Revert "arm64: Add support for app specific settings"

This reverts commit 7ab05c20ad43 ("arm64: Add support
for app specific settings").

Feature is not applicable to msmcobalt and only applicable
to MSM8996.

CRs-Fixed: 1054373
Change-Id: I12d3a22362b965c7d302976c83ab0e757c98d3c6
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>

5 files changed, 16 insertions, 210 deletions

diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 57e55e4d5fcc..9f7794c5743f 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -43,8 +43,6 @@ arm64-obj-$(CONFIG_EFI)			+= efi.o efi-entry.stub.o
 arm64-obj-$(CONFIG_PCI)			+= pci.o
 arm64-obj-$(CONFIG_ARMV8_DEPRECATED)	+= armv8_deprecated.o
 arm64-obj-$(CONFIG_ACPI)		+= acpi.o
-arm64-obj-$(CONFIG_MSM_APP_API)		+= app_api.o
-arm64-obj-$(CONFIG_MSM_APP_SETTINGS)	+= app_setting.o
 
 obj-y					+= $(arm64-obj-y) vdso/
 obj-m					+= $(arm64-obj-m)
diff --git a/arch/arm64/kernel/app_api.c b/arch/arm64/kernel/app_api.c
deleted file mode 100644
index 39eeee1a9029..000000000000
--- a/arch/arm64/kernel/app_api.c
+++ /dev/null
@@ -1,75 +0,0 @@
-/* Copyright (c) 2016, The Linux Foundation. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 and
- * only version 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-#include <linux/bitops.h>
-#include <linux/spinlock.h>
-#include <linux/cpu.h>
-#include <linux/export.h>
-
-#include <asm/app_api.h>
-
-static spinlock_t spinlock;
-static DEFINE_PER_CPU(int, app_config_applied);
-static unsigned long app_config_set[NR_CPUS];
-static unsigned long app_config_clear[NR_CPUS];
-
-void set_app_setting_bit(uint32_t bit)
-{
-	unsigned long flags;
-	uint64_t reg;
-	int cpu;
-
-	spin_lock_irqsave(&spinlock, flags);
-	asm volatile("mrs %0, S3_1_C15_C15_0" : "=r" (reg));
-	reg = reg | BIT(bit);
-	isb();
-	asm volatile("msr S3_1_C15_C15_0, %0" : : "r" (reg));
-	isb();
-	if (bit == APP_SETTING_BIT) {
-		cpu = raw_smp_processor_id();
-		app_config_set[cpu]++;
-
-		this_cpu_write(app_config_applied, 1);
-	}
-	spin_unlock_irqrestore(&spinlock, flags);
-
-}
-EXPORT_SYMBOL(set_app_setting_bit);
-
-void clear_app_setting_bit(uint32_t bit)
-{
-	unsigned long flags;
-	uint64_t reg;
-	int cpu;
-
-	spin_lock_irqsave(&spinlock, flags);
-	asm volatile("mrs %0, S3_1_C15_C15_0" : "=r" (reg));
-	reg = reg & ~BIT(bit);
-	isb();
-	asm volatile("msr S3_1_C15_C15_0, %0" : : "r" (reg));
-	isb();
-	if (bit == APP_SETTING_BIT) {
-		cpu = raw_smp_processor_id();
-		app_config_clear[cpu]++;
-
-		this_cpu_write(app_config_applied, 0);
-	}
-	spin_unlock_irqrestore(&spinlock, flags);
-}
-EXPORT_SYMBOL(clear_app_setting_bit);
-
-static int __init init_app_api(void)
-{
-	spin_lock_init(&spinlock);
-	return 0;
-}
-early_initcall(init_app_api);
diff --git a/arch/arm64/kernel/app_setting.c b/arch/arm64/kernel/app_setting.c
deleted file mode 100644
index 6b4eb28d0e24..000000000000
--- a/arch/arm64/kernel/app_setting.c
+++ /dev/null
@@ -1,120 +0,0 @@
-/* Copyright (c) 2016, The Linux Foundation. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 and
- * only version 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-#include <linux/module.h>
-#include <linux/cpu.h>
-#include <linux/slab.h>
-#include <linux/notifier.h>
-
-#include <asm/app_api.h>
-
-#define MAX_LEN		100
-
-static char *lib_names[MAX_ENTRIES];
-static unsigned int count;
-static struct mutex mutex;
-
-static char lib_str[MAX_LEN] = "";
-static struct kparam_string kps = {
-	.string			= lib_str,
-	.maxlen			= MAX_LEN,
-};
-static int set_name(const char *str, struct kernel_param *kp);
