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-rw-r--r--sys/arch/amd64/amd64/gdt.c112
-rw-r--r--sys/arch/amd64/amd64/vm_machdep.c5
-rw-r--r--sys/arch/amd64/include/gdt.h8
3 files changed, 34 insertions, 91 deletions
diff --git a/sys/arch/amd64/amd64/gdt.c b/sys/arch/amd64/amd64/gdt.c
index 1f36bcfdb4b..0753153a884 100644
--- a/sys/arch/amd64/amd64/gdt.c
+++ b/sys/arch/amd64/amd64/gdt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: gdt.c,v 1.13 2009/01/17 23:44:46 guenther Exp $ */
+/* $OpenBSD: gdt.c,v 1.14 2009/02/03 11:24:19 mikeb Exp $ */
/* $NetBSD: gdt.c,v 1.1 2003/04/26 18:39:28 fvdl Exp $ */
/*-
@@ -40,45 +40,27 @@
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
-#include <sys/rwlock.h>
#include <sys/user.h>
+#include <sys/mutex.h>
#include <uvm/uvm.h>
#include <machine/gdt.h>
-int gdt_size; /* size of GDT in bytes */
-int gdt_dyncount; /* number of dyn. allocated GDT entries in use */
-int gdt_dynavail;
int gdt_next; /* next available slot for sweeping */
int gdt_free; /* next free slot; terminated with GNULL_SEL */
-struct rwlock gdt_lock_store = RWLOCK_INITIALIZER("gdtlk");
+struct mutex gdt_lock_store = MUTEX_INITIALIZER(IPL_HIGH);
-static __inline void gdt_lock(void);
-static __inline void gdt_unlock(void);
void gdt_init(void);
-void gdt_grow(void);
int gdt_get_slot(void);
void gdt_put_slot(int);
/*
- * Lock and unlock the GDT, to avoid races in case gdt_{ge,pu}t_slot() sleep
- * waiting for memory.
+ * Lock and unlock the GDT.
*/
-static __inline void
-gdt_lock(void)
-{
- if (curproc != NULL) /* XXX - ugh. needed for startup */
- rw_enter_write(&gdt_lock_store);
-}
-
-static __inline void
-gdt_unlock(void)
-{
- if (curproc != NULL)
- rw_exit_write(&gdt_lock_store);
-}
+#define gdt_lock() (mtx_enter(&gdt_lock_store))
+#define gdt_unlock() (mtx_leave(&gdt_lock_store))
void
set_mem_gdt(struct mem_segment_descriptor *sd, void *base, size_t limit,
@@ -126,16 +108,12 @@ gdt_init(void)
vaddr_t va;
struct cpu_info *ci = &cpu_info_primary;
- gdt_size = MINGDTSIZ;
- gdt_dyncount = 0;
gdt_next = 0;
gdt_free = GNULL_SEL;
- gdt_dynavail =
- (gdt_size - DYNSEL_START) / sizeof (struct sys_segment_descriptor);
old_gdt = gdtstore;
gdtstore = (char *)uvm_km_valloc(kernel_map, MAXGDTSIZ);
- for (va = (vaddr_t)gdtstore; va < (vaddr_t)gdtstore + gdt_size;
+ for (va = (vaddr_t)gdtstore; va < (vaddr_t)gdtstore + MAXGDTSIZ;
va += PAGE_SIZE) {
pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_ZERO);
if (pg == NULL) {
@@ -144,7 +122,7 @@ gdt_init(void)
pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg),
VM_PROT_READ | VM_PROT_WRITE);
}
- memcpy(gdtstore, old_gdt, DYNSEL_START);
+ bcopy(old_gdt, gdtstore, DYNSEL_START);
ci->ci_gdt = gdtstore;
set_sys_segment(GDT_ADDR_SYS(gdtstore, GLDT_SEL), ldtstore,
LDT_SIZE - 1, SDT_SYSLDT, SEL_KPL, 0);
@@ -159,12 +137,22 @@ gdt_init(void)
void
gdt_alloc_cpu(struct cpu_info *ci)
{
- ci->ci_gdt = (char *)uvm_km_valloc(kernel_map, MAXGDTSIZ);
- uvm_map_pageable(kernel_map, (vaddr_t)ci->ci_gdt,
- (vaddr_t)ci->ci_gdt + MINGDTSIZ, FALSE, FALSE);
- memset(ci->ci_gdt, 0, MINGDTSIZ);
- memcpy(ci->ci_gdt, gdtstore,
- DYNSEL_START + gdt_dyncount * sizeof(struct sys_segment_descriptor));
+ struct vm_page *pg;
+ vaddr_t va;
+
+ ci->ci_gdt = (char *)uvm_km_valloc(kernel_map, MAXGDTSIZ);
+ uvm_map_pageable(kernel_map, (vaddr_t)ci->ci_gdt,
+ (vaddr_t)ci->ci_gdt + MAXGDTSIZ, FALSE, FALSE);
+ for (va = (vaddr_t)ci->ci_gdt; va < (vaddr_t)ci->ci_gdt + MAXGDTSIZ;
+ va += PAGE_SIZE) {
+ pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_ZERO);
+ if (pg == NULL)
+ panic("gdt_init: no pages");
+ pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg),
+ VM_PROT_READ | VM_PROT_WRITE);
+ }
+ bzero(ci->ci_gdt, MAXGDTSIZ);
+ bcopy(gdtstore, ci->ci_gdt, MAXGDTSIZ);
}
#endif /* MULTIPROCESSOR */
@@ -194,46 +182,11 @@ gdt_reload_cpu(struct cpu_info *ci)
}
#endif
-
-/*
- * Grow or shrink the GDT.
