| Message ID | 20200629161659.3006329-1-Jonathan.Cameron@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [RFC] ACPI: Only create numa nodes from entries in SRAT or SRAT emulation. | expand |
On Tue, 30 Jun 2020 00:16:59 +0800 Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > Here, I will use the term Proximity Domains for the ACPI description > and Numa Nodes for the in kernel representation. > > Until ACPI 6.3 it was arguably possible to interpret the > specification as allowing _PXM in DSDT and similar to define > additional Proximity Domains. > > The reality was that was never the intent, and a 'clarification' was > added in ACPI 6.3 [1]. In practice I think the kernel has never > allowed any other interpretaion, except possibly on adhoc base within > some out of tree driver (using it very very carefully given potential > to crash when using various standard calls such as devm_kzalloc). > > Proximity Domains are always defined in SRAT. In ACPI, there are > methods defined in ACPI to allow their characteristics to be tweaked > later but Proximity Domains have to be referenced in this table at > boot, thus allowing Linux to instantiate relevant Numa Node data > structures. > > We ran into a problem when enabling _PXM handling for PCI devices and > found there were boards out there advertising devices in proximity > domains that didn't exist [2]. > > The fix suggested here is to modfiy the function acpi_map_pxm_to_node. > This function is both used to create and lookup proximity domains. > A parameter is added to specify whether it should create a new > proximity domain when it encounters a Proximity Domain ID that it > hasn't seen before. > > Naturally there is a quirk. For SRAT ITS entries on ARM64 the > handling is done with an additional pass of SRAT, potentially later > in the boot. We could modify that behaviour so we could identify the > existence of Proximity Domains unique to the ITS structures, and > handle them as a special case of a Genric Initiator (once support for > those merges) however... > > Currently (5.8-rc2) setting the Proximity Domain of an ITS to one > that hasn't been instantiated by being specified in another type of > SRAT resource entry results in: > > ITS [mem 0x202100000-0x20211ffff] > ITS@0x0000000202100000: Using ITS number 0 > Unable to handle kernel paging request at virtual address > 0000000000001a08 Mem abort info: > ESR = 0x96000004 > EC = 0x25: DABT (current EL), IL = 32 bits > SET = 0, FnV = 0 > EA = 0, S1PTW = 0 > Data abort info: > ISV = 0, ISS = 0x00000004 > CM = 0, WnR = 0 > [0000000000001a08] user address but active_mm is swapper > Internal error: Oops: 96000004 [#1] PREEMPT SMP > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Tainted: G A 5.8.0-rc2 > #483 pstate: 80000089 (Nzcv daIf -PAN -UAO BTYPE=--) > pc : __alloc_pages_nodemask+0xe8/0x338 > lr : __alloc_pages_nodemask+0xc0/0x338 > sp : ffffa81540c139b0 > x29: ffffa81540c139b0 x28: 0000000000000001 > x27: 0000000000000100 x26: ffffa81540c1ad38 > x25: 0000000000000000 x24: 0000000000000000 > x23: ffffa81540c23c00 x22: 0000000000000004 > x21: 0000000000000002 x20: 0000000000001a00 > x19: 0000000000000100 x18: 0000000000000010 > x17: 000000000001f000 x16: 000000000000007f > x15: ffffa81540c24070 x14: ffffffffffffffff > x13: ffffa815c0c137d7 x12: ffffa81540c137e4 > x11: ffffa81540c3e000 x10: ffffa81540ecee68 > x9 : ffffa8153f0f61d8 x8 : ffffa81540ecf000 > x7 : 0000000000000141 x6 : ffffa81540ecf401 > x5 : 