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Author SHA1 Message Date
Samuel Holland
bfd6fc5d80
riscv: Fix early alternative patching
Now that the text to patch is located using a relative offset from the
alternative entry, the text address should be computed without applying
the kernel mapping offset, both before and after VM setup.

Fixes: 8d23e94a44 ("riscv: switch to relative alternative entries")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230212021534.59121-2-samuel@sholland.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-14 16:10:35 -08:00
Conor Dooley
5f365c133b
RISC-V: re-order Kconfig selects alphanumerically
Selects should be sorted alphanumerically, and were tidied up originally
by Palmer in commit e8c7ef7d58 ("RISC-V: Sort select statements
alphanumerically") since then, things have gotten out of order again.
Fish RMK's original script out of commit b1b3f49ce4 ("ARM: config:
sort select statements alphanumerically") and do some spring cleaning.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20221219172836.134709-1-conor@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-14 16:00:03 -08:00
Conor Dooley
2a5303b499
Documentation: riscv: fix insufficient list item indent
When adding the ISA string ordering rules, I didn't sufficiently indent
one of the list items.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/linux-doc/202301300743.bp7Dpazv-lkp@intel.com/
Fixes: f07b2b3f9d ("Documentation: riscv: add a section about ISA string ordering in /proc/cpuinfo")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20230129235701.2393241-1-conor@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-14 16:00:02 -08:00
Palmer Dabbelt
9daca9a5b9
Merge patch series "riscv: improve boot time isa extensions handling"
Jisheng Zhang <jszhang@kernel.org> says:

Generally, riscv ISA extensions are fixed for any specific hardware
platform, so a hart's features won't change after booting, this
chacteristic makes it straightforward to use a static branch to check
a specific ISA extension is supported or not to optimize performance.

However, some ISA extensions such as SVPBMT and ZICBOM are handled
via. the alternative sequences.

Basically, for ease of maintenance, we prefer to use static branches
in C code, but recently, Samuel found that the static branch usage in
cpu_relax() breaks building with CONFIG_CC_OPTIMIZE_FOR_SIZE[1]. As
Samuel pointed out, "Having a static branch in cpu_relax() is
problematic because that function is widely inlined, including in some
quite complex functions like in the VDSO. A quick measurement shows
this static branch is responsible by itself for around 40% of the jump
table."

Samuel's findings pointed out one of a few downsides of static branches
usage in C code to handle ISA extensions detected at boot time:
static branch's metadata in the __jump_table section, which is not
discarded after ISA extensions are finalized, wastes some space.

I want to try to solve the issue for all possible dynamic handling of
ISA extensions at boot time. Inspired by Mark[2], this patch introduces
riscv_has_extension_*() helpers, which work like static branches but
are patched using alternatives, thus the metadata can be freed after
patching.

[1]https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/
[2]https://lore.kernel.org/linux-arm-kernel/20220912162210.3626215-8-mark.rutland@arm.com/
[3]https://lore.kernel.org/linux-riscv/20221130225614.1594256-1-heiko@sntech.de/

* b4-shazam-merge:
  riscv: remove riscv_isa_ext_keys[] array and related usage
  riscv: KVM: Switch has_svinval() to riscv_has_extension_unlikely()
  riscv: cpu_relax: switch to riscv_has_extension_likely()
  riscv: alternative: patch alternatives in the vDSO
  riscv: switch to relative alternative entries
  riscv: module: Add ADD16 and SUB16 rela types
  riscv: module: move find_section to module.h
  riscv: fpu: switch has_fpu() to riscv_has_extension_likely()
  riscv: introduce riscv_has_extension_[un]likely()
  riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensions
  riscv: hwcap: make ISA extension ids can be used in asm
  riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier
  riscv: move riscv_noncoherent_supported() out of ZICBOM probe

Link: https://lore.kernel.org/r/20230128172856.3814-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-01 19:36:25 -08:00
Jisheng Zhang
03966594e1
riscv: remove riscv_isa_ext_keys[] array and related usage
All users have switched to riscv_has_extension_*, remove unused
definitions, vars and related setting code.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230128172856.3814-14-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:45 -08:00
Andrew Jones
e8ad17d2b5
riscv: KVM: Switch has_svinval() to riscv_has_extension_unlikely()
Switch has_svinval() from static branch to the new helper
riscv_has_extension_unlikely().

