1 files changed, 153 insertions, 57 deletions

diff --git a/arch/x86/include/asm/desc_defs.h b/arch/x86/include/asm/desc_defs.h
index 278441f39856..7e6b9314758a 100644
--- a/arch/x86/include/asm/desc_defs.h
+++ b/arch/x86/include/asm/desc_defs.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* Written 2000 by Andi Kleen */
 #ifndef _ASM_X86_DESC_DEFS_H
 #define _ASM_X86_DESC_DEFS_H
@@ -7,38 +8,84 @@
  * archs.
  */
 
-#ifndef __ASSEMBLY__
+/*
+ * Low-level interface mapping flags/field names to bits
+ */
 
-#include <linux/types.h>
+/* Flags for _DESC_S (non-system) descriptors */
+#define _DESC_ACCESSED		0x0001
+#define _DESC_DATA_WRITABLE	0x0002
+#define _DESC_CODE_READABLE	0x0002
+#define _DESC_DATA_EXPAND_DOWN	0x0004
+#define _DESC_CODE_CONFORMING	0x0004
+#define _DESC_CODE_EXECUTABLE	0x0008
+
+/* Common flags */
+#define _DESC_S			0x0010
+#define _DESC_DPL(dpl)		((dpl) << 5)
+#define _DESC_PRESENT		0x0080
+
+#define _DESC_LONG_CODE		0x2000
+#define _DESC_DB		0x4000
+#define _DESC_GRANULARITY_4K	0x8000
+
+/* System descriptors have a numeric "type" field instead of flags */
+#define _DESC_SYSTEM(code)	(code)
 
 /*
- * 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 an union,
- * so we can get rid of it transparently in the future -- glommer
+ * High-level interface mapping intended usage to low-level combinations
+ * of flags
  */
+
+#define _DESC_DATA		(_DESC_S | _DESC_PRESENT | _DESC_ACCESSED | \
+				 _DESC_DATA_WRITABLE)
+#define _DESC_CODE		(_DESC_S | _DESC_PRESENT | _DESC_ACCESSED | \
+				 _DESC_CODE_READABLE | _DESC_CODE_EXECUTABLE)
+
+#define DESC_DATA16		(_DESC_DATA)
+#define DESC_CODE16		(_DESC_CODE)
+
+#define DESC_DATA32		(_DESC_DATA | _DESC_GRANULARITY_4K | _DESC_DB)
+#define DESC_DATA32_BIOS	(_DESC_DATA | _DESC_DB)
+
+#define DESC_CODE32		(_DESC_CODE | _DESC_GRANULARITY_4K | _DESC_DB)
+#define DESC_CODE32_BIOS	(_DESC_CODE | _DESC_DB)
+
+#define DESC_TSS32		(_DESC_SYSTEM(9) | _DESC_PRESENT)
+
+#define DESC_DATA64		(_DESC_DATA | _DESC_GRANULARITY_4K | _DESC_DB)
+#define DESC_CODE64		(_DESC_CODE | _DESC_GRANULARITY_4K | _DESC_LONG_CODE)
+
+#define DESC_USER		(_DESC_DPL(3))
+
+#ifndef __ASSEMBLER__
+
+#include <linux/types.h>
+
 /* 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		= ((limit) >>  0) & 0xFFFF,	\
+		.limit1		= ((limit) >> 16) & 0x000F,	\
+		.base0		= ((base)  >>  0) & 0xFFFF,	\
+		.base1		= ((base)  >> 16) & 0x00FF,	\
+		.base2		= ((base)  >> 24) & 0x00FF,	\
+		.type		= ((flags) >>  0) & 0x000F,	\
+		.s		= ((flags) >>  4) & 0x0001,	\
+		.dpl		= ((flags) >>  5) & 0x0003,	\
+		.p		= ((flags) >>  7) & 0x0001,	\
+		.avl		= ((flags) >> 12) & 0x0001,	\
+		.l		= ((flags) >> 13) & 0x0001,	\
+		.d		= ((flags) >> 14) & 0x0001,	\
+		.g		= ((flags) >> 15) & 0x0001,	\
+	}
 
 enum {
 	GATE_INTERRUPT = 0xE,
@@ -47,48 +94,71 @@ enum {
 	GATE_TASK = 0x5,
 };
 
-/* 16byte gate */
-struct gate_struct64 {
-	u16 offset_low;
-	u16 segment;
-	unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
-	u16 offset_middle;
-	u32 offset_high;
-	u32 zero1;
-} __attribute__((packed));
-
-#define PTR_LOW(x) ((unsigned long long)(x) & 0xFFFF)
-#define PTR_MIDDLE(x) (((unsigned long long)(x) >> 16) & 0xFFFF)
-#define PTR_HIGH(x) ((unsigned long long)(x) >> 32)
-
 enum {
 	DESC_TSS = 0x9,
 	DESC_LDT = 0x2,
 	DESCTYPE_S = 0x10,	/* !system */
 };
 
