Merge "arm: traps: emulate a MRC instruction reading CNTFRQ register" (b3981928) · Commits · e / devices / android_kernel_fairphone_FP5

arch/arm/include/asm/traps.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,8 @@ static inline int __in_irqentry_text(unsigned long ptr)
		ptr < (unsigned long)&__irqentry_text_end;
		}

		extern void get_timer_freq_hook_init(void);
		extern void get_timer_count_hook_init(void);
		extern void __init early_trap_init(void *);
		extern void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame);
		extern void ptrace_break(struct pt_regs *regs);

arch/arm/kernel/traps.c

+72 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@
		#include <linux/irq.h>

		#include <linux/atomic.h>
		#include <asm/arch_timer.h>
		#include <asm/cacheflush.h>
		#include <asm/exception.h>
		#include <asm/unistd.h>
		@@ -711,6 +712,77 @@ late_initcall(arm_mrc_hook_init);

		#endif

		static int get_timer_count_trap(struct pt_regs *regs, unsigned int instr)
		{
		u64 cval;
		unsigned int res;
		int rd = (instr >> 12) & 0xF;
		int rn = (instr >> 16) & 0xF;

		res = arm_check_condition(instr, regs->ARM_cpsr);
		if (res == ARM_OPCODE_CONDTEST_FAIL) {
		regs->ARM_pc += 4;
		return 0;
		}

		if (rd == 15 \|\| rn == 15)
		return 1;
		cval = __arch_counter_get_cntvct();
		regs->uregs[rd] = cval;
		regs->uregs[rn] = cval >> 32;
		regs->ARM_pc += 4;
		return 0;
		}

		static struct undef_hook get_timer_count_hook = {
		.instr_mask = 0x0ff00fff,
		.instr_val = 0x0c500f1e,
		.cpsr_mask = MODE_MASK,
		.cpsr_val = USR_MODE,
		.fn = get_timer_count_trap,
		};

		void get_timer_count_hook_init(void)
		{
		register_undef_hook(&get_timer_count_hook);
		}
		EXPORT_SYMBOL(get_timer_count_hook_init);

		static int get_freq_trap(struct pt_regs *regs, unsigned int instr)
		{
		u32 fval;
		unsigned int res;
		int rd = (instr >> 12) & 0xF;

		res = arm_check_condition(instr, regs->ARM_cpsr);
		if (res == ARM_OPCODE_CONDTEST_FAIL) {
		regs->ARM_pc += 4;
		return 0;
		}

		if (rd == 15)
		return 1;

		fval = arch_timer_get_cntfrq();
		regs->uregs[rd] = fval;
		regs->ARM_pc += 4;
		return 0;
		}

		static struct undef_hook get_freq_hook = {
		.instr_mask = 0x0fff0fff,
		.instr_val = 0x0e1e0f10,
		.cpsr_mask = MODE_MASK,
		.cpsr_val = USR_MODE,
		.fn = get_freq_trap,
		};

		void get_timer_freq_hook_init(void)
		{
		register_undef_hook(&get_freq_hook);
		}
		EXPORT_SYMBOL(get_timer_freq_hook_init);

		/*
		* A data abort trap was taken, but we did not handle the instruction.
		* Try to abort the user program, or panic if it was the kernel.

arch/arm64/include/asm/traps.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -110,4 +110,6 @@ static inline u32 arm64_ras_serror_get_severity(u32 esr)

		bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned int esr);
		void __noreturn arm64_serror_panic(struct pt_regs *regs, u32 esr);
		static inline void get_timer_count_hook_init(void) {}
		static inline void get_timer_freq_hook_init(void) {}
		#endif

drivers/clocksource/Kconfig

+1 −1

Original line number	Diff line number	Diff line
		@@ -387,7 +387,7 @@ config SUN50I_ERRATUM_UNKNOWN1

		config ARM_ARCH_TIMER_VCT_ACCESS
		bool "Support for ARM architected timer virtual counter access in userspace"
		default !ARM64
		default n
		depends on ARM_ARCH_TIMER
		help
		This option enables support for reading the ARM architected timer's

drivers/clocksource/arm_arch_timer.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@
		#include <linux/acpi.h>

		#include <asm/arch_timer.h>
		#include <asm/traps.h>
		#include <asm/virt.h>

		#include <clocksource/arm_arch_timer.h>
		@@ -1519,6 +1520,8 @@ static int __init arch_timer_mem_of_init(struct device_node *np)
		ret = arch_timer_mem_frame_register(frame);
		if (!ret && !arch_timer_needs_of_probing())
		ret = arch_timer_common_init();
		get_timer_count_hook_init();
		get_timer_freq_hook_init();
		out:
		kfree(timer_mem);
		return ret;