linux.git/arch/riscv/kernel/setup.c, branch v5.14

riscv: Fix a number of free'd resources in init_resources()

2021-08-20T17:15:51+00:00

Function init_resources() allocates a boot memory block to hold an array of
resources which it adds to iomem_resource. The array is filled in from its
end and the function then attempts to free any unused memory at the
beginning. The problem is that size of the unused memory is incorrectly
calculated and this can result in releasing memory which is in use by
active resources. Their data then gets corrupted later when the memory is
reused by a different part of the system.

Fix the size of the released memory to correctly match the number of unused
resource entries.

Fixes: ffe0e5261268 ("RISC-V: Improve init_resources()")
Signed-off-by: Petr Pavlu 
Reviewed-by: Sunil V L 
Acked-by: Nick Kossifidis 
Tested-by: Sunil V L 
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt

Merge tag 'riscv-for-linus-5.14-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2021-07-09T17:36:29+00:00

Pull RISC-V updates from Palmer Dabbelt:
 "We have a handful of new features for 5.14:

   - Support for transparent huge pages.

   - Support for generic PCI resources mapping.

   - Support for the mem= kernel parameter.

   - Support for KFENCE.

   - A handful of fixes to avoid W+X mappings in the kernel.

   - Support for VMAP_STACK based overflow detection.

   - An optimized copy_{to,from}_user"

* tag 'riscv-for-linus-5.14-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (37 commits)
  riscv: xip: Fix duplicate included asm/pgtable.h
  riscv: Fix PTDUMP output now BPF region moved back to module region
  riscv: __asm_copy_to-from_user: Optimize unaligned memory access and pipeline stall
  riscv: add VMAP_STACK overflow detection
  riscv: ptrace: add argn syntax
  riscv: mm: fix build errors caused by mk_pmd()
  riscv: Introduce structure that group all variables regarding kernel mapping
  riscv: Map the kernel with correct permissions the first time
  riscv: Introduce set_kernel_memory helper
  riscv: Enable KFENCE for riscv64
  RISC-V: Use asm-generic for {in,out}{bwlq}
  riscv: add ASID-based tlbflushing methods
  riscv: pass the mm_struct to __sbi_tlb_flush_range
  riscv: Add mem kernel parameter support
  riscv: Simplify xip and !xip kernel address conversion macros
  riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED
  riscv: Only initialize swiotlb when necessary
  riscv: fix typo in init.c
  riscv: Cleanup unused functions
  riscv: mm: Use better bitmap_zalloc()
  ...

riscv: convert to setup_initial_init_mm()

2021-07-08T18:48:21+00:00

Use setup_initial_init_mm() helper to simplify code.

Link: https://lkml.kernel.org/r/20210608083418.137226-13-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Acked-by: Palmer Dabbelt 
Cc: Paul Walmsley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'riscv-wx-mappings' into for-next

2021-07-01T04:50:32+00:00

This contains both the short-term fix for the W+X boot mappings and the
larger cleanup.

* riscv-wx-mappings:
  riscv: Map the kernel with correct permissions the first time
  riscv: Introduce set_kernel_memory helper
  riscv: Simplify xip and !xip kernel address conversion macros
  riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED
  riscv: mm: Fix W+X mappings at boot

riscv: Map the kernel with correct permissions the first time

2021-07-01T04:18:58+00:00

For 64-bit kernels, we map all the kernel with write and execute
permissions and afterwards remove writability from text and executability
from data.

For 32-bit kernels, the kernel mapping resides in the linear mapping, so we
map all the linear mapping as writable and executable and afterwards we
remove those properties for unused memory and kernel mapping as
described above.

Change this behavior to directly map the kernel with correct permissions
and avoid going through the whole mapping to fix the permissions.

At the same time, this fixes an issue introduced by commit 2bfc6cd81bd1
("riscv: Move kernel mapping outside of linear mapping") as reported
here https://github.com/starfive-tech/linux/issues/17.

Signed-off-by: Alexandre Ghiti 
Reviewed-by: Anup Patel 
Signed-off-by: Palmer Dabbelt

riscv: Only initialize swiotlb when necessary

2021-06-11T20:42:26+00:00

The SWIOTLB buffer is not needed unless the physical address space
is beyond the limit of dma, only initialize swiotlb when swiotlb_force
is true or not all system memory is DMA-able.

Also move the swiotlb_init() into mem_init().

Signed-off-by: Kefeng Wang 
Signed-off-by: Palmer Dabbelt

RISC-V: Fix memblock_free() usages in init_resources()

2021-06-02T04:16:42+00:00

`memblock_free()` takes a physical address as its first argument.
Fix the wrong usages in `init_resources()`.

Fixes: ffe0e526126884cf036a6f724220f1f9b4094fd2 ("RISC-V: Improve init_resources()")
Fixes: 797f0375dd2ef5cdc68ac23450cbae9a5c67a74e ("RISC-V: Do not allocate memblock while iterating reserved memblocks")
Signed-off-by: Wende Tan 
Signed-off-by: Palmer Dabbelt

riscv: Move setup_bootmem into paging_init

2021-05-26T05:50:50+00:00

Make setup_bootmem() static.

Signed-off-by: Kefeng Wang 
Signed-off-by: Palmer Dabbelt

riscv: Consistify protect_kernel_linear_mapping_text_rodata() use

2021-05-06T16:40:15+00:00

The various uses of protect_kernel_linear_mapping_text_rodata() are
not consistent:
  - Its definition depends on "64BIT && !XIP_KERNEL",
  - Its forward declaration depends on MMU,
  - Its single caller depends on "STRICT_KERNEL_RWX && 64BIT && MMU &&
    !XIP_KERNEL".

Fix this by settling on the dependencies of the caller, which can be
simplified as STRICT_KERNEL_RWX depends on "MMU && !XIP_KERNEL".
Provide a dummy definition, as the caller is protected by
"IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)" instead of "#ifdef
CONFIG_STRICT_KERNEL_RWX".

Signed-off-by: Geert Uytterhoeven 
Tested-by: Alexandre Ghiti 
Signed-off-by: Palmer Dabbelt

RISC-V: enable XIP

2021-04-26T15:31:28+00:00

Introduce XIP (eXecute In Place) support for RISC-V platforms.
It allows code to be executed directly from non-volatile storage
directly addressable by the CPU, such as QSPI NOR flash which can
be found on many RISC-V platforms. This makes way for significant
optimization of RAM footprint. The XIP kernel is not compressed
since it has to run directly from flash, so it will occupy more
space on the non-volatile storage. The physical flash address used
to link the kernel object files and for storing it has to be known
at compile time and is represented by a Kconfig option.

XIP on RISC-V will for the time being only work on MMU-enabled
kernels.

Signed-off-by: Vitaly Wool 
[Alex: Rebase on top of "Move kernel mapping outside the linear mapping" ]
Signed-off-by: Alexandre Ghiti 
[Palmer: disable XIP for allyesconfig]
Signed-off-by: Palmer Dabbelt