[PATCH v2 1/3] powerpc/mm/drconf: Use NUMA_NO_NODE on failures instead of node 0

[PATCH v2 1/3] powerpc/mm/drconf: Use NUMA_NO_NODE on failures instead of node 0

[Aneesh Kumar K.V]

If we fail to parse the associativity array we should default to
NUMA_NO_NODE instead of NODE 0. Rest of the code fallback to the
right default if we find the numa node value NUMA_NO_NODE.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/mm/numa.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 917904d2fe97..aee718509085 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -416,17 +416,19 @@ static int of_get_assoc_arrays(struct assoc_arrays *aa)
 static int of_drconf_to_nid_single(struct drmem_lmb *lmb)
 {
 	struct assoc_arrays aa = { .arrays = NULL };
-	int default_nid = 0;
+	int default_nid = NUMA_NO_NODE;
 	int nid = default_nid;
 	int rc, index;
 
+	if (min_common_depth < 0)
+		return default_nid;
+
 	rc = of_get_assoc_arrays(&aa);
 	if (rc)
 		return default_nid;
 
-	if (min_common_depth > 0 && min_common_depth <= aa.array_sz &&
-	    !(lmb->flags & DRCONF_MEM_AI_INVALID) &&
-	    lmb->aa_index < aa.n_arrays) {
+	if (min_common_depth <= aa.array_sz &&
+	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
 		index = lmb->aa_index * aa.array_sz + min_common_depth - 1;
 		nid = of_read_number(&aa.arrays[index], 1);
 
-- 
2.21.0

[PATCH v2 2/3] powerpc/mm: Fix node look up with numa=off boot

[Aneesh Kumar K.V]

If we boot with numa=off, we need to make sure we return NUMA_NO_NODE when
looking up associativity details of resources. Without this, we hit crash
like below

BUG: Unable to handle kernel data access at 0x40000000008
Faulting instruction address: 0xc000000008f31704
cpu 0x1b: Vector: 380 (Data SLB Access) at [c00000000b9bb320]
    pc: c000000008f31704: _raw_spin_lock+0x14/0x100
    lr: c0000000083f41fc: ____cache_alloc_node+0x5c/0x290
    sp: c00000000b9bb5b0
   msr: 800000010280b033
   dar: 40000000008
  current = 0xc00000000b9a2700
  paca    = 0xc00000000a740c00   irqmask: 0x03   irq_happened: 0x01
    pid   = 1, comm = swapper/27
Linux version 5.2.0-rc4-00925-g74e188c620b1 (root@linux-d8ip) (gcc version 7.4.1 20190424 [gcc-7-branch revision 270538] (SUSE Linux)) #34 SMP Sat Jun 29 00:41:02 EDT 2019
enter ? for help
[link register   ] c0000000083f41fc ____cache_alloc_node+0x5c/0x290
[c00000000b9bb5b0] 0000000000000dc0 (unreliable)
[c00000000b9bb5f0] c0000000083f48c8 kmem_cache_alloc_node_trace+0x138/0x360
[c00000000b9bb670] c000000008aa789c devres_alloc_node+0x4c/0xa0
[c00000000b9bb6a0] c000000008337218 devm_memremap+0x58/0x130
[c00000000b9bb6f0] c000000008aed00c devm_nsio_enable+0xdc/0x170
[c00000000b9bb780] c000000008af3b6c nd_pmem_probe+0x4c/0x180
[c00000000b9bb7b0] c000000008ad84cc nvdimm_bus_probe+0xac/0x260
[c00000000b9bb840] c000000008aa0628 really_probe+0x148/0x500
[c00000000b9bb8d0] c000000008aa0d7c driver_probe_device+0x19c/0x1d0
[c00000000b9bb950] c000000008aa11bc device_driver_attach+0xcc/0x100
[c00000000b9bb990] c000000008aa12ec __driver_attach+0xfc/0x1e0
[c00000000b9bba10] c000000008a9d0a4 bus_for_each_dev+0xb4/0x130
[c00000000b9bba70] c000000008a9fc04 driver_attach+0x34/0x50
[c00000000b9bba90] c000000008a9f118 bus_add_driver+0x1d8/0x300
[c00000000b9bbb20] c000000008aa2358 driver_register+0x98/0x1a0
[c00000000b9bbb90] c000000008ad7e6c __nd_driver_register+0x5c/0x100
[c00000000b9bbbf0] c0000000093efbac nd_pmem_driver_init+0x34/0x48
[c00000000b9bbc10] c0000000080106c0 do_one_initcall+0x60/0x2d0
[c00000000b9bbce0] c00000000938463c kernel_init_freeable+0x384/0x48c
[c00000000b9bbdb0] c000000008010a5c kernel_init+0x2c/0x160
[c00000000b9bbe20] c00000000800ba54 ret_from_kernel_thread+0x5c/0x68