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20230128172856.3814-13-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:44 -08:00
Jisheng Zhang
95bc69a47b
riscv: cpu_relax: switch to riscv_has_extension_likely()
Switch cpu_relax() from static branch to the new helper
riscv_has_extension_likely()

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-12-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:43 -08:00
Jisheng Zhang
cabfd146b3
riscv: alternative: patch alternatives in the vDSO
Make it possible to use alternatives in the vDSO, so that better
implementations can be used if possible.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230128172856.3814-11-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:42 -08:00
Jisheng Zhang
8d23e94a44
riscv: switch to relative alternative entries
Instead of using absolute addresses for both the old instrucions and
the alternative instructions, use offsets relative to the alt_entry
values. So this not only cuts the size of the alternative entry, but
also meets the prerequisite for patching alternatives in the vDSO,
since absolute alternative entries are subject to dynamic relocation,
which is incompatible with the vDSO building.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-10-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:41 -08:00
Andrew Jones
1bc400ffb5
riscv: module: Add ADD16 and SUB16 rela types
To prepare for 16-bit relocation types to be emitted in alternatives
add support for ADD16 and SUB16.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-9-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:40 -08:00
Jisheng Zhang
e0c267e03b
riscv: module: move find_section to module.h
Move find_section() to module.h so that the implementation can be shared
by the alternatives code. This will allow us to use alternatives in
the vdso.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20230128172856.3814-8-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:39 -08:00
Jisheng Zhang
702e64550b
riscv: fpu: switch has_fpu() to riscv_has_extension_likely()
Switch has_fpu() from static branch to the new helper
riscv_has_extension_likely().

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-7-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:38 -08:00
Jisheng Zhang
bdda5d554e
riscv: introduce riscv_has_extension_[un]likely()
Generally, riscv ISA extensions are fixed for any specific hardware
platform, so a hart's features won't change after booting. This
chacteristic makes it straightforward to use a static branch to check
if a specific ISA extension is supported or not to optimize
performance.

However, some ISA extensions such as SVPBMT and ZICBOM are handled
via. the alternative sequences.

Basically, for ease of maintenance, we prefer to use static branches
in C code, but recently, Samuel found that the static branch usage in
cpu_relax() breaks building with CONFIG_CC_OPTIMIZE_FOR_SIZE[1]. As
Samuel pointed out, "Having a static branch in cpu_relax() is
problematic because that function is widely inlined, including in some
quite complex functions like in the VDSO. A quick measurement shows
this static branch is responsible by itself for around 40% of the jump
table."

Samuel's findings pointed out one of a few downsides of static branches
usage in C code to handle ISA extensions detected at boot time:
static branch's metadata in the __jump_table section, which is not
discarded after ISA extensions are finalized, wastes some space.

I want to try to solve the issue for all possible dynamic handling of
ISA extensions at boot time. Inspired by Mark[2], this patch introduces
riscv_has_extension_*() helpers, which work like static branches but
are patched using alternatives, thus the metadata can be freed after
patching.

