[PATCH RFC 12/17] arm64: text replication: boot secondary CPUs with appropriate TTBR1

[Russell King (Oracle)]

Arrange for secondary CPUs to boot with TTBR1 pointing at the
appropriate per-node copy of the kernel page tables for the CPUs NUMA
node.

Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
---
 arch/arm64/include/asm/smp.h    | 1 +
 arch/arm64/kernel/asm-offsets.c | 1 +
 arch/arm64/kernel/head.S        | 3 ++-
 arch/arm64/kernel/smp.c         | 3 +++
 4 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index f2d26235bfb4..9a4246141599 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -79,6 +79,7 @@ asmlinkage void secondary_start_kernel(void);
 struct secondary_data {
 	struct task_struct *task;
 	long status;
+	phys_addr_t ttbr1;
 };
 
 extern struct secondary_data secondary_data;
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 0996094b0d22..f3b8cf661de2 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -121,6 +121,7 @@ int main(void)
   DEFINE(IRQ_CPUSTAT_SOFTIRQ_PENDING, offsetof(irq_cpustat_t, __softirq_pending));
   BLANK();
   DEFINE(CPU_BOOT_TASK,		offsetof(struct secondary_data, task));
+  DEFINE(CPU_BOOT_TTBR1,	offsetof(struct secondary_data, ttbr1));
   BLANK();
   DEFINE(FTR_OVR_VAL_OFFSET,	offsetof(struct arm64_ftr_override, val));
   DEFINE(FTR_OVR_MASK_OFFSET,	offsetof(struct arm64_ftr_override, mask));
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index e92caebff46a..e66ee578f755 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -646,7 +646,8 @@ SYM_FUNC_START_LOCAL(secondary_startup)
 	ldr_l	x0, vabits_actual
 #endif
 	bl	__cpu_setup			// initialise processor
-	adrp	x1, swapper_pg_dir
+	adr_l	x1, secondary_data
+	ldr	x1, [x1, #CPU_BOOT_TTBR1]
 	adrp	x2, idmap_pg_dir
 	bl	__enable_mmu
 	ldr	x8, =__secondary_switched
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index d00d4cbb31b1..8b4cd4924abf 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -119,6 +119,9 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
 	 * page tables.
 	 */
 	secondary_data.task = idle;
+	secondary_data.ttbr1 = __swapper_pg_dir_node_phys(cpu_to_node(cpu));
+	dcache_clean_poc((uintptr_t)&secondary_data,
+			 (uintptr_t)&secondary_data + sizeof(secondary_data));
 	update_cpu_boot_status(CPU_MMU_OFF);
 
 	/* Now bring the CPU into our world */
-- 
2.30.2