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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>, Peter Anvin <hpa@zytor.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: [patch V3 26/44] x86/gdt: Use bitfields for initialization
Date: Mon, 28 Aug 2017 08:47:41 +0200	[thread overview]
Message-ID: <20170828064958.197673367@linutronix.de> (raw)
In-Reply-To: <20170828064715.802987421@linutronix.de>

[-- Attachment #1: x86-gdt--Use-bitfields-for-initialization.patch --]
[-- Type: text/plain, Size: 5037 bytes --]

The GDT entry related code uses partially bitfields and macros which
initialize the two 16 bit parts of the entry by magic shift and mask
operations.

Clean it up and use the bitfields to initialize and access entries.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/entry/vdso/vma.c        |    2 -
 arch/x86/include/asm/desc.h      |   26 ++++++++++++++---------
 arch/x86/include/asm/desc_defs.h |   44 +++++++++++++++++----------------------
 arch/x86/math-emu/fpu_system.h   |    2 -
 4 files changed, 38 insertions(+), 36 deletions(-)

--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -351,7 +351,7 @@ static void vgetcpu_cpu_init(void *arg)
 	 * and 8 bits for the node)
 	 */
 	d.limit0 = cpu | ((node & 0xf) << 12);
-	d.limit = node >> 4;
+	d.limit1 = node >> 4;
 	d.type = 5;		/* RO data, expand down, accessed */
 	d.dpl = 3;		/* Visible to user code */
 	d.s = 1;		/* Not a system segment */
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -23,7 +23,7 @@ static inline void fill_ldt(struct desc_
 	desc->s			= 1;
 	desc->dpl		= 0x3;
 	desc->p			= info->seg_not_present ^ 1;
-	desc->limit		= (info->limit & 0xf0000) >> 16;
+	desc->limit1		= (info->limit & 0xf0000) >> 16;
 	desc->avl		= info->useable;
 	desc->d			= info->seg_32bit;
 	desc->g			= info->limit_in_pages;
@@ -170,14 +170,20 @@ static inline void pack_descriptor(struc
 				   unsigned long limit, unsigned char type,
 				   unsigned char flags)
 {
-	desc->a = ((base & 0xffff) << 16) | (limit & 0xffff);
-	desc->b = (base & 0xff000000) | ((base & 0xff0000) >> 16) |
-		(limit & 0x000f0000) | ((type & 0xff) << 8) |
-		((flags & 0xf) << 20);
-	desc->p = 1;
+	desc->limit0		= (u16) limit;
+	desc->base0		= (u16) base;
+	desc->base1		= (base >> 16) & 0xFF;
+	desc->type		= type & 0x0F;
+	desc->s			= 0;
+	desc->dpl		= 0;
+	desc->p			= 1;
+	desc->limit1		= (limit >> 16) & 0xF;
+	desc->avl		= (flags >> 0) & 0x01;
+	desc->l			= (flags >> 1) & 0x01;
+	desc->d			= (flags >> 2) & 0x01;
+	desc->g			= (flags >> 3) & 0x01;
 }
 
-
 static inline void set_tssldt_descriptor(void *d, unsigned long addr,
 					 unsigned type, unsigned size)
 {
@@ -195,7 +201,7 @@ static inline void set_tssldt_descriptor
 	desc->base2		= (addr >> 24) & 0xFF;
 	desc->base3		= (u32) (addr >> 32);
 #else
-	pack_descriptor((struct desc_struct *)d, addr, size, 0x80 | type, 0);
+	pack_descriptor((struct desc_struct *)d, addr, size, type, 0);
 #endif
 }
 
@@ -395,13 +401,13 @@ static inline void set_desc_base(struct
 
 static inline unsigned long get_desc_limit(const struct desc_struct *desc)
 {
-	return desc->limit0 | (desc->limit << 16);
+	return desc->limit0 | (desc->limit1 << 16);
 }
 
 static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit)
 {
 	desc->limit0 = limit & 0xffff;
-	desc->limit = (limit >> 16) & 0xf;
+	desc->limit1 = (limit >> 16) & 0xf;
 }
 
 #ifdef CONFIG_X86_64
--- a/arch/x86/include/asm/desc_defs.h
+++ b/arch/x86/include/asm/desc_defs.h
@@ -11,34 +11,30 @@
 
 #include <linux/types.h>
 
-/*
- * FIXME: Accessing the desc_struct through its fields is more elegant,
- * and should be the one valid thing to do. However, a lot of open code
- * still touches the a and b accessors, and doing this allow us to do it
- * incrementally. We keep the signature as a struct, rather than a union,
- * so we can get rid of it transparently in the future -- glommer
- */
 /* 8 byte segment descriptor */
 struct desc_struct {
-	union {
-		struct {
-			unsigned int a;
-			unsigned int b;
-		};
-		struct {
-			u16 limit0;
-			u16 base0;
-			unsigned base1: 8, type: 4, s: 1, dpl: 2, p: 1;
-			unsigned limit: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
-		};
-	};
+	u16	limit0;
+	u16	base0;
+	u16	base1: 8, type: 4, s: 1, dpl: 2, p: 1;
+	u16	limit1: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
 } __attribute__((packed));
 
