[PATCH v6 03/11] arm64: realm: Query IPA size from the RMM

[Steven Price <steven.price@arm.com>]

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.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
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 v4:
 * Make PROT_NS_SHARED check is_realm_world() to reduce impact on
   non-CCA systems.
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 | 4 ++++
 arch/arm64/include/asm/rsi.h          | 2 +-
 arch/arm64/kernel/rsi.c               | 8 ++++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index 2a11d0c10760..820a3b06f08c 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -68,8 +68,12 @@
 
 #include <asm/cpufeature.h>
 #include <asm/pgtable-types.h>
+#include <asm/rsi.h>
 
 extern bool arm64_use_ng_mappings;
+extern unsigned long prot_ns_shared;
+
+#define PROT_NS_SHARED		(is_realm_world() ? prot_ns_shared : 0)
 
 #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/include/asm/rsi.h b/arch/arm64/include/asm/rsi.h
index e4c01796c618..acba065eb00e 100644
--- a/arch/arm64/include/asm/rsi.h
+++ b/arch/arm64/include/asm/rsi.h
@@ -27,7 +27,7 @@ static inline int rsi_set_memory_range(phys_addr_t start, phys_addr_t end,
 
 	while (start != end) {
 		ret = rsi_set_addr_range_state(start, end, state, flags, &top);
-		if (WARN_ON(ret || top < start || top > end))
+		if (ret || top < start || top > end)
 			return -EINVAL;
 		start = top;
 	}
diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c
index 9bf757b4b00c..a6495a64d9bb 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);
 
@@ -67,6 +72,9 @@ void __init arm64_rsi_init(void)
 		return;
 	if (!rsi_version_matches())
 		return;
+	if (WARN_ON(rsi_get_realm_config(&config)))
+		return;
+	prot_ns_shared = BIT(config.ipa_bits - 1);
 
 	arm64_rsi_setup_memory();
 
-- 
2.34.1