From 34ceea275f626ae624b55f2b388a07f806988a55 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Mon, 21 Nov 2016 10:01:34 +0000 Subject: [PATCH] ACPI/IORT: Introduce linker section for IORT entries probing Since commit e647b532275b ("ACPI: Add early device probing infrastructure") the kernel has gained the infrastructure that allows adding linker script section entries to execute ACPI driver callbacks (ie probe routines) for all subsystems that register a table entry in the respective kernel section (eg clocksource, irqchip). Since ARM IOMMU devices data is described through IORT tables when booting with ACPI, the ARM IOMMU drivers must be made able to hook ACPI callback routines that are called to probe IORT entries and initialize the respective IOMMU devices. To avoid adding driver specific hooks into IORT table initialization code (breaking therefore code modularity - ie ACPI IORT code must be made aware of ARM SMMU drivers ACPI init callbacks), this patch adds code that allows ARM SMMU drivers to take advantage of the ACPI early probing infrastructure, so that they can add linker script section entries containing drivers callback to be executed on IORT tables detection. Since IORT nodes are differentiated by a type, the callback routines can easily parse the IORT table entries, check the IORT nodes and carry out some actions whenever the IORT node type associated with the driver specific callback is matched. Signed-off-by: Lorenzo Pieralisi Reviewed-by: Hanjun Guo Reviewed-by: Tomasz Nowicki Tested-by: Hanjun Guo Tested-by: Tomasz Nowicki Cc: Tomasz Nowicki Cc: "Rafael J. Wysocki" Cc: Marc Zyngier Signed-off-by: Will Deacon --- drivers/acpi/arm64/iort.c | 13 ++++++++++--- include/asm-generic/vmlinux.lds.h | 1 + include/linux/acpi_iort.h | 3 +++ 3 files changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index 6b81746cd13c..2c46ebca01af 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -361,8 +361,15 @@ void __init acpi_iort_init(void) acpi_status status; status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table); - if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { - const char *msg = acpi_format_exception(status); - pr_err("Failed to get table, %s\n", msg); + if (ACPI_FAILURE(status)) { + if (status != AE_NOT_FOUND) { + const char *msg = acpi_format_exception(status); + + pr_err("Failed to get table, %s\n", msg); + } + + return; } + + acpi_probe_device_table(iort); } diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 31e1d639abed..9e3aa34341f4 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -566,6 +566,7 @@ IRQCHIP_OF_MATCH_TABLE() \ ACPI_PROBE_TABLE(irqchip) \ ACPI_PROBE_TABLE(clksrc) \ + ACPI_PROBE_TABLE(iort) \ EARLYCON_TABLE() #define INIT_TEXT \ diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h index 0e32dac8fd03..d16fddaf230e 100644 --- a/include/linux/acpi_iort.h +++ b/include/linux/acpi_iort.h @@ -39,4 +39,7 @@ static inline struct irq_domain *iort_get_device_domain(struct device *dev, { return NULL; } #endif +#define IORT_ACPI_DECLARE(name, table_id, fn) \ + ACPI_DECLARE_PROBE_ENTRY(iort, name, table_id, 0, NULL, 0, fn) + #endif /* __ACPI_IORT_H__ */ -- 2.20.1