[PATCH RFC 13/17] arm64: text replication: update cnp support

Russell King (Oracle) rmk+kernel at armlinux.org.uk
Tue May 30 07:05:36 PDT 2023


Add changes for CNP (Common Not Private) support of kernel text
replication. Although text replication has only been tested on
dual-socket Ampere A1 systems, provided the different NUMA nodes
are not part of the same inner shareable domain, CNP should not
be a problem.

Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
---
 arch/arm64/include/asm/mmu_context.h | 2 +-
 arch/arm64/kernel/cpufeature.c       | 2 +-
 arch/arm64/kernel/suspend.c          | 3 ++-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index 4aa6afc6f935..c0e13dc73fd7 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -159,7 +159,7 @@ static inline void cpu_replace_ttbr1_phys(phys_addr_t pgd_phys, pgd_t *idmap)
 	phys_addr_t ttbr1 = phys_to_ttbr(pgd_phys);
 
 	if (system_supports_cnp() &&
-	    !WARN_ON(pgd_phys != virt_to_phys(lm_alias(swapper_pg_dir)))) {
+	    !WARN_ON(pgd_phys != swapper_pg_dir_node_phys())) {
 		/*
 		 * cpu_replace_ttbr1() is used when there's a boot CPU
 		 * up (i.e. cpufeature framework is not up yet) and
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 7d7128c65161..fdb93b5b7d8e 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -3341,7 +3341,7 @@ subsys_initcall_sync(init_32bit_el0_mask);
 
 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
 {
-	cpu_replace_ttbr1(lm_alias(swapper_pg_dir), idmap_pg_dir);
+	cpu_replace_ttbr1_phys(swapper_pg_dir_node_phys(), idmap_pg_dir);
 }
 
 /*
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
index 0fbdf5fe64d8..49fa80bafd6d 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -55,7 +55,8 @@ void notrace __cpu_suspend_exit(void)
 
 	/* Restore CnP bit in TTBR1_EL1 */
 	if (system_supports_cnp())
-		cpu_replace_ttbr1(lm_alias(swapper_pg_dir), idmap_pg_dir);
+		cpu_replace_ttbr1_phys(swapper_pg_dir_node_phys(),
+				       idmap_pg_dir);
 
 	/*
 	 * PSTATE was not saved over suspend/resume, re-enable any detected
-- 
2.30.2




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