x86, um: ... and asm-x86 move

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 409 insertions, 0 deletions

diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
new file mode 100644
index 00000000000..f06adac7938
--- /dev/null
+++ b/arch/x86/include/asm/desc.h
@@ -0,0 +1,409 @@
+#ifndef ASM_X86__DESC_H
+#define ASM_X86__DESC_H
+
+#ifndef __ASSEMBLY__
+#include <asm/desc_defs.h>
+#include <asm/ldt.h>
+#include <asm/mmu.h>
+#include <linux/smp.h>
+
+static inline void fill_ldt(struct desc_struct *desc,
+			    const struct user_desc *info)
+{
+	desc->limit0 = info->limit & 0x0ffff;
+	desc->base0 = info->base_addr & 0x0000ffff;
+
+	desc->base1 = (info->base_addr & 0x00ff0000) >> 16;
+	desc->type = (info->read_exec_only ^ 1) << 1;
+	desc->type |= info->contents << 2;
+	desc->s = 1;
+	desc->dpl = 0x3;
+	desc->p = info->seg_not_present ^ 1;
+	desc->limit = (info->limit & 0xf0000) >> 16;
+	desc->avl = info->useable;
+	desc->d = info->seg_32bit;
+	desc->g = info->limit_in_pages;
+	desc->base2 = (info->base_addr & 0xff000000) >> 24;
+	/*
+	 * Don't allow setting of the lm bit. It is useless anyway
+	 * because 64bit system calls require __USER_CS:
+	 */
+	desc->l = 0;
+}
+
+extern struct desc_ptr idt_descr;
+extern gate_desc idt_table[];
+
+struct gdt_page {
+	struct desc_struct gdt[GDT_ENTRIES];
+} __attribute__((aligned(PAGE_SIZE)));
+DECLARE_PER_CPU(struct gdt_page, gdt_page);
+
+static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
+{
+	return per_cpu(gdt_page, cpu).gdt;
+}
+
+#ifdef CONFIG_X86_64
+
+static inline void pack_gate(gate_desc *gate, unsigned type, unsigned long func,
+			     unsigned dpl, unsigned ist, unsigned seg)
+{
+	gate->offset_low = PTR_LOW(func);
+	gate->segment = __KERNEL_CS;
+	gate->ist = ist;
+	gate->p = 1;
+	gate->dpl = dpl;
+	gate->zero0 = 0;
+	gate->zero1 = 0;
+	gate->type = type;
+	gate->offset_middle = PTR_MIDDLE(func);
+	gate->offset_high = PTR_HIGH(func);
+}
+
+#else
+static inline void pack_gate(gate_desc *gate, unsigned char type,
+			     unsigned long base, unsigned dpl, unsigned flags,
+			     unsigned short seg)
+{
+	gate->a = (seg << 16) | (base & 0xffff);
+	gate->b = (base & 0xffff0000) |
+		  (((0x80 | type | (dpl << 5)) & 0xff) << 8);
+}
+
+#endif
+
+static inline int desc_empty(const void *ptr)
+{
+	const u32 *desc = ptr;
+	return !(desc[0] | desc[1]);
+}
+
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
+#define load_TR_desc() native_load_tr_desc()
+#define load_gdt(dtr) native_load_gdt(dtr)
+#define load_idt(dtr) native_load_idt(dtr)
+#define load_tr(tr) asm volatile("ltr %0"::"m" (tr))
+#define load_ldt(ldt) asm volatile("lldt %0"::"m" (ldt))
+
+#define store_gdt(dtr) native_store_gdt(dtr)
+#define store_idt(dtr) native_store_idt(dtr)
+#define store_tr(tr) (tr = native_store_tr())
+#define store_ldt(ldt) asm("sldt %0":"=m" (ldt))
+
+#define load_TLS(t, cpu) native_load_tls(t, cpu)
+#define set_ldt native_set_ldt
+
+#define write_ldt_entry(dt, entry, desc)	\
+	native_write_ldt_entry(dt, entry, desc)
+#define write_gdt_entry(dt, entry, desc, type)		\
+	native_write_gdt_entry(dt, entry, desc, type)
+#define write_idt_entry(dt, entry, g)		\
+	native_write_idt_entry(dt, entry, g)
+
+static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries)
+{
+}
+
+static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries)
+{
+}
+#endif	/* CONFIG_PARAVIRT */
+
+static inline void native_write_idt_entry(gate_desc *idt, int entry,
+					  const gate_desc *gate)
+{
+	memcpy(&idt[entry], gate, sizeof(*gate));
+}
+
+static inline void native_write_ldt_entry(struct desc_struct *ldt, int entry,
+					  const void *desc)
+{