0000000000000000 x4 : 0000000000000000 > x3 : 0000000000000000 x2 : 0000000000000000 > x1 : 0000000000000081 x0 : 0000000000001a00 > Call trace: > __alloc_pages_nodemask+0xe8/0x338 > alloc_pages_node.constprop.0+0x34/0x40 > its_probe_one+0x2f8/0xb18 > gic_acpi_parse_madt_its+0x108/0x150 > acpi_table_parse_entries_array+0x17c/0x264 > acpi_table_parse_entries+0x48/0x6c > acpi_table_parse_madt+0x30/0x3c > its_init+0x1c4/0x644 > gic_init_bases+0x4b8/0x4ec > gic_acpi_init+0x134/0x264 > acpi_match_madt+0x4c/0x84 > acpi_table_parse_entries_array+0x17c/0x264 > acpi_table_parse_entries+0x48/0x6c > acpi_table_parse_madt+0x30/0x3c > __acpi_probe_device_table+0x8c/0xe8 > irqchip_init+0x3c/0x48 > init_IRQ+0xcc/0x100 > start_kernel+0x33c/0x548 > > As we die in this case in existing kernels, we can be fairly sure > that no one actually has such a firmware in production. As such this > patch avoids the complexity that would be needed to handle this > corner case, and simply does not allow the ITS entry parsing code to > instantiate new Numa Nodes. If one is encountered that does not > already exist, then NO_NUMA_NODE is assigned and a warning printed > just as if the value had been greater than allowed Numa Nodes. > > "SRAT: Invalid NUMA node -1 in ITS affinity" > > I have only tested this for now on our ARM64 Kunpeng920 servers. > > Open questions: > * should we warn about a broken firmware or insufficent value of > NUMA_NODES_SHIFT if we find a firmware trying to assign any device > to a non existent Proximity Domain. > * previously an smmuv3 in IORT with a Proximity Domain set to a non > existent value would have resulted in a failure to add the device. > After this change it will be added to the default node. Is that a > problem? > > [1] Note in ACPI Specification 6.3 5.2.16 System Resource Affinity > Table (SRAT) [2] https://patchwork.kernel.org/patch/10597777/ > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Note this is very much an "RFC". I missed a call in drivers/iommu/intel/dmar.c for which the parameter should be false. If people are happy with the general approach I'll tidy that up in the next version. Sorry about that, I should have remembered to do build tests on x86 at least :( Jonathan > --- > arch/arm64/kernel/acpi_numa.c | 2 +- > arch/ia64/kernel/acpi.c | 2 +- > arch/x86/mm/srat.c | 4 ++-- > drivers/acpi/arm64/iort.c | 2 +- > drivers/acpi/nfit/core.c | 2 +- > drivers/acpi/numa/hmat.c | 2 +- > drivers/acpi/numa/srat.c | 8 ++++---- > drivers/irqchip/irq-gic-v3-its.c | 6 +++++- > include/acpi/acpi_numa.h | 2 +- > include/linux/acpi.h | 6 +++--- > 10 files changed, 20 insertions(+), 16 deletions(-) > > diff --git a/arch/arm64/kernel/acpi_numa.c > b/arch/arm64/kernel/acpi_numa.c index 7ff800045434..6ed47b058d76 > 100644 --- a/arch/arm64/kernel/acpi_numa.c > +++ b/arch/arm64/kernel/acpi_numa.c > @@ -107,7 +107,7 @@ void __init acpi_numa_gicc_affinity_init(struct > acpi_srat_gicc_affinity *pa) return; > > pxm = pa->proximity_domain; > - node = acpi_map_pxm_to_node(pxm); > + node = acpi_map_pxm_to_node(pxm, true); > > if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) { > pr_err("SRAT: Too many proximity domains %d\n", pxm); > diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c > index a5636524af76..760a468864b7 100644 > --- a/arch/ia64/kernel/acpi.c > +++ b/arch/ia64/kernel/acpi.c > @@ -456,7 +456,7 @@ void __init acpi_numa_fixup(void) > nodes_clear(node_online_map); > for (i = 0; i < MAX_PXM_DOMAINS; i++) { > if (pxm_bit_test(i)) { > - int nid = acpi_map_pxm_to_node(i); > + int nid = acpi_map_pxm_to_node(i, true); > node_set_online(nid); > } > } > diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c > index dac07e4f5834..6497d7c241ec 100644 > --- a/arch/x86/mm/srat.c > +++ b/arch/x86/mm/srat.c > @@ -45,7 +45,7 @@ acpi_numa_x2apic_affinity_init(struct > acpi_srat_x2apic_cpu_affinity *pa) pxm, apic_id); > return; > } > - node = acpi_map_pxm_to_node(pxm); > + node = acpi_map_pxm_to_node(pxm, true); > if (node < 0) { > printk(KERN_ERR "SRAT: Too many proximity domains > %x\n", pxm); bad_srat(); > @@ -80,7 +80,7 @@ acpi_numa_processor_affinity_init(struct > acpi_srat_cpu_affinity *pa) pxm = pa->proximity_domain_lo; > if (acpi_srat_revision >= 2) > pxm |= *((unsigned int*)pa->proximity_domain_hi) << > 8; > - node = acpi_map_pxm_to_node(pxm); > + node = acpi_map_pxm_to_node(pxm, true); > if (node < 0) { > printk(KERN_ERR "SRAT: Too many proximity domains > %x\n", pxm); bad_srat(); > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index 28a6b387e80e..8133e7e6f9e3 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -1293,7 +1293,7 @@ static int __init > arm_smmu_v3_set_proximity(struct device *dev, > smmu = (struct acpi_iort_smmu_v3 *)node->node_data; > if (smmu->flags & ACPI_IORT_SMMU_V3_PXM_VALID) { > - int dev_node = acpi_map_pxm_to_node(smmu->pxm); > + int dev_node = acpi_map_pxm_to_node(smmu->pxm, > false); > if (dev_node != NUMA_NO_NODE && > !node_online(dev_node)) return -EINVAL; > diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c > index 7c138a4edc03..6cb44bbaa71f 100644 > --- a/drivers/acpi/nfit/core.c > +++ b/drivers/acpi/nfit/core.c > @@ -2948,7 +2948,7 @@ static int acpi_nfit_register_region(struct > acpi_nfit_desc *acpi_desc, ndr_desc->numa_node = > acpi_map_pxm_to_online_node( spa->proximity_domain); > ndr_desc->target_node = acpi_map_pxm_to_node( > - spa->proximity_domain); > + spa->proximity_domain, false); > } else { > ndr_desc->numa_node = NUMA_NO_NODE; > ndr_desc->target_node = NUMA_NO_NODE; > diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c > index 2c32cfb72370..3c0414816772 100644 > --- a/drivers/acpi/numa/hmat.c > +++ b/drivers/acpi/numa/hmat.c > @@ -666,7 +666,7 @@ static void hmat_register_target_device(struct > memory_target *target, > pdev->dev.numa_node = > acpi_map_pxm_to_online_node(target->memory_pxm); info = (struct > memregion_info) { > - .target_node = > acpi_map_pxm_to_node(target->memory_pxm), > + .target_node = > acpi_map_pxm_to_node(target->memory_pxm, false), }; > rc = platform_device_add_data(pdev, &info, sizeof(info)); > if (rc < 0) { > diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c > index 5be5a977da1b..ed7d31795f4d 100644 > --- a/drivers/acpi/numa/srat.c > +++ b/drivers/acpi/numa/srat.c > @@ -52,7 +52,7 @@ static void __acpi_map_pxm_to_node(int pxm, int > node) node_to_pxm_map[node] = pxm; > } > > -int acpi_map_pxm_to_node(int pxm) > +int acpi_map_pxm_to_node(int pxm, bool create) > { > int node; > > @@ -62,7 +62,7 @@ int acpi_map_pxm_to_node(int pxm) > node = pxm_to_node_map[pxm]; > > if (node == NUMA_NO_NODE) { > - if (nodes_weight(nodes_found_map) >= MAX_NUMNODES) > + if (nodes_weight(nodes_found_map) >= MAX_NUMNODES || > !create) return NUMA_NO_NODE; > node = first_unset_node(nodes_found_map); > __acpi_map_pxm_to_node(pxm, node); > @@ -229,7 +229,7 @@ acpi_numa_memory_affinity_init(struct > acpi_srat_mem_affinity *ma) if (acpi_srat_revision <= 1) > pxm &= 0xff; > > - node = acpi_map_pxm_to_node(pxm); > + node = acpi_map_pxm_to_node(pxm, true); > if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) { > pr_err("SRAT: Too many proximity domains.