The printk timestamps are very useful information to visually see
where kernel is spending time during boot. It also helps us see
the timing of hotplug events at runtime.

This patch enables printk timestamps in RISC-V defconfig so that
we have it enabled by default (similar to other architectures
such as x86_64, arm64, etc).

Signed-off-by: Anup Patel <anup@brainfault.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

This patch updates defconfig using savedefconfig on Linux-4.19.  It is
intended to have no functional change.

Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

We don't want 64-bit divide in the kernel.

This reverts commit 6315730e

.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

I'm removing the generic 64-bit divide support, which means this will no
longer work.

This reverts commit 757331db

.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

This should never have been inside our arch port to begin with, it's
just a relic from when we were maintaining out of tree patches.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

On the Hifive-U platform, cpu 0 is a masked cpu with less capabilities
than the other cpus.  Ignore it for the purpose of determining the
hardware capabilities of the system.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

RISC-V Patches for the 4.20 Merge Window, Part 1

This patch set contains a lot (at least, for me) of improvements to the
RISC-V kernel port:

* The removal of some cacheinfo values that were bogus.
* On systems with F but without D the kernel will not show the F
  extension to userspace, as it isn't actually supported.
* Support for futexes.
* Removal of some unused code.
* Cleanup of some menuconfig entries.
* Support for systems without a floating-point unit, and for building
  kernels that will never use the floating-point unit.
* More fixes to the RV32I port, which regressed again.  It's really time
  to get this into a regression test somewhere so I stop breaking it.
  Thanks to Zong for resurrecting it again!
* Various fixes that resulted from a year old review of our original
  patch set that I finally got around to.
* Various improvements to SMP support, largely based around having
  switched to logical hart numbering, as well as some interrupt
  improvements.  This one is in the same patch set as above, thanks to
  Atish for sheparding everything though as my patch set was a bit of a
  mess.

I'm pretty sure this is our largest patch set since the original kernel
contribution, and it's certainly the one with the most contributors.
While I don't have anything else I know I'm going to submit for the
merge window, I would be somewhat surprised if I didn't screw anything
up.

Thanks for the help, everyone!

This patch series now has evolved to contain several related changes.

1. Updated the assorted cleanup series by Palmer.
The original cleanup patch series can be found here.
http://lists.infradead.org/pipermail/linux-riscv/2018-August/001232.html



2. Implemented decoupling linux logical CPU ids from hart id.
Some of the work has been inspired from ARM64.
Tested on QEMU & HighFive Unleashed board with/without SMP enabled.

3. Included Anup's cleanup and IPI stat patch.

All the patch series have been combined to avoid conflicts as a lot of
common code is changed different patch sets. Atish has mostly addressed
review comments and fixed checkpatch errors from Palmer's and Anup's
series.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

This patch set fixes up various failures in the RV32I port.  The fixes
are all nominally independent, but are really only testable together
because the RV32I port fails to build without all of them.  The patch
set includes:

* The removal of tishift on RV32I targets, as 128-bit integers are not
  supported by the toolchain.
* The removal of swiotlb from RV32I targets, since all physical
  addresses can be mapped by all hardware on all existing RV32I targets.
* The addition of ummodi3 and udivmoddi4 from an old version of GCC that
  was licensed under GPLv2 as generic code, along with their use on
  RV32I targets.
* A fix to our page alignment logic within ioremap for RV32I targets.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

This patchset adds an option, CONFIG_FPU, to enable/disable floating-
point support within the kernel.  The kernel's new behavior will be as
follows:

* with CONFIG_FPU=y
  All FPU codes are reserved.  If no FPU is found during booting, a
  global flag will be set, and those functions will be bypassed with
  condition check to that flag.

* with CONFIG_FPU=n
  No floating-point instructions in kernel and all related settings
  are excluded.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

* Move the built-in cmdline configuration on a new menu entry "Boot
  options", it doesn't make much sense to be part of the debuging menu.

