From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: Thu, 17 Oct 2024 13:14:28 +0000 (+0100)
Subject: arm64: rsi: Map unprotected MMIO as decrypted
X-Git-Tag: v6.13-rc1~15^2~5^13~6
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=3c6c706139564f74ec48229378873c1d930a8bc8;p=linux-block.git

arm64: rsi: Map unprotected MMIO as decrypted

Instead of marking every MMIO as shared, check if the given region is
"Protected" and apply the permissions accordingly.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20241017131434.40935-6-steven.price@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---

diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c
index 7e7934c4fca0..3e0c83e2296f 100644
--- a/arch/arm64/kernel/rsi.c
+++ b/arch/arm64/kernel/rsi.c
@@ -6,6 +6,8 @@
 #include <linux/jump_label.h>
 #include <linux/memblock.h>
 #include <linux/psci.h>
+
+#include <asm/io.h>
 #include <asm/rsi.h>
 
 static struct realm_config config;
@@ -93,6 +95,16 @@ bool __arm64_is_protected_mmio(phys_addr_t base, size_t size)
 }
 EXPORT_SYMBOL(__arm64_is_protected_mmio);
 
+static int realm_ioremap_hook(phys_addr_t phys, size_t size, pgprot_t *prot)
+{
+	if (__arm64_is_protected_mmio(phys, size))
+		*prot = pgprot_encrypted(*prot);
+	else
+		*prot = pgprot_decrypted(*prot);
+
+	return 0;
+}
+
 void __init arm64_rsi_init(void)
 {
 	if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_SMC)
@@ -103,6 +115,9 @@ void __init arm64_rsi_init(void)
 		return;
 	prot_ns_shared = BIT(config.ipa_bits - 1);
 
+	if (arm64_ioremap_prot_hook_register(realm_ioremap_hook))
+		return;
+
 	arm64_rsi_setup_memory();
 
 	static_branch_enable(&rsi_present);