\n"); > goto out_err_bad_srat; > @@ -444,6 +444,6 @@ int acpi_get_node(acpi_handle handle) > > pxm = acpi_get_pxm(handle); > > - return acpi_map_pxm_to_node(pxm); > + return acpi_map_pxm_to_node(pxm, false); > } > EXPORT_SYMBOL(acpi_get_node); > diff --git a/drivers/irqchip/irq-gic-v3-its.c > b/drivers/irqchip/irq-gic-v3-its.c index cd685f521c77..0b11876d0799 > 100644 --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -5248,7 +5248,11 @@ static int __init > gic_acpi_parse_srat_its(union acpi_subtable_headers *header, return > -EINVAL; } > > - node = acpi_map_pxm_to_node(its_affinity->proximity_domain); > + /* > + * Note that in theory a new proximity node could be created > by this > + * entry as it is an SRAT resource allocation structure > + */ > + node = acpi_map_pxm_to_node(its_affinity->proximity_domain, > false); > if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) { > pr_err("SRAT: Invalid NUMA node %d in ITS > affinity\n", node); diff --git a/include/acpi/acpi_numa.h > b/include/acpi/acpi_numa.h index fdebcfc6c8df..6935c7516262 100644 > --- a/include/acpi/acpi_numa.h > +++ b/include/acpi/acpi_numa.h > @@ -15,7 +15,7 @@ > > extern int pxm_to_node(int); > extern int node_to_pxm(int); > -extern int acpi_map_pxm_to_node(int); > +extern int acpi_map_pxm_to_node(int, bool); > extern unsigned char acpi_srat_revision; > extern int acpi_numa __initdata; > > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index d661cd0ee64d..1414b7e0a486 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -416,7 +416,7 @@ extern void acpi_osi_setup(char *str); > extern bool acpi_osi_is_win8(void); > > #ifdef CONFIG_ACPI_NUMA > -int acpi_map_pxm_to_node(int pxm); > +int acpi_map_pxm_to_node(int pxm, bool create); > int acpi_get_node(acpi_handle handle); > > /** > @@ -436,7 +436,7 @@ int acpi_get_node(acpi_handle handle); > */ > static inline int acpi_map_pxm_to_online_node(int pxm) > { > - int node = acpi_map_pxm_to_node(pxm); > + int node = acpi_map_pxm_to_node(pxm, false); > > return numa_map_to_online_node(node); > } > @@ -445,7 +445,7 @@ static inline int acpi_map_pxm_to_online_node(int > pxm) { > return 0; > } > -static inline int acpi_map_pxm_to_node(int pxm) > +static inline int acpi_map_pxm_to_node(int pxm, bool create) > { > return 0; > }
diff --git a/arch/arm64/kernel/acpi_numa.c b/arch/arm64/kernel/acpi_numa.c index 7ff800045434..6ed47b058d76 100644 --- a/arch/arm64/kernel/acpi_numa.c +++ b/arch/arm64/kernel/acpi_numa.c @@ -107,7 +107,7 @@ void __init acpi_numa_gicc_affinity_init(struct acpi_srat_gicc_affinity *pa) return; pxm = pa->proximity_domain; - node = acpi_map_pxm_to_node(pxm); + node = acpi_map_pxm_to_node(pxm, true); if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) { pr_err("SRAT: Too many proximity domains %d\n", pxm); diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c index a5636524af76..760a468864b7 100644 --- a/arch/ia64/kernel/acpi.c +++ b/arch/ia64/kernel/acpi.c @@ -456,7 +456,7 @@ void __init acpi_numa_fixup(void) nodes_clear(node_online_map); for (i = 0; i < MAX_PXM_DOMAINS; i++) { if (pxm_bit_test(i)) { - int nid = acpi_map_pxm_to_node(i); + int nid = acpi_map_pxm_to_node(i, true); node_set_online(nid); } } diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c index