong cycle. When it shifts right
"UDELAY_SHIFT" bits, it either delays 0 cycle or 1 cycle. It only works
correctly in RV64. Because the 'ucycles' always needs to be 64 bits
variable.
Signed-off-by: NNick Hu <nickhu@andestech.com>
Reviewed-by: NPalmer Dabbelt <palmer@sifive.com>
[paul.walmsley@sifive.com: fixed minor spelling error]
Signed-off-by: NPaul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit bf587caae305ae3b4393077fb22c98478ee55755 upstream.

Because RISC-V compliant implementations can cache invalid entries
in TLB, an SFENCE.VMA is necessary after changes to the page table.
This patch adds an SFENCE.vma for the vmalloc_fault path.
Signed-off-by: NShihPo Hung <shihpo.hung@sifive.com>
[paul.walmsley@sifive.com: reversed tab->whitespace conversion,
 wrapped comment lines]
Signed-off-by: NPaul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: linux-riscv@lists.infradead.org
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit dbee9c9c45846f003ec2f819710c2f4835630a6a ]

A memory save operation to 8-byte variable in RV32 is divided into
two sw instructions in the put_user macro.  The current fixup returns
execution flow to the second sw instead of the one after it.

This patch fixes this fixup code according to the load access part.

Signed-off-by: Alan Kao<alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 10a16997db3d99fc02c026cf2c6e6c670acafab0 upstream.

RISC-V syscall arguments are located in orig_a0,a1..a5 fields
of struct pt_regs.

Due to an off-by-one bug and a bug in pointer arithmetic
syscall_get_arguments() was reading s3..s7 fields instead of a1..a5.
Likewise, syscall_set_arguments() was writing s3..s7 fields
instead of a1..a5.

Link: http://lkml.kernel.org/r/20190329171221.GA32456@altlinux.org

Fixes: e2c0cdfb ("RISC-V: User-facing API")
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org
Cc: stable@vger.kernel.org # v4.15+
Acked-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NDmitry V. Levin <ldv@altlinux.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit ae662eec8a515ab550524e04c793b5ddf1aae3a1 ]

This ratio is the most used among all other architectures and make
icache_hygiene libhugetlbfs test pass: this test mmap lots of
hugepages whose addresses, without this patch, reach the end of
the process user address space.
Signed-off-by: NAlexandre Ghiti <aghiti@upmem.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 28198c4639b39899a728ac89aea29d2a7a72562f ]

max_low_pfn should be pfn_size not byte_size.
Signed-off-by: NGuo Ren <ren_guo@c-sky.com>
Signed-off-by: NMao Han <mao_han@c-sky.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit e3613bb8afc2a9474c9214d65c8326c5ac02135e upstream.

Previously, invalid PTEs and swap PTEs had the same binary
representation, causing errors when attempting to unmap PROT_NONE
mappings, including implicit unmap on exit.

Typical error:

swap_info_get: Bad swap file entry 40000000007a9879
BUG: Bad page map in process a.out  pte:3d4c3cc0 pmd:3e521401

Cc: stable@vger.kernel.org
Signed-off-by: NStefan O'Rear <sorear2@gmail.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 775800b0f1d7303d4fd8ce0e0d9eca4ff2f338f2 ]

Fix compilation error.
Signed-off-by: NDavid Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 0138ebb90c633f76bc71617f8f23635ce41c84fd ]

Fixes warning: 'struct module' declared inside parameter list will not be
visible outside of this definition or declaration
Signed-off-by: NDavid Abdurachmanov <david.abdurachmanov@gmail.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit e949b6db51dc172a35c962bc4414ca148315fe21 upstream.

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 riscv 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: Greentime Hu <greentime@andestech.com>
Cc: Alan Kao <alankao@andestech.com>
Cc: stable@kernel.org
Fixes: 03274a3f ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: NPalmer Dabbelt <palmer@sifive.com>
Reviewed-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit ef3a61406618291c46da168ff91acaa28d85944c ]

Fixes:

arch/riscv/kernel/module.c: In function 'apply_r_riscv_32_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:23:27: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_pcrel_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:104:23: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:146:23: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_got_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:190:60: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_call_plt_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:214:24: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_call_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:236:23: note: format string is defined here
Signed-off-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit f157d411a9eb170d2ee6b766da7a381962017cc9 ]

Building kernel 4.20 for Fedora as RPM fails, because riscv is missing
vdso_install target in arch/riscv/Makefile.
Signed-off-by: NDavid Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 21f70d4abf9e17c2e3d7e64b7bfa3424e017f176 upstream.

