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Commit c8b877a5 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Thomas Gleixner
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x86/pci/amd-bus: Convert to hotplug state machine 



Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

The smp_call_function_single() is dropped because the ONLINE callback is
invoked on the target CPU since commit 1cf4f629 ("cpu/hotplug: Move
online calls to hotplugged cpu"). smp_call_function_single() invokes the
invoked function with interrupts disabled, but this calling convention is
not preserved as the MSR is not modified by anything else than this code.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: rt@linuxtronix.de
Link: http://lkml.kernel.org/r/20161117183541.8588-21-bigeasy@linutronix.de


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 89666c50

arch/x86/pci/amd_bus.c

+7 −27
Original line number Diff line number Diff line
@@ -327,35 +327,18 @@ static int __init early_root_info_init(void) 


#define ENABLE_CF8_EXT_CFG      (1ULL << 46)



static void enable_pci_io_ecs(void *unused)

static int amd_bus_cpu_online(unsigned int cpu)

{

	u64 reg;



	rdmsrl(MSR_AMD64_NB_CFG, reg);

	if (!(reg & ENABLE_CF8_EXT_CFG)) {

		reg |= ENABLE_CF8_EXT_CFG;

		wrmsrl(MSR_AMD64_NB_CFG, reg);

	}

	return 0;

}



static int amd_cpu_notify(struct notifier_block *self, unsigned long action,

			  void *hcpu)

{

	int cpu = (long)hcpu;

	switch (action) {

	case CPU_ONLINE:

	case CPU_ONLINE_FROZEN:

		smp_call_function_single(cpu, enable_pci_io_ecs, NULL, 0);

		break;

	default:

		break;

	}

	return NOTIFY_OK;

}



static struct notifier_block amd_cpu_notifier = {

	.notifier_call	= amd_cpu_notify,

};



static void __init pci_enable_pci_io_ecs(void)

{

#ifdef CONFIG_AMD_NB
@@ -385,7 +368,7 @@ static void __init pci_enable_pci_io_ecs(void) 


static int __init pci_io_ecs_init(void)

{

	int cpu;

	int ret;



	/* assume all cpus from fam10h have IO ECS */

	if (boot_cpu_data.x86 < 0x10)
@@ -395,12 +378,9 @@ static int __init pci_io_ecs_init(void) 
	if (early_pci_allowed())

		pci_enable_pci_io_ecs();



	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)

		amd_cpu_notify(&amd_cpu_notifier, (unsigned long)CPU_ONLINE,

			       (void *)(long)cpu);

	__register_cpu_notifier(&amd_cpu_notifier);

	cpu_notifier_register_done();

	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "pci/amd_bus:online",

				amd_bus_cpu_online, NULL);

	WARN_ON(ret < 0);



	pci_probe |= PCI_HAS_IO_ECS;