Commit Graph

41 Commits

Author SHA1 Message Date
Vitaly Wool
f105aa940e
riscv: add BUILTIN_DTB support for MMU-enabled targets
Sometimes, especially in a production system we may not want to
use a "smart bootloader" like u-boot to load kernel, ramdisk and
device tree from a filesystem on eMMC, but rather load the kernel
from a NAND partition and just run it as soon as we can, and in
this case it is convenient to have device tree compiled into the
kernel binary. Since this case is not limited to MMU-less systems,
let's support it for these which have MMU enabled too.

While at it, provide __dtb_start as a parameter to setup_vm() in
BUILTIN_DTB case, so we don't have to duplicate BUILTIN_DTB specific
processing in MMU-enabled and MMU-disabled versions of setup_vm().

Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-02-18 23:17:54 -08:00
Linus Torvalds
e2ae634014 RISC-V Patches for the 5.11 Merge Window, Part 1
We have a handful of new kernel features for 5.11:
 
 * Support for the contiguous memory allocator.
 * Support for IRQ Time Accounting
 * Support for stack tracing
 * Support for strict /dev/mem
 * Support for kernel section protection
 
 I'm being a bit conservative on the cutoff for this round due to the
 timing, so this is all the new development I'm going to take for this
 cycle (even if some of it probably normally would have been OK).  There
 are, however, some fixes on the list that I will likely be sending along
 either later this week or early next week.
 
 There is one issue in here: one of my test configurations
 (PREEMPT{,_DEBUG}=y) fails to boot on QEMU 5.0.0 (from April) as of the
 .text.init alignment patch.  With any luck we'll sort out the issue, but
 given how many bugs get fixed all over the place and how unrelated those
 features seem my guess is that we're just running into something that's
 been lurking for a while and has already been fixed in the newer QEMU
 (though I wouldn't be surprised if it's one of these implicit
 assumptions we have in the boot flow).  If it was hardware I'd be
 strongly inclined to look more closely, but given that users can upgrade
 their simulators I'm less worried about it.
 
 There are two merge conflicts, both in build files.  They're both a bit
 clunky: arch/riscv/Kconfig is out of order (I have a script that's
 supposed to keep them in order, I'll fix it) and lib/Makefile is out of
 order (though GENERIC_LIB here doesn't mean quite what it does above).
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEKzw3R0RoQ7JKlDp6LhMZ81+7GIkFAl/cHO4THHBhbG1lckBk
 YWJiZWx0LmNvbQAKCRAuExnzX7sYiTlmD/4uDyNHBM1XH/XD4fSEwTYJvGLqt/Jo
 vtrGR/fm0SlQFUKCcywSzxcVAeGn56CACbEIDYLuL4xXRJmbwEuaRrHVx2sEhS9p
 pNhy+wus/SgDz5EUAawMyR2AEWgzl77hY5T/+AAo4yv65SGGBfsIdz5noIVwGNqW
 r0g5cw2O99z0vwu1aSrK4isWHconG9MfQnnVyepPSh67pyWS4aUCr1K3vLiqD2dE
 XcgtwdcgzUIY5aEoJNrWo5qTrcaG8m6MRNCDAKJ6MKdDA2wdGIN868G0wQnoURRm
 Y+yW7w3P20kM0b87zH50jujTWg38NBKOfaXb0mAfawZMapL60veTVmvs2kNtFXCy
 F6JWRkgTiRnGY72FtRR0igWXT5M7fz0EiLFXLMItGcgj79TUget4l/3sRMN47S/O
 cA/WiwptJH3mh8IkL6z5ZxWEThdOrbFt8F1T+Gyq/ayblcPnJaLn/wrWoeOwviWR
 fvEC7smuF5SBTbWZK5tBOP21Nvhb7bfr49Sgr8Tvdjl15tz97qK+2tsLXwkBoQnJ
 wU45jcXfzr5wgiGBOQANRite5bLsJ0TuOrTgA5gsGpv+JSDGbpcJbm0833x00nX/
 3GsW5xr+vsLCvljgPAtKsyDNRlGQu908Gxrat2+s8u92bLr1bwn30uKL5h6i/n1w
 QgWATuPPGXZZdw==
 =GWIH
 -----END PGP SIGNATURE-----

Merge tag 'riscv-for-linus-5.11-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:
 "We have a handful of new kernel features for 5.11:

   - Support for the contiguous memory allocator.