Sparse highlighted it, and appears to be a pure bug (from vs to).

./arch/riscv/include/asm/uaccess.h:403:35: warning: incorrect type in argument 1 (different address spaces)
./arch/riscv/include/asm/uaccess.h:403:39: warning: incorrect type in argument 2 (different address spaces)
./arch/riscv/include/asm/uaccess.h:409:37: warning: incorrect type in argument 1 (different address spaces)
./arch/riscv/include/asm/uaccess.h:409:41: warning: incorrect type in argument 2 (different address spaces)
Signed-off-by: NOlof Johansson <olof@lixom.net>
Cc: stable@vger.kernel.org
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use memblock_end_of_DRAM which provides correct last low memory
PFN. Without that, DMA32 region becomes empty resulting in zero
pages being allocated for DMA32.

This patch is based on earlier patch from palmer which never
merged into 4.19. I just edited the commit text to make more
sense.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Building a riscv kernel with CONFIG_FUNCTION_TRACER and
CONFIG_MODVERSIONS enabled results in these two warnings:

  MODPOST vmlinux.o
WARNING: EXPORT symbol "return_to_handler" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "_mcount" [vmlinux] version generation failed, symbol will not be versioned.

When exporting symbols from an assembly file, the MODVERSIONS code
requires their prototypes to be defined in asm-prototypes.h (see
scripts/Makefile.build). Since both of these symbols have prototypes
defined in linux/ftrace.h, include this header from RISC-V's
asm-prototypes.h.
Reported-by: NKarsten Merker <merker@debian.org>
Signed-off-by: NJames Cowgill <jcowgill@debian.org>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

setup_initrd() overwrites initrd_start and initrd_end if __initramfs_size
is larger than 0, which is always true even if there is no embedded
initramfs. This prevents booting qemu with "-initrd" parameter.
Overwriting initrd_start and initrd_end is not necessary since
__initramfs_start and __initramfs_size are used directly in
populate_rootfs() to load the built-in initramfs, so just drop
that code.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Thanks to Christoph Hellwig for pointing out a cleaner way to do this,
as my approach was quite ugly.

CC: Christoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

As of commit fd1102f0 ("mm: mmu_notifier fix for tlb_end_vma"),
asm-generic/tlb.h now calls tlb_flush() from a static inline function,
so we need to make sure that it's declared before #including the
asm-generic header in the arch header.
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Fixes: fd1102f0 ("mm: mmu_notifier fix for tlb_end_vma")
Signed-off-by: NWill Deacon <will.deacon@arm.com>
[groeck: Use forward declaration instead of moving inline function]
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Commit a0f97e06 ("kbuild: enable 'make CFLAGS=...' to add
additional options to CC") renamed CFLAGS to KBUILD_CFLAGS.

Commit 222d394d ("kbuild: enable 'make AFLAGS=...' to add
additional options to AS") renamed AFLAGS to KBUILD_AFLAGS.

Commit 06c5040c ("kbuild: enable 'make CPPFLAGS=...' to add
additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS.

For some reason, LDFLAGS was not renamed.

Using a well-known variable like LDFLAGS may result in accidental
override of the variable.

Kbuild generally uses KBUILD_ prefixed variables for the internally
appended options, so here is one more conversion to sanitize the
naming convention.

I did not touch Makefiles under tools/ since the tools build system
is a different world.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: NPalmer Dabbelt <palmer@sifive.com>

riscv does not enable CONFIG_COMPAT in default configurations:
defconfig, allmodconfig and allnoconfig.
Remove the asm/compat.h as it does not seem to add any value to
the architecture without CONFIG_COMPAT.

Now that time compat syscalls are being reused in non CONFIG_COMPAT
modes, asm-generic/compat.h provides definitions for riscv 32 bit
mode.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Cc: palmer@sifive.com
Cc: linux-riscv@lists.infradead.org
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

This file is expected to be included multiple times in the same file in
order to allow the __SYSCALL macro to generate system call tables.  With
a global include guard we end up missing __NR_riscv_flush_icache in the
syscall table, which results in icache flushes that escape the vDSO call
to not actually do anything.

The fix is to move to per-#define include guards, which allows the
system call tables to actually be populated.  Thanks to Macrus Comstedt
for finding and fixing the bug!

