[PATCH 2/4] ACE implementation, conifguration and makefile

[PATCH 2/4] ACE implementation, conifguration and makefile

[Wink Saville]

Signed-off-by: Wink Saville <wink-hKg/bvL8yClBDgjK7y7TUQ@public.gmane.org>
---
  arch/x86_64/kernel/Makefile |    2
  arch/x86_64/kernel/ace.S    |  204 ++++++++++++++++++++++++++++++++++++
  arch/x86_64/kernel/entry.S  |   45 ++++++++
  drivers/Makefile            |    1
  drivers/ace/Kconfig         |   15 ++
  drivers/ace/Makefile        |    5
  drivers/ace/ace_device.c    |  246 ++++++++++++++++++++++++++++++++++++++++++++
  include/asm-x86_64/ace.h    |  124 ++++++++++++++++++++++
  mm/Kconfig                  |    2
  9 files changed, 644 insertions(+)
  create mode 100644 arch/x86_64/kernel/ace.S
  create mode 100644 drivers/ace/Kconfig
  create mode 100644 drivers/ace/Makefile
  create mode 100644 drivers/ace/ace_device.c
  create mode 100644 include/asm-x86_64/ace.h

Index: linux-2.6/arch/x86_64/kernel/Makefile
===================================================================
--- linux-2.6.orig/arch/x86_64/kernel/Makefile
+++ linux-2.6/arch/x86_64/kernel/Makefile
@@ -41,6 +41,8 @@ obj-$(CONFIG_AUDIT)		+= audit.o
  obj-$(CONFIG_MODULES)		+= module.o
  obj-$(CONFIG_PCI)		+= early-quirks.o

+obj-$(CONFIG_ACE_DEVICE)	+= ace.o
+
  obj-y				+= topology.o
  obj-y				+= intel_cacheinfo.o
  obj-y				+= pcspeaker.o
Index: linux-2.6/arch/x86_64/kernel/ace.S
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86_64/kernel/ace.S
@@ -0,0 +1,204 @@
+/**
+ * ace.S
+ *
+ * This must be position independent code
+ * and must not use any stack.
+ *
+ * Copyright (C) 2006 Saville Software, Inc.
+ *
+ * This code may be used for any purpose whatsoever, but
+ * no warranty of any kind is provided.
+ *
+ * Register usage:
+ *  r11 = return address
+ *  rdi = parm1
+ *  rsi = parm2
+ *  rdx = parm3
+ *  rcx = parm4
+ *  r8  = parm5
+ *  r9  = parm6
+ *
+ * Preserved registers:
+ * rbx, rsp, rbp, r12, r13, r14, r15
+ *
+ * Stack usage:
+ *  THE STACK MAY NOT BE USED!
+ */
+
+#define __ASSEMBLY__		1
+#include <asm/ace.h>
+
+#define	ACE_SPIN_LOCK_UNLOCKED	1
+#define	ACE_CONFIG_SMP		1
+#define MP_LIST_STRUCT_SIZE	16
+
+#####################################
+# Globals we're exporting
+#####################################
+
+	.global	ace_code_beg, ace_code_end, ace_code_vtable, ace_code_vtable_end
+
+
+#####################################
+# Enter/leave an ace routine.
+#####################################
+
+	.macro	ENTER_ROUTINE	tag, name, sep="_"
+	.global \tag\sep\name
+	.section ace_thunk,"ax"
+\tag\sep\name:
+	popq	%r11
+	jmpq	*vtable_\name(%rip)
+	.previous
+
+	.section ace_vtable,"ax"
+vtable_\name:
+	.quad	ACE_CODE_ADDR + \name - ace_code_beg
+	.previous
+
+\name:
+	.endm
+
+	.macro LEAVE_ROUTINE
+	jmpq	*%r11
+	.endm
+
+#####################################
+# Begin an ace routine.