   - Support for IRQ Time Accounting

   - Support for stack tracing

   - Support for strict /dev/mem

   - Support for kernel section protection

  I'm being a bit conservative on the cutoff for this round due to the
  timing, so this is all the new development I'm going to take for this
  cycle (even if some of it probably normally would have been OK). There
  are, however, some fixes on the list that I will likely be sending
  along either later this week or early next week.

  There is one issue in here: one of my test configurations
  (PREEMPT{,_DEBUG}=y) fails to boot on QEMU 5.0.0 (from April) as of
  the .text.init alignment patch.

  With any luck we'll sort out the issue, but given how many bugs get
  fixed all over the place and how unrelated those features seem my
  guess is that we're just running into something that's been lurking
  for a while and has already been fixed in the newer QEMU (though I
  wouldn't be surprised if it's one of these implicit assumptions we
  have in the boot flow). If it was hardware I'd be strongly inclined to
  look more closely, but given that users can upgrade their simulators
  I'm less worried about it"

* tag 'riscv-for-linus-5.11-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  arm64: Use the generic devmem_is_allowed()
  arm: Use the generic devmem_is_allowed()
  RISC-V: Use the new generic devmem_is_allowed()
  lib: Add a generic version of devmem_is_allowed()
  riscv: Fixed kernel test robot warning
  riscv: kernel: Drop unused clean rule
  riscv: provide memmove implementation
  RISC-V: Move dynamic relocation section under __init
  RISC-V: Protect all kernel sections including init early
  RISC-V: Align the .init.text section
  RISC-V: Initialize SBI early
  riscv: Enable ARCH_STACKWALK
  riscv: Make stack walk callback consistent with generic code
  riscv: Cleanup stacktrace
  riscv: Add HAVE_IRQ_TIME_ACCOUNTING
  riscv: Enable CMA support
  riscv: Ignore Image.* and loader.bin
  riscv: Clean up boot dir
  riscv: Fix compressed Image formats build
  RISC-V: Add kernel image sections to the resource tree
2020-12-18 10:43:07 -08:00
Kefeng Wang
5cb0080f1b
riscv: Enable ARCH_STACKWALK
Convert to ARCH_STACKWALK to reduce duplicated code in stack trace.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-11-25 16:03:59 -08:00
Sean Anderson
79605f1394
riscv: Set text_offset correctly for M-Mode
M-Mode Linux is loaded at the start of RAM, not 2MB later. Perhaps this
should be calculated based on PAGE_OFFSET somehow? Even better would be to
deprecate text_offset and instead introduce something absolute.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-11-05 17:32:27 -08:00
Atish Patra
cb7d2dd561
RISC-V: Add PE/COFF header for EFI stub
Linux kernel Image can appear as an EFI application With appropriate
PE/COFF header fields in the beginning of the Image header. An EFI
application loader can directly load a Linux kernel Image and an EFI
stub residing in kernel can boot Linux kernel directly.

Add the necessary PE/COFF header.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20200421033336.9663-3-atish.patra@wdc.com
[ardb: - use C prefix for c.li to ensure the expected opcode is emitted
       - align all image sections according to PE/COFF section alignment ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-10-02 14:31:16 -07:00
Anup Patel
8f3a2b4a96
RISC-V: Move DT mapping outof fixmap
Currently, RISC-V reserves 1MB of fixmap memory for device tree. However,
it maps only single PMD (2MB) space for fixmap which leaves only < 1MB space
left for other kernel features such as early ioremap which requires fixmap
as well. The fixmap size can be increased by another 2MB but it brings
additional complexity and changes the virtual memory layout as well.
If we require some additional feature requiring fixmap again, it has to be
moved again.

