parisc: Restore possibility to execute 64-bit applications

Executing 64-bit applications was broken. This patch restores this
support and cleans up some code paths.

Signed-off-by: Helge Deller <[e-mail]>

arch/parisc/include/asm/elf.h

···
 #define SET_PERSONALITY(ex) \
 ({	\
 	set_personality((current->personality & ~PER_MASK) | PER_LINUX); \
+	clear_thread_flag(TIF_32BIT); \
 	current->thread.map_base = DEFAULT_MAP_BASE; \
 	current->thread.task_size = DEFAULT_TASK_SIZE; \
  })
···
 
 #define COMPAT_SET_PERSONALITY(ex) \
 ({	\
-	set_thread_flag(TIF_32BIT); \
-	current->thread.map_base = DEFAULT_MAP_BASE32; \
-	current->thread.task_size = DEFAULT_TASK_SIZE32; \
+	if ((ex).e_ident[EI_CLASS] == ELFCLASS32) { \
+		set_thread_flag(TIF_32BIT); \
+		current->thread.map_base = DEFAULT_MAP_BASE32; \
+		current->thread.task_size = DEFAULT_TASK_SIZE32; \
+	} else clear_thread_flag(TIF_32BIT); \
  })
 
 /*

arch/parisc/include/asm/processor.h

···
  * it in here from the current->personality
  */
 
-#ifdef CONFIG_64BIT
-#define USER_WIDE_MODE	(!test_thread_flag(TIF_32BIT))
-#else
-#define USER_WIDE_MODE	0
-#endif
+#define USER_WIDE_MODE	(!is_32bit_task())
 
 #define start_thread(regs, new_pc, new_sp) do {		\
 	elf_addr_t *sp = (elf_addr_t *)new_sp;		\

arch/parisc/include/asm/traps.h

···
 #ifndef __ASM_TRAPS_H
 #define __ASM_TRAPS_H
 
-#ifdef __KERNEL__
+#define PARISC_ITLB_TRAP	6 /* defined by architecture. Do not change. */
+
+#if !defined(__ASSEMBLY__)
 struct pt_regs;
 
 /* traps.c */

arch/parisc/kernel/entry.S

···
 #include <asm/signal.h>
 #include <asm/unistd.h>
 #include <asm/ldcw.h>
+#include <asm/traps.h>
 #include <asm/thread_info.h>
 
 #include <linux/linkage.h>
···
 	def		 3
 	extint		 4
 	def		 5
-	itlb_20		 6
+	itlb_20		 PARISC_ITLB_TRAP
 	def		 7
 	def		 8
 	def              9
···
 	def		 3
 	extint		 4
 	def		 5
-	itlb_11		 6
+	itlb_11		 PARISC_ITLB_TRAP
 	def		 7
 	def		 8
 	def              9
···
 	save_specials	%r29
 
 	/* If this trap is a itlb miss, skip saving/adjusting isr/ior */
-
-	/*
-	 * FIXME: 1) Use a #define for the hardwired "6" below (and in
-	 *           traps.c.
-	 *        2) Once we start executing code above 4 Gb, we need
-	 *           to adjust iasq/iaoq here in the same way we
-	 *           adjust isr/ior below.
-	 */
-
-	cmpib,COND(=),n        6,%r26,skip_save_ior
+	cmpib,COND(=),n        PARISC_ITLB_TRAP,%r26,skip_save_ior
 
 
-	mfctl           %cr20, %r16 /* isr */
+	mfctl           %isr, %r16
 	nop		/* serialize mfctl on PA 2.0 to avoid 4 cycle penalty */
-	mfctl           %cr21, %r17 /* ior */
+	mfctl           %ior, %r17
 
 
 #ifdef CONFIG_64BIT
···
 	extrd,u,*<>     %r8,PSW_W_BIT,1,%r0
 	depdi           0,1,2,%r17
 
-	/*
-	 * FIXME: This code has hardwired assumptions about the split
-	 *        between space bits and offset bits. This will change
-	 *        when we allow alternate page sizes.
-	 */
-
-	/* adjust isr/ior. */
-	extrd,u         %r16,63,SPACEID_SHIFT,%r1	/* get high bits from isr for ior */
-	depd            %r1,31,SPACEID_SHIFT,%r17	/* deposit them into ior */
-	depdi           0,63,SPACEID_SHIFT,%r16		/* clear them from isr */
+	/* adjust isr/ior: get high bits from isr and deposit in ior */
+	space_adjust	%r16,%r17,%r1
 #endif
 	STREG           %r16, PT_ISR(%r29)
 	STREG           %r17, PT_IOR(%r29)
 
+#if 0 && defined(CONFIG_64BIT)
+	/* Revisit when we have 64-bit code above 4Gb */
+	b,n		intr_save2
 
 skip_save_ior:
+	/* We have a itlb miss, and when executing code above 4 Gb on ILP64, we
+	 * need to adjust iasq/iaoq here in the same way we adjusted isr/ior
+	 * above.
+	 */
+	extrd,u,*	%r8,PSW_W_BIT,1,%r1
+	cmpib,COND(=),n	1,%r1,intr_save2
+	LDREG		PT_IASQ0(%r29), %r16
+	LDREG		PT_IAOQ0(%r29), %r17
+	/* adjust iasq/iaoq */
+	space_adjust	%r16,%r17,%r1
+	STREG           %r16, PT_IASQ0(%r29)
+	STREG           %r17, PT_IAOQ0(%r29)
+#else
+skip_save_ior:
+#endif
+
+intr_save2:
 	virt_map
 	save_general	%r29
 

arch/parisc/kernel/sys_parisc.c

···
 	int do_color_align, last_mmap;
 	struct vm_unmapped_area_info info;
 
-#ifdef CONFIG_64BIT
-	/* This should only ever run for 32-bit processes.  */
-	BUG_ON(!test_thread_flag(TIF_32BIT));
-#endif
-
 	/* requested length too big for entire address space */
 	if (len > TASK_SIZE)
 		return -ENOMEM;

arch/parisc/kernel/traps.c

···
 		cpu_lpmc(5, regs);
 		return;
 
-	case  6:
+	case  PARISC_ITLB_TRAP:
 		/* Instruction TLB miss fault/Instruction page fault */
 		fault_address = regs->iaoq[0];
 		fault_space   = regs->iasq[0];