[PATCH 2/5] arm64/alternative_cb: add nr_alts parameter to callback handlers

[Ard Biesheuvel]

Callback handlers for alternative patching will shortly be able to
access a set of alternative instructions provided at assembly time.
So update the callback handler prototypes so we can pass this number.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
 arch/arm64/include/asm/alternative.h |  4 ++--
 arch/arm64/include/asm/kvm_mmu.h     |  4 ++--
 arch/arm64/kernel/alternative.c      | 11 +++++++----
 arch/arm64/kernel/cpu_errata.c       | 10 ++++------
 arch/arm64/kvm/va_layout.c           |  8 ++++----
 5 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h
index 77da798e888b..987c1514183a 100644
--- a/arch/arm64/include/asm/alternative.h
+++ b/arch/arm64/include/asm/alternative.h
@@ -29,8 +29,8 @@ struct alt_instr_cb {
 	__le32 insn[];		/* sequence of alternative instructions */
 };
 
-typedef void (*alternative_cb_t)(struct alt_instr *alt,
-				 __le32 *origptr, __le32 *updptr, int nr_inst);
+typedef void (*alternative_cb_t)(struct alt_instr *alt, __le32 *origptr,
+				 __le32 *updptr, int nr_inst, int nr_alts);
 
 void __init apply_alternatives_all(void);
 
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 658657367f2f..5e32e314b9f0 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -100,8 +100,8 @@ alternative_cb_end
 #include <asm/mmu_context.h>
 #include <asm/pgtable.h>
 
-void kvm_update_va_mask(struct alt_instr *alt,
-			__le32 *origptr, __le32 *updptr, int nr_inst);
+void kvm_update_va_mask(struct alt_instr *alt, __le32 *origptr,
+			__le32 *updptr, int nr_insti, int nr_alts);
 
 static inline unsigned long __kern_hyp_va(unsigned long v)
 {
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
index a49930843784..f55afa0bbaa4 100644
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -107,8 +107,8 @@ static u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnp
 	return insn;
 }
 
-static void patch_alternative(struct alt_instr *alt,
-			      __le32 *origptr, __le32 *updptr, int nr_inst)
+static void patch_alternative(struct alt_instr *alt, __le32 *origptr,
+			      __le32 *updptr, int nr_inst, int nr_alts)
 {
 	__le32 *replptr;
 	int i;
@@ -154,7 +154,7 @@ static void __apply_alternatives(void *alt_region, bool is_module)
 	struct alt_instr_cb *alt_cb_insn;
 
 	for (alt = region->begin; alt < region->end; alt++) {
-		int nr_inst;
+		int nr_inst, nr_alts;
 
 		/* Use ARM64_CB_PATCH as an unconditional patch */
 		if (alt->cpufeature < ARM64_CB_PATCH &&
@@ -174,12 +174,15 @@ static void __apply_alternatives(void *alt_region, bool is_module)
 
 		if (alt->cpufeature < ARM64_CB_PATCH) {
 			alt_cb = patch_alternative;
+			nr_alts = alt->alt_len / AARCH64_INSN_SIZE;
 		} else {
 			alt_cb_insn = ALT_REPL_PTR(alt);
 			alt_cb = offset_to_ptr(&alt_cb_insn->cb_offset);
+			nr_alts = (alt->alt_len - sizeof(*alt_cb_insn)) / AARCH64_INSN_SIZE;
+
 		}
 
-		alt_cb(alt, origptr, updptr, nr_inst);
+		alt_cb(alt, origptr, updptr, nr_inst, nr_alts);
 
 		if (!is_module) {
 			clean_dcache_range_nopatch((u64)origptr,
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 6ad715d67df8..c5489b4612c5 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -305,9 +305,8 @@ static int __init ssbd_cfg(char *buf)
 }
 early_param("ssbd", ssbd_cfg);
 
-void __init arm64_update_smccc_conduit(struct alt_instr *alt,
-				       __le32 *origptr, __le32 *updptr,
-				       int nr_inst)
+void __init arm64_update_smccc_conduit(struct alt_instr *alt, __le32 *origptr,
+				       __le32 *updptr, int nr_inst, int nr_alts)
 {
 	u32 insn;
 
@@ -327,9 +326,8 @@ void __init arm64_update_smccc_conduit(struct alt_instr *alt,
 	*updptr = cpu_to_le32(insn);
 }
 
-void __init arm64_enable_wa2_handling(struct alt_instr *alt,
-				      __le32 *origptr, __le32 *updptr,
-				      int nr_inst)
+void __init arm64_enable_wa2_handling(struct alt_instr *alt, __le32 *origptr,
+				      __le32 *updptr, int nr_inst, int nr_alts)
 {
 	BUG_ON(nr_inst != 1);
 	/*
diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index c712a7376bc1..db7ba73e306a 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -114,8 +114,8 @@ static u32 compute_instruction(int n, u32 rd, u32 rn)
 	return insn;
 }
 
-void __init kvm_update_va_mask(struct alt_instr *alt,
-			       __le32 *origptr, __le32 *updptr, int nr_inst)
+void __init kvm_update_va_mask(struct alt_instr *alt, __le32 *origptr,
+			       __le32 *updptr, int nr_inst, int nr_alts)
 {
 	int i;
 
@@ -154,8 +154,8 @@ void __init kvm_update_va_mask(struct alt_instr *alt,
 void *__kvm_bp_vect_base;
 int __kvm_harden_el2_vector_slot;
 
-void kvm_patch_vector_branch(struct alt_instr *alt,
-			     __le32 *origptr, __le32 *updptr, int nr_inst)
+void kvm_patch_vector_branch(struct alt_instr *alt, __le32 *origptr,
+			     __le32 *updptr, int nr_inst, int nr_alts)
 {
 	u64 addr;
 	u32 insn;
-- 
2.19.2