On Tue, Dec 04, 2018 at 08:59:41PM +1100, Michael Ellerman wrote:

Hi Mike,

Thanks for trying to clean these up.

I think a few could be improved though ...

Mike Rapoport [off-list ref] writes:

quoted

diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 913bfca..fa884ad 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c

@@ -42,17 +42,15 @@ static void *__init alloc_paca_data(unsigned long size, unsigned long align,
 		nid = early_cpu_to_node(cpu);
 	}
 
-	pa = memblock_alloc_base_nid(size, align, limit, nid, MEMBLOCK_NONE);
-	if (!pa) {
-		pa = memblock_alloc_base(size, align, limit);
-		if (!pa)
-			panic("cannot allocate paca data");
-	}
+	ptr = memblock_alloc_try_nid_raw(size, align, MEMBLOCK_LOW_LIMIT,
+					 limit, nid);
+	if (!ptr)
+		panic("cannot allocate paca data");

  
The old code doesn't zero, but two of the three callers of
alloc_paca_data() *do* zero the whole allocation, so I'd be happy if we
did it in here instead.

I looked at the callers and couldn't tell if zeroing memory in
init_lppaca() would be ok.
I'll remove the _raw here.
 

That would mean we could use memblock_alloc_try_nid() avoiding the need
to panic() manually.

Actual, my plan was to remove panic() from all memblock_alloc* and make all
callers to check the returned value.
I believe it's cleaner and also allows more meaningful panic messages. Not
mentioning the reduction of memblock code.
 

quoted

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 236c115..d11ee7f 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_raw(THREAD_SIZE, THREAD_SIZE,
+					 MEMBLOCK_LOW_LIMIT, limit,
+					 early_cpu_to_node(cpu));
+	if (!ptr)
+		panic("cannot allocate stacks");

 
Similarly here, several of the callers zero the stack, and I'd rather
all of them did.

So again we could use memblock_alloc_try_nid() here and remove the
memset()s from emergency_stack_init().

Ok
 

quoted

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 9311560..415a1eb0 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c

@@ -51,24 +51,18 @@ static int native_register_process_table(unsigned long base, unsigned long pg_sz
 static __ref void *early_alloc_pgtable(unsigned long size, int nid,
 			unsigned long region_start, unsigned long region_end)
 {
-	unsigned long pa = 0;
+	phys_addr_t min_addr = MEMBLOCK_LOW_LIMIT;
+	phys_addr_t max_addr = MEMBLOCK_ALLOC_ANYWHERE;
 	void *pt;
 
-	if (region_start || region_end) /* has region hint */
-		pa = memblock_alloc_range(size, size, region_start, region_end,
-						MEMBLOCK_NONE);
-	else if (nid != -1) /* has node hint */
-		pa = memblock_alloc_base_nid(size, size,
-						MEMBLOCK_ALLOC_ANYWHERE,
-						nid, MEMBLOCK_NONE);
+	if (region_start)
+		min_addr = region_start;
+	if (region_end)
+		max_addr = region_end;
 
-	if (!pa)
-		pa = memblock_alloc_base(size, size, MEMBLOCK_ALLOC_ANYWHERE);
-
-	BUG_ON(!pa);
-
-	pt = __va(pa);
-	memset(pt, 0, size);
+	pt = memblock_alloc_try_nid_nopanic(size, size, min_addr, max_addr,
+					    nid);
+	BUG_ON(!pt);

I don't think there's any reason to BUG_ON() here rather than letting
memblock() call panic() for us. So this could also be memblock_alloc_try_nid().

I'd prefer to panic here.
 

quoted

diff --git a/arch/powerpc/platforms/pasemi/iommu.c b/arch/powerpc/platforms/pasemi/iommu.c
index f297152..f62930f 100644
--- a/arch/powerpc/platforms/pasemi/iommu.c
+++ b/arch/powerpc/platforms/pasemi/iommu.c

@@ -208,7 +208,9 @@ static int __init iob_init(struct device_node *dn)
 	pr_debug(" -> %s\n", __func__);
 
 	/* For 2G space, 8x64 pages (2^21 bytes) is max total l2 size */
-	iob_l2_base = (u32 *)__va(memblock_alloc_base(1UL<<21, 1UL<<21, 0x80000000));
+	iob_l2_base = memblock_alloc_try_nid_raw(1UL << 21, 1UL << 21,
+					MEMBLOCK_LOW_LIMIT, 0x80000000,
+					NUMA_NO_NODE);

This isn't equivalent is it?

memblock_alloc_base() panics on failure but memblock_alloc_try_nid_raw()
doesn't?

Right, this should be either a memblock function that panic()'s or a call
to panic() if the returned value is NULL.
My preference is for the second variant :)
 

Same comment for the other locations that do that conversion.

cheers

-- 
Sincerely yours,
Mike.


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