Commit f5848e5f authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86/tss: Move I/O bitmap data into a seperate struct 



Move the non hardware portion of I/O bitmap data into a seperate struct for
readability sake.

Originally-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent ecc7e37d

arch/x86/include/asm/processor.h

+21 −14
Original line number Diff line number Diff line
@@ -328,11 +328,11 @@ struct x86_hw_tss { 
 * IO-bitmap sizes:

 */

#define IO_BITMAP_BITS			65536

#define IO_BITMAP_BYTES			(IO_BITMAP_BITS/8)

#define IO_BITMAP_BYTES			(IO_BITMAP_BITS / BITS_PER_BYTE)

#define IO_BITMAP_LONGS			(IO_BITMAP_BYTES / sizeof(long))



#define IO_BITMAP_OFFSET_VALID					\

	(offsetof(struct tss_struct, io_bitmap) -	\

	(offsetof(struct tss_struct, io_bitmap.bitmap) -	\

	 offsetof(struct tss_struct, x86_tss))



/*
@@ -356,14 +356,10 @@ struct entry_stack_page { 
	struct entry_stack stack;

} __aligned(PAGE_SIZE);



struct tss_struct {

/*

	 * The fixed hardware portion.  This must not cross a page boundary

	 * at risk of violating the SDM's advice and potentially triggering

	 * errata.

 * All IO bitmap related data stored in the TSS:

 */

	struct x86_hw_tss	x86_tss;



struct x86_io_bitmap {

	/*

	 * Store the dirty size of the last io bitmap offender. The next

	 * one will have to do the cleanup as the switch out to a non io
@@ -371,7 +367,7 @@ struct tss_struct { 
	 * outside of the TSS limit. So for sane tasks there is no need to

	 * actually touch the io_bitmap at all.

	 */

	unsigned int		io_bitmap_prev_max;

	unsigned int		prev_max;



	/*

	 * The extra 1 is there because the CPU will access an
@@ -379,7 +375,18 @@ struct tss_struct { 
	 * bitmap. The extra byte must be all 1 bits, and must

	 * be within the limit.

	 */

	unsigned long		io_bitmap[IO_BITMAP_LONGS + 1];

	unsigned long		bitmap[IO_BITMAP_LONGS + 1];

};



struct tss_struct {

	/*

	 * The fixed hardware portion.  This must not cross a page boundary

	 * at risk of violating the SDM's advice and potentially triggering

	 * errata.

	 */

	struct x86_hw_tss	x86_tss;



	struct x86_io_bitmap	io_bitmap;

} __aligned(PAGE_SIZE);



DECLARE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw);

arch/x86/kernel/cpu/common.c

+2 −2
Original line number Diff line number Diff line
@@ -1861,8 +1861,8 @@ void cpu_init(void) 
	/* Initialize the TSS. */

	tss_setup_ist(tss);

	tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_INVALID;

	tss->io_bitmap_prev_max = 0;

	memset(tss->io_bitmap, 0xff, sizeof(tss->io_bitmap));

	tss->io_bitmap.prev_max = 0;

	memset(tss->io_bitmap.bitmap, 0xff, sizeof(tss->io_bitmap.bitmap));

	set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);



	load_TR_desc();

arch/x86/kernel/ioport.c

+2 −2
Original line number Diff line number Diff line
@@ -81,9 +81,9 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) 


	/* Update the TSS */

	tss = this_cpu_ptr(&cpu_tss_rw);

	memcpy(tss->io_bitmap, t->io_bitmap_ptr, bytes_updated);

	memcpy(tss->io_bitmap.bitmap, t->io_bitmap_ptr, bytes_updated);

	/* Store the new end of the zero bits */

	tss->io_bitmap_prev_max = bytes;

	tss->io_bitmap.prev_max = bytes;

	/* Make the bitmap base in the TSS valid */

	tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_VALID;

	/* Make sure the TSS limit covers the I/O bitmap. */

arch/x86/kernel/process.c

+3 −3
Original line number Diff line number Diff line
@@ -374,11 +374,11 @@ static inline void switch_to_bitmap(struct thread_struct *next, 
		 * bits permitted, then the copy needs to cover those as

		 * well so they get turned off.

		 */

		memcpy(tss->io_bitmap, next->io_bitmap_ptr,

		       max(tss->io_bitmap_prev_max, next->io_bitmap_max));

		memcpy(tss->io_bitmap.bitmap, next->io_bitmap_ptr,

		       max(tss->io_bitmap.prev_max, next->io_bitmap_max));



		/* Store the new max and set io_bitmap_base valid */

		tss->io_bitmap_prev_max = next->io_bitmap_max;

		tss->io_bitmap.prev_max = next->io_bitmap_max;

		tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_VALID;



		/*