[PATCH 17/19] unify paravirt pieces of descriptor handling

Glauber de Oliveira Costa
2007-12-13T04:50:42Z

With the types used to access descriptors in x86_64 and i386
now being the same, the code that effectively handles them can
now be easily shared. This patch moves the paravirt part of
desc_32.h into desc.h, and then, we get paravirt support in x86_64
for free.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
---
include/asm-x86/desc.h | 169 +++++++++++++++++++++++++++++++++++++++++++
include/asm-x86/desc_32.h | 130 ---------------------------------
include/asm-x86/desc_64.h | 104 +++------------------------
include/asm-x86/desc_defs.h | 6 +-
4 files changed, 183 insertions(+), 226 deletions(-)

Index: linux-2.6-x86/include/asm-x86/desc_32.h
===================================================================
--- linux-2.6-x86.orig/include/asm-x86/desc_32.h
+++ linux-2.6-x86/include/asm-x86/desc_32.h
@@ -8,31 +8,10 @@
#ifndef __ASSEMBLY__

#include <linux/preempt.h>
-#include <linux/smp.h>
#include <linux/percpu.h>

-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;
-}
-
extern void set_intr_gate(unsigned int irq, void * addr);

-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 pack_gate(gate_desc *gate,
unsigned long base, unsigned short seg, unsigned char type, unsigned char flags)
{
@@ -40,115 +19,6 @@ static inline void pack_gate(gate_desc *
gate->b = (base & 0xffff0000) | ((type & 0xff) << 8) | (flags & 0xff);
}

-#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)
-#endif
-
-static inline void native_write_ldt_entry(struct desc_struct *ldt, int entry,
- const void *desc)
-{
- memcpy(&ldt[entry], desc, sizeof(struct desc_struct));
-}
-
-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_gdt_entry(struct desc_struct *gdt, int entry,
- const void *desc, int type)
-{
- memcpy(&gdt[entry], desc, sizeof(struct desc_struct));
-}
-
-static inline void write_dt_entry(struct desc_struct *dt,
- int entry, u32 entry_low, u32 entry_high)
-{
- dt[entry].a = entry_low;
- dt[entry].b = entry_high;
-}
-
-
-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;
-
- pack_descriptor(&ldt, (unsigned long)addr,
- entries * sizeof(struct desc_struct) - 1,
- DESC_LDT, 0);
- 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 ("sgdt %0":"=m" (*dtr));
-}
-
-static inline void native_store_idt(struct desc_ptr *dtr)
-{
- asm ("sidt %0":"=m" (*dtr));
-}
-
-static inline unsigned long native_store_tr(void)
-{
- unsigned long tr;
- asm ("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];
-}
-
static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg)
{
gate_desc g;
Index: linux-2.6-x86/include/asm-x86/desc_64.h
===================================================================
--- linux-2.6-x86.orig/include/asm-x86/desc_64.h
+++ linux-2.6-x86/include/asm-x86/desc_64.h
@@ -8,47 +8,10 @@
#ifndef __ASSEMBLY__

#include <linux/string.h>
-#include <linux/smp.h>

#include <asm/segment.h>

-extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
-
-#define load_TR_desc() asm volatile("ltr %w0"::"r" (GDT_ENTRY_TSS*8))
-#define load_LDT_desc() asm volatile("lldt %w0"::"r" (GDT_ENTRY_LDT*8))
-
-static inline unsigned long __store_tr(void)
-{
- unsigned long tr;
-
- asm volatile ("str %w0":"=r" (tr));
- return tr;
-}
-
-#define store_tr(tr) (tr) = __store_tr()
-
-extern struct desc_ptr cpu_gdt_descr[];
-
-static inline void write_ldt_entry(struct desc_struct *ldt,
- int entry, void *ptr)
-{
- memcpy(&ldt[entry], ptr, 8);
-}
-
-/* the cpu gdt accessor */
-#define get_cpu_gdt_table(x) ((struct desc_struct *)cpu_gdt_descr[x].address)
-
-static inline void load_gdt(const struct desc_ptr *ptr)
-{
- asm volatile("lgdt %w0"::"m" (*ptr));
-}
-
-static inline void store_gdt(struct desc_ptr *ptr)
-{
- asm("sgdt %w0":"=m" (*ptr));
-}
-
-static inline void _set_gate(void *adr, unsigned type, unsigned long func,
+static inline void _set_gate(int gate, unsigned type, unsigned long func,
unsigned dpl, unsigned ist)
{
gate_desc s;
@@ -67,61 +30,37 @@ static inline void _set_gate(void *adr,
* does not need to be atomic because it is only done once at
* setup time
*/
- memcpy(adr, &s, 16);
+ write_idt_entry(idt_table, gate, &s);
}

static inline void set_intr_gate(int nr, void *func)
{
BUG_ON((unsigned)nr > 0xFF);
- _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0);
+ _set_gate(nr, GATE_INTERRUPT, (unsigned long) func, 0, 0);
}

static inline void set_intr_gate_ist(int nr, void *func, unsigned ist)
{
BUG_ON((unsigned)nr > 0xFF);
- _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist);
+ _set_gate(nr, GATE_INTERRUPT, (unsigned long) func, 0, ist);
}

