source: mainline/kernel/arch/amd64/include/asm.h@ b0b2ac1

/*
 * Copyright (c) 2005 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup amd64
 * @{
 */
/** @file
 */

#ifndef KERN_amd64_ASM_H_
#define KERN_amd64_ASM_H_

#include <config.h>
#include <typedefs.h>
#include <arch/cpu.h>

extern void asm_delay_loop(uint32_t t);
extern void asm_fake_loop(uint32_t t);

/** Return base address of current stack.
 *
 * Return the base address of the current stack.
 * The stack is assumed to be STACK_SIZE bytes long.
 * The stack must start on page boundary.
 *
 */
static inline uintptr_t get_stack_base(void)
{
        uintptr_t v;
        
        asm volatile (
                "andq %%rsp, %[v]\n"
                : [v] "=r" (v)
                : "0" (~((uint64_t) STACK_SIZE-1))
        );
        
        return v;
}

static inline void cpu_sleep(void)
{
        asm volatile ("hlt\n");
}

static inline void __attribute__((noreturn)) cpu_halt(void)
{
        while (true) {
                asm volatile (
                        "hlt\n"
                );
        }
}


/** Byte from port
 *
 * Get byte from port
 *
 * @param port Port to read from
 * @return Value read
 *
 */
static inline uint8_t pio_read_8(ioport8_t *port)
{
        uint8_t val;
        
        asm volatile (
                "inb %w[port], %b[val]\n"
                : [val] "=a" (val)
                : [port] "d" (port)
        );
        
        return val;
}

/** Word from port
 *
 * Get word from port
 *
 * @param port Port to read from
 * @return Value read
 *
 */
static inline uint16_t pio_read_16(ioport16_t *port)
{
        uint16_t val;
        
        asm volatile (
                "inw %w[port], %w[val]\n"
                : [val] "=a" (val)
                : [port] "d" (port)
        );
        
        return val;
}

/** Double word from port
 *
 * Get double word from port
 *
 * @param port Port to read from
 * @return Value read
 *
 */
static inline uint32_t pio_read_32(ioport32_t *port)
{
        uint32_t val;
        
        asm volatile (
                "inl %w[port], %[val]\n"
                : [val] "=a" (val)
                : [port] "d" (port)
        );
        
        return val;
}

/** Byte to port
 *
 * Output byte to port
 *
 * @param port Port to write to
 * @param val Value to write
 *
 */
static inline void pio_write_8(ioport8_t *port, uint8_t val)
{
        asm volatile (
                "outb %b[val], %w[port]\n"
                :: [val] "a" (val), [port] "d" (port)
        );
}

/** Word to port
 *
 * Output word to port
 *
 * @param port Port to write to
 * @param val Value to write
 *
 */
static inline void pio_write_16(ioport16_t *port, uint16_t val)
{
        asm volatile (
                "outw %w[val], %w[port]\n"
                :: [val] "a" (val), [port] "d" (port)
        );
}

/** Double word to port
 *
 * Output double word to port
 *
 * @param port Port to write to
 * @param val Value to write
 *
 */
static inline void pio_write_32(ioport32_t *port, uint32_t val)
{
        asm volatile (
                "outl %[val], %w[port]\n"
                :: [val] "a" (val), [port] "d" (port)
        );
}

/** Swap Hidden part of GS register with visible one */
static inline void swapgs(void)
{
        asm volatile("swapgs");
}

/** Enable interrupts.
 *
 * Enable interrupts and return previous
 * value of EFLAGS.
 *
 * @return Old interrupt priority level.
 *
 */
static inline ipl_t interrupts_enable(void) {
        ipl_t v;
        
        asm volatile (
                "pushfq\n"
                "popq %[v]\n"
                "sti\n"
                : [v] "=r" (v)
        );
        
        return v;
}

/** Disable interrupts.
 *
 * Disable interrupts and return previous
 * value of EFLAGS.
 *
 * @return Old interrupt priority level.
 *
 */
static inline ipl_t interrupts_disable(void) {
        ipl_t v;
        
        asm volatile (
                "pushfq\n"
                "popq %[v]\n"
                "cli\n"
                : [v] "=r" (v)
        );
        
        return v;
}

/** Restore interrupt priority level.
 *
 * Restore EFLAGS.
 *
 * @param ipl Saved interrupt priority level.
 *
 */
static inline void interrupts_restore(ipl_t ipl) {
        asm volatile (
                "pushq %[ipl]\n"
                "popfq\n"
                :: [ipl] "r" (ipl)
        );
}