-/* LDT or TSS descriptor in the GDT. 16 bytes. */
-struct ldttss_desc64 {
-	u16 limit0;
-	u16 base0;
-	unsigned base1 : 8, type : 5, dpl : 2, p : 1;
-	unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
-	u32 base3;
-	u32 zero1;
+/* LDT or TSS descriptor in the GDT. */
+struct ldttss_desc {
+	u16	limit0;
+	u16	base0;
+
+	u16	base1 : 8, type : 5, dpl : 2, p : 1;
+	u16	limit1 : 4, zero0 : 3, g : 1, base2 : 8;
+#ifdef CONFIG_X86_64
+	u32	base3;
+	u32	zero1;
+#endif
+} __attribute__((packed));
+
+typedef struct ldttss_desc ldt_desc;
+typedef struct ldttss_desc tss_desc;
+
+struct idt_bits {
+	u16		ist	: 3,
+			zero	: 5,
+			type	: 5,
+			dpl	: 2,
+			p	: 1;
 } __attribute__((packed));
 
+struct idt_data {
+	unsigned int	vector;
+	unsigned int	segment;
+	struct idt_bits	bits;
+	const void	*addr;
+};
+
+struct gate_struct {
+	u16		offset_low;
+	u16		segment;
+	struct idt_bits	bits;
+	u16		offset_middle;
 #ifdef CONFIG_X86_64
-typedef struct gate_struct64 gate_desc;
-typedef struct ldttss_desc64 ldt_desc;
-typedef struct ldttss_desc64 tss_desc;
-#define gate_offset(g) ((g).offset_low | ((unsigned long)(g).offset_middle << 16) | ((unsigned long)(g).offset_high << 32))
-#define gate_segment(g) ((g).segment)
+	u32		offset_high;
+	u32		reserved;
+#endif
+} __attribute__((packed));
+
+typedef struct gate_struct gate_desc;
+
+#ifndef _SETUP
+static inline unsigned long gate_offset(const gate_desc *g)
+{
+#ifdef CONFIG_X86_64
+	return g->offset_low | ((unsigned long)g->offset_middle << 16) |
+		((unsigned long) g->offset_high << 32);
 #else
-typedef struct desc_struct gate_desc;
-typedef struct desc_struct ldt_desc;
-typedef struct desc_struct tss_desc;
-#define gate_offset(g)		(((g).b & 0xffff0000) | ((g).a & 0x0000ffff))
-#define gate_segment(g)		((g).a >> 16)
+	return g->offset_low | ((unsigned long)g->offset_middle << 16);
+#endif
+}
+
+static inline unsigned long gate_segment(const gate_desc *g)
+{
+	return g->segment;
+}
 #endif
 
 struct desc_ptr {
@@ -96,6 +166,32 @@ struct desc_ptr {
 	unsigned long address;
 } __attribute__((packed)) ;
 
-#endif /* !__ASSEMBLY__ */
+#endif /* !__ASSEMBLER__ */
+
+/* Boot IDT definitions */
+#define	BOOT_IDT_ENTRIES	32
+
+/* Access rights as returned by LAR */
+#define AR_TYPE_RODATA		(0 * (1 << 9))
+#define AR_TYPE_RWDATA		(1 * (1 << 9))
+#define AR_TYPE_RODATA_EXPDOWN	(2 * (1 << 9))
+#define AR_TYPE_RWDATA_EXPDOWN	(3 * (1 << 9))
+#define AR_TYPE_XOCODE		(4 * (1 << 9))
+#define AR_TYPE_XRCODE		(5 * (1 << 9))
+#define AR_TYPE_XOCODE_CONF	(6 * (1 << 9))
+#define AR_TYPE_XRCODE_CONF	(7 * (1 << 9))
+#define AR_TYPE_MASK		(7 * (1 << 9))
+
+#define AR_DPL0			(0 * (1 << 13))
+#define AR_DPL3			(3 * (1 << 13))
+#define AR_DPL_MASK		(3 * (1 << 13))
+
+#define AR_A			(1 << 8)   /* "Accessed" */
+#define AR_S			(1 << 12)  /* If clear, "System" segment */
+#define AR_P			(1 << 15)  /* "Present" */
+#define AR_AVL			(1 << 20)  /* "AVaiLable" (no HW effect) */
+#define AR_L			(1 << 21)  /* "Long mode" for code segments */
+#define AR_DB			(1 << 22)  /* D/B, effect depends on type */
+#define AR_G			(1 << 23)  /* "Granularity" (limit in pages) */
 
 #endif /* _ASM_X86_DESC_DEFS_H */