+# Generate the preamble for an
+# ace routine, which always begins
+# with acquring the ace_spin_lock
+#####################################
+
+	.macro	BEG_ROUTINE	tag, name, sep="_"
+	ENTER_ROUTINE	\tag, \name, \sep
+
+#if ACE_CONFIG_SMP
+test_spin_lock_\name:
+	lock; decq ace_spinlock(%rip)
+	js	wait_spin_lock_\name
+#endif
+	.endm
+
+	.macro RET_ROUTINE
+#if ACE_CONFIG_SMP
+	movq	$ACE_SPIN_LOCK_UNLOCKED, ace_spinlock(%rip)
+#endif
+	LEAVE_ROUTINE
+	.endm
+
+#####################################
+# End an ace routine.
+# Generate the postamble for an
+# ace routine, which always ends
+# releasing the ace_spin_lock.
+#
+# This macro also generates the
+# routines ace_thunk which allows
+# the ace routine to be called from
+# C and it generates the vtable
+# entry.
+#####################################
+
+	.macro	END_ROUTINE tag, name, sep="_"
+	RET_ROUTINE
+
+#if ACE_CONFIG_SMP
+wait_spin_lock_\name:
+	pause
+	cmpq	$0, ace_spinlock(%rip)
+	jle	wait_spin_lock_\name
+	jmp	test_spin_lock_\name
+#endif
+
+	.endm
+
+
+#####################################
+# Begin the ace_code on a page boundry
+#####################################
+
+	.text
+	.code64
+	.align	ACE_CODE_SIZE
+ace_code_beg:
+
+#####################################
+# Reserve space for pAce_data
+#####################################
+
+	.rept	ACE_DATA_MAX_SIZE
+	.byte	0
+	.endr
+
+
+#####################################
+# Other ace data
+#####################################
+
+	.align	64
+ace_spinlock:
+	.quad	ACE_SPIN_LOCK_UNLOCKED	/* Spin lock */
+
+	.align	64
+counters:
+	.rept	ACE_TEST_NUM_COUNTERS
+	.quad	0
+	.endr
+
+#####################################
+# Define the beginning of the vtable
+#####################################
+
+	.section ace_vtable, "ax"
+ace_code_vtable:
+	.previous
+
+	.align	64
+
+#####################################
+# Increment two of the test counters
+# rdi is index of the first and
+# rsi is the index of the second
+#####################################
+
+BEG_ROUTINE ace, inc_two_counters
+	lea	counters(%rip), %rax
+	movq	(%rax, %rdi, 8), %rdx
+	incq	%rdx
+	movq	%rdx, (%rax, %rdi, 8)
+	movq	(%rax, %rsi, 8), %rdx
+	incq	%rdx
+	movq	%rdx, (%rax, %rsi, 8)
+END_ROUTINE ace, inc_two_counters
+
+#####################################
+# Return the address of a snapshot of
+# the counters
+#####################################
+
+BEG_ROUTINE ace, get_counters_snapshot
+	lea	counters(%rip), %rsi
+	movq	$ACE_TEST_NUM_COUNTERS, %rcx
+	rep movsq
+END_ROUTINE ace, get_counters_snapshot
+
+#####################################
+# Define the end of the ace code
+#####################################
+
+ace_code_end:
+	.byte	0
+
+
+#####################################
+# Define the end of the vtable
+#####################################
+
+	.section ace_vtable,"ax"
+ace_code_vtable_end:
+	.previous
+
+
+	.end
+
Index: linux-2.6/arch/x86_64/kernel/entry.S
===================================================================
--- linux-2.6.orig/arch/x86_64/kernel/entry.S
+++ linux-2.6/arch/x86_64/kernel/entry.S
@@ -464,6 +464,50 @@ ENTRY(stub_rt_sigreturn)
  	CFI_ENDPROC
  END(stub_rt_sigreturn)

+#ifdef CONFIG_ACE_DEVICE
+/*
+ * Atomic Code Execution handling
+ */
+#include <asm/ace.h>
+
+ace_common:
+	pushq	%r9				# Save r9
+	xchgq	4*8(%rsp), %r11			# Exchange the return-rip for what's in r11. When this
+						# interrupt completes it will continue at the
+						# address that was in r11.