dac07e4f5834..6497d7c241ec 100644 --- a/arch/x86/mm/srat.c +++ b/arch/x86/mm/srat.c @@ -45,7 +45,7 @@ acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa) pxm, apic_id); return; } - node = acpi_map_pxm_to_node(pxm); + node = acpi_map_pxm_to_node(pxm, true); if (node < 0) { printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm); bad_srat(); @@ -80,7 +80,7 @@ acpi_numa_processor_affinity_init(struct acpi_srat_cpu_affinity *pa) pxm = pa->proximity_domain_lo; if (acpi_srat_revision >= 2) pxm |= *((unsigned int*)pa->proximity_domain_hi) << 8; - node = acpi_map_pxm_to_node(pxm); + node = acpi_map_pxm_to_node(pxm, true); if (node < 0) { printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm); bad_srat(); diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index 28a6b387e80e..8133e7e6f9e3 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -1293,7 +1293,7 @@ static int __init arm_smmu_v3_set_proximity(struct device *dev, smmu = (struct acpi_iort_smmu_v3 *)node->node_data; if (smmu->flags & ACPI_IORT_SMMU_V3_PXM_VALID) { - int dev_node = acpi_map_pxm_to_node(smmu->pxm); + int dev_node = acpi_map_pxm_to_node(smmu->pxm, false); if (dev_node != NUMA_NO_NODE && !node_online(dev_node)) return -EINVAL; diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 7c138a4edc03..6cb44bbaa71f 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -2948,7 +2948,7 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc, ndr_desc->numa_node = acpi_map_pxm_to_online_node( spa->proximity_domain); ndr_desc->target_node = acpi_map_pxm_to_node( - spa->proximity_domain); + spa->proximity_domain, false); } else { ndr_desc->numa_node = NUMA_NO_NODE; ndr_desc->target_node = NUMA_NO_NODE; diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c index 2c32cfb72370..3c0414816772 100644 --- a/drivers/acpi/numa/hmat.c +++ b/drivers/acpi/numa/hmat.c @@ -666,7 +666,7 @@ static void hmat_register_target_device(struct memory_target *target, pdev->dev.numa_node = acpi_map_pxm_to_online_node(target->memory_pxm); info = (struct memregion_info) { - .target_node = acpi_map_pxm_to_node(target->memory_pxm), + .target_node = acpi_map_pxm_to_node(target->memory_pxm, false), }; rc = platform_device_add_data(pdev, &info, sizeof(info)); if (rc < 0) { diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c index 5be5a977da1b..ed7d31795f4d 100644 --- a/drivers/acpi/numa/srat.c +++ b/drivers/acpi/numa/srat.c @@ -52,7 +52,7 @@ static void __acpi_map_pxm_to_node(int pxm, int node) node_to_pxm_map[node] = pxm; } -int acpi_map_pxm_to_node(int pxm) +int acpi_map_pxm_to_node(int pxm, bool create) { int node; @@ -62,7 +62,7 @@ int acpi_map_pxm_to_node(int pxm) node = pxm_to_node_map[pxm]; if (node == NUMA_NO_NODE) { - if (nodes_weight(nodes_found_map) >= MAX_NUMNODES) + if (nodes_weight(nodes_found_map) >= MAX_NUMNODES || !create) return NUMA_NO_NODE; node = first_unset_node(nodes_found_map); __acpi_map_pxm_to_node(pxm, node); @@ -229,7 +229,7 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma) if (acpi_srat_revision <= 1) pxm &= 0xff; - node = acpi_map_pxm_to_node(pxm); + node = acpi_map_pxm_to_node(pxm, true); if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) { pr_err("SRAT: Too many proximity domains.