Technically, DT doesn't need a fixmap as the memory occupied by the DT is
only used during boot. That's why, We map device tree in early page table
using two consecutive PGD mappings at lower addresses (< PAGE_OFFSET).
This frees lot of space in fixmap and also makes maximum supported
device tree size supported as PGDIR_SIZE. Thus, init memory section can be used
for the same purpose as well. This simplifies fixmap implementation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-10-02 14:30:57 -07:00
Tian Tao
54701a0d12
RISC-V: Fix duplicate included thread_info.h
asm/thread_info.h is included more than once, Remove the one that isn't
necessary.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-09-15 18:46:12 -07:00
Qiu Wenbo
76d4467a97
riscv: Setup exception vector for nommu platform
Exception vector is missing on nommu platform and that is an issue.
This patch is tested in Sipeed Maix Bit Dev Board.

Fixes: 79b1feba54 ("RISC-V: Setup exception vector early")
Suggested-by: Anup Patel <anup@brainfault.org>
Suggested-by: Atish Patra <atishp@atishpatra.org>
Signed-off-by: Qiu Wenbo <qiuwenbo@phytium.com.cn>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-08-14 16:28:20 -07:00
Atish Patra
79b1feba54
RISC-V: Setup exception vector early
The trap vector is set only in trap_init which may be too late in some
cases. Early ioremap/efi spits many warning messages which may be useful.

Setup the trap vector early so that any warning/bug can be handled before
generic code invokes trap_init.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-07-30 11:37:48 -07:00
Palmer Dabbelt
eb077c9c38
RISC-V: Skip setting up PMPs on traps
The RISC-V ISA manual says that PMPs are WARL, but it appears the K210
doesn't implement them and instead traps on the unsupported accesses.
This patch handles those traps by just skipping the PMP
initialization entirely, under the theory that machines that trap on PMP
accesses must allow memory accesses as otherwise they're pretty useless.

Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-05-18 11:38:08 -07:00
Damien Le Moal
335b139057
riscv: Add SOC early init support
Add a mechanism for early SoC initialization for platforms that need
additional hardware initialization not possible through the regular
device tree and drivers mechanism. With this, a SoC specific
initialization function can be called very early, before DTB parsing
is done by parse_dtb() in Linux RISC-V kernel setup code.

This can be very useful for early hardware initialization for No-MMU
kernels booted directly in M-mode because it is quite likely that no
other booting stage exist prior to the No-MMU kernel.

Example use of a SoC early initialization is as follows:

static void vendor_abc_early_init(const void *fdt)
{
	/*
	 * some early init code here that can use simple matches
	 * against the flat device tree file.
	 */
}
SOC_EARLY_INIT_DECLARE("vendor,abc", abc_early_init);

This early initialization function is executed only if the flat device
tree for the board has a 'compatible = "vendor,abc"' entry;

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-04-03 10:46:43 -07:00
Atish Patra
cfafe26013
RISC-V: Add supported for ordered booting method using HSM
Currently, all harts have to jump Linux in RISC-V. This complicates the
multi-stage boot process as every transient stage also has to ensure all
harts enter to that stage and jump to Linux afterwards. It also obstructs
a clean Kexec implementation.

SBI HSM extension provides alternate solutions where only a single hart
need to boot and enter Linux. The booting hart can bring up secondary
harts one by one afterwards.

Add SBI HSM based cpu_ops that implements an ordered booting method in
RISC-V. This change is also backward compatible with older firmware not
implementing HSM extension. If a latest kernel is used with older
firmware, it will continue to use the default spinning booting method.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-31 11:27:50 -07:00
Atish Patra
e011995e82
RISC-V: Move relocate and few other functions out of __init
The secondary hart booting and relocation code are under .init section.
As a result, it will be freed once kernel booting is done. However,
ordered booting protocol and CPU hotplug always requires these functions
to be present to bringup harts after initial kernel boot.