Link: https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ [1]
Link: https://lore.kernel.org/linux-arm-kernel/20220912162210.3626215-8-mark.rutland@arm.com/ [2]
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-6-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:37 -08:00
Jisheng Zhang
4bf8860760
riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensions
riscv_cpufeature_patch_func() currently only scans a limited set of
cpufeatures, explicitly defined with macros. Extend it to probe for all
ISA extensions.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-5-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:36 -08:00
Jisheng Zhang
d8a3d8a752
riscv: hwcap: make ISA extension ids can be used in asm
So that ISA extensions can be used in assembly files, convert the
multi-letter RISC-V ISA extension IDs enums to macros.
In order to make them visible, move the #ifndef __ASSEMBLY__ guard
to a later point in the header

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-4-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:35 -08:00
Jisheng Zhang
191b27c7c0
riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier
Currently riscv_cpufeature_patch_func() does nothing at the
RISCV_ALTERNATIVES_EARLY_BOOT stage. Add a check to detect whether we
are in this stage and exit early. This will allow us to use
riscv_cpufeature_patch_func() for scanning of all ISA extensions.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-3-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:34 -08:00
Jisheng Zhang
abcc445acd
riscv: move riscv_noncoherent_supported() out of ZICBOM probe
It's a bit weird to call riscv_noncoherent_supported() each time when
insmoding a module. Move the calling out of feature patch func.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-2-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 23:29:33 -08:00
Palmer Dabbelt
75ab93a244
Merge patch series "Zbb string optimizations"
Heiko Stuebner <heiko@sntech.de> says:

From: Heiko Stuebner <heiko.stuebner@vrull.eu>

This series still tries to allow optimized string functions for specific
extensions. The last approach of using an inline base function to hold
the alternative calls did cause some issues in a number of places

So instead of that we're now just using an alternative j at the beginning
of the generic function to jump to a separate place inside the function
itself.

* b4-shazam-merge:
  RISC-V: add zbb support to string functions
  RISC-V: add infrastructure to allow different str* implementations

Link: https://lore.kernel.org/r/20230113212301.3534711-1-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 11:43:27 -08:00
Heiko Stuebner
b6fcdb191e
RISC-V: add zbb support to string functions
Add handling for ZBB extension and add support for using it as a
variant for optimized string functions.

Support for the Zbb-str-variants is limited to the GNU-assembler
for now, as LLVM has not yet acquired the functionality to
selectively change the arch option in assembler code.
This is still under review at
    https://reviews.llvm.org/D123515

Co-developed-by: Christoph Muellner <christoph.muellner@vrull.eu>
Signed-off-by: Christoph Muellner <christoph.muellner@vrull.eu>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230113212301.3534711-3-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 11:43:24 -08:00
Heiko Stuebner
56e0790c7f
RISC-V: add infrastructure to allow different str* implementations
Depending on supported extensions on specific RISC-V cores,
optimized str* functions might make sense.

This adds basic infrastructure to allow patching the function calls
via alternatives later on.

The Linux kernel provides standard implementations for string functions
but when architectures want to extend them, they need to provide their
own.

The added generic string functions are done in assembler (taken from
disassembling the main-kernel functions for now) to allow us to control
the used registers and extend them with optimized variants.

This doesn't override the compiler's use of builtin replacements. So still
first of all the compiler will select if a builtin will be better suitable
i.e. for known strings. For all regular cases we will want to later
select possible optimized variants and in the worst case fall back to the
generic implemention added with this change.

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230113212301.3534711-2-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-31 11:43:23 -08:00
Heiko Stuebner
285b6a18da
RISC-V: Fix do_notify_resume / do_work_pending prototype
Commit b0f4c74ead ("RISC-V: Fix unannoted hardirqs-on in return to
userspace slow-path") renamed the do_notify_resume function to
do_work_pending but did not change the prototype in signal.h
Do that now, as the original function does not exist anymore.

Fixes: b0f4c74ead ("RISC-V: Fix unannoted hardirqs-on in return to userspace slow-path")
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230118142252.337103-1-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-24 22:13:15 -08:00
Jisheng Zhang
9d5567ccf9
riscv: fix jal offsets in patched alternatives
Alternatives live in a different section, so offsets used by jal
instruction will point to wrong locations after the patch got applied.

Similar to arm64, adjust the location to consider that offset.