-module_param_call(lib_name, set_name, param_get_string, &kps, S_IWUSR);
-
-bool use_app_setting = true;
-module_param(use_app_setting, bool, 0644);
-MODULE_PARM_DESC(use_app_setting, "control use of app specific settings");
-
-static int set_name(const char *str, struct kernel_param *kp)
-{
-	int len = strlen(str);
-	char *name;
-
-	if (len >= MAX_LEN) {
-		pr_err("app_setting: name string too long\n");
-		return -ENOSPC;
-	}
-
-	/*
-	 * echo adds '\n' which we need to chop off later
-	 */
-	name = kzalloc(len + 1, GFP_KERNEL);
-	if (!name)
-		return -ENOMEM;
-
-	strlcpy(name, str, len + 1);
-
-	if (name[len - 1] == '\n')
-		name[len - 1] = '\0';
-
-	mutex_lock(&mutex);
-	if (count < MAX_ENTRIES) {
-		lib_names[count] = name;
-		/*
-		 * mb to ensure that the new lib_names entry is present
-		 * before updating the view presented by get_lib_names
-		 */
-		mb();
-		count++;
-	} else {
-		pr_err("app_setting: set name failed. Max entries reached\n");
-		kfree(name);
-		mutex_unlock(&mutex);
-		return -EPERM;
-	}
-	mutex_unlock(&mutex);
-
-	return 0;
-}
-
-void switch_app_setting_bit(struct task_struct *prev, struct task_struct *next)
-{
-	if (prev->mm && unlikely(prev->mm->app_setting))
-		clear_app_setting_bit(APP_SETTING_BIT);
-
-	if (next->mm && unlikely(next->mm->app_setting))
-		set_app_setting_bit(APP_SETTING_BIT);
-}
-EXPORT_SYMBOL(switch_app_setting_bit);
-
-void apply_app_setting_bit(struct file *file)
-{
-	bool found = false;
-	int i;
-
-	if (file && file->f_path.dentry) {
-		const char *name = file->f_path.dentry->d_name.name;
-
-		for (i = 0; i < count; i++) {
-			if (unlikely(!strcmp(name, lib_names[i]))) {
-				found = true;
-				break;
-			}
-		}
-		if (found) {
-			preempt_disable();
-			set_app_setting_bit(APP_SETTING_BIT);
-			/* This will take care of child processes as well */
-			current->mm->app_setting = 1;
-			preempt_enable();
-		}
-	}
-}
-EXPORT_SYMBOL(apply_app_setting_bit);
-
-static int __init app_setting_init(void)
-{
-	mutex_init(&mutex);
-	return 0;
-}
-module_init(app_setting_init);
diff --git a/arch/arm64/kernel/entry-fpsimd.S b/arch/arm64/kernel/entry-fpsimd.S
index 1ffe15459c92..d90efa4852b2 100644
--- a/arch/arm64/kernel/entry-fpsimd.S
+++ b/arch/arm64/kernel/entry-fpsimd.S
@@ -78,6 +78,22 @@ ENTRY(fpsimd_disable_trap)
 	msr cpacr_el1, x0
 	ret
 ENDPROC(fpsimd_disable_trap)
+ENTRY(fpsimd_settings_enable)
+	mrs x0, s3_1_c15_c15_0
+	orr x0, x0, #(1 << 31)
+	isb
+	msr s3_1_c15_c15_0, x0
+	isb
+	ret
+ENDPROC(fpsimd_settings_enable)
+ENTRY(fpsimd_settings_disable)
+	mrs x0, s3_1_c15_c15_0
+	bic x0, x0, #(1 << 31)
+	isb
+	msr s3_1_c15_c15_0, x0
+	isb
+	ret
+ENDPROC(fpsimd_settings_disable)
 #endif
 
 #endif
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 2ed553f3a4ae..74bc79e99717 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -28,7 +28,6 @@
 
 #include <asm/fpsimd.h>
 #include <asm/cputype.h>
-#include <asm/app_api.h>
 
 #define FPEXC_IOF	(1 << 0)
 #define FPEXC_DZF	(1 << 1)
@@ -37,8 +36,6 @@
 #define FPEXC_IXF	(1 << 4)
 #define FPEXC_IDF	(1 << 7)
 
-#define FP_SIMD_BIT	31
-
 /*
  * In order to reduce the number of times the FPSIMD state is needlessly saved
  * and restored, we need to keep track of two things:
@@ -97,16 +94,6 @@ static DEFINE_PER_CPU(int, fpsimd_stg_enable);
 static int fpsimd_settings = 0x1; /* default = 0x1 */
 module_param(fpsimd_settings, int, 0644);
 
-void fpsimd_settings_enable(void)
-{
-	set_app_setting_bit(FP_SIMD_BIT);
-}
-
-void fpsimd_settings_disable(void)
-{
-	clear_app_setting_bit(FP_SIMD_BIT);
-}
-
 /*
  * Trapped FP/ASIMD access.
  */