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Commit 1f7d497b authored by Sanrio Alvares's avatar Sanrio Alvares Committed by David Keitel
Browse files

arm64: fpsimd: add support to enable/disable fpsimd_settings. 



Add support to enable/disable fpsimd_settings at runtime through
kernel command line.

fpsimd.fpsimd_settings=0 should disable it.

Change-Id: I14bf5f20e36ec4547aad45382cfffc91666a2ff4
Signed-off-by: default avatarSanrio Alvares <salvares@codeaurora.org>
parent d4440534

arch/arm64/include/asm/elf.h

+0 −2
Original line number Diff line number Diff line
@@ -180,8 +180,6 @@ typedef compat_elf_greg_t compat_elf_gregset_t[COMPAT_ELF_NGREG]; 
#define compat_start_thread		compat_start_thread

#define COMPAT_SET_PERSONALITY(ex)					\

do {									\

	if (current->mm)						\

		fpsimd_enable_trap();					\

	set_thread_flag(TIF_32BIT);					\

} while (0)

arch/arm64/kernel/fpsimd.c

+14 −1
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/cpu.h>

#include <linux/cpu_pm.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/sched.h>

#include <linux/signal.h>
@@ -90,11 +91,17 @@ 
static DEFINE_PER_CPU(struct fpsimd_state *, fpsimd_last_state);

static DEFINE_PER_CPU(int, fpsimd_stg_enable);



static int fpsimd_settings = 0x1; /* default = 0x1 */

module_param(fpsimd_settings, int, 0644);



/*

 * Trapped FP/ASIMD access.

 */

void do_fpsimd_acc(unsigned int esr, struct pt_regs *regs)

{

	if (!fpsimd_settings)

		return;



	fpsimd_disable_trap();

	fpsimd_settings_disable();

	this_cpu_write(fpsimd_stg_enable, 0);
@@ -102,6 +109,9 @@ void do_fpsimd_acc(unsigned int esr, struct pt_regs *regs) 


void do_fpsimd_acc_compat(unsigned int esr, struct pt_regs *regs)

{

	if (!fpsimd_settings)

		return;



	fpsimd_disable_trap();

	fpsimd_settings_enable();

	this_cpu_write(fpsimd_stg_enable, 1);
@@ -144,7 +154,7 @@ void fpsimd_thread_switch(struct task_struct *next) 
	if (current->mm && !test_thread_flag(TIF_FOREIGN_FPSTATE))

		fpsimd_save_state(&current->thread.fpsimd_state);



	if (__this_cpu_read(fpsimd_stg_enable)) {

	if (fpsimd_settings && __this_cpu_read(fpsimd_stg_enable)) {

		fpsimd_settings_disable();

		this_cpu_write(fpsimd_stg_enable, 0);

	}
@@ -167,6 +177,9 @@ void fpsimd_thread_switch(struct task_struct *next) 
			set_ti_thread_flag(task_thread_info(next),

					   TIF_FOREIGN_FPSTATE);



		if (!fpsimd_settings)

			return;



		if (test_ti_thread_flag(task_thread_info(next), TIF_32BIT))

			fpsimd_enable_trap();

		else