+	pushfq					# Get the current flags
+	popq	%r10				#   to r10
+	andq	$~0xCD5, %r10			# Zero the app level bits (OF,DF,SF,ZF,AF,PF,CF)
+	movq	6*8(%rsp), %r9			# Get return-rflags
+	andq	$0xCD5, %r9			# Isolaate app level flags (OF,DF,SF,ZF,AF,PF,CF)
+	orq	%r9, %r10			# Use the flags when we continue
+	pushq	%r10
+	popfq					# Restore flags
+	popq	%r9				# Restore r9
+	popq	%r10				# Restore r10
+	pushq	%r11				# Push return-rip which is where we'll continue the ace code
+	movq	$ace_return, %r11		# ace code will return to ace_return
+	ret					# Complete ace code
+ace_return:
+	ret					# Return to invoker
+
+	.align	8
+ace_code_addr:
+	.quad	ACE_CODE_ADDR
+
+	.macro HANDLE_ACE
+	pushq	$1f				# Push the return address
+	pushq	%r10				# r10 will be used as a temporary register
+	movq	3*8(%rsp), %r10			# Get return-rip
+	andq	$ACE_CODE_ADDR_MASK, %r10	# Align return-rip to the page boundary
+	cmp	ace_code_addr(%rip), %r10	# Is this in the ace_page
+	je	ace_common			# Jump if it was
+	popq	%r10				# Restore r10
+	ret					# Return to 1f aka: 1: below
+1:
+	.endm
+#endif
+
  /*
   * initial frame state for interrupts and exceptions
   */
@@ -494,6 +538,7 @@ END(stub_rt_sigreturn)

  /* 0(%rsp): interrupt number */
  	.macro interrupt func
+	HANDLE_ACE
  	cld
  	SAVE_ARGS
  	leaq -ARGOFFSET(%rsp),%rdi	# arg1 for handler
Index: linux-2.6/drivers/Makefile
===================================================================
--- linux-2.6.orig/drivers/Makefile
+++ linux-2.6/drivers/Makefile
@@ -80,3 +80,4 @@ obj-$(CONFIG_GENERIC_TIME)	+= clocksourc
  obj-$(CONFIG_DMA_ENGINE)	+= dma/
  obj-$(CONFIG_HID)		+= hid/
  obj-$(CONFIG_PPC_PS3)		+= ps3/
+obj-$(CONFIG_ACE_DEVICE)	+= ace/
Index: linux-2.6/drivers/ace/Kconfig
===================================================================
--- /dev/null
+++ linux-2.6/drivers/ace/Kconfig
@@ -0,0 +1,15 @@
+#
+# ACE configuration
+#
+
+menu "Atomic Code Execution (ACE)"
+
+config ACE_DEVICE
+	bool "ACE support"
+	---help---
+	  ACE allows code to be atomically executed either from kernel
+          space or user space as if it was surrounded by spin_lock_irqsave
+          and spin_lock_irqrestore.
+
+endmenu
+
Index: linux-2.6/drivers/ace/Makefile
===================================================================
--- /dev/null
+++ linux-2.6/drivers/ace/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for ACE.
+#
+
+obj-$(CONFIG_ACE_DEVICE)	+= ace_device.o
Index: linux-2.6/drivers/ace/ace_device.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/ace/ace_device.c
@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) 2006 Saville Software, Inc.
+ *
+ * This code may be used for any purpose whatsoever, but
+ * no warranty of any kind is provided.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/cdev.h>
+#include <linux/jiffies.h>
+#include <linux/timer.h>
+#include <linux/device.h>
+#include <linux/kshmem.h>
+
+#include <asm/ace.h>
+
+#define ACE_DEBUG
+#ifdef ACE_DEBUG
+#define DPK(fmt, args...) printk(KERN_ERR "ace " fmt, ## args)
+#else
+#define DPK(fmt, args...)
