13 Commits

Author SHA1 Message Date
Linus Torvalds
568d850e3c RISC-V additional updates for v5.4-rc1
Some additional RISC-V updates for v5.4-rc1.  This includes one
 significant fix:
 
 - Prevent interrupts from being unconditionally re-enabled during
   exception handling if they were disabled in the context in which the
   exception occurred
 
 Also a few other fixes:
 
 - Fix a build error when sparse memory support is manually enabled
 
 - Prevent CPUs beyond CONFIG_NR_CPUS from being enabled in early boot
 
 And a few minor improvements:
 
 - DT improvements: in the FU540 SoC DT files, improve U-Boot
   compatibility by adding an "ethernet0" alias, drop an unnecessary
   property from the DT files, and add support for the PWM device
 
 - KVM preparation: add a KVM-related macro for future RISC-V KVM
   support, and export some symbols required to build KVM support as
   modules
 
 - defconfig additions: build more drivers by default for QEMU
   configurations
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Merge tag 'riscv/for-v5.4-rc1-b' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull more RISC-V updates from Paul Walmsley:
 "Some additional RISC-V updates.

  This includes one significant fix:

   - Prevent interrupts from being unconditionally re-enabled during
     exception handling if they were disabled in the context in which
     the exception occurred

  Also a few other fixes:

   - Fix a build error when sparse memory support is manually enabled

   - Prevent CPUs beyond CONFIG_NR_CPUS from being enabled in early boot

  And a few minor improvements:

   - DT improvements: in the FU540 SoC DT files, improve U-Boot
     compatibility by adding an "ethernet0" alias, drop an unnecessary
     property from the DT files, and add support for the PWM device

   - KVM preparation: add a KVM-related macro for future RISC-V KVM
     support, and export some symbols required to build KVM support as
     modules

   - defconfig additions: build more drivers by default for QEMU
     configurations"

* tag 'riscv/for-v5.4-rc1-b' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Avoid interrupts being erroneously enabled in handle_exception()
  riscv: dts: sifive: Drop "clock-frequency" property of cpu nodes
  riscv: dts: sifive: Add ethernet0 to the aliases node
  RISC-V: Export kernel symbols for kvm
  KVM: RISC-V: Add KVM_REG_RISCV for ONE_REG interface
  arch/riscv: disable excess harts before picking main boot hart
  RISC-V: Enable VIRTIO drivers in RV64 and RV32 defconfig
  RISC-V: Fix building error when CONFIG_SPARSEMEM_MANUAL=y
  riscv: dts: Add DT support for SiFive FU540 PWM driver
2019-09-27 13:08:36 -07:00
Mike Rapoport
782de70c42 mm: consolidate pgtable_cache_init() and pgd_cache_init()
Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem
cache for page table allocations on several architectures that do not use
PAGE_SIZE tables for one or more levels of the page table hierarchy.

Most architectures do not implement these functions and use __weak default
NOP implementation of pgd_cache_init().  Since there is no such default
for pgtable_cache_init(), its empty stub is duplicated among most
architectures.

Rename the definitions of pgd_cache_init() to pgtable_cache_init() and
drop empty stubs of pgtable_cache_init().

Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Will Deacon <will@kernel.org>		[arm64]
Acked-by: Thomas Gleixner <tglx@linutronix.de>	[x86]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:09 -07:00
Greentime Hu
b6f2b2e600 RISC-V: Fix building error when CONFIG_SPARSEMEM_MANUAL=y
Fix a build break by adjusting where VMALLOC_* and FIXADDR_* are
defined.  This fixes the definition of the MEMMAP_* macros.

  CC      init/main.o
In file included from ./include/linux/mm.h:99,
                 from ./include/linux/ring_buffer.h:5,
                 from ./include/linux/trace_events.h:6,
                 from ./include/trace/syscall.h:7,
                 from ./include/linux/syscalls.h:85,
                 from init/main.c:21:
./arch/riscv/include/asm/pgtable.h: In function ‘pmd_page’:
./arch/riscv/include/asm/pgtable.h:95:24: error: ‘VMALLOC_START’ undeclared (first use in this function); did you mean ‘VMEMMAP_START’?
 #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE)
                        ^~~~~~~~~~~~~

Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem")
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
[paul.walmsley@sifive.com: minor patch description fix]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-09-19 05:44:34 -07:00
Logan Gunthorpe
d95f1a542c RISC-V: Implement sparsemem
Implement sparsemem support for Risc-v which helps pave the
way for memory hotplug and eventually P2P support.