Cc: Marcus Comstedt <marcus@mc.pp.se>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

This would be necessary to make non-SMP builds work, but there is
another error in the implementation of our syscall linkage that actually
just causes sys_riscv_flush_icache to never build.  I've build tested
this on allnoconfig and allnoconfig+SMP=y, as well as defconfig like
normal.

CC: Christoph Hellwig <hch@infradead.org>
CC: Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <20180809055830.GA17533@infradead.org>
In-Reply-To: <20180809132612.GA31058@roeck-us.net>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f4220 ("mm: change return type to vm_fault_t")

In this patch all the caller of handle_mm_fault() are changed to return
vm_fault_t type.

Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PCSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
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: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Enabling both CONFIG_PERF_EVENTS without !CONFIG_SMP
generates following compilation error.

arch/riscv/include/asm/perf_event.h:80:2: error: expected
specifier-qualifier-list before 'irqreturn_t'

  irqreturn_t (*handle_irq)(int irq_num, void *dev);
  ^~~~~~~~~~~

Include interrupt.h in proper place to avoid compilation
error.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Add a driver for the SiFive implementation of the RISC-V Platform Level
Interrupt Controller (PLIC).  The PLIC connects global interrupt sources
to the local interrupt controller on each hart.

This driver is based on the driver in the RISC-V tree from Palmer Dabbelt,
but has been almost entirely rewritten since, and includes many fixes
from Atish Patra.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAtish Patra <atish.patra@wdc.com>
[Binding update by Palmer]
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

The stvec's value must be 4 byte alignment by specification definition.
These directives avoid to stvec be set the non-alignment value.
Signed-off-by: NZong Li <zong@andestech.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

The RISC-V ISA defines a per-hart real-time clock and timer, which is
present on all systems.  The clock is accessed via the 'rdtime'
pseudo-instruction (which reads a CSR), and the timer is set via an SBI
call.

Contains various improvements from Atish Patra <atish.patra@wdc.com>.
Signed-off-by: NDmitriy Cherkasov <dmitriy@oss-tech.org>
Signed-off-by: NPalmer Dabbelt <palmer@dabbelt.com>
[hch: remove dead code, add SPDX tags, used riscv_of_processor_hart(),
 minor cleanups, merged  hotplug cpu support and other improvements
 from Atish]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAtish Patra <atish.patra@wdc.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Add support for a routine that dispatches exceptions with the interrupt
flags set to either the IPI or irqdomain code (and the clock source in the
future).

Loosely based on the irq-riscv-int.c irqchip driver from the RISC-V tree.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

This mirrors the SIE_SSIE and SETE bits that are used in a similar
fashion.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

These are only of use to the local irq controller driver, so add them in
that driver implementation instead, which will be submitted soon.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Rename handle_ipi to riscv_software_interrupt, drop the unused return
value and move the prototype to irq.h together with riscv_timer_interupt.
This allows simplifying the upcoming interrupt handling support.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

This code is currently unused and will be added back later in a different
place with the real interrupt and clocksource support.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

This code lives entirely within the RISC-V arch code.  I've left it
within an "#ifdef CONFIG_EARLY_PRINTK" despite always having
EARLY_PRINTK support on RISC-V just in case someone wants to remove
it.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Adding 4 to sepc is pointless, and is wrong if we executed a 2-byte
compressed breakpoint.  This plus a corresponding gdb patch allows
compressed breakpoints to work in gdb.  Gdb maintainers have already
agreed that this is the right approach.
Signed-off-by: NJim Wilson <jimw@sifive.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Signed-off-by: NAlex Guo <xfguo@jlsemi.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

If you use a 64-bit compiler to build a 32-bit kernel then you'll get an
error when building the vDSO due to a library mismatch.  The happens
because the relevant "-march" argument isn't supplied to the GCC run
that generates one of the vDSO intermediate files.

I'm not actually sure what the right thing to do here is as I'm not
particularly familiar with the kernel build system.  I poked the
documentation and it appears that KCFLAGS is the correct thing to do
(it's suggested that should be used when building modules), but we set
KBUILD_CFLAGS in arch/riscv/Makefile.

This does at least fix the build error.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Almost all architectures include it.  Add a ARCH_NO_PREEMPT symbol to
disable preempt support for alpha, hexagon, non-coldfire m68k and
user mode Linux.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>