[v7,03/13] riscv: allow different stages with alternatives

Commit Message

Heiko Stübner March 7, 2022, 8:53 p.m. UTC

Future features may need to be applied at a different
time during boot, so allow defining stages for alternatives
and handling them differently depending on the stage.

Also make the alternatives-location more flexible so that
future stages may provide their own location.

Signed-off-by: Heiko Stuebner <[e-mail]>
---
 arch/riscv/errata/sifive/errata.c    |  3 ++-
 arch/riscv/include/asm/alternative.h |  5 ++++-
 arch/riscv/kernel/alternative.c      | 26 +++++++++++++++++---------
 3 files changed, 23 insertions(+), 11 deletions(-)

Patch

diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
index f5e5ae70e829..4fe03ac41fd7 100644
--- a/arch/riscv/errata/sifive/errata.c
+++ b/arch/riscv/errata/sifive/errata.c
@@ -80,7 +80,8 @@  static void __init warn_miss_errata(u32 miss_errata)
 }
 
 void __init sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
-				     unsigned long archid, unsigned long impid)
+				     unsigned long archid, unsigned long impid,
+				     unsigned int stage)
 {
 	struct alt_entry *alt;
 	u32 cpu_req_errata = sifive_errata_probe(archid, impid);
diff --git a/arch/riscv/include/asm/alternative.h b/arch/riscv/include/asm/alternative.h
index e625d3cafbed..811bdd8027db 100644
--- a/arch/riscv/include/asm/alternative.h
+++ b/arch/riscv/include/asm/alternative.h
@@ -17,6 +17,8 @@ 
 #include <linux/stddef.h>
 #include <asm/hwcap.h>
 
+#define RISCV_ALTERNATIVES_BOOT		0 /* alternatives applied during regular boot */
+
 void __init apply_boot_alternatives(void);
 
 struct alt_entry {
@@ -33,7 +35,8 @@  struct errata_checkfunc_id {
 };
 
 void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
-			      unsigned long archid, unsigned long impid);
+			      unsigned long archid, unsigned long impid,
+			      unsigned int stage);
 
 #endif
 #endif
diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
index e8b4a0fe488c..02db62f55bac 100644
--- a/arch/riscv/kernel/alternative.c
+++ b/arch/riscv/kernel/alternative.c
@@ -22,8 +22,8 @@  static struct cpu_manufacturer_info_t {
 } cpu_mfr_info;
 
 static void (*vendor_patch_func)(struct alt_entry *begin, struct alt_entry *end,
-				 unsigned long archid,
-				 unsigned long impid) __initdata;
+				 unsigned long archid, unsigned long impid,
+				 unsigned int stage) __initdata;
 
 static inline void __init riscv_fill_cpu_mfr_info(void)
 {
@@ -58,6 +58,18 @@  static void __init init_alternative(void)
  * a feature detect on the boot CPU). No need to worry about other CPUs
  * here.
  */
+static void __init _apply_alternatives(struct alt_entry *begin,
+				       struct alt_entry *end,
+				       unsigned int stage)
+{
+	if (!vendor_patch_func)
+		return;
+
+	vendor_patch_func(begin, end,
+			  cpu_mfr_info.arch_id, cpu_mfr_info.imp_id,
+			  stage);
+}
+
 void __init apply_boot_alternatives(void)
 {
 	/* If called on non-boot cpu things could go wrong */
@@ -65,11 +77,7 @@  void __init apply_boot_alternatives(void)
 
 	init_alternative();
 
-	if (!vendor_patch_func)
-		return;
-
-	vendor_patch_func((struct alt_entry *)__alt_start,
-			  (struct alt_entry *)__alt_end,
-			  cpu_mfr_info.arch_id, cpu_mfr_info.imp_id);
+	_apply_alternatives((struct alt_entry *)__alt_start,
+			    (struct alt_entry *)__alt_end,
+			    RISCV_ALTERNATIVES_BOOT);
 }
-