* Rename "Kernel Type" menu to "Kernel features" to be more consistent with
  what other architectures are using, plus "type" is a bit misleading here.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

This becomes much neater in Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

This export is not only not needed, but also breaks symbol versioning
due to being an undeclared assembly export.

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

Here is an attempt to add the missing futex support.  I started with the MIPS
version of futex.h and modified it until I got it working.  I tested it on
a HiFive Unleashed running Fedora Core 29 using the fc29 4.15 version of the
kernel.  This was tested against the glibc testsuite, where it fixes 14 nptl
related testsuite failures.  That unfortunately only tests the cmpxchg support,
so I also used the testcase at the end of

    https://lwn.net/Articles/148830/



which tests the atomic_op functionality, except that it doesn't verify that
the operations are atomic, which they obviously are.  This testcase runs
successfully with the patch and fails without it.

I'm not a kernel expert, so there could be details I got wrong here.  I wasn't
sure about the memory model support, so I used aqrl which seemed safest, and
didn't add fences which seemed unnecessary.  I'm not sure about the copyright
statements, I left in Ralf Baechle's line because I started with his code.
Checkpatch reports some style problems, but it is the same style as the MIPS
futex.h, and the uses of ENOSYS appear correct even though it complains about
them.  I don't know if any of that matters.

This patch was tested on qemu with the glibc nptl/tst-cond-except
testcase, and the wake_op testcase from above.

Signed-off-by: Jim Wilson <jimw@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

Add a variable and a macro to describe FP registers, assuming only D is
supported.  FP code is conditional on CONFIG_FPU.  The FP regs and FCSR
are copied separately to avoid copying struct padding.  Tested by hand and
with the gdb testsuite.

Signed-off-by: Jim Wilson <jimw@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

The RISC-V Linux port doesn't support systems that have the F extension
but don't have the D extension -- we actually don't support systems
without D either, but Alan's patch set is rectifying that soon.  For now
I think we can leave this in a semi-broken state and just wait for
Alan's patch set to get merged for proper non-FPU support -- the patch
set is starting to look good, so doing something in-between doesn't seem
like it's worth the work.

I don't think it's worth fretting about support for systems with F but
not D for now: our glibc ABIs are IMAC and IMAFDC so they probably won't
end up being popular.  We can always extend this in the future.

CC: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

These are just hard coded in the RISC-V port, which doesn't make any
sense.  We should probably be setting these from device tree entries
when they exist, but for now I think it's saner to just leave them all
as their default values.

Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

This patch provides arch_show_interrupts() implementation to
show IPI stats via /proc/interrupts.

Now the contents of /proc/interrupts" will look like below:
           CPU0       CPU1       CPU2       CPU3
  8:         17          7          6         14  SiFive PLIC   8  virtio0
 10:         10         10          9         11  SiFive PLIC  10  ttyS0
IPI0:       170        673        251         79  Rescheduling interrupts
IPI1:         1         12         27          1  Function call interrupts

Signed-off-by: Anup Patel <anup@brainfault.org>
[Atish - Fixed checkpatch errors]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>

Changes since v2:
 - Remove use of IPI_CALL_WAKEUP because it's being removed

Changes since v1:
 - Add stub inline show_ipi_stats() function for !CONFIG_SMP
 - Make ipi_names[] dynamically sized at compile time
 - Minor beautification of ipi_names[] using tabs

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

Currently, /proc/cpuinfo show logical CPU ID as Hart ID which
is in-correct. This patch shows CPU ID and Hart ID separately
in /proc/cpuinfo using cpuid_to_hardid_map().

