patch-2.4.8 linux/arch/ia64/ia32/ia32_support.c

• Lines: 143
• Date: Tue Jul 31 10:30:08 2001
• Orig file: v2.4.7/linux/arch/ia64/ia32/ia32_support.c
• Orig date: Thu Apr 5 12:51:47 2001

diff -u --recursive --new-file v2.4.7/linux/arch/ia64/ia32/ia32_support.c linux/arch/ia64/ia32/ia32_support.c
@@ -1,6 +1,11 @@
 /*
  * IA32 helper functions
  *
+ * Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
+ * Copyright (C) 2000 Asit K. Mallick <asit.k.mallick@intel.com>
+ * Copyright (C) 2001 Hewlett-Packard Co
+ * Copyright (C) 2001 David Mosberger-Tang <davidm@hpl.hp.com>
+ *
  * 06/16/00	A. Mallick	added csd/ssd/tssd for ia32 thread context
  * 02/19/01	D. Mosberger	dropped tssd; it's not needed
  */
@@ -21,7 +26,7 @@
 extern void die_if_kernel (char *str, struct pt_regs *regs, long err);
 
 void
-ia32_save_state (struct thread_struct *thread)
+ia32_save_state (struct task_struct *t)
 {
 	unsigned long eflag, fsr, fcr, fir, fdr, csd, ssd;
 
@@ -33,28 +38,30 @@
 	     "mov %5=ar.csd;"
 	     "mov %6=ar.ssd;"
 	     : "=r"(eflag), "=r"(fsr), "=r"(fcr), "=r"(fir), "=r"(fdr), "=r"(csd), "=r"(ssd));
-	thread->eflag = eflag;
-	thread->fsr = fsr;
-	thread->fcr = fcr;
-	thread->fir = fir;
-	thread->fdr = fdr;
-	thread->csd = csd;
-	thread->ssd = ssd;
-	asm ("mov ar.k0=%0 ;;" :: "r"(thread->old_iob));
+	t->thread.eflag = eflag;
+	t->thread.fsr = fsr;
+	t->thread.fcr = fcr;
+	t->thread.fir = fir;
+	t->thread.fdr = fdr;
+	t->thread.csd = csd;
+	t->thread.ssd = ssd;
+	ia64_set_kr(IA64_KR_IO_BASE, t->thread.old_iob);
 }
 
 void
-ia32_load_state (struct thread_struct *thread)
+ia32_load_state (struct task_struct *t)
 {
 	unsigned long eflag, fsr, fcr, fir, fdr, csd, ssd;
+	struct pt_regs *regs = ia64_task_regs(t);
+	int nr;
 
-	eflag = thread->eflag;
-	fsr = thread->fsr;
-	fcr = thread->fcr;
-	fir = thread->fir;
-	fdr = thread->fdr;
-	csd = thread->csd;
-	ssd = thread->ssd;
+	eflag = t->thread.eflag;
+	fsr = t->thread.fsr;
+	fcr = t->thread.fcr;
+	fir = t->thread.fir;
+	fdr = t->thread.fdr;
+	csd = t->thread.csd;
+	ssd = t->thread.ssd;
 
 	asm volatile ("mov ar.eflag=%0;"
 		      "mov ar.fsr=%1;"
@@ -64,17 +71,22 @@
 		      "mov ar.csd=%5;"
 		      "mov ar.ssd=%6;"
 		      :: "r"(eflag), "r"(fsr), "r"(fcr), "r"(fir), "r"(fdr), "r"(csd), "r"(ssd));
-	asm ("mov %0=ar.k0 ;;" : "=r"(thread->old_iob));
-	asm ("mov ar.k0=%0 ;;" :: "r"(IA32_IOBASE));
+	current->thread.old_iob = ia64_get_kr(IA64_KR_IO_BASE);
+	ia64_set_kr(IA64_KR_IO_BASE, IA32_IOBASE);
+
+	/* load TSS and LDT while preserving SS and CS: */
+	nr = smp_processor_id();
+	regs->r17 = (_TSS(nr) << 48) | (_LDT(nr) << 32) | (__u32) regs->r17;
 }
 
 /*
- * Setup IA32 GDT and TSS 
+ * Setup IA32 GDT and TSS
  */
 void
-ia32_gdt_init(void)
+ia32_gdt_init (void)
 {
-	unsigned long gdt_and_tss_page;
+	unsigned long gdt_and_tss_page, ldt_size;
+	int nr;
 
 	/* allocate two IA-32 pages of memory: */
 	gdt_and_tss_page = __get_free_pages(GFP_KERNEL,
@@ -86,17 +98,28 @@
 	/* Zero the gdt and tss */
 	memset((void *) gdt_and_tss_page, 0, 2*IA32_PAGE_SIZE);
 
-	/* CS descriptor in IA-32 format */
-	ia32_gdt_table[4] = IA32_SEG_DESCRIPTOR(0L, 0xBFFFFFFFL, 0xBL, 1L,
-						3L, 1L, 1L, 1L, 1L);
-
-	/* DS descriptor in IA-32 format */
-	ia32_gdt_table[5] = IA32_SEG_DESCRIPTOR(0L, 0xBFFFFFFFL, 0x3L, 1L,
-						3L, 1L, 1L, 1L, 1L);
+	/* CS descriptor in IA-32 (scrambled) format */
+	ia32_gdt_table[__USER_CS >> 3] =
+		IA32_SEG_DESCRIPTOR(0, (IA32_PAGE_OFFSET - 1) >> IA32_PAGE_SHIFT,
+				    0xb, 1, 3, 1, 1, 1, 1);
+
+	/* DS descriptor in IA-32 (scrambled) format */
+	ia32_gdt_table[__USER_DS >> 3] =
+		IA32_SEG_DESCRIPTOR(0, (IA32_PAGE_OFFSET - 1) >> IA32_PAGE_SHIFT,
+				    0x3, 1, 3, 1, 1, 1, 1);
+
+	/* We never change the TSS and LDT descriptors, so we can share them across all CPUs.  */
+	ldt_size = PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
+	for (nr = 0; nr < NR_CPUS; ++nr) {
+		ia32_gdt_table[_TSS(nr)] = IA32_SEG_DESCRIPTOR(IA32_TSS_OFFSET, 235,
+							       0xb, 0, 3, 1, 1, 1, 0);
+		ia32_gdt_table[_LDT(nr)] = IA32_SEG_DESCRIPTOR(IA32_LDT_OFFSET, ldt_size - 1,
+							       0x2, 0, 3, 1, 1, 1, 0);
+	}
 }
 
 /*
- * Handle bad IA32 interrupt via syscall 
+ * Handle bad IA32 interrupt via syscall
  */
 void
 ia32_bad_interrupt (unsigned long int_num, struct pt_regs *regs)
@@ -106,8 +129,7 @@
 	die_if_kernel("Bad IA-32 interrupt", regs, int_num);
 
 	siginfo.si_signo = SIGTRAP;
-	siginfo.si_errno = int_num;	/* XXX is it legal to abuse si_errno like this? */
+	siginfo.si_errno = int_num;	/* XXX is it OK to abuse si_errno like this? */
 	siginfo.si_code = TRAP_BRKPT;
 	force_sig_info(SIGTRAP, &siginfo, current);
 }
-