+#endif
+
+struct ace_dev_struct
+{
+	struct	cdev		cdev;			/* Character device structure */
+	struct page *		ace_code_page;		/* The ace code page struct */
+	unsigned long		ace_code_kvaddr;	/* The ace code page as kernel virtual address */
+	unsigned long		ace_code_addr;		/* The ace code page */
+	unsigned long		ace_code_size;		/* Size of ace_code_addr */
+	struct timer_list	timer;			/* Timer */
+	unsigned long		timer_delay;		/* Delay for timer */
+};
+
+MODULE_AUTHOR("Wink Saville");
+MODULE_LICENSE("Dual BSD/GPL");
+
+int ace_open(struct inode *inode, struct file *pFile);
+int ace_release(struct inode *inode, struct file *pFile);
+int ace_ioctl(struct inode *pInode, struct file *pFile, unsigned int cmd, unsigned long arg);
+
+/*
+ * Module parameters
+ */
+static int major = 240;	/* 240 a "local/expermental" device number for the moment */
+static int minor = 0;
+
+module_param(major, int, S_IRUGO);
+module_param(minor, int, S_IRUGO);
+
+/*
+ * Globals
+ */
+struct ace_dev_struct ace_dev;
+EXPORT_SYMBOL(ace_dev);
+
+/*
+ * File operations
+ */
+struct file_operations ace_f_ops = {
+	.owner		=	THIS_MODULE,
+	.open		=	ace_open,
+	.ioctl		=	ace_ioctl,
+	.release	=	ace_release,
+};
+
+/*
+ * Initialize the ace page.
+ *
+ * NO-ONE may be using the ACE_CODE at the time this is called.
+ */
+void ace_init(void)
+{
+	unsigned long	ace_code_len = &ace_code_end - &ace_code_beg;
+
+	DPK("ace_init: E\n");
+
+	/*
+	 * Be sure there is enough space for the ACE_DATA
+	 */
+	BUG_ON(sizeof(struct ace_data_struct) > ACE_DATA_MAX_SIZE);
+
+	/*
+	 * Allocate an ace page and copy the code to it
+	 */
+	ace_dev.ace_code_size = ACE_CODE_SIZE;
+	ace_dev.ace_code_addr = (unsigned long)kshmem_alloc_at(ACE_CODE_ADDR, ace_dev.ace_code_size, PAGE_SHARED_EXEC);
+	ace_dev.ace_code_page = vmalloc_to_page((unsigned char *)ace_dev.ace_code_addr);
+	ace_dev.ace_code_kvaddr = kshmem_addr_to_kvaddr(ace_dev.ace_code_addr);
+
+	memcpy((void *)ace_dev.ace_code_addr, &ace_code_beg, ace_code_len);
+
+	/*
+	 * Validate
+	 */
+	BUG_ON(ace_dev.ace_code_addr != ACE_CODE_ADDR);
+	BUG_ON(ace_dev.ace_code_page != virt_to_page(ace_dev.ace_code_kvaddr));
+
+	DPK("ace_init: X\n");
+}
+EXPORT_SYMBOL(ace_init);
+
+/*
+ * test timer
+ */
+static void ace_timer(unsigned long arg)
+{
+	struct ace_dev_struct *pDev = (struct ace_dev_struct *)arg;
+
+	ace_inc_two_counters(0, 1);
+
+	pDev->timer.expires += pDev->timer_delay;
+	add_timer(&pDev->timer);
+}
+
+/*
+ * Open
+ */
+int ace_open(struct inode *inode, struct file *pFile)
+{
+	int result = 0;
+	struct ace_dev_struct *pDev;
+
+	DPK("ace_open: E\n");
+
+	pDev = container_of(inode->i_cdev, struct ace_dev_struct, cdev);
+	pFile->private_data = (void *)pDev;
