linux_dsm_epyc7002/arch/x86/kernel/x86_init.c
Rahul Tanwar c311ed6183 x86/init: Allow DT configured systems to disable RTC at boot time
Systems which do not support RTC run into boot problems as the kernel
assumes the availability of the RTC by default.

On device tree configured systems the availability of the RTC can be
detected by querying the corresponding device tree node.

Implement a wallclock init function to query the device tree and disable
RTC if the RTC is marked as not available in the corresponding node.

[ tglx: Rewrote changelog and comments. Added proper __init(const)
  	annotations. ]

Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/b84d9152ce0c1c09896ff4987e691a0715cb02df.1570693058.git.rahul.tanwar@linux.intel.com
2019-11-12 15:46:53 +01:00

183 lines
4.7 KiB
C

/*
* Copyright (C) 2009 Thomas Gleixner <tglx@linutronix.de>
*
* For licencing details see kernel-base/COPYING
*/
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <asm/acpi.h>
#include <asm/bios_ebda.h>
#include <asm/paravirt.h>
#include <asm/pci_x86.h>
#include <asm/mpspec.h>
#include <asm/setup.h>
#include <asm/apic.h>
#include <asm/e820/api.h>
#include <asm/time.h>
#include <asm/irq.h>
#include <asm/io_apic.h>
#include <asm/hpet.h>
#include <asm/pat.h>
#include <asm/tsc.h>
#include <asm/iommu.h>
#include <asm/mach_traps.h>
void x86_init_noop(void) { }
void __init x86_init_uint_noop(unsigned int unused) { }
static int __init iommu_init_noop(void) { return 0; }
static void iommu_shutdown_noop(void) { }
bool __init bool_x86_init_noop(void) { return false; }
void x86_op_int_noop(int cpu) { }
static __init int set_rtc_noop(const struct timespec64 *now) { return -EINVAL; }
static __init void get_rtc_noop(struct timespec64 *now) { }
static __initconst const struct of_device_id of_cmos_match[] = {
{ .compatible = "motorola,mc146818" },
{}
};
/*
* Allow devicetree configured systems to disable the RTC by setting the
* corresponding DT node's status property to disabled. Code is optimized
* out for CONFIG_OF=n builds.
*/
static __init void x86_wallclock_init(void)
{
struct device_node *node = of_find_matching_node(NULL, of_cmos_match);
if (node && !of_device_is_available(node)) {
x86_platform.get_wallclock = get_rtc_noop;
x86_platform.set_wallclock = set_rtc_noop;
}
}
/*
* The platform setup functions are preset with the default functions
* for standard PC hardware.
*/
struct x86_init_ops x86_init __initdata = {
.resources = {
.probe_roms = probe_roms,
.reserve_resources = reserve_standard_io_resources,
.memory_setup = e820__memory_setup_default,
},
.mpparse = {
.mpc_record = x86_init_uint_noop,
.setup_ioapic_ids = x86_init_noop,
.mpc_apic_id = default_mpc_apic_id,
.smp_read_mpc_oem = default_smp_read_mpc_oem,
.mpc_oem_bus_info = default_mpc_oem_bus_info,
.find_smp_config = default_find_smp_config,
.get_smp_config = default_get_smp_config,
},
.irqs = {
.pre_vector_init = init_ISA_irqs,
.intr_init = native_init_IRQ,
.trap_init = x86_init_noop,
.intr_mode_init = apic_intr_mode_init
},
.oem = {
.arch_setup = x86_init_noop,
.banner = default_banner,
},
.paging = {
.pagetable_init = native_pagetable_init,
},
.timers = {
.setup_percpu_clockev = setup_boot_APIC_clock,
.timer_init = hpet_time_init,
.wallclock_init = x86_wallclock_init,
},
.iommu = {
.iommu_init = iommu_init_noop,
},
.pci = {
.init = x86_default_pci_init,
.init_irq = x86_default_pci_init_irq,
.fixup_irqs = x86_default_pci_fixup_irqs,
},
.hyper = {
.init_platform = x86_init_noop,
.guest_late_init = x86_init_noop,
.x2apic_available = bool_x86_init_noop,
.init_mem_mapping = x86_init_noop,
.init_after_bootmem = x86_init_noop,
},
.acpi = {
.set_root_pointer = x86_default_set_root_pointer,
.get_root_pointer = x86_default_get_root_pointer,
.reduced_hw_early_init = acpi_generic_reduced_hw_init,
},
};
struct x86_cpuinit_ops x86_cpuinit = {
.early_percpu_clock_init = x86_init_noop,
.setup_percpu_clockev = setup_secondary_APIC_clock,
};
static void default_nmi_init(void) { };
struct x86_platform_ops x86_platform __ro_after_init = {
.calibrate_cpu = native_calibrate_cpu_early,
.calibrate_tsc = native_calibrate_tsc,
.get_wallclock = mach_get_cmos_time,
.set_wallclock = mach_set_rtc_mmss,
.iommu_shutdown = iommu_shutdown_noop,
.is_untracked_pat_range = is_ISA_range,
.nmi_init = default_nmi_init,
.get_nmi_reason = default_get_nmi_reason,
.save_sched_clock_state = tsc_save_sched_clock_state,
.restore_sched_clock_state = tsc_restore_sched_clock_state,
.hyper.pin_vcpu = x86_op_int_noop,
};
EXPORT_SYMBOL_GPL(x86_platform);
#if defined(CONFIG_PCI_MSI)
struct x86_msi_ops x86_msi __ro_after_init = {
.setup_msi_irqs = native_setup_msi_irqs,
.teardown_msi_irq = native_teardown_msi_irq,
.teardown_msi_irqs = default_teardown_msi_irqs,
.restore_msi_irqs = default_restore_msi_irqs,
};
/* MSI arch specific hooks */
int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
return x86_msi.setup_msi_irqs(dev, nvec, type);
}
void arch_teardown_msi_irqs(struct pci_dev *dev)
{
x86_msi.teardown_msi_irqs(dev);
}
void arch_teardown_msi_irq(unsigned int irq)
{
x86_msi.teardown_msi_irq(irq);
}
void arch_restore_msi_irqs(struct pci_dev *dev)
{
x86_msi.restore_msi_irqs(dev);
}
#endif
struct x86_apic_ops x86_apic_ops __ro_after_init = {
.io_apic_read = native_io_apic_read,
.restore = native_restore_boot_irq_mode,
};