+	memcpy(&ldt[entry], desc, 8);
+}
+
+static inline void native_write_gdt_entry(struct desc_struct *gdt, int entry,
+					  const void *desc, int type)
+{
+	unsigned int size;
+	switch (type) {
+	case DESC_TSS:
+		size = sizeof(tss_desc);
+		break;
+	case DESC_LDT:
+		size = sizeof(ldt_desc);
+		break;
+	default:
+		size = sizeof(struct desc_struct);
+		break;
+	}
+	memcpy(&gdt[entry], desc, size);
+}
+
+static inline void pack_descriptor(struct desc_struct *desc, unsigned long base,
+				   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;
+}
+
+
+static inline void set_tssldt_descriptor(void *d, unsigned long addr,
+					 unsigned type, unsigned size)
+{
+#ifdef CONFIG_X86_64
+	struct ldttss_desc64 *desc = d;
+	memset(desc, 0, sizeof(*desc));
+	desc->limit0 = size & 0xFFFF;
+	desc->base0 = PTR_LOW(addr);
+	desc->base1 = PTR_MIDDLE(addr) & 0xFF;
+	desc->type = type;
+	desc->p = 1;
+	desc->limit1 = (size >> 16) & 0xF;
+	desc->base2 = (PTR_MIDDLE(addr) >> 8) & 0xFF;
+	desc->base3 = PTR_HIGH(addr);
+#else
+	pack_descriptor((struct desc_struct *)d, addr, size, 0x80 | type, 0);
+#endif
+}
+
+static inline void __set_tss_desc(unsigned cpu, unsigned int entry, void *addr)
+{
+	struct desc_struct *d = get_cpu_gdt_table(cpu);
+	tss_desc tss;
+
+	/*
+	 * sizeof(unsigned long) coming from an extra "long" at the end
+	 * of the iobitmap. See tss_struct definition in processor.h
+	 *
+	 * -1? seg base+limit should be pointing to the address of the
+	 * last valid byte
+	 */
+	set_tssldt_descriptor(&tss, (unsigned long)addr, DESC_TSS,
+			      IO_BITMAP_OFFSET + IO_BITMAP_BYTES +
+			      sizeof(unsigned long) - 1);
+	write_gdt_entry(d, entry, &tss, DESC_TSS);
+}
+
+#define set_tss_desc(cpu, addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
+
+static inline void native_set_ldt(const void *addr, unsigned int entries)
+{
+	if (likely(entries == 0))
+		asm volatile("lldt %w0"::"q" (0));
+	else {
+		unsigned cpu = smp_processor_id();
+		ldt_desc ldt;
+
+		set_tssldt_descriptor(&ldt, (unsigned long)addr, DESC_LDT,
+				      entries * LDT_ENTRY_SIZE - 1);
+		write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT,
+				&ldt, DESC_LDT);
+		asm volatile("lldt %w0"::"q" (GDT_ENTRY_LDT*8));
+	}
+}
+
+static inline void native_load_tr_desc(void)
+{
+	asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8));
+}
+
+static inline void native_load_gdt(const struct desc_ptr *dtr)
+{
+	asm volatile("lgdt %0"::"m" (*dtr));
+}
+
+static inline void native_load_idt(const struct desc_ptr *dtr)
+{
+	asm volatile("lidt %0"::"m" (*dtr));
+}
+
+static inline void native_store_gdt(struct desc_ptr *dtr)
+{
+	asm volatile("sgdt %0":"=m" (*dtr));
+}
+
+static inline void native_store_idt(struct desc_ptr *dtr)
+{
+	asm volatile("sidt %0":"=m" (*dtr));
+}
+
+static inline unsigned long native_store_tr(void)
+{
+	unsigned long tr;
+	asm volatile("str %0":"=r" (tr));
+	return tr;
+}
+
+static inline void native_load_tls(struct thread_struct *t, unsigned int cpu)
+{
+	unsigned int i;
+	struct desc_struct *gdt = get_cpu_gdt_table(cpu);
+
+	for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
+		gdt[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i];
+}
+
+#define _LDT_empty(info)				\
+	((info)->base_addr		== 0	&&	\
+	 (info)->limit			== 0	&&	\
+	 (info)->contents		== 0	&&	\
+	 (info)->read_exec_only		== 1	&&	\
+	 (info)->seg_32bit		== 0	&&	\
+	 (info)->limit_in_pages		== 0	&&	\
+	 (info)->seg_not_present	== 1	&&	\
+	 (info)->useable		== 0)
+
+#ifdef CONFIG_X86_64
+#define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
+#else
+#define LDT_empty(info) (_LDT_empty(info))
+#endif
+
+static inline void clear_LDT(void)
