RISC-V Fixes for 5.7-rc4

This tag contains a handful of fixes that I'd like to target for 5.7.
 Specifically:
 
 * The change of a linker argument to allow linking with lld.
 * A build fix for configurations without a frame pointer.
 * A handful of build fixes related the SBI 0.1 vs 0.2 split.
 * The removal of STRICT_KERNEL_RWX for !MMU, which isn't useful
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Merge tag 'riscv-for-linus-5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:
 "A handful of fixes.

  Specifically:

   - fix linker argument to allow linking with lld

   - build fix for configurations without a frame pointer

   - a handful of build fixes related the SBI 0.1 vs 0.2 split

   - remove STRICT_KERNEL_RWX for !MMU, which isn't useful"

* tag 'riscv-for-linus-5.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: select ARCH_HAS_STRICT_KERNEL_RWX only if MMU
  riscv: sbi: Fix undefined reference to sbi_shutdown
  tty: riscv: Using RISCV_SBI_V01 instead of RISCV_SBI
  riscv: sbi: Correct sbi_shutdown() and sbi_clear_ipi() export
  riscv: fix vdso build with lld
  RISC-V: stacktrace: Declare sp_in_global outside ifdef

arch/riscv/Kconfig

@@ -60,7 +60,7 @@ config RISCV
 	select ARCH_HAS_GIGANTIC_PAGE
 	select ARCH_HAS_SET_DIRECT_MAP
 	select ARCH_HAS_SET_MEMORY
-	select ARCH_HAS_STRICT_KERNEL_RWX
+	select ARCH_HAS_STRICT_KERNEL_RWX if MMU
 	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
 	select SPARSEMEM_STATIC if 32BIT
 	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU

arch/riscv/kernel/sbi.c

@@ -102,7 +102,7 @@ void sbi_shutdown(void)
 {
 	sbi_ecall(SBI_EXT_0_1_SHUTDOWN, 0, 0, 0, 0, 0, 0, 0);
 }
-EXPORT_SYMBOL(sbi_set_timer);
+EXPORT_SYMBOL(sbi_shutdown);
 
 /**
  * sbi_clear_ipi() - Clear any pending IPIs for the calling hart.
@@ -113,7 +113,7 @@ void sbi_clear_ipi(void)
 {
 	sbi_ecall(SBI_EXT_0_1_CLEAR_IPI, 0, 0, 0, 0, 0, 0, 0);
 }
-EXPORT_SYMBOL(sbi_shutdown);
+EXPORT_SYMBOL(sbi_clear_ipi);
 
 /**
  * sbi_set_timer_v01() - Program the timer for next timer event.
@@ -167,6 +167,11 @@ static int __sbi_rfence_v01(int fid, const unsigned long *hart_mask,
 
 	return result;
 }
+
+static void sbi_set_power_off(void)
+{
+	pm_power_off = sbi_shutdown;
+}
 #else
 static void __sbi_set_timer_v01(uint64_t stime_value)
 {
@@ -191,6 +196,8 @@ static int __sbi_rfence_v01(int fid, const unsigned long *hart_mask,
 
 	return 0;
 }
+
+static void sbi_set_power_off(void) {}
 #endif /* CONFIG_RISCV_SBI_V01 */
 
 static void __sbi_set_timer_v02(uint64_t stime_value)
@@ -540,16 +547,12 @@ static inline long sbi_get_firmware_version(void)
 	return __sbi_base_ecall(SBI_EXT_BASE_GET_IMP_VERSION);
 }
 
-static void sbi_power_off(void)
-{
-	sbi_shutdown();
-}
 
 int __init sbi_init(void)
 {
 	int ret;
 
-	pm_power_off = sbi_power_off;
+	sbi_set_power_off();
 	ret = sbi_get_spec_version();
 	if (ret > 0)
 		sbi_spec_version = ret;

arch/riscv/kernel/stacktrace.c

@@ -12,6 +12,8 @@
 #include <linux/stacktrace.h>
 #include <linux/ftrace.h>
 
+register unsigned long sp_in_global __asm__("sp");
+
 #ifdef CONFIG_FRAME_POINTER
 
 struct stackframe {
@@ -19,8 +21,6 @@ struct stackframe {
 	unsigned long ra;
 };
 
-register unsigned long sp_in_global __asm__("sp");
-
 void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 			     bool (*fn)(unsigned long, void *), void *arg)
 {

arch/riscv/kernel/vdso/Makefile

@@ -33,15 +33,15 @@ $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
 	$(call if_changed,vdsold)
 
 # We also create a special relocatable object that should mirror the symbol
-# table and layout of the linked DSO.  With ld -R we can then refer to
-# these symbols in the kernel code rather than hand-coded addresses.
+# table and layout of the linked DSO. With ld --just-symbols we can then
+# refer to these symbols in the kernel code rather than hand-coded addresses.
 
 SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
 	-Wl,--build-id -Wl,--hash-style=both
 $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
 	$(call if_changed,vdsold)
 
-LDFLAGS_vdso-syms.o := -r -R
+LDFLAGS_vdso-syms.o := -r --just-symbols
 $(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
 	$(call if_changed,ld)
 

drivers/tty/hvc/Kconfig

@@ -88,7 +88,7 @@ config HVC_DCC
 
 config HVC_RISCV_SBI
 	bool "RISC-V SBI console support"
-	depends on RISCV_SBI
+	depends on RISCV_SBI_V01
 	select HVC_DRIVER
 	help
 	  This enables support for console output via RISC-V SBI calls, which

drivers/tty/serial/Kconfig

@@ -86,7 +86,7 @@ config SERIAL_EARLYCON_ARM_SEMIHOST
 
 config SERIAL_EARLYCON_RISCV_SBI
 	bool "Early console using RISC-V SBI"
-	depends on RISCV_SBI
+	depends on RISCV_SBI_V01
 	select SERIAL_CORE
 	select SERIAL_CORE_CONSOLE
 	select SERIAL_EARLYCON