Commit Graph

24 Commits

Author SHA1 Message Date
Palmer Dabbelt
abc71bf0a7
RISC-V: Stop using LOCAL for the uaccess fixups
LLVM's integrated assembler doesn't support the LOCAL directive, which we're
using when generating our uaccess fixup tables.  Luckily the table fragment is
small enough that there's only one internal symbol, so using a relative symbol
reference doesn't really complicate anything.

Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-03 10:45:14 -08:00
Nick Hu
8ad8b72721
riscv: Add KASAN support
This patch ports the feature Kernel Address SANitizer (KASAN).

Note: The start address of shadow memory is at the beginning of kernel
space, which is 2^64 - (2^39 / 2) in SV39. The size of the kernel space is
2^38 bytes so the size of shadow memory should be 2^38 / 8. Thus, the
shadow memory would not overlap with the fixmap area.

There are currently two limitations in this port,

1. RV64 only: KASAN need large address space for extra shadow memory
region.

2. KASAN can't debug the modules since the modules are allocated in VMALLOC
area. We mapped the shadow memory, which corresponding to VMALLOC area, to
the kasan_early_shadow_page because we don't have enough physical space for
all the shadow memory corresponding to VMALLOC area.

Signed-off-by: Nick Hu <nickhu@andestech.com>
Reported-by: Greentime Hu <green.hu@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-01-22 13:09:58 -08:00
Olof Johansson
fc585d4a5c riscv: Less inefficient gcc tishift helpers (and export their symbols)
The existing __lshrti3 was really inefficient, and the other two helpers
are also needed to compile some modules.

Add the missing versions, and export all of the symbols like arm64
already does.

This code is based on the assembly generated by libgcc builds.

This fixes a build break triggered by ubsan:

riscv64-unknown-linux-gnu-ld: lib/ubsan.o: in function `.L2':
ubsan.c:(.text.unlikely+0x38): undefined reference to `__ashlti3'
riscv64-unknown-linux-gnu-ld: ubsan.c:(.text.unlikely+0x42): undefined reference to `__ashrti3'

Signed-off-by: Olof Johansson <olof@lixom.net>
[paul.walmsley@sifive.com: use SYM_FUNC_{START,END} instead of
 ENTRY/ENDPROC; note libgcc origin]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2020-01-18 19:13:41 -08:00
Luc Van Oostenryck
4d47ce158e riscv: fix compile failure with EXPORT_SYMBOL() & !MMU
When support for !MMU was added, the declaration of
__asm_copy_to_user() & __asm_copy_from_user() were #ifdefed
out hence their EXPORT_SYMBOL() give an error message like:
  .../riscv_ksyms.c:13:15: error: '__asm_copy_to_user' undeclared here
  .../riscv_ksyms.c:14:15: error: '__asm_copy_from_user' undeclared here

Since these symbols are not defined with !MMU it's wrong to export them.
Same for __clear_user() (even though this one is also declared in
include/asm-generic/uaccess.h and thus doesn't give an error message).

Fix this by doing the EXPORT_SYMBOL() directly where these symbols
are defined: inside lib/uaccess.S itself.

Fixes: 6bd33e1ece ("riscv: fix compile failure with EXPORT_SYMBOL() & !MMU")
Reported-by: kbuild test robot <lkp@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-12-27 21:44:36 -08:00
Christoph Hellwig
6bd33e1ece riscv: add nommu support
The kernel runs in M-mode without using page tables, and thus can't run
bare metal without help from additional firmware.

Most of the patch is just stubbing out code not needed without page
tables, but there is an interesting detail in the signals implementation:

 - The normal RISC-V syscall ABI only implements rt_sigreturn as VDSO
   entry point, but the ELF VDSO is not supported for nommu Linux.
   We instead copy the code to call the syscall onto the stack.

In addition to enabling the nommu code a new defconfig for a small
kernel image that can run in nommu mode on qemu is also provided, to run
a kernel in qemu you can use the following command line:

qemu-system-riscv64 -smp 2 -m 64 -machine virt -nographic \
	-kernel arch/riscv/boot/loader \
	-drive file=rootfs.ext2,format=raw,id=hd0 \
	-device virtio-blk-device,drive=hd0

Contains contributions from Damien Le Moal <Damien.LeMoal@wdc.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
[paul.walmsley@sifive.com: updated to apply; add CONFIG_MMU guards
 around PCI_IOBASE definition to fix build issues; fixed checkpatch
 issues; move the PCI_IO_* and VMEMMAP address space macros along
 with the others; resolve sparse warning]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-17 15:17:39 -08:00
Christoph Hellwig
a4c3733d32 riscv: abstract out CSR names for supervisor vs machine mode
Many of the privileged CSRs exist in a supervisor and machine version
that are used very similarly.  Provide versions of the CSR names and
fields that map to either the S-mode or M-mode variant depending on
a new CONFIG_RISCV_M_MODE kconfig symbol.

