RISC-V Fixes for 6.3-rc5

* A fix for FPU probing in XIP kernels.
 * Always enable the alternative framework for non-XIP kernels.
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Merge tag 'riscv-for-linus-6.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:

 - A fix for FPU probing in XIP kernels

 - Always enable the alternative framework for non-XIP kernels

* tag 'riscv-for-linus-6.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels
  RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely()

arch/riscv/Kconfig

@@ -126,6 +126,7 @@ config RISCV
 	select OF_IRQ
 	select PCI_DOMAINS_GENERIC if PCI
 	select PCI_MSI if PCI
+	select RISCV_ALTERNATIVE if !XIP_KERNEL
 	select RISCV_INTC
 	select RISCV_TIMER if RISCV_SBI
 	select SIFIVE_PLIC
@@ -401,9 +402,8 @@ config RISCV_ISA_C
 config RISCV_ISA_SVPBMT
 	bool "SVPBMT extension support"
 	depends on 64BIT && MMU
-	depends on !XIP_KERNEL
+	depends on RISCV_ALTERNATIVE
 	default y
-	select RISCV_ALTERNATIVE
 	help
 	   Adds support to dynamically detect the presence of the SVPBMT
 	   ISA-extension (Supervisor-mode: page-based memory types) and
@@ -428,8 +428,8 @@ config TOOLCHAIN_HAS_ZBB
 config RISCV_ISA_ZBB
 	bool "Zbb extension support for bit manipulation instructions"
 	depends on TOOLCHAIN_HAS_ZBB
-	depends on !XIP_KERNEL && MMU
-	select RISCV_ALTERNATIVE
+	depends on MMU
+	depends on RISCV_ALTERNATIVE
 	default y
 	help
 	   Adds support to dynamically detect the presence of the ZBB
@@ -443,9 +443,9 @@ config RISCV_ISA_ZBB
 
 config RISCV_ISA_ZICBOM
 	bool "Zicbom extension support for non-coherent DMA operation"
-	depends on !XIP_KERNEL && MMU
+	depends on MMU
+	depends on RISCV_ALTERNATIVE
 	default y
-	select RISCV_ALTERNATIVE
 	select RISCV_DMA_NONCOHERENT
 	help
 	   Adds support to dynamically detect the presence of the ZICBOM

arch/riscv/Kconfig.erratas

@@ -2,8 +2,7 @@ menu "CPU errata selection"
 
 config ERRATA_SIFIVE
 	bool "SiFive errata"
-	depends on !XIP_KERNEL
-	select RISCV_ALTERNATIVE
+	depends on RISCV_ALTERNATIVE
 	help
 	  All SiFive errata Kconfig depend on this Kconfig. Disabling
 	  this Kconfig will disable all SiFive errata. Please say "Y"
@@ -35,8 +34,7 @@ config ERRATA_SIFIVE_CIP_1200
 
 config ERRATA_THEAD
 	bool "T-HEAD errata"
-	depends on !XIP_KERNEL
-	select RISCV_ALTERNATIVE
+	depends on RISCV_ALTERNATIVE
 	help
 	  All T-HEAD errata Kconfig depend on this Kconfig. Disabling
 	  this Kconfig will disable all T-HEAD errata. Please say "Y"

arch/riscv/include/asm/hwcap.h

@@ -57,18 +57,31 @@ struct riscv_isa_ext_data {
 	unsigned int isa_ext_id;
 };
 
+unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
+
+#define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext)
+
+bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit);
+#define riscv_isa_extension_available(isa_bitmap, ext)	\
+	__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
+
 static __always_inline bool
 riscv_has_extension_likely(const unsigned long ext)
 {
 	compiletime_assert(ext < RISCV_ISA_EXT_MAX,
 			   "ext must be < RISCV_ISA_EXT_MAX");
 
-	asm_volatile_goto(
-	ALTERNATIVE("j	%l[l_no]", "nop", 0, %[ext], 1)
-	:
-	: [ext] "i" (ext)
-	:
-	: l_no);
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
+		asm_volatile_goto(
+		ALTERNATIVE("j	%l[l_no]", "nop", 0, %[ext], 1)
+		:
+		: [ext] "i" (ext)
+		:
+		: l_no);
+	} else {
+		if (!__riscv_isa_extension_available(NULL, ext))
+			goto l_no;
+	}
 
 	return true;
 l_no:
@@ -81,26 +94,23 @@ riscv_has_extension_unlikely(const unsigned long ext)
 	compiletime_assert(ext < RISCV_ISA_EXT_MAX,
 			   "ext must be < RISCV_ISA_EXT_MAX");
 
-	asm_volatile_goto(
-	ALTERNATIVE("nop", "j	%l[l_yes]", 0, %[ext], 1)
-	:
-	: [ext] "i" (ext)
-	:
-	: l_yes);
+	if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) {
+		asm_volatile_goto(
+		ALTERNATIVE("nop", "j	%l[l_yes]", 0, %[ext], 1)
+		:
+		: [ext] "i" (ext)
+		:
+		: l_yes);
+	} else {
+		if (__riscv_isa_extension_available(NULL, ext))
+			goto l_yes;
+	}
 
 	return false;
 l_yes:
 	return true;
 }
 
-unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
-
-#define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext)
-
-bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit);
-#define riscv_isa_extension_available(isa_bitmap, ext)	\
-	__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
-
 #endif
 
 #endif /* _ASM_RISCV_HWCAP_H */