Re: [PATCH V17 0/7] Rust Support for powerpc
From: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Date: 2026-08-05 12:57:10
Also in:
lkml, llvm, rust-for-linux
Le 04/08/2026 à 15:40, FUJITA Tomonori a écrit :
quoted hunk ↗ jump to hunk
[Vous ne recevez pas souvent de courriers de tomo@flapping.org. D?couvrez pourquoi ceci est important ? https://aka.ms/LearnAboutSenderIdentification ] On Tue, 4 Aug 2026 12:11:57 +0200 Link Mauve [off-list ref] wrote:quoted
Hi, On Mon, Aug 03, 2026 at 12:27:13PM +0530, Madhavan Srinivasan wrote:quoted
On Wed, 08 Jul 2026 13:54:47 +0530, Mukesh Kumar Chaurasiya (IBM) wrote:quoted
Enable experimental rust support for ppc64le and ppc32be. The patch for ppc32 has been provided by Link Mauve[1] and ppc64le support[2] has been merged over it. ppc32 needs some toolchain fixes mentioned in the patch `rust: Add PowerPC support` and the discussion for that is done here[1]. This has been tested on - powernv9 hardware - pseries P11 hardware - pseries(9, 10) qemu - powernv(9, 10) qemu - rustdoc on x86 and powerpc64le - rusttest on x86 and powerpc64le [...]Applied to powerpc/next. [1/7] rust: Fix "multiple candidates for rmeta dependency core" error https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2F00cdfd072c709c608606461d7d44d4613119bfa9&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617198585%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=4qQe1qS37TGv6%2Bf9H56kWVqMYSAHsWiDx5oz8WHZ8%2Bg%3D&reserved=0 [2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fbe809b60cbb61aab96179f44ac3670242ae72996&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617235654%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=cw2l64D3ah%2FM3pxFmvMpUnNmcqcSvN3RFoDiYAIR76g%3D&reserved=0 [3/7] powerpc/jump_label: adjust inline asm to be consistent https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2F13244c0a40139fe66c4c5c5655f4d732a6002957&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617259593%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=xNvcH9k5RA5ktJupn90VdDuwx4YBvezuDcapqKlYfjs%3D&reserved=0 [4/7] rust/powerpc: Set min rustc version for powerpc https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fe299147cdc8e19c6421a6b7863dc82a35b09d967&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617280683%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=uNZA7AulROQGv%2B2l4M%2FqC5W4ncWktRoSRRp8eaF%2FcCY%3D&reserved=0 [5/7] rust: Make __udivdi3() and __umoddi3() panic https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fc93c194e4ee71a734986fd99a8b1ec9fbb7a9b8b&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617303292%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=znZPWXM7k5FpRlekIyUN1bHzmMyk1YESR56WsiwBuMA%3D&reserved=0 [6/7] rust: Add PowerPC support https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2F73b741adb264967093ef4eb59905618a7e0d0de0&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617326590%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=aFHGhd7RX%2Ft5%2BMjqt6pBmIKPKAKmFEQndKP1F%2F8HSxk%3D&reserved=0 [7/7] powerpc: Enable Rust for ppc64le https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpowerpc%2Fc%2Fbc87cbdb952e9223616b839d64bdb4723aa2ed1d&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C34e4deafcc1d41c1738a08def22e01b0%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639214476617346994%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=ITEFv9C1CSUVLqJNe5Y8sStUE3KoOVYVzSzbP0qis74%3D&reserved=0 cheersI just tested those again in linux-next, with the Wii support series on top, but now the kernel fails to build due to ARCH_WARN_ASM and ARCH_WARN_REACHABLE not being defined on PowerPC:error: no rules expected `ARCH_WARN_ASM` --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_warn_asm.rs:1:28 | 1 | ::kernel::concat_literals!(ARCH_WARN_ASM("{file}", "{line}", "{flags}", "{size}")) | ^^^^^^^^^^^^^ no rules expected this token in macro call | ::: ../rust/kernel/lib.rs:279:1 | 279 | macro_rules! concat_literals { | ---------------------------- when calling this macro | = note: while trying to match sequence start error: no rules expected `ARCH_WARN_REACHABLE` --> /home/linkmauve/dev/linux/wii/rust/kernel/generated_arch_reachable_asm.rs:1:28 | 1 | ::kernel::concat_literals!(ARCH_WARN_REACHABLE) | ^^^^^^^^^^^^^^^^^^^ no rules expected this token in macro call | ::: ../rust/kernel/lib.rs:279:1 | 279 | macro_rules! concat_literals { | ---------------------------- when calling this macro | = note: while trying to match sequence start error: aborting due to 2 previous errorsThis is in addition to the bindings::kvfree_call_rcu() call, but that one is already being handled in a different thread.Looks like powerpc needs something like the followings:diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h index 0db48977c70c..8aba39e0cf26 100644 --- a/arch/powerpc/include/asm/bug.h +++ b/arch/powerpc/include/asm/bug.h@@ -32,34 +32,38 @@ #endif /* verbose */ #else /* !__ASSEMBLER__ */ -/* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3 to be FILE, LINE, flags and - sizeof(struct bug_entry), respectively */ #ifdef CONFIG_DEBUG_BUGVERBOSE -#define _EMIT_BUG_ENTRY \ +#define _EMIT_BUG_ENTRY(file, line, flags) \ ".section __bug_table,\"aw\"\n" \ "2: .4byte 1b - .\n" \ - " .4byte %0 - .\n" \ - " .short %1, %2\n" \ - ".org 2b+%3\n" \ - ".previous\n" + " .4byte " file " - .\n" \ + " .short " line ", " flags "\n" #else -#define _EMIT_BUG_ENTRY \ +#define _EMIT_BUG_ENTRY(file, line, flags) \ ".section __bug_table,\"aw\"\n" \ "2: .4byte 1b - .\n" \ - " .short %2\n" \ - ".org 2b+%3\n" \ - ".previous\n" + " .short " flags "\n" #endif #define BUG_ENTRY(cond_str, insn, flags, ...) \ __asm__ __volatile__( \ "1: " insn "\n" \ - _EMIT_BUG_ENTRY \ + _EMIT_BUG_ENTRY("%0", "%1", "%2") \ + ".org 2b+%3\n" \ + ".previous\n" \ : : "i" (WARN_CONDITION_STR(cond_str) __FILE__), "i" (__LINE__), \ "i" (flags), \ "i" (sizeof(struct bug_entry)), \ ##__VA_ARGS__) +#define ARCH_WARN_ASM(file, line, flags, size) \ + "1: twi 31, 0, 0\n" \ + _EMIT_BUG_ENTRY(file, line, flags) \ + ".org 2b+" size "\n" \ + ".previous\n"
Will this build ? Isn't ARCH_WARN_ASM() for use in ASM .S files ? _EMIT_BUG_ENTRY is defined in a !__ASSEMBLER__ ifdef. powerpc already has EMIT_BUG_ENTRY macro for ASM for that. Why do you need to modify _EMIT_BUG_ENTRY and BUG_ENTRY() which are for C only (in a #ifdef !__ASSEMBLER__) ? https://elixir.bootlin.com/linux/v7.2-rc5/source/arch/powerpc/include/asm/bug.h#L10 Christophe