Thread (28 messages) 28 messages, 6 authors, 2024-05-24
STALE740d REVIEWED: 5 (4M)
Revisions (4)
  1. rfc [diff vs current]
  2. v2 [diff vs current]
  3. v3 [diff vs current]
  4. v4 current

[PATCH v4 07/15] LoongArch: Implement ARCH_HAS_KERNEL_FPU_SUPPORT

From: Samuel Holland <samuel.holland@sifive.com>
Date: 2024-03-29 07:24:52
Also in: amd-gfx, linux-arch, linux-arm-kernel, linux-riscv, lkml, loongarch
Subsystem: loongarch, the rest · Maintainers: Huacai Chen, Linus Torvalds

LoongArch already provides kernel_fpu_begin() and kernel_fpu_end() in
asm/fpu.h, so it only needs to add kernel_fpu_available() and export
the CFLAGS adjustments.

Acked-by: WANG Xuerui <redacted>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
---

(no changes since v3)

Changes in v3:
 - Rebase on v6.9-rc1

 arch/loongarch/Kconfig           | 1 +
 arch/loongarch/Makefile          | 5 ++++-
 arch/loongarch/include/asm/fpu.h | 1 +
 3 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index a5f300ec6f28..2266c6c41c38 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -18,6 +18,7 @@ config LOONGARCH
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_KERNEL_FPU_SUPPORT if CPU_HAS_FPU
 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_PTE_SPECIAL
diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile
index df6caf79537a..efb5440a43ec 100644
--- a/arch/loongarch/Makefile
+++ b/arch/loongarch/Makefile
@@ -26,6 +26,9 @@ endif
 32bit-emul		= elf32loongarch
 64bit-emul		= elf64loongarch
 
+CC_FLAGS_FPU		:= -mfpu=64
+CC_FLAGS_NO_FPU		:= -msoft-float
+
 ifdef CONFIG_UNWINDER_ORC
 orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h
 orc_hash_sh := $(srctree)/scripts/orc_hash.sh
@@ -59,7 +62,7 @@ ld-emul			= $(64bit-emul)
 cflags-y		+= -mabi=lp64s
 endif
 
-cflags-y			+= -pipe -msoft-float
+cflags-y			+= -pipe $(CC_FLAGS_NO_FPU)
 LDFLAGS_vmlinux			+= -static -n -nostdlib
 
 # When the assembler supports explicit relocation hint, we must use it.
diff --git a/arch/loongarch/include/asm/fpu.h b/arch/loongarch/include/asm/fpu.h
index c2d8962fda00..3177674228f8 100644
--- a/arch/loongarch/include/asm/fpu.h
+++ b/arch/loongarch/include/asm/fpu.h
@@ -21,6 +21,7 @@
 
 struct sigcontext;
 
+#define kernel_fpu_available() cpu_has_fpu
 extern void kernel_fpu_begin(void);
 extern void kernel_fpu_end(void);
 
-- 
2.44.0
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