+	kshmem_user_enable();
+
+	DPK("ace_open: X result=%d\n", result);
+	return result;
+}
+
+/*
+ * Release/Close
+ */
+int ace_release(struct inode *inode, struct file *pFile)
+{
+	int	result = 0;
+
+	DPK("ace_release: E\n");
+
+	kshmem_user_disable();
+
+	DPK("ace_release: X result=%d\n", result);
+	return result;
+}
+
+/*
+ * Ioctl
+ */
+int ace_ioctl(struct inode *pInode, struct file *pFile, unsigned int cmd, unsigned long arg)
+{
+	int result = -EFAULT;
+
+	DPK("ace_ioctl: E\n");
+
+	DPK("ace_ioctl: X result=%d\n", result);
+	return result;
+}
+
+/*
+ * Init routine for the ace device
+ */
+static int ace_device_init(void)
+{
+	int 		result;
+	dev_t 		dev_number = 0;
+	static struct class *ace_class;
+
+	DPK("ace_device_init: E\n");
+
+	if (major) {
+		dev_number = MKDEV(major, minor);
+		result = register_chrdev_region(dev_number, 1, "ace");
+		DPK("ace_device_init: static major result=%d\n", result);
+	} else {
+		result = alloc_chrdev_region(&dev_number, minor, 1, "ace");
+		major = MAJOR(dev_number);
+		DPK("ace_device_init: dynamic major result=%d\n", result);
+	}
+
+	if (result < 0) {
+		printk(KERN_WARNING "ace: can't get major %d\n", major);
+		goto done;
+	}
+
+	if (ace_dev.ace_code_addr == 0)
+		ace_init();
+
+	cdev_init(&ace_dev.cdev, &ace_f_ops);
+	ace_dev.cdev.owner = THIS_MODULE;
+	ace_dev.cdev.ops = &ace_f_ops;
+
+	result = cdev_add(&ace_dev.cdev, dev_number, 1);
+	if (result)
+	{
+		DPK("ace_device_init: cdev_add failed\n");
+		goto done;
+	}
+
+	/*
+	 * Make an ace class and create the device
+	 */
+	ace_class = class_create(THIS_MODULE, "ace");
+	class_device_create(ace_class, NULL, dev_number, NULL, "ace");
+
+	/*
+	 * Start timer
+	 */
+	ace_dev.timer_delay = msecs_to_jiffies(1);
+	ace_dev.timer.expires = jiffies + ace_dev.timer_delay;
+	ace_dev.timer.data = (unsigned long)&ace_dev;
+	ace_dev.timer.function = ace_timer;
+	init_timer(&ace_dev.timer);
+	add_timer(&ace_dev.timer);
+
+done:
+	DPK("ace_device_init: X result=%d major=%d minor=%d\n", result, major, minor);
+	return result;
+}
+
+/*
+ * Exit routine for ace device
+ */
+static void ace_device_exit(void)
+{
+	dev_t dev_number = MKDEV(major, minor);
+
+	DPK("ace_device_exit: E\n");
+
+	del_timer_sync(&ace_dev.timer);
+
+	unregister_chrdev_region(dev_number, 1);
+
+	DPK("ace_device_exit: X\n");
+}
+
+module_init(ace_device_init);
+module_exit(ace_device_exit);
+
Index: linux-2.6/include/asm-x86_64/ace.h
===================================================================
--- /dev/null
+++ linux-2.6/include/asm-x86_64/ace.h
@@ -0,0 +1,124 @@
+/** * Copyright (C) 2006 Saville Software, Inc.
+ *
+ * This code may be used for any purpose whatsoever, but
+ * no warranty of any kind is provided.