- */
-void
-gdt_grow(void)
-{
- CPU_INFO_ITERATOR cii;
- struct cpu_info *ci;
- struct vm_page *pg;
- size_t old_len;
- vaddr_t va;
-
- old_len = gdt_size;
- gdt_size = 2 * gdt_size;
- gdt_dynavail =
- (gdt_size - DYNSEL_START) / sizeof (struct sys_segment_descriptor);
-
- CPU_INFO_FOREACH(cii, ci) {
- for (va = (vaddr_t)(ci->ci_gdt) + old_len;
- va < (vaddr_t)(ci->ci_gdt) + gdt_size;
- va += PAGE_SIZE) {
- while ((pg =
- uvm_pagealloc(NULL, 0, NULL, UVM_PGA_ZERO)) ==
- NULL) {
- uvm_wait("gdt_grow");
- }
- pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg),
- VM_PROT_READ | VM_PROT_WRITE);
- }
- }
-}
-
/*
* Allocate a GDT slot as follows:
* 1) If there are entries on the free list, use those.
- * 2) If there are fewer than gdt_dynavail entries in use, there are free slots
+ * 2) If there are fewer than MAXGDTSIZ entries in use, there are free slots
* near the end that we can sweep through.
- * 3) As a last resort, we increase the size of the GDT, and sweep through
- * the new slots.
*/
int
gdt_get_slot(void)
@@ -249,21 +202,11 @@ gdt_get_slot(void)
slot = gdt_free;
gdt_free = gdt[slot].sd_xx3; /* XXXfvdl res. field abuse */
} else {
-#ifdef DIAGNOSTIC
- if (gdt_next != gdt_dyncount)
- panic("gdt_get_slot botch 1");
-#endif
- if (gdt_next >= gdt_dynavail) {
-#ifdef DIAGNOSTIC
- if (gdt_size >= MAXGDTSIZ)
- panic("gdt_get_slot botch 2");
-#endif
- gdt_grow();
- }
+ if (gdt_next >= MAXGDTSIZ)
+ panic("gdt_get_slot: out of GDT descriptors");
slot = gdt_next++;
}
- gdt_dyncount++;
gdt_unlock();
return (slot);
}
@@ -279,7 +222,6 @@ gdt_put_slot(int slot)
gdt = (struct sys_segment_descriptor *)&gdtstore[DYNSEL_START];
gdt_lock();
- gdt_dyncount--;
gdt[slot].sd_type = SDT_SYSNULL;
gdt[slot].sd_xx3 = gdt_free;
diff --git a/sys/arch/amd64/amd64/vm_machdep.c b/sys/arch/amd64/amd64/vm_machdep.c
index d9607ed1747..144ecf99541 100644
--- a/sys/arch/amd64/amd64/vm_machdep.c
+++ b/sys/arch/amd64/amd64/vm_machdep.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: vm_machdep.c,v 1.14 2009/01/28 08:02:02 grange Exp $ */
+/* $OpenBSD: vm_machdep.c,v 1.15 2009/02/03 11:24:19 mikeb Exp $ */
/* $NetBSD: vm_machdep.c,v 1.1 2003/04/26 18:39:33 fvdl Exp $ */
/*-
@@ -160,6 +160,7 @@ cpu_exit(struct proc *p)
mtrr_clean(p);
pmap_deactivate(p);
+ tss_free(p->p_md.md_tss_sel);
sched_exit(p);
}
@@ -171,8 +172,6 @@ cpu_exit(struct proc *p)
void
cpu_wait(struct proc *p)
{
- /* Nuke the TSS. */
- tss_free(p->p_md.md_tss_sel);
}
/*
diff --git a/sys/arch/amd64/include/gdt.h b/sys/arch/amd64/include/gdt.h
index 3b4abd01071..b52bc98e3eb 100644
--- a/sys/arch/amd64/include/gdt.h
+++ b/sys/arch/amd64/include/gdt.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: gdt.h,v 1.3 2008/06/26 05:42:09 ray Exp $ */
+/* $OpenBSD: gdt.h,v 1.4 2009/02/03 11:24:19 mikeb Exp $ */
/* $NetBSD: gdt.h,v 1.1 2003/04/26 18:39:40 fvdl Exp $ */
/*-
@@ -51,6 +51,8 @@ void set_sys_gdt(struct sys_segment_descriptor *, void *, size_t, int, int,
int);
#endif
-/* MINGDTSIZ must be a multiple of PAGE_SIZE or gdt_grow breaks */
-#define MINGDTSIZ PAGE_SIZE
+/*
+ * Maximum GDT size. It cannot exceed 65536 since the selector field of
+ * a descriptor is just 16 bits, and used as free list link.
+ */
#define MAXGDTSIZ 65536
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-18 15:01:00 +0000