static inline void set_system_gate(int nr, void *func)
{
BUG_ON((unsigned)nr > 0xFF);
- _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0);
+ _set_gate(nr, GATE_INTERRUPT, (unsigned long) func, 3, 0);
}

static inline void set_system_gate_ist(int nr, void *func, unsigned ist)
{
- _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, ist);
-}
-
-static inline void load_idt(const struct desc_ptr *ptr)
-{
- asm volatile("lidt %w0"::"m" (*ptr));
-}
-
-static inline void store_idt(struct desc_ptr *dtr)
-{
- asm("sidt %w0":"=m" (*dtr));
-}
-
-static inline void set_tssldt_descriptor(void *ptr, unsigned long tss,
- unsigned type, unsigned size)
-{
- struct ldttss_desc64 d;
-
- memset(&d, 0, sizeof(d));
- d.limit0 = size & 0xFFFF;
- d.base0 = PTR_LOW(tss);
- d.base1 = PTR_MIDDLE(tss) & 0xFF;
- d.type = type;
- d.p = 1;
- d.limit1 = (size >> 16) & 0xF;
- d.base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF;
- d.base3 = PTR_HIGH(tss);
- memcpy(ptr, &d, 16);
+ _set_gate(nr, GATE_INTERRUPT, (unsigned long) func, 3, ist);
}

static inline void set_tss_desc(unsigned cpu, 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
@@ -129,31 +68,10 @@ static inline void set_tss_desc(unsigned
* -1? seg base+limit should be pointing to the address of the
* last valid byte
*/
- set_tssldt_descriptor(&get_cpu_gdt_table(cpu)[GDT_ENTRY_TSS],
+ set_tssldt_descriptor(&tss,
(unsigned long)addr, DESC_TSS,
IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1);
-}
-
-static inline void set_ldt(void *addr, int entries)
-{
- if (likely(entries == 0))
- __asm__ __volatile__("lldt %w0"::"q" (0));
- else {
- unsigned cpu = smp_processor_id();
-
- set_tssldt_descriptor(&get_cpu_gdt_table(cpu)[GDT_ENTRY_LDT],
- (unsigned long)addr, DESC_LDT, entries * 8 - 1);
- __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8));
- }
-}
-
-static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
-{
- unsigned int i;
- struct desc_struct *gdt = (get_cpu_gdt_table(cpu) + GDT_ENTRY_TLS_MIN);
-
- for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
- gdt[i] = t->tls_array[i];
+ write_gdt_entry(d, GDT_ENTRY_TSS, &tss, DESC_TSS);
}

#endif /* !__ASSEMBLY__ */
Index: linux-2.6-x86/include/asm-x86/desc_defs.h
===================================================================
--- linux-2.6-x86.orig/include/asm-x86/desc_defs.h
+++ linux-2.6-x86/include/asm-x86/desc_defs.h
@@ -48,9 +48,9 @@ struct gate_struct64 {
u32 zero1;
} __attribute__((packed));

-#define PTR_LOW(x) ((unsigned long)(x) & 0xFFFF)
-#define PTR_MIDDLE(x) (((unsigned long)(x) >> 16) & 0xFFFF)
-#define PTR_HIGH(x) ((unsigned long)(x) >> 32)
+#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,
Index: linux-2.6-x86/include/asm-x86/desc.h
===================================================================
--- linux-2.6-x86.orig/include/asm-x86/desc.h
+++ linux-2.6-x86/include/asm-x86/desc.h
@@ -5,6 +5,7 @@
#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, struct user_desc *info)
{
@@ -27,6 +28,174 @@ static inline void fill_ldt(struct desc_
extern struct desc_ptr idt_descr;
extern gate_desc idt_table[];

+#ifdef CONFIG_X86_64
+extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
+extern struct desc_ptr cpu_gdt_descr[];
+/* the cpu gdt accessor */
+#define get_cpu_gdt_table(x) ((struct desc_struct *)cpu_gdt_descr[x].address)
+#else
+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;
+}
+#endif
+
+#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)
+#endif
+
+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 set_tssldt_descriptor(struct ldttss_desc64 *d,
+ unsigned long tss, unsigned type,
+ unsigned size)
+{
+ memset(d, 0, sizeof(*d));
+ d->limit0 = size & 0xFFFF;
+ d->base0 = PTR_LOW(tss);
+ d->base1 = PTR_MIDDLE(tss) & 0xFF;
+ d->type = type;
+ d->p = 1;
+ d->limit1 = (size >> 16) & 0xF;
+ d->base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF;
+ d->base3 = PTR_HIGH(tss);
+}
+
+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 pack_ldt(ldt_desc *ldt, unsigned long addr,
+ unsigned size)
+{
+
+#ifdef CONFIG_X86_64
+ set_tssldt_descriptor(ldt,
+ addr, DESC_LDT, size);
+#else
+ pack_descriptor(ldt, (unsigned long)addr,
+ size,
+ 0x80 | DESC_LDT, 0);
+#endif
+}
+
+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;
+
+ pack_ldt(&ldt, (unsigned long)addr,
+ entries * sizeof(ldt) - 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];
+}
+
#ifdef CONFIG_X86_32
# include "desc_32.h"
#else