Contains contributions from Damien Le Moal <Damien.LeMoal@wdc.com>
and Paul Walmsley <paul.walmsley@sifive.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource, drivers/irqchip
[paul.walmsley@sifive.com: updated to apply]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-05 09:20:42 -08:00
Bin Meng
4f3f900846 riscv: Using CSR numbers to access CSRs
Since commit a3182c91ef ("RISC-V: Access CSRs using CSR numbers"),
we should prefer accessing CSRs using their CSR numbers, but there
are several leftovers like sstatus / sptbr we missed.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-30 11:04:19 -07:00
Palmer Dabbelt
81a48ee417 RISC-V: Remove udivdi3
This should never have landed in the first place: it was added as part
of 64-bit divide support for 32-bit systems, but the kernel doesn't
allow this sort of division.  I must have forgotten to remove it.

This patch removes the support.  Since this routine only worked on
64-bit platforms but was only built on 32-bit platforms, it's
essentially just nonsense anyway.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Link: https://lore.kernel.org/linux-riscv/nycvar.YSQ.7.76.1908061413360.19480@knanqh.ubzr/T/#t
Reported-by: Eric Lin <tesheng@andestech.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-08 16:05:38 -07:00
Paul Walmsley
66cc016ab7 riscv: delay: use do_div() instead of __udivdi3()
In preparation for removing __udivdi3() from the RISC-V
architecture-specific files, convert its one user to use do_div().
This avoids breaking the RV32 build after __udivdi3() is removed.

This second version removes the assignment of the remainder to an
unused temporary variable.  Thanks to Nicolas Pitre <nico@fluxnic.net>
for the suggestion.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Nicolas Pitre <nico@fluxnic.net>
2019-08-08 16:05:38 -07:00
Linus Torvalds
eb7c825bf7 RISC-V patches for v5.2-rc6
This tag contains fixes, defconfig, and DT data changes for the v5.2-rc
 series.  The fixes are relatively straightforward:
 
 - Addition of a TLB fence in the vmalloc_fault path, so the CPU doesn't
   enter an infinite page fault loop;
 - Readdition of the pm_power_off export, so device drivers that
   reassign it can now be built as modules;
 - A udelay() fix for RV32, fixing a miscomputation of the delay time;
 - Removal of deprecated smp_mb__*() barriers.
 
 The tag also adds initial DT data infrastructure for arch/riscv, along
 with initial data for the SiFive FU540-C000 SoC and the corresponding
 HiFive Unleashed board.
 
 We also update the RV64 defconfig to include some core drivers for the
 FU540 in the build.
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Merge tag 'riscv-for-v5.2/fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Paul Walmsley:
 "This contains fixes, defconfig, and DT data changes for the v5.2-rc
  series.

  The fixes are relatively straightforward:

   - Addition of a TLB fence in the vmalloc_fault path, so the CPU
     doesn't enter an infinite page fault loop

   - Readdition of the pm_power_off export, so device drivers that
     reassign it can now be built as modules

   - A udelay() fix for RV32, fixing a miscomputation of the delay time

   - Removal of deprecated smp_mb__*() barriers

  This also adds initial DT data infrastructure for arch/riscv, along
  with initial data for the SiFive FU540-C000 SoC and the corresponding
  HiFive Unleashed board.

  We also update the RV64 defconfig to include some core drivers for the
  FU540 in the build"

