[RFC PATCH v2 2/3] riscv: errata: sifive: support auipc/load pair in patched alternatives

[Bo Gan]

Enhance the errata/sifive patching function to support auipc/load
insn pair by fixing the offsets in immediate, just like in function
`riscv_cpufeature_patch_func`. Refer to commit 27c653c06505
("RISC-V: fix auipc-jalr addresses in patched alternatives")

Signed-off-by: Bo Gan <ganboing at gmail.com>
---
 arch/riscv/errata/sifive/errata.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/errata/sifive/errata.c b/arch/riscv/errata/sifive/errata.c
index d0c61f86cba33..f26c997e04e59 100644
--- a/arch/riscv/errata/sifive/errata.c
+++ b/arch/riscv/errata/sifive/errata.c
@@ -80,6 +80,7 @@ void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
 			      unsigned int stage)
 {
 	struct alt_entry *alt;
+	void *oldptr, *altptr;
 	u32 cpu_req_errata;
 	u32 tmp;
 
@@ -100,9 +101,12 @@ void sifive_errata_patch_func(struct alt_entry *begin, struct alt_entry *end,
 
 		tmp = (1U << alt->patch_id);
 		if (cpu_req_errata & tmp) {
+			oldptr = ALT_OLD_PTR(alt);
+			altptr = ALT_ALT_PTR(alt);
+
 			mutex_lock(&text_mutex);
-			patch_text_nosync(ALT_OLD_PTR(alt), ALT_ALT_PTR(alt),
-					  alt->alt_len);
+			patch_text_nosync(oldptr, altptr, alt->alt_len);
+			riscv_alternative_fix_offsets(oldptr, alt->alt_len, oldptr - altptr);
 			mutex_unlock(&text_mutex);
 		}
 	}
-- 
2.34.1