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powerpc/8xx: Simplify flush_tlb_kernel_range()

In the same spirit as commit 63f501e07a85 ("powerpc/8xx: Simplify TLB
handling"), simplify flush_tlb_kernel_range() for 8xx.

8xx cannot be SMP, and has 'tlbie' and 'tlbia' instructions, so
an inline version of flush_tlb_kernel_range() for 8xx is worth it.

With this page, first leg of change_page_attr() is:

2c: 55 29 00 3c rlwinm r9,r9,0,0,30
30: 91 23 00 00 stw r9,0(r3)
34: 7c 00 22 64 tlbie r4,r0
38: 7c 00 04 ac hwsync
3c: 38 60 00 00 li r3,0
40: 4e 80 00 20 blr

Before the patch it was:

30: 55 29 00 3c rlwinm r9,r9,0,0,30
34: 91 2a 00 00 stw r9,0(r10)
38: 94 21 ff f0 stwu r1,-16(r1)
3c: 7c 08 02 a6 mflr r0
40: 38 83 10 00 addi r4,r3,4096
44: 90 01 00 14 stw r0,20(r1)
48: 48 00 00 01 bl 48 <change_page_attr+0x48>
48: R_PPC_REL24 flush_tlb_kernel_range
4c: 80 01 00 14 lwz r0,20(r1)
50: 38 60 00 00 li r3,0
54: 7c 08 03 a6 mtlr r0
58: 38 21 00 10 addi r1,r1,16
5c: 4e 80 00 20 blr

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d2610043419ce3e0e53a85386baf2c3625af5cfb.1647877442.git.christophe.leroy@csgroup.eu

authored by

Christophe Leroy and committed by
Michael Ellerman 9290c379 e59596a2

+13 -1
+11 -1
arch/powerpc/include/asm/nohash/tlbflush.h
··· 30 30 31 31 extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, 32 32 unsigned long end); 33 - extern void flush_tlb_kernel_range(unsigned long start, unsigned long end); 34 33 35 34 #ifdef CONFIG_PPC_8xx 36 35 static inline void local_flush_tlb_mm(struct mm_struct *mm) ··· 44 45 { 45 46 asm volatile ("tlbie %0; sync" : : "r" (vmaddr) : "memory"); 46 47 } 48 + 49 + static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end) 50 + { 51 + start &= PAGE_MASK; 52 + 53 + if (end - start <= PAGE_SIZE) 54 + asm volatile ("tlbie %0; sync" : : "r" (start) : "memory"); 55 + else 56 + asm volatile ("sync; tlbia; isync" : : : "memory"); 57 + } 47 58 #else 59 + extern void flush_tlb_kernel_range(unsigned long start, unsigned long end); 48 60 extern void local_flush_tlb_mm(struct mm_struct *mm); 49 61 extern void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr); 50 62
+2
arch/powerpc/mm/nohash/tlb.c
··· 358 358 /* 359 359 * Flush kernel TLB entries in the given range 360 360 */ 361 + #ifndef CONFIG_PPC_8xx 361 362 void flush_tlb_kernel_range(unsigned long start, unsigned long end) 362 363 { 363 364 #ifdef CONFIG_SMP ··· 371 370 #endif 372 371 } 373 372 EXPORT_SYMBOL(flush_tlb_kernel_range); 373 + #endif 374 374 375 375 /* 376 376 * Currently, for range flushing, we just do a full mm flush. This should