-#define GDT_ENTRY_INIT(flags, base, limit) { { { \
-		.a = ((limit) & 0xffff) | (((base) & 0xffff) << 16), \
-		.b = (((base) & 0xff0000) >> 16) | (((flags) & 0xf0ff) << 8) | \
-			((limit) & 0xf0000) | ((base) & 0xff000000), \
-	} } }
+#define GDT_ENTRY_INIT(flags, base, limit)			\
+	{							\
+		.limit0		= (u16) (limit),		\
+		.limit1		= ((limit) >> 16) & 0x0F,	\
+		.base0		= (u16) (base),			\
+		.base1		= ((base) >> 16) & 0xFF,	\
+		.base2		= ((base) >> 24) & 0xFF,	\
+		.type		= (flags & 0x0f),		\
+		.s		= (flags >> 4) & 0x01,		\
+		.dpl		= (flags >> 5) & 0x03,		\
+		.p		= (flags >> 7) & 0x01,		\
+		.avl		= (flags >> 12) & 0x01,		\
+		.l		= (flags >> 13) & 0x01,		\
+		.d		= (flags >> 14) & 0x01,		\
+		.g		= (flags >> 15) & 0x01,		\
+	}
 
 enum {
 	GATE_INTERRUPT = 0xE,
--- a/arch/x86/math-emu/fpu_system.h
+++ b/arch/x86/math-emu/fpu_system.h
@@ -49,7 +49,7 @@ static inline unsigned long seg_get_base
 
 static inline unsigned long seg_get_limit(struct desc_struct *d)
 {
-	return ((unsigned long)d->limit << 16) | d->limit0;
+	return ((unsigned long)d->limit1 << 16) | d->limit0;
 }
 
 static inline unsigned long seg_get_granularity(struct desc_struct *d)

  parent reply	other threads:[~2017-08-28  6:53 UTC|newest]

