Samuel Holland <samuel.holland@sifive.com> says:
Currently, RISC-V NOMMU kernels are linked at CONFIG_PAGE_OFFSET, and
since they are not relocatable, must be loaded at this address as well.
CONFIG_PAGE_OFFSET is not a user-visible Kconfig option, so its value is
not obvious, and users must patch the kernel source if they want to load
it at a different address.
Make NOMMU kernels more portable by making them relocatable by default.
This allows a single kernel binary to work when loaded at any address.
* b4-shazam-merge:
riscv: Remove CONFIG_PAGE_OFFSET
riscv: Support CONFIG_RELOCATABLE on riscv32
asm-generic: Always define Elf_Rel and Elf_Rela
riscv: Support CONFIG_RELOCATABLE on NOMMU
riscv: Allow NOMMU kernels to access all of RAM
riscv: Remove duplicate CONFIG_PAGE_OFFSET definition
Link: https://lore.kernel.org/r/20241026171441.3047904-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The current definition of CONFIG_PAGE_OFFSET is problematic for a couple
of reasons:
1) The value is misleading for normal 64-bit kernels, where it is
overridden at runtime if Sv48 or Sv39 is chosen. This is especially
the case for XIP kernels, which always use Sv39.
2) The option is not user-visible, but for NOMMU kernels it must be a
valid RAM address, and for !RELOCATABLE it must additionally be the
exact address where the kernel is loaded.
Fix both of these by removing the option.
1) For MMU kernels, drop the indirection through Kconfig. Additionally,
for XIP, drop the indirection through kernel_map.
2) For NOMMU kernels, use the user-visible physical RAM base if
provided. Otherwise, force the kernel to be relocatable.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Jesse Taube <mr.bossman075@gmail.com>
Link: https://lore.kernel.org/r/20241026171441.3047904-7-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
When adjusted to use the correctly-sized ELF types, relocate_kernel()
works on riscv32 as well. The caveat about crossing an intermediate page
table boundary does not apply to riscv32, since for Sv32 the early
kernel mapping uses only PGD entries. Since KASLR is not yet supported
on riscv32, this option is mostly useful for NOMMU.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20241026171441.3047904-6-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Move relocate_kernel() out of the CONFIG_MMU block so it can be called
from the NOMMU version of setup_vm(). Set some offsets in kernel_map so
relocate_kernel() does not need to be modified. Relocatable NOMMU
kernels can be loaded to any physical memory address; they no longer
depend on CONFIG_PAGE_OFFSET.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20241026171441.3047904-4-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
We're trying to mix non-PIC/PIE objects into the otherwise-PIE
relocatable kernels, to avoid GOT/PLT references during early boot
alternative resolution (which happens before the GOT/PLT are set up).
riscv64-unknown-linux-gnu-ld: arch/riscv/errata/sifive/errata.o: relocation R_RISCV_HI20 against `tlb_flush_all_threshold' can not be used when making a shared object; recompile with -fPIC
riscv64-unknown-linux-gnu-ld: arch/riscv/errata/thead/errata.o: relocation R_RISCV_HI20 against `riscv_cbom_block_size' can not be used when making a shared object; recompile with -fPIC
Fixes: 8dc2a7e802 ("riscv: Fix relocatable kernels with early alternatives using -fno-pie")
Link: https://lore.kernel.org/r/20250326224506.27165-2-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
riscv patches for 6.15-rc1
* A bunch of fixes:
- We were missing a secondary mmu notifier call when flushing the tlb which is required for IOMMU
- Fix ftrace panics by saving the registers as expected by ftrace
- Fix a couple of stimecmp usage related to cpu hotplug
- Fix a bunch of issues in the misaligned probing handling
* Perf improvements:
- Introduce support for runtime constant improving perf of d_hash()
- Add support for huge pfnmaps to improve tlb utilization
- Use Zawrs to improve smp_cond_load8/16() used by the queued spinlocks
* Hwprobe additions:
- Add support for Zicntr and Zihpm
- Add support for Zaamo and Zalrsc
- Add support for bfloat16 extensiosn
- Add support for Zicbom (only enabling clean and flush, not inval for security reasons)
* Misc:
- Add a kernel parameter to bypass the misaligned speed probing since we can't rely on Zicclsm
* tag 'riscv-mw1-6.15-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/alexghiti/linux: (1585 commits)
riscv: Add runtime constant support
riscv: Move nop definition to insn-def.h
Documentation/kernel-parameters: Add riscv unaligned speed parameters
riscv: Add parameter for skipping access speed tests
riscv: Fix set up of vector cpu hotplug callback
riscv: Fix set up of cpu hotplug callbacks
riscv: Change check_unaligned_access_speed_all_cpus to void
riscv: Fix check_unaligned_access_all_cpus
riscv: Fix riscv_online_cpu_vec
riscv: Annotate unaligned access init functions
KVM: riscv: selftests: Add Zaamo/Zalrsc extensions to get-reg-list test
RISC-V: KVM: Allow Zaamo/Zalrsc extensions for Guest/VM
riscv: hwprobe: export Zaamo and Zalrsc extensions
riscv: add parsing for Zaamo and Zalrsc extensions
dt-bindings: riscv: add Zaamo and Zalrsc ISA extension description
riscv: fgraph: Fix stack layout to match __arch_ftrace_regs argument of ftrace_return_to_handler
riscv: fgraph: Select HAVE_FUNCTION_GRAPH_TRACER depends on HAVE_DYNAMIC_FTRACE_WITH_ARGS
riscv: Fix missing __free_pages() in check_vector_unaligned_access()
riscv: Fix the __riscv_copy_vec_words_unaligned implementation
riscv: mm: Don't use %pK through printk
...
