On Tue, 30 Jun 2020 00:16:59 +0800 Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> 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@xxxxxxxxxx> 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; > }
