xref: /openbmc/linux/arch/parisc/include/asm/tlbflush.h (revision 1edd0337)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _PARISC_TLBFLUSH_H
3 #define _PARISC_TLBFLUSH_H
4 
5 /* TLB flushing routines.... */
6 
7 #include <linux/mm.h>
8 #include <linux/sched.h>
9 #include <asm/mmu_context.h>
10 
11 extern void flush_tlb_all(void);
12 extern void flush_tlb_all_local(void *);
13 
14 #define smp_flush_tlb_all()	flush_tlb_all()
15 
16 int __flush_tlb_range(unsigned long sid,
17 	unsigned long start, unsigned long end);
18 
19 #define flush_tlb_range(vma, start, end) \
20 	__flush_tlb_range((vma)->vm_mm->context.space_id, start, end)
21 
22 #define flush_tlb_kernel_range(start, end) \
23 	__flush_tlb_range(0, start, end)
24 
25 /*
26  * flush_tlb_mm()
27  *
28  * The code to switch to a new context is NOT valid for processes
29  * which play with the space id's.  Thus, we have to preserve the
30  * space and just flush the entire tlb.  However, the compilers,
31  * dynamic linker, etc, do not manipulate space id's, so there
32  * could be a significant performance benefit in switching contexts
33  * and not flushing the whole tlb.
34  */
35 
36 static inline void flush_tlb_mm(struct mm_struct *mm)
37 {
38 	BUG_ON(mm == &init_mm); /* Should never happen */
39 
40 #if 1 || defined(CONFIG_SMP)
41 	/* Except for very small threads, flushing the whole TLB is
42 	 * faster than using __flush_tlb_range.  The pdtlb and pitlb
43 	 * instructions are very slow because of the TLB broadcast.
44 	 * It might be faster to do local range flushes on all CPUs
45 	 * on PA 2.0 systems.
46 	 */
47 	flush_tlb_all();
48 #else
49 	/* FIXME: currently broken, causing space id and protection ids
50 	 * to go out of sync, resulting in faults on userspace accesses.
51 	 * This approach needs further investigation since running many
52 	 * small applications (e.g., GCC testsuite) is faster on HP-UX.
53 	 */
54 	if (mm) {
55 		if (mm->context != 0)
56 			free_sid(mm->context);
57 		mm->context = alloc_sid();
58 		if (mm == current->active_mm)
59 			load_context(mm->context);
60 	}
61 #endif
62 }
63 
64 static inline void flush_tlb_page(struct vm_area_struct *vma,
65 	unsigned long addr)
66 {
67 	purge_tlb_entries(vma->vm_mm, addr);
68 }
69 #endif
70