Andrew Jones <ajones@ventanamicro.com> says:
The first six patches of this series are fixes and cleanups of the
unaligned access speed probing code. The next patch introduces a
kernel command line option that allows the probing to be skipped.
This command line option is a different approach than Jesse's [1].
[1] takes a cpu-list for a particular speed, supporting heterogeneous
platforms. With this approach, the kernel command line should only
be used for homogeneous platforms. [1] also only allowed 'fast' and
'slow' to be selected. This parameter also supports 'unsupported',
which could be useful for testing code paths gated on that. The final
patch adds the documentation.
[1] https://lore.kernel.org/linux-riscv/20240805173816.3722002-1-jesse@rivosinc.com/
* patches from https://lore.kernel.org/r/20250304120014.143628-10-ajones@ventanamicro.com:
Documentation/kernel-parameters: Add riscv unaligned speed parameters
riscv: Add parameter for skipping access speed tests
riscv: Fix set up of vector cpu hotplug callback
riscv: Fix set up of cpu hotplug callbacks
riscv: Change check_unaligned_access_speed_all_cpus to void
riscv: Fix check_unaligned_access_all_cpus
riscv: Fix riscv_online_cpu_vec
riscv: Annotate unaligned access init functions
Link: https://lore.kernel.org/r/20250304120014.143628-10-ajones@ventanamicro.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Allow skipping scalar and vector unaligned access speed tests. This
is useful for testing alternative code paths and to skip the tests in
environments where they run too slowly. All CPUs must have the same
unaligned access speed.
The code movement is because we now need the scalar cpu hotplug
callback to always run, so we need to bring it and its supporting
functions out of CONFIG_RISCV_PROBE_UNALIGNED_ACCESS.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20250304120014.143628-17-ajones@ventanamicro.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
check_vector_unaligned_access_emulated_all_cpus(), like its name
suggests, will return true when all cpus emulate unaligned vector
accesses. If the function returned false it may have been because
vector isn't supported at all (!has_vector()) or because at least
one cpu doesn't emulate unaligned vector accesses. Since false may
be returned for two cases, checking for it isn't sufficient when
attempting to determine if we should proceed with the vector speed
check. Move the !has_vector() functionality to
check_unaligned_access_all_cpus() in order for
check_vector_unaligned_access_emulated_all_cpus() to return false
for a single case.
Fixes: e7c9d66e31 ("RISC-V: Report vector unaligned access speed hwprobe")
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20250304120014.143628-13-ajones@ventanamicro.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
This patch adds parentheses to parameters caller and callee of macros
make_call_t0 and make_call_ra. Every existing invocation of these two
macros uses a single variable for each argument, so the absence of the
parentheses seems okay. However, future invocations might use more
complex expressions as arguments. For example, a future invocation might
look like this: make_call_t0(a - b, c, call). Without parentheses in the
macro definition, the macro invocation expands to:
...
unsigned int offset = (unsigned long) c - (unsigned long) a - b;
...
which is clearly wrong.
The use of parentheses ensures arguments are correctly evaluated and
potentially saves future users of make_call_t0 and make_call_ra debugging
trouble.
Fixes: 6724a76cff ("riscv: ftrace: Reduce the detour code size to half")
Signed-off-by: Juhan Jin <juhan.jin@foxmail.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/tencent_AE90AA59903A628E87E9F80E563DA5BA5508@qq.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
The size of ®s->a0 is unknown, causing the error:
../include/linux/fortify-string.h:571:25: warning: call to
'__write_overflow_field' declared with attribute warning: detected write
beyond size of field (1st parameter); maybe use struct_group()?
[-Wattribute-warning]
Fix this by wrapping the required registers in pt_regs with
struct_group() and reference the group when doing the offending
memcpy().
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20250224-fix_ftrace_partial_regs-v1-1-54b906417e86@rivosinc.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
