arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors

Users of trans_pgd may also need a copy of vector table because it is
also may be overwritten if a linear map can be overwritten.

Move setup of EL2 vectors from hibernate to trans_pgd, so it can be
later shared with kexec as well.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-3-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 25 insertions, 2 deletions

diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c
index 527f0a39c3da..26bd8f2d95af 100644
--- a/arch/arm64/mm/trans_pgd.c
+++ b/arch/arm64/mm/trans_pgd.c
@@ -5,8 +5,8 @@
  *
  * This file derived from: arch/arm64/kernel/hibernate.c
  *
- * Copyright (c) 2020, Microsoft Corporation.
- * Pavel Tatashin <pasha.tatashin@soleen.com>
+ * Copyright (c) 2021, Microsoft Corporation.
+ * Pasha Tatashin <pasha.tatashin@soleen.com>
  *
  */
 
@@ -322,3 +322,26 @@ int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
 
 	return 0;
 }
+
+/*
+ * Create a copy of the vector table so we can call HVC_SET_VECTORS or
+ * HVC_SOFT_RESTART from contexts where the table may be overwritten.
+ */
+int trans_pgd_copy_el2_vectors(struct trans_pgd_info *info,
+			       phys_addr_t *el2_vectors)
+{
+	void *hyp_stub = trans_alloc(info);
+
+	if (!hyp_stub)
+		return -ENOMEM;
+	*el2_vectors = virt_to_phys(hyp_stub);
+	memcpy(hyp_stub, &trans_pgd_stub_vectors, ARM64_VECTOR_TABLE_LEN);
+	caches_clean_inval_pou((unsigned long)hyp_stub,
+			       (unsigned long)hyp_stub +
+			       ARM64_VECTOR_TABLE_LEN);
+	dcache_clean_inval_poc((unsigned long)hyp_stub,
+			       (unsigned long)hyp_stub +
+			       ARM64_VECTOR_TABLE_LEN);
+
+	return 0;
+}