+ */
+
+#ifndef _ACE_H
+#define _ACE_H
+
+#define	ACE_CODE_ADDR		0x6ffffffff000
+#define	ACE_CODE_SIZE		4096
+#define	ACE_CODE_ADDR_MASK	(~(ACE_CODE_SIZE-1))
+#define ACE_DATA_MAX_SIZE	256
+#define ACE_TEST_NUM_COUNTERS	16
+
+#ifndef __ASSEMBLY__
+
+/*
+ * This data is located at ACE_CODE_ADDR and
+ * must not exceed ACE_DATA_MAX_SIZE.
+ */
+struct ace_data_struct {
+	struct mp_struct *		pMprocs;	/* array of mprocs, pMprocs[0] is kernel's */
+	unsigned long			mprocs_count;	/* Number elements in pMprocs */
+	unsigned int			kernel_pool;	/* Id of kernel pool, must be 0 */
+	struct mp_mem_pool_struct *	pMem_pools;	/* Array of mem pools */
+	unsigned long			mem_pools_count;/* Number of elements in pMem_pools */
+	struct mp_msg_list_struct *	pMsg_lists;	/* Array of msg lists */
+	unsigned long			msg_lists_count;/* Number of elements in pMsg_lists */
+};
+#define pAce_data		((struct ace_data_struct *)ACE_CODE_ADDR)
+
+/*
+ * Beginning and end of the ace code in ace.S
+ */
+extern char			ace_code_beg;
+extern char 			ace_code_end;
+
+/*
+ * Initialization routine, called from init/main.c
+ */
+extern void			ace_init(void);
+
+/*
+ * Ace routines for testing
+ */
+extern uint64_t			ace_inc_two_counters(uint64_t cnt0, uint64_t cnt1);
+extern void			ace_get_counters_snapshot(uint64_t snapshot[ACE_TEST_NUM_COUNTERS]);
+
+/**
+ * Atomic operations. For x86_64 these are
+ * inherenently atomic so they do not need
+ * to be executed in the ace page. For other
+ * architectures this may need to be defined
+ * in the ace page.
+ */
+
+/*
+ * Atomic increment
+ */
+static __inline__ void ace_inc(volatile int *pVal)
+{
+	__asm__ __volatile__(
+		"lock incl %0"
+		:"=m" (*pVal)
+		:"m" (*pVal));
+}
+
+/*
+ * Atomic decrement
+ */
+static __inline__ void ace_dec(volatile int *pVal)
+{
+	__asm__ __volatile__(
+		"lock decl %0"
+		:"=m" (*pVal)
+		:"m" (*pVal));
+}
+
+/*
+ * Atomic decrement.
+ *
+ * Return true if the value becomes zero
+ * else return false.
+ */
+static __inline__ int ace_dec_and_test(volatile int *pVal)
+{
+	unsigned char c;
+
+	__asm__ __volatile__(
+		"lock decl %0; sete %1"
+		:"=m" (*pVal), "=qm" (c)
+		:"m" (*pVal) : "memory");
+	return c != 0;
+}
+
+/*
+ * Atomic compare and exchange, atomicly
+ * execute the following algrothim:
+ *
+ * if the current value equals old_value
+ * then change it to new value but
+ * always return the current value
+ *
+ * If (*pVal == old_val) {
+ * 	*pVal = new;
+ * 	return old_val;
+ * } else {
+ *  	return *pVal;
+ * }
+ */
+static __inline__ int ace_cmpxchg(volatile int *pVal, int old_val, int new_val)
+{
+	int prev_val;
+
+	__asm__ __volatile__("lock cmpxchg %1,%2"
+			     : "=a"(prev_val)
+			     : "r"(new_val), "m"(*pVal), "0"(old_val)
+			     : "memory");
+	return prev_val;
+}
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ACE_H */
Index: linux-2.6/mm/Kconfig
===================================================================
--- linux-2.6.orig/mm/Kconfig
+++ linux-2.6/mm/Kconfig
@@ -171,3 +171,5 @@ config KSHMEM
  	  user space programs. For instance interrupt service routines
  	  and user space programs may share the same memory.

+source "drivers/ace/Kconfig"
+


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