* tag 'riscv-for-v5.2/fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: remove unused barrier defines
  riscv: mm: synchronize MMU after pte change
  riscv: dts: add initial board data for the SiFive HiFive Unleashed
  riscv: dts: add initial support for the SiFive FU540-C000 SoC
  dt-bindings: riscv: convert cpu binding to json-schema
  dt-bindings: riscv: sifive: add YAML documentation for the SiFive FU540
  arch: riscv: add support for building DTB files from DT source data
  riscv: Fix udelay in RV32.
  riscv: export pm_power_off again
  RISC-V: defconfig: enable clocks, serial console
2019-06-17 10:34:03 -07:00
Nick Hu
d0e1f2110a riscv: Fix udelay in RV32.
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: Nick Hu <nickhu@andestech.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
[paul.walmsley@sifive.com: fixed minor spelling error]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-06-11 08:04:26 -07:00
Thomas Gleixner
50acfb2b76 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation version 2 this program is distributed
  in the hope that it will be useful but without any warranty without
  even the implied warranty of merchantability or fitness for a
  particular purpose see the gnu general public license for more
  details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 97 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Olof Johansson
a266cdba17
RISC-V: lib: minor asm cleanup
Fix tab/space conversion and use ENTRY/ENDPROC macros.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-21 08:17:02 -08:00
Olof Johansson
85d90b9180
RISC-V: lib: Fix build error for 64-bit
Fixes the following build error from tinyconfig:

riscv64-unknown-linux-gnu-ld: kernel/sched/fair.o: in function `.L8':
fair.c:(.text+0x70): undefined reference to `__lshrti3'
riscv64-unknown-linux-gnu-ld: kernel/time/clocksource.o: in function `.L0 ':
clocksource.c:(.text+0x334): undefined reference to `__lshrti3'

Fixes: 7f47c73b35 ("RISC-V: Build tishift only on 64-bit")
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-11-12 18:09:55 -08:00
Zong Li
7f47c73b35
RISC-V: Build tishift only on 64-bit
Only RV64 supports 128 integer size.

Signed-off-by: Zong Li <zong@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22 17:02:55 -07:00
Alex Guo
a89757daf2
RISC-V: implement __lshrti3.
Signed-off-by: Alex Guo <xfguo@jlsemi.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:30 -07:00
Palmer Dabbelt
e0e0c87c02
RISC-V: Make our port sparse-clean
This patch set contains a handful of fixes that clean up the sparse
results for the RISC-V port.  These patches shouldn't have any
functional difference.  The patches:

* Use NULL instead of 0.
* Clean up __user annotations.
* Split __copy_user into two functions, to make the __user annotations
  valid.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2018-06-11 09:09:49 -07:00
Luc Van Oostenryck
86406d51d3
riscv: split the declaration of __copy_user
We use a single __copy_user assembly function to copy memory both from
and to userspace. While this works, it triggers sparse errors because
we're implicitly casting between the kernel and user address spaces by
calling __copy_user.

This patch splits the C declaration into a pair of functions,
__asm_copy_{to,from}_user, that have sane semantics WRT __user. This
split make things fine from sparse's point of view. The assembly
implementation keeps a single definition but add a double ENTRY() for it,
one for __asm_copy_to_user and another one for __asm_copy_from_user.
The result is a spare-safe implementation that pays no performance
or code size penalty.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-06-09 12:34:31 -07:00
Alan Kao
ebcbd75e39
riscv: Fix the bug in memory access fixup code
A piece of fixup code is currently shared by __copy_user and
__clear_user.  It first disables the access to user-space memory
and then returns the "n" argument, which represents #(bytes not processed).
However,__copy_user's "n" is in register a2, while __clear_user's in a1,
and thus it causes errors for programs like setdomainname02 testcase in LTP.

This patch fixes this issue by separating their fixup code and returning
the right value for the kernel to handle a relative fault properly.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-06-04 13:33:31 -07:00
Olof Johansson
24948b7ec0 RISC-V: Export some expected symbols for modules
These are the ones needed by current allmodconfig, so add them instead
of everything other architectures are exporting -- the rest can be
added on demand later if needed.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 10:01:10 -08:00
Palmer Dabbelt
fbe934d69e RISC-V: Build Infrastructure
This patch contains all the build infrastructure that actually enables
the RISC-V port.  This includes Makefiles, linker scripts, and Kconfig
files.  It also contains the only top-level change, which adds RISC-V to
the list of architectures that need a sed run to produce the ARCH
variable when building locally.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:49 -07:00
Palmer Dabbelt
6d60b6ee0c RISC-V: Device, timer, IRQs, and the SBI
This patch contains code that interfaces with devices that are mandated
by the RISC-V supervisor specification and that don't have explicit
drivers anywhere else in the tree.  This includes the staticly defined
interrupts, the CSR-mapped timer, and virtualized SBI devices.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:47 -07:00
Palmer Dabbelt
5d8544e2d0 RISC-V: Generic library routines and assembly
This patch contains code that is more specific to the RISC-V ISA than it
is to Linux.  It contains string and math operations, C wrappers for
various assembly instructions, stack walking code, and uaccess.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:45 -07:00