Re: [PATCH v7 02/17] ACPI: scan: Add a weak function to reorder the IRQCHIP probe
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2024-07-31 19:41:15
Also in:
linux-pci, linux-riscv, lkml
On Mon, Jul 29, 2024 at 07:52:24PM +0530, Sunil V L wrote:
Unlike OF framework, the irqchip probe using IRQCHIP_ACPI_DECLARE has no order defined. Depending on the Makefile is not a good idea. So, usually it is worked around by mandating only root interrupt controller probed using IRQCHIP_ACPI_DECLARE and other interrupt controllers are probed via cascade mechanism. However, this is also not a clean solution because if there are multiple root controllers (ex: RINTC in RISC-V which is per CPU) which need to be probed first, then the cascade will happen for every root controller. So, introduce a architecture specific weak function to order the probing of the interrupt controllers which can be implemented by different architectures as per their interrupt controller hierarchy.
Nit: I think it's nice if the commit log and even the subject line includes the actual *name* of the function being added. s/a architecture/an architecture/ No need to repost for these.
quoted hunk ↗ jump to hunk
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> --- drivers/acpi/scan.c | 3 +++ include/linux/acpi.h | 2 ++ 2 files changed, 5 insertions(+)diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 59771412686b..52a9dfc8e18c 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c@@ -2755,6 +2755,8 @@ static int __init acpi_match_madt(union acpi_subtable_headers *header, return 0; } +void __weak arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr) { } + int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr) { int count = 0;@@ -2763,6 +2765,7 @@ int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr) return 0; mutex_lock(&acpi_probe_mutex); + arch_sort_irqchip_probe(ap_head, nr); for (ape = ap_head; nr; ape++, nr--) { if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) { acpi_probe_count = 0;diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 0687a442fec7..3fff86f95c2f 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h@@ -1343,6 +1343,8 @@ struct acpi_probe_entry { kernel_ulong_t driver_data; }; +void arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr); + #define ACPI_DECLARE_PROBE_ENTRY(table, name, table_id, subtable, \ valid, data, fn) \ static const struct acpi_probe_entry __acpi_probe_##name \-- 2.43.0