With this patch, contents of /proc/cpuinfo looks as follows:
processor	: 0
hart		: 1
isa		: rv64imafdc
mmu		: sv48

processor	: 1
hart		: 0
isa		: rv64imafdc
mmu		: sv48

processor	: 2
hart		: 2
isa		: rv64imafdc
mmu		: sv48

processor	: 3
hart		: 3
isa		: rv64imafdc
mmu		: sv48

Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

Setup the cpu_logical_map during boot. Moreover, every SBI call
and PLIC context are based on the physical hartid. Use the logical
CPU to hartid mapping to pass correct hartid to respective functions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

Currently, both Linux CPU id and hart id are same.
This is not recommended as it will lead to discontinuous CPU
indexing in Linux. Moreover, kdump kernel will run from CPU0
which would be absent if we follow existing scheme.

Implement a logical mapping between Linux CPU id and hart
id to decouple these two. Always mark the boot processor as
CPU0 and all other CPUs get the logical CPU id based on their
booting order.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

The secondary harts spin on couple of per cpu variables until both of
these are non-zero so it's not necessary to have any ordering here.
However, WRITE_ONCE should be used to avoid tearing.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

commit f1f10076

 ("mm: add new mmgrab() helper") added a
helper that we missed out on.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

The old name was a bit odd.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

It's a bit confusing exactly what this function does: it actually
returns the hartid of an OF processor node, failing with -1 on invalid
nodes.  I've changed the name to _hartid() in order to make that a bit
more clear, as well as adding a comment.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

I'm not sure how I managed to miss this the first time, but this is much
better.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: code comment formatting and other fixes]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

Currently, irq is enabled before preemption disabling happens.
If the scheduler fired right here and cpu is scheduled then it
may blow up.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: Commit text and code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

This isn't readily apparent from reading the code.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

We shouldn't be directly passing device tree values to userspace, both
because there could be mistakes in device trees and because the kernel
doesn't support arbitrary ISAs.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
[Atish: checkpatch fix and code comment formatting update]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

These are just hard coded in the RISC-V port, which doesn't make any
sense.  We should probably be setting these from device tree entries
when they exist, but for now I think it's saner to just leave them all
as their default values.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

The scause is already part of pt_regs so no need to pass
scause as separate arg to do_IRQ().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

For 32bit, the upper 32-bit of phys_addr_t will be flushed to zero
after AND with PAGE_MASK because the data type of PAGE_MASK is
unsigned long. To fix this problem, the page alignment is done by
subtracting the page offset instead of AND with PAGE_MASK.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

On 32-bit, it need to use __umoddi3 by some drivers.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

Add umoddi3 and udivmoddi4 support for 32-bit.

The RV32 need the umoddi3 to do modulo when the operands are long long
type, like other libraries implementation such as ucmpdi2, lshrdi3 and
so on.

I encounter the undefined reference 'umoddi3' when I use the in
house dma driver, although it is in house driver, but I think that
umoddi3 is a common function for RV32.

The udivmoddi4 and umoddi3 are copies from libgcc in gcc. There are other
functions use the udivmoddi4 in libgcc, so I separate the umoddi3 and
udivmoddi4 for flexible extension in the future.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

Only RV64 supports swiotlb. On RV32, it don't select the SWIOTLB.

Signed-off-by: Zong Li <zong@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

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>

We expect that a kernel with CONFIG_FPU=y can still support no-FPU
machines. To do so, the kernel should first examine the existence of a
FPU, then do nothing if a FPU does exist; otherwise, it should
disable/bypass all FPU-related functions.

In this patch, a new global variable, has_fpu, is created and determined
when parsing the hardware capability from device tree during booting.
This variable is used in those FPU-related functions.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

FPU codes have been separated from common part in previous patches.
This patch add the CONFIG_FPU option and some stubs, so that a no-FPU
configuration is allowed.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

This patch cleanup the MARCH string passing to both compiler and
assembler.  Note that the CFLAGS should not contain "fd" before we
have mechnisms like kernel_fpu_begin/end in other architectures.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

FPU-related logic is separated from normal signal handling path in
this patch.  Kernel can easily be configured to exclude those procedures
for no-FPU systems.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>