Move the required functions to a different section and make sure that
they are in memory within first 2MB offset as trampoline page directory
only maps first 2MB.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-31 11:25:50 -07:00
Greentime Hu
c68a903229
riscv: set pmp configuration if kernel is running in M-mode
When the kernel is running in S-mode, the expectation is that the
bootloader or SBI layer will configure the PMP to allow the kernel to
access physical memory.  But, when the kernel is running in M-mode and is
started with the ELF "loader", there's probably no bootloader or SBI layer
involved to configure the PMP.  Thus, we need to configure the PMP
ourselves to enable the kernel to access all regions.

Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-18 09:41:24 -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
Greentime Hu
20d2292754 riscv: make sure the cores stay looping in .Lsecondary_park
The code in secondary_park is currently placed in the .init section. The
kernel reclaims and clears this code when it finishes booting. That
causes the cores parked in it to go to somewhere unpredictable, so we
move this function out of init to make sure the cores stay looping there.

The instruction bgeu a0, t0, .Lsecondary_park may have "a relocation
truncated to fit" issue during linking time. It is because that sections
are too far to jump. Let's use tail to jump to the .Lsecondary_park.

Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Anup Patel <anup.patel@sifive.com>
Cc: Andreas Schwab <schwab@suse.de>
Cc: stable@vger.kernel.org
Fixes: 76d2a0493a ("RISC-V: Init and Halt Code")
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2020-01-15 18:07:54 -08:00
Guo Ren
dc6fcba72f riscv: Fixup obvious bug for fp-regs reset
CSR_MISA is defined in Privileged Architectures' spec: 3.1.1 Machine
ISA Register misa. Every bit:1 indicate a feature, so we should beqz
reset_done when there is no F/D bit in csr_misa register.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
[paul.walmsley@sifive.com: fix typo in commit message]
Fixes: 9e80635619 ("riscv: clear the instruction cache and all registers when booting")
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2020-01-12 10:12:44 -08:00
Greentime Hu
d411cf02ed riscv: fix scratch register clearing in M-mode.
This patch fixes that the sscratch register clearing in M-mode. It cleared
sscratch register in M-mode, but it should clear mscratch register. That will
cause kernel trap if the CPU core doesn't support S-mode when trying to access
sscratch.

Fixes: 9e80635619 ("riscv: clear the instruction cache and all registers when booting")
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-12-20 03:32:24 -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
9e80635619 riscv: clear the instruction cache and all registers when booting
When we get booted we want a clear slate without any leaks from previous
supervisors or the firmware.  Flush the instruction cache and then clear
all registers to known good values.  This is really important for the
upcoming nommu support that runs on M-mode, but can't really harm when
running in S-mode either.  Vaguely based on the concepts from opensbi.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-17 15:17:39 -08:00
Damien Le Moal
accb9dbc4a riscv: read the hart ID from mhartid on boot
When in M-Mode, we can use the mhartid CSR to get the ID of the running
HART. Doing so, direct M-Mode boot without firmware is possible.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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
Xiang Wang
b47613da3b arch/riscv: disable excess harts before picking main boot hart
Harts with id greater than or equal to CONFIG_NR_CPUS need to be
disabled.  But the kernel can pick any hart as the main hart.  So,
before picking the main hart, the kernel must disable harts with ids
greater than or equal to CONFIG_NR_CPUS.

Signed-off-by: Xiang Wang <merle@hardenedlinux.org>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
[paul.walmsley@sifive.com: updated to apply; cleaned up patch
 description]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-09-20 08:36:36 -07:00
Linus Torvalds
58d4fafd0b RISC-V updates for v5.4-rc1
Add the following new features:
 
 - Generic CPU topology description support for DT-based platforms,
   including ARM64, ARM and RISC-V.
 