\n"); goto out_err_bad_srat; @@ -444,6 +444,6 @@ int acpi_get_node(acpi_handle handle) pxm = acpi_get_pxm(handle); - return acpi_map_pxm_to_node(pxm); + return acpi_map_pxm_to_node(pxm, false); } EXPORT_SYMBOL(acpi_get_node); diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index cd685f521c77..0b11876d0799 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -5248,7 +5248,11 @@ static int __init gic_acpi_parse_srat_its(union acpi_subtable_headers *header, return -EINVAL; } - node = acpi_map_pxm_to_node(its_affinity->proximity_domain); + /* + * Note that in theory a new proximity node could be created by this + * entry as it is an SRAT resource allocation structure + */ + node = acpi_map_pxm_to_node(its_affinity->proximity_domain, false); if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) { pr_err("SRAT: Invalid NUMA node %d in ITS affinity\n", node); diff --git a/include/acpi/acpi_numa.h b/include/acpi/acpi_numa.h index fdebcfc6c8df..6935c7516262 100644 --- a/include/acpi/acpi_numa.h +++ b/include/acpi/acpi_numa.h @@ -15,7 +15,7 @@ extern int pxm_to_node(int); extern int node_to_pxm(int); -extern int acpi_map_pxm_to_node(int); +extern int acpi_map_pxm_to_node(int, bool); extern unsigned char acpi_srat_revision; extern int acpi_numa __initdata; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index d661cd0ee64d..1414b7e0a486 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -416,7 +416,7 @@ extern void acpi_osi_setup(char *str); extern bool acpi_osi_is_win8(void); #ifdef CONFIG_ACPI_NUMA -int acpi_map_pxm_to_node(int pxm); +int acpi_map_pxm_to_node(int pxm, bool create); int acpi_get_node(acpi_handle handle); /** @@ -436,7 +436,7 @@ int acpi_get_node(acpi_handle handle); */ static inline int acpi_map_pxm_to_online_node(int pxm) { - int node = acpi_map_pxm_to_node(pxm); + int node = acpi_map_pxm_to_node(pxm, false); return numa_map_to_online_node(node); } @@ -445,7 +445,7 @@ static inline int acpi_map_pxm_to_online_node(int pxm) { return 0; } -static inline int acpi_map_pxm_to_node(int pxm) +static inline int acpi_map_pxm_to_node(int pxm, bool create) { return 0; }
Here, I will use the term Proximity Domains for the ACPI description and Numa Nodes for the in kernel representation. Until ACPI 6.3 it was arguably possible to interpret the specification as allowing _PXM in DSDT and similar to define additional Proximity Domains. The reality was that was never the intent, and a 'clarification' was added in ACPI 6.3 [1]. In practice I think the kernel has never allowed any other interpretaion, except possibly on adhoc base within some out of tree driver (using it very very carefully given potential to crash when using various standard calls such as devm_kzalloc). Proximity Domains are always defined in SRAT. In ACPI, there are methods defined in ACPI to allow their characteristics to be tweaked later but Proximity Domains have to be referenced in this table at boot, thus allowing Linux to instantiate relevant Numa Node data structures. We ran into a problem when enabling _PXM handling for PCI devices and found there were boards out there advertising devices in proximity domains that didn't exist [2]. The fix suggested here is to modfiy the function acpi_map_pxm_to_node. This function is both used to create and lookup proximity domains. A parameter is added to specify whether it should create a new proximity domain when it encounters a Proximity Domain ID that it hasn't seen before. Naturally there is a quirk. For SRAT ITS entries on ARM64 the handling is done with an additional pass of SRAT, potentially later in the boot. We could modify that behaviour so we could identify the existence of Proximity Domains unique to the ITS structures, and handle them as a special