Co-developed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20230113212205.3534622-1-heiko@sntech.de
Fixes: 27c653c065 ("RISC-V: fix auipc-jalr addresses in patched alternatives")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-24 18:43:56 -08:00
Geert Uytterhoeven
451fb217cd
RISC-V: Kconfig: Remove trailing whitespace
Remove trailing whitespace that hurts my eyes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/080aa959266ad842a8e7efca7111f1350c6a065a.1673424858.git.geert+renesas@glider.be
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-24 18:09:12 -08:00
Guo Ren
6be1ff430d
riscv: pgtable: Fixup comment for KERN_VIRT_SIZE
KERN_VIRT_SIZE is 1/4 of the entries of the page global directory,
not half.

Fixes: f7ae02333d ("riscv: Move KASAN mapping next to the kernel mapping")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230110080419.931185-1-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-24 16:19:07 -08:00
Palmer Dabbelt
61a9b71290
Merge patch series "Putting some basic order on isa extension lists"
This cleans up the ISA string handling to more closely match a version
of the ISA spec.  This is visible in /proc/cpuinfo and the ordering
changes may break something in userspace, but these orderings have
changed before without issues so with any luck that's still the case.

This also adds documentation so userspace has a better idea of what is
intended when it comes to compatibility for /proc/cpuinfo, which should
help everyone as this will likely keep changing.

* b4-shazam-merge:
  Documentation: riscv: add a section about ISA string ordering in /proc/cpuinfo
  RISC-V: resort all extensions in consistent orders
  RISC-V: clarify ISA string ordering rules in cpu.c

Link: https://lore.kernel.org/r/20221205144525.2148448-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-19 16:41:04 -08:00
Conor Dooley
f07b2b3f9d
Documentation: riscv: add a section about ISA string ordering in /proc/cpuinfo
The RISC-V specs are permissive in what they allow as the ISA string,
but how we output this to userspace in /proc/cpuinfo is quasi uABI.

Formalise this as part of the uABI, by documenting the list of rules
we use at this point in time.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221205144525.2148448-4-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-17 22:05:33 -08:00
Conor Dooley
80c200b34e
RISC-V: resort all extensions in consistent orders
Ordering between each and every list of extensions is wildly
inconsistent. Per discussion on the lists pick the following policy:

- The array defining order in /proc/cpuinfo follows a narrow
  interpretation of the ISA specifications, described in a comment
  immediately presiding it.

- All other lists of extensions are sorted alphabetically.

This will hopefully allow for easier review & future additions, and
reduce conflicts between patchsets as the number of extensions grows.

Link: https://lore.kernel.org/all/20221129144742.2935581-2-conor.dooley@microchip.com/
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221205144525.2148448-3-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-17 22:05:32 -08:00
Conor Dooley
99e2266f24
RISC-V: clarify ISA string ordering rules in cpu.c
While the current list of rules may have been accurate when created
it now lacks some clarity in the face of isa-manual updates. Instead of
trying to continuously align this rule-set with the one in the
specifications, change the role of this comment.

This particular comment is important, as the array it "decorates"
defines the order in which the ISA string appears to userspace in
/proc/cpuinfo.

Re-jig and strengthen the wording to provide contributors with a set
order in which to add entries & note why this particular struct needs
more attention than others.

While in the area, add some whitespace and tweak some wording for
readability's sake.

Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221205144525.2148448-2-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-17 22:05:31 -08:00
Palmer Dabbelt
ae4d39f753
Merge patch "RISC-V: fix incorrect type of ARCH_CANAAN_K210_DTB_SOURCE"
This fixes an issue with the K210 Kconfig cleanups, I'm just merging it
from that to avoid crossing the streams.

