diff mbox series

[v4,04/15] arm64: realm: Query IPA size from the RMM

Message ID 20240701095505.165383-5-steven.price@arm.com (mailing list archive)
State New
Headers show
Series arm64: Support for running as a guest in Arm CCA | expand

Commit Message

Steven Price July 1, 2024, 9:54 a.m. UTC 
The top bit of the configured IPA size is used as an attribute to
control whether the address is protected or shared. Query the
configuration from the RMM to assertain which bit this is.

Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v2:
 * Drop unneeded extra brackets from PROT_NS_SHARED.
 * Drop the explicit alignment from 'config' as struct realm_config now
   specifies the alignment.
---
 arch/arm64/include/asm/pgtable-prot.h | 3 +++
 arch/arm64/kernel/rsi.c               | 8 ++++++++
 2 files changed, 11 insertions(+)
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index b11cfb9fdd37..6c29f3b32eba 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -70,6 +70,9 @@ 
 #include <asm/pgtable-types.h>
 
 extern bool arm64_use_ng_mappings;
+extern unsigned long prot_ns_shared;
+
+#define PROT_NS_SHARED		(prot_ns_shared)
 
 #define PTE_MAYBE_NG		(arm64_use_ng_mappings ? PTE_NG : 0)
 #define PMD_MAYBE_NG		(arm64_use_ng_mappings ? PMD_SECT_NG : 0)
diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c
index f01bff9dab04..231c1a3ecdeb 100644
--- a/arch/arm64/kernel/rsi.c
+++ b/arch/arm64/kernel/rsi.c
@@ -8,6 +8,11 @@ 
 #include <linux/psci.h>
 #include <asm/rsi.h>
 
+struct realm_config config;
+
+unsigned long prot_ns_shared;
+EXPORT_SYMBOL(prot_ns_shared);
+
 DEFINE_STATIC_KEY_FALSE_RO(rsi_present);
 EXPORT_SYMBOL(rsi_present);
 
@@ -71,6 +76,9 @@  void __init arm64_rsi_init(void)
 		return;
 	if (!rsi_version_matches())
 		return;
+	if (rsi_get_realm_config(&config))
+		return;
+	prot_ns_shared = BIT(config.ipa_bits - 1);
 
 	static_branch_enable(&rsi_present);
 }