Merge "arm: highmem: Add support for flushing kmap_atomic mappings" (c1fd3de9) · Commits · e / devices / android_kernel_fairphone_FP3

arch/arm/Kconfig

+4 −0

Original line number	Diff line number	Diff line
		@@ -230,6 +230,9 @@ config NEED_RET_TO_USER
		config ARCH_MTD_XIP
		bool

		config ARCH_WANT_KMAP_ATOMIC_FLUSH
		bool

		config VECTORS_BASE
		hex
		default 0xffff0000 if MMU \|\| CPU_HIGH_VECTOR
		@@ -567,6 +570,7 @@ config ARCH_QCOM
		select SPARSE_IRQ
		select USE_OF
		select PINCTRL
		select ARCH_WANT_KMAP_ATOMIC_FLUSH
		help
		Support for Qualcomm MSM/QSD based systems. This runs on the
		apps processor of the MSM/QSD and depends on a shared memory

+56 −0

Original line number	Diff line number	Diff line
		@@ -10,6 +10,7 @@
		* published by the Free Software Foundation.
		*/

		#include <linux/cpu.h>
		#include <linux/module.h>
		#include <linux/highmem.h>
		#include <linux/interrupt.h>
		@@ -147,3 +148,58 @@ void *kmap_atomic_pfn(unsigned long pfn)

		return (void *)vaddr;
		}

		#ifdef CONFIG_ARCH_WANT_KMAP_ATOMIC_FLUSH
		static void kmap_remove_unused_cpu(int cpu)
		{
		int start_idx, idx, type;

		pagefault_disable();
		type = kmap_atomic_idx();
		start_idx = type + 1 + KM_TYPE_NR * cpu;

		for (idx = start_idx; idx < KM_TYPE_NR + KM_TYPE_NR * cpu; idx++) {
		unsigned long vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
		pte_t ptep;

		ptep = get_top_pte(vaddr);
		if (ptep)
		set_top_pte(vaddr, __pte(0));
		}
		pagefault_enable();
		}

		static void kmap_remove_unused(void *unused)
		{
		kmap_remove_unused_cpu(smp_processor_id());
		}

		void kmap_atomic_flush_unused(void)
		{
		on_each_cpu(kmap_remove_unused, NULL, 1);
		}

		static int hotplug_kmap_atomic_callback(struct notifier_block *nfb,
		unsigned long action, void *hcpu)
		{
		switch (action & (~CPU_TASKS_FROZEN)) {
		case CPU_DYING:
		kmap_remove_unused_cpu((int)hcpu);
		break;
		default:
		break;
		}

		return NOTIFY_OK;
		}

		static struct notifier_block hotplug_kmap_atomic_notifier = {
		.notifier_call = hotplug_kmap_atomic_callback,
		};

		static int __init init_kmap_atomic(void)
		{
		return register_hotcpu_notifier(&hotplug_kmap_atomic_notifier);
		}
		early_initcall(init_kmap_atomic);
		#endif