* b4-shazam-merge:
  RISC-V: fix incorrect type of ARCH_CANAAN_K210_DTB_SOURCE

Link: https://lore.kernel.org/r/20230111104848.2088516-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-17 20:14:59 -08:00
Conor Dooley
6fb4c59398
RISC-V: fix incorrect type of ARCH_CANAAN_K210_DTB_SOURCE
When adding the ARCH_ symbol for the builtin K210 dtb, I erroneously
used the bool type for something that is quite obviously a string.
Unfortunately, there is no such thing as "def_string", but in this case
we can use "default" to propagate the value of
SOC_CANAAN_K210_DTB_SOURCE to ARCH_CANAAN_K210_DTB_SOURCE.
ARCH_CANAAN_K210_DTB_SOURCE is not user selectable, so using
olddefconfig etc will update ARCH_CANAAN_K210_DTB_SOURCE to reflect any
changes made to SOC_CANAAN_K210_DTB_SOURCE.

Fixes: fc43211939 ("RISC-V: kconfig.socs: convert usage of SOC_CANAAN to ARCH_CANAAN")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/all/20230111104848.2088516-1-conor.dooley@microchip.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-01-17 20:14:11 -08:00
Palmer Dabbelt
b07de94d45
Merge patch series "Allow calls in alternatives"
Heiko Stuebner <heiko@sntech.de> says:

From: Heiko Stuebner <heiko.stuebner@vrull.eu>

This series is split out of my work on optimizing string functions
and provides the basics to:

- actually allowing calls in alternatives
  Function calls use auipc + jalr to reach those 32bit relative
  addresses but when they're compiled the offset will be wrong
  as alternatives live in a different section. So when the patch
  gets applied the address will point to the wrong location.

  So similar to arm64 the target addresses need to be updated.

  This is probably also helpful for other things needing more
  complex code in alternatives.

For v2 I got into some sort of cleanup spree for the general instruction
parsing that already existed. A number of places do their own
instruction parsing and I tried consolidating some of them.

Noteable, the kvm parts still do, but I had to stop somewhere :-)

* b4-shazam-merge:
  RISC-V: fix auipc-jalr addresses in patched alternatives
  RISC-V: add helpers for handling immediates in U-type and I-type pairs
  RISC-V: add rd reg parsing to insn.h header
  RISC-V: add U-type imm parsing to insn.h header
  RISC-V: kprobes: use central defined funct3 constants
  RISC-V: rename parse_asm.h to insn.h
  RISC-V: Move riscv_insn_is_* macros into a common header
  RISC-V: add auipc elements to parse_asm header
  RISC-V: add ebreak instructions to definitions
  RISC-V: detach funct-values from their offset
  RISC-V: add prefix to all constants/macros in parse_asm.h
  RISC-V: fix funct4 definition for c.jalr in parse_asm.h

Link: https://lore.kernel.org/r/20221223221332.4127602-1-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 07:01:01 -08:00
Heiko Stuebner
27c653c065
RISC-V: fix auipc-jalr addresses in patched alternatives
Alternatives live in a different section, so addresses used by call
functions will point to wrong locations after the patch got applied.

Similar to arm64, adjust the location to consider that offset.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-13-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:52 -08:00
Heiko Stuebner
47f05757d3
RISC-V: add helpers for handling immediates in U-type and I-type pairs
Used together U-type and I-type instructions can for example be used to
generate bigger jumps (i.e. in auipc+jalr pairs) by splitting the value
into an upper immediate (i.e. auipc) and a 12bit immediate (i.e. jalr).

Due to both immediates being considered signed this creates some corner
cases, so add some helper to prevent this from getting duplicated in
different places.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-12-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:51 -08:00
Heiko Stuebner
088ec01fce
RISC-V: add rd reg parsing to insn.h header
Add a macro to allow parsing of the rd register from an instruction.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-11-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:50 -08:00
Heiko Stuebner
8963d62240
RISC-V: add U-type imm parsing to insn.h header
Similar to other existing types, allow extracting the immediate
for a U-type instruction.

U-type immediates are special in that regard, that the value
in the instruction in bits [31:12] already represents the same
bits of the immediate, so no shifting is required.