 - Sparsemem support
 
 - Perf callchain support
 
 - SiFive PLIC irqchip modifications, in preparation for M-mode Linux
 
 and clean up the code base:
 
 - Clean up chip-specific register (CSR) manipulation code, IPIs, TLB
   flushing, and the RISC-V CPU-local timer code
 
 - Kbuild cleanup from one of the Kbuild maintainers
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEElRDoIDdEz9/svf2Kx4+xDQu9KksFAl1/pGEACgkQx4+xDQu9
 Kkvkyw/9GulLK2yeXG8SoXiXWZAhrgUn487GM87BJXFwXkjDCRvYVk4RD8BKfOGt
 w1td6BXK5PjceH+d2m3kHa1aBQwT7sgsfQD0mBiHQ7TG+CMHMPV31eqjgIgnklEY
 f6bRl4JGokanPnLWE8tnQrMpu91kDI0XS2pnnQNNrAK3DbWocsdUIei14+auwygp
 Djbwssb8R/5RQdFO1dRa+0dWo1omzCJBgkMQBXipvD/z7u8BApioYdEUN1pEg6Yg
 YLdVtBUIF5gXIsq9jdqEZHWzvTPnq+5HZPy8pAYe/fPcnga89fCfgpWA9DfqjIEA
 bNFHJJKWc/lFAcMmXWWkYwgIbx8PUiktdv27S/DYLdyZ4SIX5YEtmdD6aK4ZStQT
 ZQcvCMDq9C3Y4s1PIwl9ORI8aVs3k1cI4Ee0xWS/x6D9h/84Ky1uBFgrPXai2G6q
 AUxnu0zWhllNahxp+rvUh0rnfHOMalaTG8eUb1GEoLzFcRhKYrKWLgFG/eBCAiit
 dofD24KpYSpZNrhZWgVUuE0Jcc58JSHp/LzDUloR2AcAvdxyQZ2Vd+vwE5BGGTzR
 t/V4zjSvndXUxFBVe28zHO2qrDzA+jUE8d+vO8w+lDGjbITYYZwIJPBL3f8Z0s6b
 wQWBwWlM4ZATqR662sBpz8P/t+RCcTMfLlatIV/07GRerjvPrd8=
 =N9WW
 -----END PGP SIGNATURE-----

Merge tag 'riscv/for-v5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Paul Walmsley:
 "Add the following new features:

   - Generic CPU topology description support for DT-based platforms,
     including ARM64, ARM and RISC-V.

   - Sparsemem support

   - Perf callchain support

   - SiFive PLIC irqchip modifications, in preparation for M-mode Linux

  and clean up the code base:

   - Clean up chip-specific register (CSR) manipulation code, IPIs, TLB
     flushing, and the RISC-V CPU-local timer code

   - Kbuild cleanup from one of the Kbuild maintainers"

[ The CPU topology parts came in through the arm64 tree with a shared
  branch   - Linus ]

* tag 'riscv/for-v5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  irqchip/sifive-plic: set max threshold for ignored handlers
  riscv: move the TLB flush logic out of line
  riscv: don't use the rdtime(h) pseudo-instructions
  riscv: cleanup riscv_cpuid_to_hartid_mask
  riscv: optimize send_ipi_single
  riscv: cleanup send_ipi_mask
  riscv: refactor the IPI code
  riscv: Add support for libdw
  riscv: Add support for perf registers sampling
  riscv: Add perf callchain support
  riscv: add arch/riscv/Kbuild
  RISC-V: Implement sparsemem
  riscv: Using CSR numbers to access CSRs
2019-09-16 15:29:34 -07:00
Paul Walmsley
474efecb65 riscv: modify the Image header to improve compatibility with the ARM64 header
Part of the intention during the definition of the RISC-V kernel image
header was to lay the groundwork for a future merge with the ARM64
image header.  One error during my original review was not noticing
that the RISC-V header's "magic" field was at a different size and
position than the ARM64's "magic" field.  If the existing ARM64 Image
header parsing code were to attempt to parse an existing RISC-V kernel
image header format, it would see a magic number 0.  This is
undesirable, since it's our intention to align as closely as possible
with the ARM64 header format.  Another problem was that the original
"res3" field was not being initialized correctly to zero.

