1 files changed, 25 insertions, 6 deletions

diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c
index ce4778141ec7..92160f2e57ff 100644
--- a/arch/arm64/kernel/rsi.c
+++ b/arch/arm64/kernel/rsi.c
@@ -12,6 +12,7 @@
 
 #include <asm/io.h>
 #include <asm/mem_encrypt.h>
+#include <asm/pgtable.h>
 #include <asm/rsi.h>
 
 static struct realm_config config;
@@ -84,7 +85,25 @@ static void __init arm64_rsi_setup_memory(void)
 	}
 }
 
-bool __arm64_is_protected_mmio(phys_addr_t base, size_t size)
+/*
+ * Check if a given PA range is Trusted (e.g., Protected memory, a Trusted Device
+ * mapping, or an MMIO emulated in the Realm world).
+ *
+ * We can rely on the RIPAS value of the region to detect if a given region is
+ * protected.
+ *
+ *  RIPAS_DEV - A trusted device memory or a trusted emulated MMIO (in the Realm
+ *		world
+ *  RIPAS_RAM - Memory (RAM), protected by the RMM guarantees. (e.g., Firmware
+ *		reserved regions for data sharing).
+ *
+ *  RIPAS_DESTROYED is a special case of one of the above, where the host did
+ *  something without our permission and as such we can't do anything about it.
+ *
+ * The only case where something is emulated by the untrusted hypervisor or is
+ * backed by shared memory is indicated by RSI_RIPAS_EMPTY.
+ */
+bool arm64_rsi_is_protected(phys_addr_t base, size_t size)
 {
 	enum ripas ripas;
 	phys_addr_t end, top;
@@ -101,18 +120,18 @@ bool __arm64_is_protected_mmio(phys_addr_t base, size_t size)
 			break;
 		if (WARN_ON(top <= base))
 			break;
-		if (ripas != RSI_RIPAS_DEV)
+		if (ripas == RSI_RIPAS_EMPTY)
 			break;
 		base = top;
 	}
 
 	return base >= end;
 }
-EXPORT_SYMBOL(__arm64_is_protected_mmio);
+EXPORT_SYMBOL(arm64_rsi_is_protected);
 
 static int realm_ioremap_hook(phys_addr_t phys, size_t size, pgprot_t *prot)
 {
-	if (__arm64_is_protected_mmio(phys, size))
+	if (arm64_rsi_is_protected(phys, size))
 		*prot = pgprot_encrypted(*prot);
 	else
 		*prot = pgprot_decrypted(*prot);
@@ -126,9 +145,9 @@ void __init arm64_rsi_init(void)
 		return;
 	if (!rsi_version_matches())
 		return;
-	if (WARN_ON(rsi_get_realm_config(&config)))
+	if (WARN_ON(rsi_get_realm_config(lm_alias(&config))))
 		return;
-	prot_ns_shared = BIT(config.ipa_bits - 1);
+	prot_ns_shared = __phys_to_pte_val(BIT(config.ipa_bits - 1));
 
 	if (arm64_ioremap_prot_hook_register(realm_ioremap_hook))
 		return;