Introduce Kconfig options for virtual and physical address bits which
are used to calculate the size of the vmemmap and set the
MAX_PHYSMEM_BITS.

The vmemmap is located directly before the VMALLOC region and sized
such that we can allocate enough pages to populate all the virtual
address space in the system (similar to the way it's done in arm64).

During initialization, call memblocks_present() and sparse_init(),
and provide a stub for vmemmap_populate() (all of which is similar to
arm64).

[greentime.hu@sifive.com: fixed pfn_valid, FIXADDR_TOP and fixed a bug
 rebasing onto v5.3]
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andrew Waterman <andrew@sifive.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Michael Clark <michaeljclark@mac.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Zong Li <zong@andestech.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
[paul.walmsley@sifive.com: updated to apply; minor commit message
 reformat]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-30 11:10:37 -07:00
Anup Patel
a256f2e329 RISC-V: Fix FIXMAP area corruption on RV32 systems
Currently, various virtual memory areas of Linux RISC-V are organized
in increasing order of their virtual addresses is as follows:
1. User space area (This is lowest area and starts at 0x0)
2. FIXMAP area
3. VMALLOC area
4. Kernel area (This is highest area and starts at PAGE_OFFSET)

The maximum size of user space aread is represented by TASK_SIZE.

On RV32 systems, TASK_SIZE is defined as VMALLOC_START which causes the
user space area to overlap the FIXMAP area. This allows user space apps
to potentially corrupt the FIXMAP area and kernel OF APIs will crash
whenever they access corrupted FDT in the FIXMAP area.

On RV64 systems, TASK_SIZE is set to fixed 256GB and no other areas
happen to overlap so we don't see any FIXMAP area corruptions.

This patch fixes FIXMAP area corruption on RV32 systems by setting
TASK_SIZE to FIXADDR_START. We also move FIXADDR_TOP, FIXADDR_SIZE,
and FIXADDR_START defines to asm/pgtable.h so that we can avoid cyclic
header includes.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-28 15:30:12 -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
Alexandre Ghiti
9e953cda5c riscv: Introduce huge page support for 32/64bit kernel
This patch implements both 4MB huge page support for 32bit kernel
and 2MB/1GB huge pages support for 64bit kernel.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-07-03 15:23:38 -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
Anup Patel
0651c263c8 RISC-V: Move setup_bootmem() to mm/init.c
The setup_bootmem() mainly populates memblocks and does early memory
reservations. The right location for this function is mm/init.c. It
calls setup_initrd() so we move that as well.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
2019-02-21 11:25:49 +05:30
Stefan O'Rear
e3613bb8af
riscv: Add pte bit to distinguish swap from invalid
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: Stefan O'Rear <sorear2@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11 15:24:45 -08:00
Christoph Hellwig
c163fb38ca
riscv: remove CONFIG_MMU ifdefs
The RISC-V port doesn't suport a nommu mode, so there is no reason
to provide some code only under a CONFIG_MMU ifdef.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-07 15:14:39 -08:00
Andrew Waterman
08f051eda3 RISC-V: Flush I$ when making a dirty page executable
The RISC-V ISA allows for instruction caches that are not coherent WRT
stores, even on a single hart.  As a result, we need to explicitly flush
the instruction cache whenever marking a dirty page as executable in
order to preserve the correct system behavior.

Local instruction caches aren't that scary (our implementations actually
flush the cache, but RISC-V is defined to allow higher-performance
implementations to exist), but RISC-V defines no way to perform an
instruction cache shootdown.  When explicitly asked to do so we can
shoot down remote instruction caches via an IPI, but this is a bit on
the slow side.

Instead of requiring an IPI to all harts whenever marking a page as
executable, we simply flush the currently running harts.  In order to
maintain correct behavior, we additionally mark every other hart as
needing a deferred instruction cache which will be taken before anything
runs on it.

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 12:58:25 -08:00
Palmer Dabbelt
07037db5d4 RISC-V: Paging and MMU
This patch contains code to manage the RISC-V MMU, including definitions
of the page tables and the page walking code.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:47 -07:00