Re: [PATCH v16 01/21] powerpc/irq: use memblock functions returning virtual address

From: Christophe Leroy <redacted>

Since only the virtual address of allocated blocks is used,
lets use functions returning directly virtual address.

Those functions have the advantage of also zeroing the block.

Suggested-by: Mike Rapoport <redacted>
Acked-by: Mike Rapoport <redacted>
Signed-off-by: Christophe Leroy <redacted>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/kernel/irq.c      |  5 -----
 arch/powerpc/kernel/setup_32.c | 26 ++++++++++++++++----------
 arch/powerpc/kernel/setup_64.c | 19 +++++++------------
 3 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index bb299613a462..4a5dd8800946 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c

@@ -725,18 +725,15 @@ void exc_lvl_ctx_init(void)
 #endif
 #endif
 
-		memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
 		tp = critirq_ctx[cpu_nr];
 		tp->cpu = cpu_nr;
 		tp->preempt_count = 0;
 
 #ifdef CONFIG_BOOKE
-		memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
 		tp = dbgirq_ctx[cpu_nr];
 		tp->cpu = cpu_nr;
 		tp->preempt_count = 0;
 
-		memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
 		tp = mcheckirq_ctx[cpu_nr];
 		tp->cpu = cpu_nr;
 		tp->preempt_count = HARDIRQ_OFFSET;

@@ -754,12 +751,10 @@ void irq_ctx_init(void)
 	int i;
 
 	for_each_possible_cpu(i) {
-		memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 		tp = softirq_ctx[i];
 		tp->cpu = i;
 		klp_init_thread_info(tp);
 
-		memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 		tp = hardirq_ctx[i];
 		tp->cpu = i;
 		klp_init_thread_info(tp);

diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 947f904688b0..1f0b7629c1a6 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c

@@ -196,6 +196,17 @@ static int __init ppc_init(void)
 }
 arch_initcall(ppc_init);
 
+static void *__init alloc_stack(void)
+{
+	void *ptr = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
+
+	if (!ptr)
+		panic("cannot allocate %d bytes for stack at %pS\n",
+		      THREAD_SIZE, (void *)_RET_IP_);
+
+	return ptr;
+}
+
 void __init irqstack_early_init(void)
 {
 	unsigned int i;

@@ -203,10 +214,8 @@ void __init irqstack_early_init(void)
 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
 	 * as the memblock is limited to lowmem by default */
 	for_each_possible_cpu(i) {
-		softirq_ctx[i] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
-		hardirq_ctx[i] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
+		softirq_ctx[i] = alloc_stack();
+		hardirq_ctx[i] = alloc_stack();
 	}
 }
 

@@ -224,13 +233,10 @@ void __init exc_lvl_early_init(void)
 		hw_cpu = 0;
 #endif
 
-		critirq_ctx[hw_cpu] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
+		critirq_ctx[hw_cpu] = alloc_stack();
 #ifdef CONFIG_BOOKE
-		dbgirq_ctx[hw_cpu] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
-		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
-			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
+		dbgirq_ctx[hw_cpu] = alloc_stack();
+		mcheckirq_ctx[hw_cpu] = alloc_stack();
 #endif
 	}
 }

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 236c1151a3a7..080dd515d587 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c

@@ -634,19 +634,17 @@ __init u64 ppc64_bolted_size(void)
 
 static void *__init alloc_stack(unsigned long limit, int cpu)
 {
-	unsigned long pa;
+	void *ptr;
 
 	BUILD_BUG_ON(STACK_INT_FRAME_SIZE % 16);
 
-	pa = memblock_alloc_base_nid(THREAD_SIZE, THREAD_SIZE, limit,
-					early_cpu_to_node(cpu), MEMBLOCK_NONE);
-	if (!pa) {
-		pa = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
-		if (!pa)
-			panic("cannot allocate stacks");
-	}
+	ptr = memblock_alloc_try_nid(THREAD_SIZE, THREAD_SIZE,
+				     MEMBLOCK_LOW_LIMIT, limit,
+				     early_cpu_to_node(cpu));