[linux-block.git] / arch / x86 / include / asm / io_bitmap.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_IOBITMAP_H
#define _ASM_X86_IOBITMAP_H

#include <linux/refcount.h>
#include <asm/processor.h>

struct io_bitmap {
	u64		sequence;
	refcount_t	refcnt;
	/* The maximum number of bytes to copy so all zero bits are covered */
	unsigned int	max;
	unsigned long	bitmap[IO_BITMAP_LONGS];
};

struct task_struct;

#ifdef CONFIG_X86_IOPL_IOPERM
void io_bitmap_share(struct task_struct *tsk);
void io_bitmap_exit(struct task_struct *tsk);

static inline void native_tss_invalidate_io_bitmap(void)
{
	/*
	 * Invalidate the I/O bitmap by moving io_bitmap_base outside the
	 * TSS limit so any subsequent I/O access from user space will
	 * trigger a #GP.
	 *
	 * This is correct even when VMEXIT rewrites the TSS limit
	 * to 0x67 as the only requirement is that the base points
	 * outside the limit.
	 */
	this_cpu_write(cpu_tss_rw.x86_tss.io_bitmap_base,
		       IO_BITMAP_OFFSET_INVALID);
}

void native_tss_update_io_bitmap(void);

#ifdef CONFIG_PARAVIRT_XXL
#include <asm/paravirt.h>
#else
#define tss_update_io_bitmap native_tss_update_io_bitmap
#define tss_invalidate_io_bitmap native_tss_invalidate_io_bitmap
#endif

#else
static inline void io_bitmap_share(struct task_struct *tsk) { }
static inline void io_bitmap_exit(struct task_struct *tsk) { }
static inline void tss_update_io_bitmap(void) { }
#endif

#endif
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _ASM_X86_IOBITMAP_H
	3	#define _ASM_X86_IOBITMAP_H
	4
	5	#include <linux/refcount.h>
	6	#include <asm/processor.h>
	7
	8	struct io_bitmap {
	9	u64 sequence;
	10	refcount_t refcnt;
	11	/* The maximum number of bytes to copy so all zero bits are covered */
	12	unsigned int max;
	13	unsigned long bitmap[IO_BITMAP_LONGS];
	14	};
	15
	16	struct task_struct;
	17
	18	#ifdef CONFIG_X86_IOPL_IOPERM
	19	void io_bitmap_share(struct task_struct *tsk);
	20	void io_bitmap_exit(struct task_struct *tsk);
	21
	22	static inline void native_tss_invalidate_io_bitmap(void)
	23	{
	24	/*
	25	* Invalidate the I/O bitmap by moving io_bitmap_base outside the
	26	* TSS limit so any subsequent I/O access from user space will
	27	* trigger a #GP.
	28	*
	29	* This is correct even when VMEXIT rewrites the TSS limit
	30	* to 0x67 as the only requirement is that the base points
	31	* outside the limit.
	32	*/
	33	this_cpu_write(cpu_tss_rw.x86_tss.io_bitmap_base,
	34	IO_BITMAP_OFFSET_INVALID);
	35	}
	36
	37	void native_tss_update_io_bitmap(void);
	38
	39	#ifdef CONFIG_PARAVIRT_XXL
	40	#include <asm/paravirt.h>
	41	#else
	42	#define tss_update_io_bitmap native_tss_update_io_bitmap
	43	#define tss_invalidate_io_bitmap native_tss_invalidate_io_bitmap
	44	#endif
	45
	46	#else
	47	static inline void io_bitmap_share(struct task_struct *tsk) { }
	48	static inline void io_bitmap_exit(struct task_struct *tsk) { }
	49	static inline void tss_update_io_bitmap(void) { }
	50	#endif
	51
	52	#endif