Merge tag 'powerpc-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - Enforce full ordering for ATOMIC operations with BPF_FETCH

 - Fix uaccess build errors seen with GCC 13/14

 - Fix build errors on ppc32 due to ARCH_HAS_KERNEL_FPU_SUPPORT

 - Drop error message from lparcfg guest name lookup

Thanks to Christophe Leroy, Guenter Roeck, Nathan Lynch, Naveen N Rao,
Puranjay Mohan, and Samuel Holland.

* tag 'powerpc-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Limit ARCH_HAS_KERNEL_FPU_SUPPORT to PPC64
  powerpc/uaccess: Use YZ asm constraint for ld
  powerpc/uaccess: Fix build errors seen with GCC 13/14
  powerpc/pseries/lparcfg: drop error message from guest name lookup
  powerpc/bpf: enforce full ordering for ATOMIC operations with BPF_FETCH

5 files changed, 54 insertions, 3 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 3c968f2f4ac4..c88c6d46a5bc 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -137,7 +137,7 @@ config PPC
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_HUGEPD			if HUGETLB_PAGE
 	select ARCH_HAS_KCOV
-	select ARCH_HAS_KERNEL_FPU_SUPPORT	if PPC_FPU
+	select ARCH_HAS_KERNEL_FPU_SUPPORT	if PPC64 && PPC_FPU
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_MEMREMAP_COMPAT_ALIGN	if PPC_64S_HASH_MMU
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index de10437fd206..fd594bf6c6a9 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -92,9 +92,25 @@ __pu_failed:							\
 		: label)
 #endif
 
+#ifdef CONFIG_CC_IS_CLANG
+#define DS_FORM_CONSTRAINT "Z<>"
+#else
+#define DS_FORM_CONSTRAINT "YZ<>"
+#endif
+
 #ifdef __powerpc64__
+#ifdef CONFIG_PPC_KERNEL_PREFIXED
 #define __put_user_asm2_goto(x, ptr, label)			\
 	__put_user_asm_goto(x, ptr, label, "std")
+#else
+#define __put_user_asm2_goto(x, addr, label)			\
+	asm goto ("1: std%U1%X1 %0,%1	# put_user\n"		\
+		EX_TABLE(1b, %l2)				\
+		:						\
+		: "r" (x), DS_FORM_CONSTRAINT (*addr)		\
+		:						\
+		: label)
+#endif // CONFIG_PPC_KERNEL_PREFIXED
 #else /* __powerpc64__ */
 #define __put_user_asm2_goto(x, addr, label)			\
 	asm goto(					\
@@ -165,8 +181,19 @@ do {								\
 #endif
 
 #ifdef __powerpc64__
+#ifdef CONFIG_PPC_KERNEL_PREFIXED
 #define __get_user_asm2_goto(x, addr, label)			\
 	__get_user_asm_goto(x, addr, label, "ld")
+#else
+#define __get_user_asm2_goto(x, addr, label)			\
+	asm_goto_output(					\
+		"1:	ld%U1%X1 %0, %1	# get_user\n"		\
+		EX_TABLE(1b, %l2)				\
+		: "=r" (x)					\
+		: DS_FORM_CONSTRAINT (*addr)			\
+		:						\
+		: label)
+#endif // CONFIG_PPC_KERNEL_PREFIXED
 #else /* __powerpc64__ */
 #define __get_user_asm2_goto(x, addr, label)			\
 	asm_goto_output(					\
diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c
index 43b97032a91c..a0c4f1bde83e 100644
--- a/arch/powerpc/net/bpf_jit_comp32.c
+++ b/arch/powerpc/net/bpf_jit_comp32.c
@@ -900,6 +900,15 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code
 
 			/* Get offset into TMP_REG */
 			EMIT(PPC_RAW_LI(tmp_reg, off));
+			/*
+			 * Enforce full ordering for operations with BPF_FETCH by emitting a 'sync'
+			 * before and after the operation.
+			 *
+			 * This is a requirement in the Linux Kernel Memory Model.
+			 * See __cmpxchg_u32() in asm/cmpxchg.h as an example.
+			 */
+			if ((imm & BPF_FETCH) && IS_ENABLED(CONFIG_SMP))
+				EMIT(PPC_RAW_SYNC());
 			tmp_idx = ctx->idx * 4;
 			/* load value from memory into r0 */
 			EMIT(PPC_RAW_LWARX(_R0, tmp_reg, dst_reg, 0));
@@ -953,6 +962,9 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code
 
 			/* For the BPF_FETCH variant, get old data into src_reg */
 			if (imm & BPF_FETCH) {
+				/* Emit 'sync' to enforce full ordering */
+				if (IS_ENABLED(CONFIG_SMP))
+					EMIT(PPC_RAW_SYNC());
 				EMIT(PPC_RAW_MR(ret_reg, ax_reg));
 				if (!fp->aux->verifier_zext)
 					EMIT(PPC_RAW_LI(ret_reg - 1, 0)); /* higher 32-bit */
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 8afc14a4a125..7703dcf48be8 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -846,6 +846,15 @@ emit_clear:
 
 			/* Get offset into TMP_REG_1 */
 			EMIT(PPC_RAW_LI(tmp1_reg, off));
+			/*
+			 * Enforce full ordering for operations with BPF_FETCH by emitting a 'sync'
+			 * before and after the operation.
+			 *
+			 * This is a requirement in the Linux Kernel Memory Model.
+			 * See __cmpxchg_u64() in asm/cmpxchg.h as an example.
+			 */
+			if ((imm & BPF_FETCH) && IS_ENABLED(CONFIG_SMP))
+				EMIT(PPC_RAW_SYNC());
 			tmp_idx = ctx->idx * 4;
 			/* load value from memory into TMP_REG_2 */
 			if (size == BPF_DW)
@@ -908,6 +917,9 @@ emit_clear:
 			PPC_BCC_SHORT(COND_NE, tmp_idx);
 
 			if (imm & BPF_FETCH) {
+				/* Emit 'sync' to enforce full ordering */
+				if (IS_ENABLED(CONFIG_SMP))
+					EMIT(PPC_RAW_SYNC());
 				EMIT(PPC_RAW_MR(ret_reg, _R0));
 				/*
 				 * Skip unnecessary zero-extension for 32-bit cmpxchg.
diff --git a/arch/powerpc/platforms/pseries/lparcfg.c b/arch/powerpc/platforms/pseries/lparcfg.c
index 6e7029640c0c..62da20f9700a 100644
--- a/arch/powerpc/platforms/pseries/lparcfg.c
+++ b/arch/powerpc/platforms/pseries/lparcfg.c
@@ -371,8 +371,8 @@ static int read_dt_lpar_name(struct seq_file *m)
 
 static void read_lpar_name(struct seq_file *m)
 {
-	if (read_rtas_lpar_name(m) && read_dt_lpar_name(m))
-		pr_err_once("Error can't get the LPAR name");
+	if (read_rtas_lpar_name(m))
+		read_dt_lpar_name(m);
 }
 
 #define SPLPAR_MAXLENGTH 1026*(sizeof(char))