U-type immediates are for example used in the auipc instruction,
so these constants make it easier to parse such instructions.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-10-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:49 -08:00
Heiko Stuebner
debe28d0a5
RISC-V: kprobes: use central defined funct3 constants
Don't redefine values that are already available in the central header
asm/insn.h . Use the values from there instead.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-9-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:48 -08:00
Heiko Stuebner
c9c1af3f18
RISC-V: rename parse_asm.h to insn.h
The current parse_asm header should become a more centralized place
for everything concerning parsing and constructing instructions.

We already have a header insn-def.h similar to aarch64, so rename
parse_asm.h to insn.h (again similar to aarch64) to show that it's
meant for more than simple instruction parsing.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-8-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:47 -08:00
Heiko Stuebner
ec5f908775
RISC-V: Move riscv_insn_is_* macros into a common header
Right now the riscv kernel has (at least) two independent sets
of functions to check if an encoded instruction is of a specific
type. One in kgdb and one kprobes simulate-insn code.

More parts of the kernel will probably need this in the future,
so instead of allowing this duplication to go on further,
move macros that do the function declaration in a common header,
similar to at least aarch64.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-7-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:46 -08:00
Heiko Stuebner
cde4a69302
RISC-V: add auipc elements to parse_asm header
Instruction parsing should not be done in individual code, but instead
supported by central

Right now kgdb and kprobes parse instructions and at least kprobes (and
the upcoming auipc+jalr alternative fixer-function) need the auipc
instruction.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-6-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:45 -08:00
Heiko Stuebner
2621cac76f
RISC-V: add ebreak instructions to definitions
kprobes need to match ebreak instructions, so add the necessary
data to enable us to centralize that functionality.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-5-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:44 -08:00
Heiko Stuebner
33e41480b2
RISC-V: detach funct-values from their offset
Rather than defining funct3, funct4, etc values pre-shifted to their
target-position in an instruction, define the values themselves and
only shift them where needed.

This allows using these funct-values in other places as well, for example
when decoding functions.

At the same time also reduces the use of magic numbers, one would need
a spec manual to understand.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-4-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:43 -08:00
Heiko Stuebner
bf0cc402d7
RISC-V: add prefix to all constants/macros in parse_asm.h
Some of the constants and macros already have suitable RV_, RVG_ or
RVC_ prefixes.

Extend this to the rest of the file as well, as we want to use these
things in a broader scope soon.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-3-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:42 -08:00
Heiko Stuebner
a3775634f6
RISC-V: fix funct4 definition for c.jalr in parse_asm.h
The opcode definition for c.jalr is
    c.jalr c_rs1_n0  1..0=2 15..13=4 12=1 6..2=0

This means funct4 consisting of bit [15:12] is 1001b, so the value is 0x9.

Fixes: edde5584c7 ("riscv: Add SW single-step support for KDB")
Reported-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-2-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-29 06:59:41 -08:00
Palmer Dabbelt
4e1ce304ea SOC_FOO to ARCH_FOO conversion for RISC-V
RISC-V is an outlier in using SOC_FOO rather than ARCH_FOO for
 vendors/micro-archs. SOC_FOO may make more sense (I personally prefer
 it), but the rest of the "world" uses ARCH_FOO. That'd be fine, with
 with an increasing number of existing SoC vendors moving to RISC-V,
 unifying our symbol names with the expectations of the rest of the world
 makes sense.
 Folks did not seem keen on changing the world (and they can't really be
 blamed for that) so convert RISC-V over to match.
 
 Add some ARCH_FOO stubs alongside the existing SOC_FOO ones, which will
 be removed once all users of SOC_FOO have been converted*, and convert
 the DT bits of RISC-V kbuild over to the new symbols.
 
 * It may be best to wait until after the next LTS to remove the SOC_FOO
   ones, for the sake of external users.
 
 Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
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Merge tag 'soc2arch-immutable' of git://git.kernel.org/pub/scm/linux/kernel/git/conor/linux into for-next

SOC_FOO to ARCH_FOO conversion for RISC-V

RISC-V is an outlier in using SOC_FOO rather than ARCH_FOO for
vendors/micro-archs. SOC_FOO may make more sense (I personally prefer
it), but the rest of the "world" uses ARCH_FOO. That'd be fine, with
with an increasing number of existing SoC vendors moving to RISC-V,
unifying our symbol names with the expectations of the rest of the world
makes sense.
Folks did not seem keen on changing the world (and they can't really be
blamed for that) so convert RISC-V over to match.

Add some ARCH_FOO stubs alongside the existing SOC_FOO ones, which will
be removed once all users of SOC_FOO have been converted*, and convert
the DT bits of RISC-V kbuild over to the new symbols.

* It may be best to wait until after the next LTS to remove the SOC_FOO
  ones, for the sake of external users.

* tag 'soc2arch-immutable' of git://git.kernel.org/pub/scm/linux/kernel/git/conor/linux:
  RISC-V: stop directly selecting drivers for SOC_CANAAN
  RISC-V: stop selecting SiFive clock and serial drivers directly
  RISC-V: stop selecting the PolarFire SoC clock driver
  RISC-V: kbuild: convert all use of SOC_FOO to ARCH_FOO
  RISC-V: kconfig.socs: convert usage of SOC_CANAAN to ARCH_CANAAN
  RISC-V: introduce ARCH_FOO kconfig aliases for SOC_FOO symbols

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-28 11:01:44 -08:00
Conor Dooley
fc43211939 RISC-V: kconfig.socs: convert usage of SOC_CANAAN to ARCH_CANAAN
While we cannot yet drop the SOC_ prefixed symbols, we can convert
uses of these symbols within Kconfig.socs to the ARCH_ variants.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2022-12-27 18:01:40 +00:00
Conor Dooley
3af577f982 RISC-V: stop directly selecting drivers for SOC_CANAAN
The serial and clock drivers will be enabled by default if the symbol
itself is enabled, so stop directly selecting the drivers in
Kconfigs.socs.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2022-12-27 18:01:40 +00:00
Conor Dooley
444c3dbdab RISC-V: introduce ARCH_FOO kconfig aliases for SOC_FOO symbols
To facilitate a transfer from SOC_FOO to ARCH_FOO, over a release cycle,
introduce some aliases so that drivers etc that use the SOC_FOO symbols
can be converted.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
To me, the most straight-forward conversion looks like so:
- this patch is applied in week 2 of the merge window, to avoid
  any conflicts with the Renesas tree
- all users of the SOC_ variants can be converted over a release cycle
  (or more) & no trees need to merge an immutable branch.
- we convert defconfig etc over after all users are converted
- doing it over at least one release cycle means that `make oldconfig`
  will keep people's configs working as they upgrade
- any new SoC families added uses ARCH_FOO
2022-12-27 18:01:40 +00:00
Conor Dooley
0e6aee5bcc RISC-V: stop selecting SiFive clock and serial drivers directly
The SiFive clock and serial drivers will now default to the value of
SOC_SIFIVE so there is no need to directly select their symbols
anymore.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2022-12-27 18:01:40 +00:00
Conor Dooley
b61032557d RISC-V: stop selecting the PolarFire SoC clock driver
The driver is now enabled by default if SOC_MICROCHIP_POLARFIRE so
there is no longer a need to select it in Kconfig.socs

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2022-12-27 18:01:40 +00:00
Conor Dooley
19ba9cf707 RISC-V: kbuild: convert all use of SOC_FOO to ARCH_FOO
Convert all non user visible use of SOC_FOO symbols to their ARCH_FOO
variants. The canaan DTs are an outlier in that they're gated at the
directory and the file level. Drop the directory level gating while we
are swapping the symbol names over.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
2022-12-27 18:01:40 +00:00