Thread overview: 95+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-28  6:47 [patch V3 00/44] x86: Cleanup IDT code Thomas Gleixner
2017-08-28  6:47 ` [patch V3 01/44] x86/irq: Remove vector_used_by_percpu_irq() Thomas Gleixner
2017-08-29 11:04   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 02/44] x86/irq: Unexport used_vectors Thomas Gleixner
2017-08-29 11:04   ` [tip:x86/apic] x86/irq: Unexport used_vectors[] tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 03/44] x86/irq: Get rid of the first_system_vector bogisity Thomas Gleixner
2017-08-29 11:04   ` [tip:x86/apic] x86/irq: Get rid of the 'first_system_vector' indirection bogosity tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 04/44] x86/irq: Remove duplicated used_vectors definition Thomas Gleixner
2017-08-29 11:05   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 05/44] x86/boot: Move EISA setup to a proper place Thomas Gleixner
2017-08-29 11:05   ` [tip:x86/apic] x86/boot: Move EISA setup to a separate file tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 06/44] x86/tracing: Introduce a static key for exception tracing Thomas Gleixner
2017-08-29 11:06   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 07/44] x86/traps: Simplify pagefault tracing logic Thomas Gleixner
2017-08-29 11:06   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 08/44] x86/apic: Remove the duplicated tracing version of local_timer_interrupt Thomas Gleixner
2017-08-29 11:07   ` [tip:x86/apic] x86/apic: Remove the duplicated tracing version of local_timer_interrupt() tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 09/44] x86/apic: Use this_cpu_ptr in local_timer_interrupt Thomas Gleixner
2017-08-29 11:07   ` [tip:x86/apic] x86/apic: Use this_cpu_ptr() in local_timer_interrupt() tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 10/44] x86/irq: Get rid of duplicated trace_x86_platform_ipi() code Thomas Gleixner
2017-08-29 11:07   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 11/44] x86/apic: Remove the duplicated tracing versions of interrupts Thomas Gleixner
2017-08-29 11:08   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 12/44] x86/irqwork: Get rid of duplicated tracing interrupt code Thomas Gleixner
2017-08-29 11:08   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 13/44] x86/mce: Remove " Thomas Gleixner
2017-08-29 11:08   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 14/44] x86/smp: Remove pointless duplicated " Thomas Gleixner
2017-08-29 11:09   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 15/44] x86/smp: Use static key for reschedule interrupt tracing Thomas Gleixner
2017-08-29 11:09   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 16/44] x86/idt: Remove tracing idt completely Thomas Gleixner
2017-08-29 11:10   ` [tip:x86/apic] x86/idt: Remove the tracing IDT completely tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 17/44] x86/idt: Cleanup the i386 low level entry macros Thomas Gleixner
2017-08-29 11:10   ` [tip:x86/apic] x86/idt: Clean up " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 18/44] x86/tracing: Disentangle pagefault and resched IPI tracing key Thomas Gleixner
2017-08-29 11:10   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 19/44] x86/ipi: Make platform IPI depend on APIC Thomas Gleixner
2017-08-29 11:11   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 20/44] x86/irq_work: Make it " Thomas Gleixner
2017-08-29 11:11   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 21/44] x86/tracing: Build tracepoints only when they are used Thomas Gleixner
2017-08-29 11:12   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 22/44] x86/idt: Unify gate_struct handling for 32/64bit Thomas Gleixner
2017-08-29 11:12   ` [tip:x86/apic] x86/idt: Unify gate_struct handling for 32/64-bit kernels tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 23/44] x86/percpu: Use static initializer for GDT entry Thomas Gleixner
2017-08-29 11:13   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 24/44] x86/fpu: Use bitfield accessors for desc_struct Thomas Gleixner
2017-08-29 11:13   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 25/44] x86: Replace access to desc_struct:a/b fields Thomas Gleixner
2017-08-29 11:13   ` [tip:x86/apic] x86/asm: " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` Thomas Gleixner [this message]
2017-08-29 11:14   ` [tip:x86/apic] x86/gdt: Use bitfields for initialization tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 27/44] x86/ldttss: Cleanup 32bit descriptors Thomas Gleixner
2017-08-29 11:14   ` [tip:x86/apic] x86/ldttss: Clean up 32-bit descriptors tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 28/44] x86/idt: Create file for IDT related code Thomas Gleixner
2017-08-29 11:15   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 29/44] x86/idt: Move 32bit idt_descr to C code Thomas Gleixner
2017-08-29 11:15   ` [tip:x86/apic] x86/idt: Move 32-bit " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 30/44] x86/idt: Remove unused set_trap_gate() Thomas Gleixner
2017-08-29 11:16   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 31/44] x86/idt: Consolidate IDT invalidation Thomas Gleixner
2017-08-29 11:16   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 32/44] x86/idt: Move early IDT handler setup to IDT code Thomas Gleixner
2017-08-29 11:16   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 33/44] x86/idt: Move early IDT setup out of 32bit asm Thomas Gleixner
2017-08-29 11:17   ` [tip:x86/apic] x86/idt: Move early IDT setup out of 32-bit asm tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 34/44] x86/idt: Prepare for table based init Thomas Gleixner
2017-08-29 11:17   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 35/44] x86/idt: Switch early trap init to IDT tables Thomas Gleixner
2017-08-29 11:18   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 36/44] x86/idt: Move debug stack init to table based Thomas Gleixner
2017-08-29 11:18   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 37/44] x86/idt: Move ist stack based traps to table init Thomas Gleixner
2017-08-29 11:18   ` [tip:x86/apic] x86/idt: Move IST " tip-bot for Thomas Gleixner
2017-09-01  6:28     ` Andrei Vagin
2017-09-01  8:26       ` [PATCH] x86/idt: Fix the X86_TRAP_BP gate Ingo Molnar
2017-09-01  8:59         ` Thomas Gleixner
2017-09-01  9:09         ` [tip:x86/apic] " tip-bot for Ingo Molnar
2017-09-01 14:39         ` [PATCH] " Andrei Vagin
2017-08-28  6:47 ` [patch V3 38/44] x86/idt: Move regular trap init to tables Thomas Gleixner
2017-08-29 11:19   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 39/44] x86/idt: Move APIC gate initialization " Thomas Gleixner
2017-08-29 11:19   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 40/44] x86/idt: Move interrupt gate initialization to IDT code Thomas Gleixner
2017-08-29 11:20   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 41/44] x86/idt: Remove unused functions/inlines Thomas Gleixner
2017-08-29 11:20   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 42/44] x86/idt: Deinline setup functions Thomas Gleixner
2017-08-29 11:20   ` [tip:x86/apic] " tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 43/44] x86/idt: Simplify alloc_intr_gate Thomas Gleixner
2017-08-28 14:35   ` KY Srinivasan
2017-08-29 11:21   ` [tip:x86/apic] x86/idt: Simplify alloc_intr_gate() tip-bot for Thomas Gleixner
2017-08-28  6:47 ` [patch V3 44/44] x86/idt: Hide set_intr_gate() Thomas Gleixner
2017-08-29 11:21   ` [tip:x86/apic] " tip-bot for Thomas Gleixner

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