+{
+	set_ldt(NULL, 0);
+}
+
+/*
+ * load one particular LDT into the current CPU
+ */
+static inline void load_LDT_nolock(mm_context_t *pc)
+{
+	set_ldt(pc->ldt, pc->size);
+}
+
+static inline void load_LDT(mm_context_t *pc)
+{
+	preempt_disable();
+	load_LDT_nolock(pc);
+	preempt_enable();
+}
+
+static inline unsigned long get_desc_base(const struct desc_struct *desc)
+{
+	return desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24);
+}
+
+static inline unsigned long get_desc_limit(const struct desc_struct *desc)
+{
+	return desc->limit0 | (desc->limit << 16);
+}
+
+static inline void _set_gate(int gate, unsigned type, void *addr,
+			     unsigned dpl, unsigned ist, unsigned seg)
+{
+	gate_desc s;
+	pack_gate(&s, type, (unsigned long)addr, dpl, ist, seg);
+	/*
+	 * does not need to be atomic because it is only done once at
+	 * setup time
+	 */
+	write_idt_entry(idt_table, gate, &s);
+}
+
+/*
+ * This needs to use 'idt_table' rather than 'idt', and
+ * thus use the _nonmapped_ version of the IDT, as the
+ * Pentium F0 0F bugfix can have resulted in the mapped
+ * IDT being write-protected.
+ */
+static inline void set_intr_gate(unsigned int n, void *addr)
+{
+	BUG_ON((unsigned)n > 0xFF);
+	_set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS);
+}
+
+#define SYS_VECTOR_FREE		0
+#define SYS_VECTOR_ALLOCED	1
+
+extern int first_system_vector;
+extern char system_vectors[];
+
+static inline void alloc_system_vector(int vector)
+{
+	if (system_vectors[vector] == SYS_VECTOR_FREE) {
+		system_vectors[vector] = SYS_VECTOR_ALLOCED;
+		if (first_system_vector > vector)
+			first_system_vector = vector;
+	} else
+		BUG();
+}
+
+static inline void alloc_intr_gate(unsigned int n, void *addr)
+{
+	alloc_system_vector(n);
+	set_intr_gate(n, addr);
+}
+
+/*
+ * This routine sets up an interrupt gate at directory privilege level 3.
+ */
+static inline void set_system_intr_gate(unsigned int n, void *addr)
+{
+	BUG_ON((unsigned)n > 0xFF);
+	_set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
+}
+
+static inline void set_system_trap_gate(unsigned int n, void *addr)
+{
+	BUG_ON((unsigned)n > 0xFF);
+	_set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS);
+}
+
+static inline void set_trap_gate(unsigned int n, void *addr)
+{
+	BUG_ON((unsigned)n > 0xFF);
+	_set_gate(n, GATE_TRAP, addr, 0, 0, __KERNEL_CS);
+}
+
+static inline void set_task_gate(unsigned int n, unsigned int gdt_entry)
+{
+	BUG_ON((unsigned)n > 0xFF);
+	_set_gate(n, GATE_TASK, (void *)0, 0, 0, (gdt_entry<<3));
+}
+
+static inline void set_intr_gate_ist(int n, void *addr, unsigned ist)
+{
+	BUG_ON((unsigned)n > 0xFF);
+	_set_gate(n, GATE_INTERRUPT, addr, 0, ist, __KERNEL_CS);
+}
+
+static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist)
+{
+	BUG_ON((unsigned)n > 0xFF);
+	_set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS);
+}
+
+#else
+/*
+ * GET_DESC_BASE reads the descriptor base of the specified segment.
+ *
+ * Args:
+ *    idx - descriptor index
+ *    gdt - GDT pointer
+ *    base - 32bit register to which the base will be written
+ *    lo_w - lo word of the "base" register
+ *    lo_b - lo byte of the "base" register
+ *    hi_b - hi byte of the low word of the "base" register
+ *
+ * Example:
+ *    GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah)
+ *    Will read the base address of GDT_ENTRY_ESPFIX_SS and put it into %eax.
+ */
+#define GET_DESC_BASE(idx, gdt, base, lo_w, lo_b, hi_b) \
+	movb idx * 8 + 4(gdt), lo_b;			\
+	movb idx * 8 + 7(gdt), hi_b;			\
+	shll $16, base;					\
+	movw idx * 8 + 2(gdt), lo_w;
+
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* ASM_X86__DESC_H */