Reported-and-debugged-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/mm/numa.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index aee718509085..27f792c0df68 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -212,7 +212,7 @@ static int associativity_to_nid(const __be32 *associativity)
 {
 	int nid = NUMA_NO_NODE;
 
-	if (min_common_depth == -1)
+	if (min_common_depth == -1 || !numa_enabled)
 		goto out;
 
 	if (of_read_number(associativity, 1) >= min_common_depth)
@@ -420,7 +420,7 @@ static int of_drconf_to_nid_single(struct drmem_lmb *lmb)
 	int nid = default_nid;
 	int rc, index;
 
-	if (min_common_depth < 0)
+	if ((min_common_depth < 0) || !numa_enabled)
 		return default_nid;
 
 	rc = of_get_assoc_arrays(&aa);
@@ -810,7 +810,7 @@ static void __init find_possible_nodes(void)
 	struct device_node *rtas;
 	u32 numnodes, i;
 
-	if (min_common_depth <= 0)
+	if (min_common_depth <= 0 || !numa_enabled)
 		return;
 
 	rtas = of_find_node_by_path("/rtas");
-- 
2.21.0

[PATCH v2 3/3] powerpc/mm: Consolidate numa_enable check and min_common_depth check

[Aneesh Kumar K.V]

If we fail to parse min_common_depth from device tree we boot with
numa disabled. Reflect the same by updating numa_enabled variable
to false. Also, switch all min_common_depth failure check to
if (!numa_enabled) check.

This helps us to avoid checking for both in different code paths.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/mm/numa.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 27f792c0df68..848b4663c7ad 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -212,7 +212,7 @@ static int associativity_to_nid(const __be32 *associativity)
 {
 	int nid = NUMA_NO_NODE;
 
-	if (min_common_depth == -1 || !numa_enabled)
+	if (!numa_enabled)
 		goto out;
 
 	if (of_read_number(associativity, 1) >= min_common_depth)
@@ -628,8 +628,14 @@ static int __init parse_numa_properties(void)
 
 	min_common_depth = find_min_common_depth();
 
-	if (min_common_depth < 0)
+	if (min_common_depth < 0) {
+		/*
+		 * if we fail to parse min_common_depth from device tree
+		 * mark the numa disabled, boot with numa disabled.
+		 */
+		numa_enabled = false;
 		return min_common_depth;
+	}
 
 	dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
 
@@ -745,7 +751,7 @@ void __init dump_numa_cpu_topology(void)
 	unsigned int node;
 	unsigned int cpu, count;
 
-	if (min_common_depth == -1 || !numa_enabled)
+	if (!numa_enabled)
 		return;
 
 	for_each_online_node(node) {
@@ -810,7 +816,7 @@ static void __init find_possible_nodes(void)
 	struct device_node *rtas;
 	u32 numnodes, i;
 
-	if (min_common_depth <= 0 || !numa_enabled)
+	if (!numa_enabled)
 		return;
 
 	rtas = of_find_node_by_path("/rtas");
@@ -1012,7 +1018,7 @@ int hot_add_scn_to_nid(unsigned long scn_addr)
 	struct device_node *memory = NULL;
 	int nid;
 
-	if (!numa_enabled || (min_common_depth < 0))
+	if (!numa_enabled)
 		return first_online_node;
 
 	memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
-- 
2.21.0

Re: [PATCH v2 1/3] powerpc/mm/drconf: Use NUMA_NO_NODE on failures instead of node 0

[Michael Ellerman]

On Mon, 2019-07-01 at 14:36:24 UTC, "Aneesh Kumar K.V" wrote:
> If we fail to parse the associativity array we should default to
> NUMA_NO_NODE instead of NODE 0. Rest of the code fallback to the
> right default if we find the numa node value NUMA_NO_NODE.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/ea9f5b702fe0215188fba2eda117419e4ae90a67

cheers