/** Return interrupt priority level.
 *
 * Return EFLAFS.
 *
 * @return Current interrupt priority level.
 *
 */
static inline ipl_t interrupts_read(void) {
        ipl_t v;
        
        asm volatile (
                "pushfq\n"
                "popq %[v]\n"
                : [v] "=r" (v)
        );
        
        return v;
}

/** Check interrupts state.
 *
 * @return True if interrupts are disabled.
 *
 */
static inline bool interrupts_disabled(void)
{
        ipl_t v;
        
        asm volatile (
                "pushfq\n"
                "popq %[v]\n"
                : [v] "=r" (v)
        );
        
        return ((v & RFLAGS_IF) == 0);
}


/** Write to MSR */
static inline void write_msr(uint32_t msr, uint64_t value)
{
        asm volatile (
                "wrmsr\n"
                :: "c" (msr),
                   "a" ((uint32_t) (value)),
                   "d" ((uint32_t) (value >> 32))
        );
}

static inline unative_t read_msr(uint32_t msr)
{
        uint32_t ax, dx;
        
        asm volatile (
                "rdmsr\n"
                : "=a" (ax), "=d" (dx)
                : "c" (msr)
        );
        
        return ((uint64_t) dx << 32) | ax;
}


/** Enable local APIC
 *
 * Enable local APIC in MSR.
 *
 */
static inline void enable_l_apic_in_msr()
{
        asm volatile (
                "movl $0x1b, %%ecx\n"
                "rdmsr\n"
                "orl $(1 << 11),%%eax\n"
                "orl $(0xfee00000),%%eax\n"
                "wrmsr\n"
                ::: "%eax","%ecx","%edx"
        );
}

/** Invalidate TLB Entry.
 *
 * @param addr Address on a page whose TLB entry is to be invalidated.
 *
 */
static inline void invlpg(uintptr_t addr)
{
        asm volatile (
                "invlpg %[addr]\n"
                :: [addr] "m" (*((unative_t *) addr))
        );
}

/** Load GDTR register from memory.
 *
 * @param gdtr_reg Address of memory from where to load GDTR.
 *
 */
static inline void gdtr_load(ptr_16_64_t *gdtr_reg)
{
        asm volatile (
                "lgdtq %[gdtr_reg]\n"
                :: [gdtr_reg] "m" (*gdtr_reg)
        );
}

/** Store GDTR register to memory.
 *
 * @param gdtr_reg Address of memory to where to load GDTR.
 *
 */
static inline void gdtr_store(ptr_16_64_t *gdtr_reg)
{
        asm volatile (
                "sgdtq %[gdtr_reg]\n"
                :: [gdtr_reg] "m" (*gdtr_reg)
        );
}

/** Load IDTR register from memory.
 *
 * @param idtr_reg Address of memory from where to load IDTR.
 *
 */
static inline void idtr_load(ptr_16_64_t *idtr_reg)
{
        asm volatile (
                "lidtq %[idtr_reg]\n"
                :: [idtr_reg] "m" (*idtr_reg));
}

/** Load TR from descriptor table.
 *
 * @param sel Selector specifying descriptor of TSS segment.
 *
 */
static inline void tr_load(uint16_t sel)
{
        asm volatile (
                "ltr %[sel]"
                :: [sel] "r" (sel)
        );
}

#define GEN_READ_REG(reg) static inline unative_t read_ ##reg (void) \
        { \
                unative_t res; \
                asm volatile ( \
                        "movq %%" #reg ", %[res]" \
                        : [res] "=r" (res) \
                ); \
                return res; \
        }

#define GEN_WRITE_REG(reg) static inline void write_ ##reg (unative_t regn) \
        { \
                asm volatile ( \
                        "movq %[regn], %%" #reg \
                        :: [regn] "r" (regn) \
                ); \
        }

GEN_READ_REG(cr0)
GEN_READ_REG(cr2)
GEN_READ_REG(cr3)
GEN_WRITE_REG(cr3)

GEN_READ_REG(dr0)
GEN_READ_REG(dr1)
GEN_READ_REG(dr2)
GEN_READ_REG(dr3)
GEN_READ_REG(dr6)
GEN_READ_REG(dr7)

GEN_WRITE_REG(dr0)
GEN_WRITE_REG(dr1)
GEN_WRITE_REG(dr2)
GEN_WRITE_REG(dr3)
GEN_WRITE_REG(dr6)
GEN_WRITE_REG(dr7)

extern size_t interrupt_handler_size;
extern void interrupt_handlers(void);

#endif

/** @}
 */