case of a Genric Initiator (once support for those merges) however... Currently (5.8-rc2) setting the Proximity Domain of an ITS to one that hasn't been instantiated by being specified in another type of SRAT resource entry results in: ITS [mem 0x202100000-0x20211ffff] ITS@0x0000000202100000: Using ITS number 0 Unable to handle kernel paging request at virtual address 0000000000001a08 Mem abort info: ESR = 0x96000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 [0000000000001a08] user address but active_mm is swapper Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G A 5.8.0-rc2 #483 pstate: 80000089 (Nzcv daIf -PAN -UAO BTYPE=--) pc : __alloc_pages_nodemask+0xe8/0x338 lr : __alloc_pages_nodemask+0xc0/0x338 sp : ffffa81540c139b0 x29: ffffa81540c139b0 x28: 0000000000000001 x27: 0000000000000100 x26: ffffa81540c1ad38 x25: 0000000000000000 x24: 0000000000000000 x23: ffffa81540c23c00 x22: 0000000000000004 x21: 0000000000000002 x20: 0000000000001a00 x19: 0000000000000100 x18: 0000000000000010 x17: 000000000001f000 x16: 000000000000007f x15: ffffa81540c24070 x14: ffffffffffffffff x13: ffffa815c0c137d7 x12: ffffa81540c137e4 x11: ffffa81540c3e000 x10: ffffa81540ecee68 x9 : ffffa8153f0f61d8 x8 : ffffa81540ecf000 x7 : 0000000000000141 x6 : ffffa81540ecf401 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000081 x0 : 0000000000001a00 Call trace: __alloc_pages_nodemask+0xe8/0x338 alloc_pages_node.constprop.0+0x34/0x40 its_probe_one+0x2f8/0xb18 gic_acpi_parse_madt_its+0x108/0x150 acpi_table_parse_entries_array+0x17c/0x264 acpi_table_parse_entries+0x48/0x6c acpi_table_parse_madt+0x30/0x3c its_init+0x1c4/0x644 gic_init_bases+0x4b8/0x4ec gic_acpi_init+0x134/0x264 acpi_match_madt+0x4c/0x84 acpi_table_parse_entries_array+0x17c/0x264 acpi_table_parse_entries+0x48/0x6c acpi_table_parse_madt+0x30/0x3c __acpi_probe_device_table+0x8c/0xe8 irqchip_init+0x3c/0x48 init_IRQ+0xcc/0x100 start_kernel+0x33c/0x548 As we die in this case in existing kernels, we can be fairly sure that no one actually has such a firmware in production. As such this patch avoids the complexity that would be needed to handle this corner case, and simply does not allow the ITS entry parsing code to instantiate new Numa Nodes. If one is encountered that does not already exist, then NO_NUMA_NODE is assigned and a warning printed just as if the value had been greater than allowed Numa Nodes. "SRAT: Invalid NUMA node -1 in ITS affinity" I have only tested this for now on our ARM64 Kunpeng920 servers. Open questions: * should we warn about a broken firmware or insufficent value of NUMA_NODES_SHIFT if we find a firmware trying to assign any device to a non existent Proximity Domain. * previously an smmuv3 in IORT with a Proximity Domain set to a non existent value would have resulted in a failure to add the device. After this change it will be added to the default node. Is that a problem? [1] Note in ACPI Specification 6.3 5.2.16 System Resource Affinity Table (SRAT) [2] https://patchwork.kernel.org/patch/10597777/ Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> --- arch/arm64/kernel/acpi_numa.c | 2 +- arch/ia64/kernel/acpi.c | 2 +- arch/x86/mm/srat.c | 4 ++-- drivers/acpi/arm64/iort.c | 2 +- drivers/acpi/nfit/core.c | 2 +- drivers/acpi/numa/hmat.c | 2 +- drivers/acpi/numa/srat.c | 8 ++++---- drivers/irqchip/irq-gic-v3-its.c | 6 +++++- include/acpi/acpi_numa.h | 2 +- include/linux/acpi.h | 6 +++--- 10 files changed, 20 insertions(+), 16 deletions(-) -- 2.19.1