linux.git/arch/riscv, branch v5.9

riscv: Fixup bootup failure with HARDENED_USERCOPY

2020-10-07T01:34:00+00:00

6184358da000 ("riscv: Fixup static_obj() fail") attempted to elide a lockdep
failure by rearranging our kernel image to place all initdata within [_stext,
_end], thus triggering lockdep to treat these as static objects.  These objects
are released and eventually reallocated, causing check_kernel_text_object() to
trigger a BUG().

This backs out the change to make [_stext, _end] all-encompassing, instead just
moving initdata.  This results in initdata being outside of [__init_begin,
__init_end], which means initdata can't be freed.

Link: https://lore.kernel.org/linux-riscv/1593266228-61125-1-git-send-email-guoren@kernel.org/T/#t
Signed-off-by: Guo Ren 
Reported-by: Aurelien Jarno 
Tested-by: Aurelien Jarno 
[Palmer: Clean up commit text]
Signed-off-by: Palmer Dabbelt

RISC-V: Make sure memblock reserves the memory containing DT

2020-10-04T23:19:28+00:00

Currently, the memory containing DT is not reserved. Thus, that region
of memory can be reallocated or reused for other purposes. This may result
in  corrupted DT for nommu virt board in Qemu. We may not face any issue
in kendryte as DT is embedded in the kernel image for that.

Fixes: 6bd33e1ece52 ("riscv: add nommu support")
Cc: stable@vger.kernel.org
Signed-off-by: Atish Patra 
Signed-off-by: Palmer Dabbelt

RISC-V: Check clint_time_val before use

2020-09-30T18:05:14+00:00

The NoMMU kernel is broken for QEMU virt machine from Linux-5.9-rc6
because clint_time_val is used even before CLINT driver is probed
at following places:
1. rand_initialize() calls get_cycles() which in-turn uses
   clint_time_val
2. boot_init_stack_canary() calls get_cycles() which in-turn
   uses clint_time_val

The issue#1 (above) is fixed by providing custom random_get_entropy()
for RISC-V NoMMU kernel. For issue#2 (above), we remove dependency of
boot_init_stack_canary() on get_cycles() and this is aligned with the
boot_init_stack_canary() implementations of ARM, ARM64 and MIPS kernel.

Fixes: d5be89a8d118 ("RISC-V: Resurrect the MMIO timer implementation for M-mode systems")
Signed-off-by: Anup Patel 
Tested-by: Damien Le Moal 
Signed-off-by: Palmer Dabbelt

Merge tag 'riscv-for-linus-5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2020-09-20T17:51:11+00:00

Pull RISC-V fixes from Palmer Dabbelt:

 - A fix for a lockdep issue to avoid an asserting triggering during
   early boot. There shouldn't be any incorrect behavior as the system
   isn't concurrent at the time.

 - The addition of a missing fence when installing early fixmap
   mappings.

 - A corretion to the K210 device tree's interrupt map.

 - A fix for M-mode timer handling on the K210.

* tag 'riscv-for-linus-5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: Resurrect the MMIO timer implementation for M-mode systems
  riscv: Fix Kendryte K210 device tree
  riscv: Add sfence.vma after early page table changes
  RISC-V: Take text_mutex in ftrace_init_nop()

RISC-V: Resurrect the MMIO timer implementation for M-mode systems

2020-09-19T20:21:11+00:00

The K210 doesn't implement rdtime in M-mode, and since that's where Linux runs
in the NOMMU systems that means we can't use rdtime.  The K210 is the only
system that anyone is currently running NOMMU or M-mode on, so here we're just
inlining the timer read directly.

This also adds the CLINT driver as an !MMU dependency, as it's currently the
only timer driver availiable for these systems and without it we get a build
failure for some configurations.

Tested-by: Damien Le Moal 
Signed-off-by: Palmer Dabbelt

riscv: Fix Kendryte K210 device tree

2020-09-19T20:20:14+00:00

The Kendryte K210 SoC CLINT is compatible with Sifive clint v0
(sifive,clint0). Fix the Kendryte K210 device tree clint entry to be
inline with the sifive timer definition documented in
Documentation/devicetree/bindings/timer/sifive,clint.yaml.
The device tree clint entry is renamed similarly to u-boot device tree
definition to improve compatibility with u-boot defined device tree.
To ensure correct initialization, the interrup-cells attribute is added
and the interrupt-extended attribute definition fixed.

This fixes boot failures with Kendryte K210 SoC boards.

Note that the clock referenced is kept as K210_CLK_ACLK, which does not
necessarilly match the clint MTIME increment rate. This however does not
seem to cause any problem for now.

Signed-off-by: Damien Le Moal 
Signed-off-by: Palmer Dabbelt

riscv: Add sfence.vma after early page table changes

2020-09-19T20:20:13+00:00

This invalidates local TLB after modifying the page tables during early init as
it's too early to handle suprious faults as we otherwise do.

Fixes: f2c17aabc917 ("RISC-V: Implement compile-time fixed mappings")
Reported-by: Syven Wang 
Signed-off-by: Syven Wang 
Signed-off-by: Greentime Hu 
Reviewed-by: Anup Patel 
[Palmer: Cleaned up the commit text]
Signed-off-by: Palmer Dabbelt

RISC-V: Take text_mutex in ftrace_init_nop()

2020-09-11T19:15:21+00:00

Without this we get lockdep failures.  They're spurious failures as SMP isn't
up when ftrace_init_nop() is called.  As far as I can tell the easiest fix is
to just take the lock, which also seems like the safest fix.

Signed-off-by: Palmer Dabbelt 
Acked-by: Guo Ren 
Signed-off-by: Palmer Dabbelt

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva

riscv: Add SiFive drivers to rv32_defconfig

2020-08-20T18:00:21+00:00

This adds SiFive drivers to rv32_defconfig, to keep in sync with the
64-bit config. This is useful when testing 32-bit kernel with QEMU
'sifive_u' 32-bit machine.

Signed-off-by: Bin Meng 
Reviewed-by: Anup Patel 
Reviewed-by: Alistair Francis 
Signed-off-by: Palmer Dabbelt