Address these issues by creating a 32-bit "magic2" field in the RISC-V
header which matches the ARM64 "magic" field.  RISC-V binaries will
store "RSC\x05" in this field.  The intention is that the use of the
existing 64-bit "magic" field in the RISC-V header will be deprecated
over time.  Increment the minor version number of the file format to
indicate this change, and update the documentation accordingly.  Fix
the assembler directives in head.S to ensure that reserved fields are
properly zero-initialized.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reported-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Atish Patra <atish.patra@wdc.com>
Cc: Karsten Merker <merker@debian.org>
Link: https://lore.kernel.org/linux-riscv/194c2f10c9806720623430dbf0cc59a965e50448.camel@wdc.com/T/#u
Link: https://lore.kernel.org/linux-riscv/mhng-755b14c4-8f35-4079-a7ff-e421fd1b02bc@palmer-si-x1e/T/#t
2019-09-13 19:03:52 -07:00
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
Atish Patra
0f327f2aaa RISC-V: Add an Image header that boot loader can parse.
Currently, the last stage boot loaders such as U-Boot can accept only
uImage which is an unnecessary additional step in automating boot
process.

Add an image header that boot loader understands and boot Linux from
flat Image directly.

This header is based on ARM64 boot image header and provides an
opportunity to combine both ARM64 & RISC-V image headers in future.

Also make sure that PE/COFF header can co-exist in the same image so
that EFI stub can be supported for RISC-V in future. EFI specification
needs PE/COFF image header in the beginning of the kernel image in order
to load it as an EFI application. In order to support EFI stub, code0
should be replaced with "MZ" magic string and res4(at offset 0x3c)
should point to the rest of the PE/COFF header (which will be added
during EFI support).

Tested on both QEMU and HiFive Unleashed using OpenSBI + U-Boot + Linux.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Karsten Merker <merker@debian.org>
Tested-by: Karsten Merker <merker@debian.org> (QEMU+OpenSBI+U-Boot)
Tested-by: Kevin Hilman <khilman@baylibre.com> (OpenSBI + U-Boot + Linux)
[paul.walmsley@sifive.com: fixed whitespace in boot-image-header.txt;
 converted structure comment to kernel-doc format and added some detail]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-07-11 11:58:20 -07:00
Anup Patel
671f9a3e2e RISC-V: Setup initial page tables in two stages
Currently, the setup_vm() does initial page table setup in one-shot
very early before enabling MMU. Due to this, the setup_vm() has to map
all possible kernel virtual addresses since it does not know size and
location of RAM. This means we have kernel mappings for non-existent
RAM and any buggy driver (or kernel) code doing out-of-bound access
to RAM will not fault and cause underterministic behaviour.

Further, the setup_vm() creates PMD mappings (i.e. 2M mappings) for
RV64 systems. This means for PAGE_OFFSET=0xffffffe000000000 (i.e.
MAXPHYSMEM_128GB=y), the setup_vm() will require 129 pages (i.e.
516 KB) of memory for initial page tables which is never freed. The
memory required for initial page tables will further increase if
we chose a lower value of PAGE_OFFSET (e.g. 0xffffff0000000000)

This patch implements two-staged initial page table setup, as follows:
1. Early (i.e. setup_vm()): This stage maps kernel image and DTB in
a early page table (i.e. early_pg_dir). The early_pg_dir will be used
only by boot HART so it can be freed as-part of init memory free-up.
2. Final (i.e. setup_vm_final()): This stage maps all possible RAM
banks in the final page table (i.e. swapper_pg_dir). The boot HART
will start using swapper_pg_dir at the end of setup_vm_final(). All
non-boot HARTs directly use the swapper_pg_dir created by boot HART.

