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Date:   Thu, 03 Aug 2023 10:00:02 -0700
Mime-Version: 1.0
Message-ID: <20230803-ppc_tlbilxlpid-v1-1-84a1bc5cf963@google.com>
Subject: [PATCH] powerpc/inst: add PPC_TLBILX_LPID
From:   ndesaulniers@google.com
To:     Michael Ellerman <mpe@ellerman.id.au>,
        Nicholas Piggin <npiggin@gmail.com>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Nathan Chancellor <nathan@kernel.org>,
        Tom Rix <trix@redhat.com>
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, llvm@lists.linux.dev,
        kernel test robot <lkp@intel.com>,
        Nick Desaulniers <ndesaulniers@google.com>
Content-Type: text/plain; charset="utf-8"
Precedence: bulk

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@intel.com>
Closes: https://lore.kernel.org/llvm/202307211945.TSPcyOhh-lkp@intel.com/
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/powerpc/include/asm/ppc-opcode.h |  4 +++-
 arch/powerpc/kvm/e500mc.c             | 10 +++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index ef6972aa33b9..72f184e06bec 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -397,7 +397,8 @@
 #define PPC_RAW_RFCI			(0x4c000066)
 #define PPC_RAW_RFDI			(0x4c00004e)
 #define PPC_RAW_RFMCI			(0x4c00004c)
-#define PPC_RAW_TLBILX(t, a, b)		(0x7c000024 | __PPC_T_TLB(t) | 	__PPC_RA0(a) | __PPC_RB(b))
+#define PPC_RAW_TLBILX_LPID (0x7c000024)
+#define PPC_RAW_TLBILX(t, a, b)		(PPC_RAW_TLBILX_LPID | __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))
 #define PPC_RAW_TLBIE(lp, a)		(0x7c000264 | ___PPC_RB(a) | ___PPC_RS(lp))
@@ -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..dc054b8b5032 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 +93,10 @@ 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@google.com>