[PATCH v3] powerpc/inst: add PPC_TLBILX_LPID

[Nick Desaulniers]

Clang didn't recognize the instruction tlbilxlpid. This was fixed in
clang-18 [0] then backported to clang-17 [1].  To support clang-16 and
older, rather than using that instruction bare in inline asm, add it to
ppc-opcode.h and use that macro as is done elsewhere for other
instructions.

Link: https://github.com/ClangBuiltLinux/linux/issues/1891
Link: https://github.com/llvm/llvm-project/issues/64080
Link: https://github.com/llvm/llvm-project/commit/53648ac1d0c953ae6d008864dd2eddb437a92468 [0]
Link: https://github.com/llvm/llvm-project-release-prs/commit/0af7e5e54a8c7ac665773ac1ada328713e8338f5 [1]
Reported-by: kernel test robot <lkp at intel.com>
Closes: https://lore.kernel.org/llvm/202307211945.TSPcyOhh-lkp@intel.com/
Suggested-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Nick Desaulniers <ndesaulniers at google.com>
---
Changes in v3:
- left comment @ https://github.com/linuxppc/issues/issues/350#issuecomment-1664417212
- restore PPC_RAW_TLBILX previous definition
- fix comment style
- Link to v2: https://lore.kernel.org/r/20230803-ppc_tlbilxlpid-v2-1-211ffa1df194@google.com

Changes in v2:
- add 2 missing tabs to PPC_RAW_TLBILX_LPID
- Link to v1: https://lore.kernel.org/r/20230803-ppc_tlbilxlpid-v1-1-84a1bc5cf963@google.com
---
 arch/powerpc/include/asm/ppc-opcode.h |  2 ++
 arch/powerpc/kvm/e500mc.c             | 11 ++++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index ef6972aa33b9..005601243dda 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -397,6 +397,7 @@
 #define PPC_RAW_RFCI			(0x4c000066)
 #define PPC_RAW_RFDI			(0x4c00004e)
 #define PPC_RAW_RFMCI			(0x4c00004c)
+#define PPC_RAW_TLBILX_LPID		(0x7c000024)
 #define PPC_RAW_TLBILX(t, a, b)		(0x7c000024 | __PPC_T_TLB(t) | 	__PPC_RA0(a) | __PPC_RB(b))
 #define PPC_RAW_WAIT_v203		(0x7c00007c)
 #define PPC_RAW_WAIT(w, p)		(0x7c00003c | __PPC_WC(w) | __PPC_PL(p))
@@ -616,6 +617,7 @@
 #define PPC_TLBILX(t, a, b)	stringify_in_c(.long PPC_RAW_TLBILX(t, a, b))
 #define PPC_TLBILX_ALL(a, b)	PPC_TLBILX(0, a, b)
 #define PPC_TLBILX_PID(a, b)	PPC_TLBILX(1, a, b)
+#define PPC_TLBILX_LPID		stringify_in_c(.long PPC_RAW_TLBILX_LPID)
 #define PPC_TLBILX_VA(a, b)	PPC_TLBILX(3, a, b)
 #define PPC_WAIT_v203		stringify_in_c(.long PPC_RAW_WAIT_v203)
 #define PPC_WAIT(w, p)		stringify_in_c(.long PPC_RAW_WAIT(w, p))
diff --git a/arch/powerpc/kvm/e500mc.c b/arch/powerpc/kvm/e500mc.c
index d58df71ace58..7c09c000c330 100644
--- a/arch/powerpc/kvm/e500mc.c
+++ b/arch/powerpc/kvm/e500mc.c
@@ -16,10 +16,11 @@
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 
-#include <asm/reg.h>
 #include <asm/cputable.h>
-#include <asm/kvm_ppc.h>
 #include <asm/dbell.h>
+#include <asm/kvm_ppc.h>
+#include <asm/ppc-opcode.h>
+#include <asm/reg.h>
 
 #include "booke.h"
 #include "e500.h"
@@ -92,7 +93,11 @@ void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500 *vcpu_e500)
 
 	local_irq_save(flags);
 	mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(&vcpu_e500->vcpu));
-	asm volatile("tlbilxlpid");
+	/*
+	 * clang-17 and older could not assemble tlbilxlpid.
+	 * https://github.com/ClangBuiltLinux/linux/issues/1891
+	 */
+	asm volatile (PPC_TLBILX_LPID);
 	mtspr(SPRN_MAS5, 0);
 	local_irq_restore(flags);
 }

---
base-commit: 7bafbd4027ae86572f308c4ddf93120c90126332
change-id: 20230803-ppc_tlbilxlpid-cfdbf4fd4f7f

Best regards,
-- 
Nick Desaulniers <ndesaulniers at google.com>