We have following advantages with this new approach:
1. Kernel mappings for non-existent RAM don't exists anymore.
2. Memory consumed by initial page tables is now indpendent of the
chosen PAGE_OFFSET.
3. Memory consumed by initial page tables on RV64 system is 2 pages
(i.e. 8 KB) which has significantly reduced and these pages will be
freed as-part of the init memory free-up.

The patch also provides a foundation for implementing strict kernel
mappings where we protect kernel text and rodata using PTE permissions.

Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
[paul.walmsley@sifive.com: updated to apply; fixed a checkpatch warning]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-07-09 09:08:04 -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
Palmer Dabbelt
4c3aeb82a0
RISC-V: Avoid using invalid intermediate translations
This is almost entirely a comment.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2019-05-16 20:42:13 -07:00
Anup Patel
a3182c91ef
RISC-V: Access CSRs using CSR numbers
We should prefer accessing CSRs using their CSR numbers because:
1. It compiles fine with older toolchains.
2. We can use latest CSR names in #define macro names of CSR numbers
   as-per RISC-V spec.
3. We can access newly added CSRs even if toolchain does not recognize
   newly addes CSRs by name.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-05-16 20:42:11 -07:00
Christoph Hellwig
ba9c014194
riscv: cleanup the parse_dtb calling conventions
No need to pass the hartid, and the dtb address passed is a physical
address, so don't pretend it is a kernel pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-04-25 14:51:11 -07:00
Christoph Hellwig
c637b911e0
riscv: simplify the stack pointer setup in head.S
We don't need THREAD_SIZE in asm-offsets.c as we can just calculate
the value of init_thread_union + THREAD_SIZE using cpp, just like
we do a few lines above.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-04-25 14:51:10 -07:00
Christoph Hellwig
df16c40cbf
riscv: clear all pending interrupts when booting
Just in case an old interrupt is pending make sure we clear everything
asserted before this kernel started.  Based on similar M-mode code in
opensbi.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nick Kossifidis <mick@ics.forth.gr>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-04-25 14:51:10 -07:00
Anup Patel
c0fbcd9918
RISC-V: Build flat and compressed kernel images
This patch extends Linux RISC-V build system to build and install:
Image - Flat uncompressed kernel image
Image.gz - Flat and GZip compressed kernel image

Quiet a few bootloaders (such as Uboot, UEFI, etc) are capable of
booting flat and compressed kernel images. In case of Uboot, booting
Image or Image.gz is achieved using bootm command.

The flat and uncompressed kernel image (i.e. Image) is very useful
in pre-silicon developent and testing because we can create back-door
HEX files for RAM on FPGAs from Image.

Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-11-20 05:19:09 -08:00
Atish Patra
f99fb607fb
RISC-V: Use Linux logical CPU number instead of hartid
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>
2018-10-22 17:03:37 -07:00
Zong Li
94f592f0e5
RISC-V: Add the directive for alignment of stvec's value
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: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:31 -07:00
Michael Clark
8b08f50152
Rename sbi_save to parse_dtb to improve code readability
The sbi_ prefix would seem to indicate an SBI interface, and save is not
very specific. After applying this patch, reading head.S makes more sense.

Signed-off-by: Michael Clark <michaeljclark@mac.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-02-20 10:56:26 -08:00
Christoph Hellwig
7549cdf59d
riscv: rename sptbr to satp
satp is the name used by the current privileged spec 1.10, use it
instead of the old name.  The most recent release binutils release
(2.29) doesn't know about the satp name yet, so stick to the name from
the previous privileged ISA release and comment on the fact.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:16:12 -08:00
Olof Johansson
83e7b8769a RISC-V: move empty_zero_page definition to C and export it
Needed by some modules (exported by other architectures).

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
76d2a0493a RISC-V: Init and Halt Code
This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system.  When a file was
init-related this patch contains the entire file.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:44 -07:00