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Commit 1c946c1b authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Michael Ellerman
Browse files

powerpc/mm/hash: Simplify the region id calculation. 



This reduces multiple comparisons in get_region_id to a bit shift operation.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 53ed7a59

arch/powerpc/include/asm/book3s/64/hash-4k.h

+3 −1
Original line number Diff line number Diff line
@@ -13,12 +13,14 @@ 
 */

#define MAX_EA_BITS_PER_CONTEXT		46



#define REGION_SHIFT		(MAX_EA_BITS_PER_CONTEXT - 2)



/*

 * Our page table limit us to 64TB. Hence for the kernel mapping,

 * each MAP area is limited to 16 TB.

 * The four map areas are:  linear mapping, vmap, IO and vmemmap

 */

#define H_KERN_MAP_SIZE		(ASM_CONST(1) << (MAX_EA_BITS_PER_CONTEXT - 2))

#define H_KERN_MAP_SIZE		(ASM_CONST(1) << REGION_SHIFT)



/*

 * Define the address range of the kernel non-linear virtual area

arch/powerpc/include/asm/book3s/64/hash-64k.h

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
 * is handled in the hotpath.

 */

#define MAX_EA_BITS_PER_CONTEXT		49

#define REGION_SHIFT		MAX_EA_BITS_PER_CONTEXT



/*

 * We use one context for each MAP area.

arch/powerpc/include/asm/book3s/64/hash.h

+15 −16
Original line number Diff line number Diff line
@@ -83,26 +83,26 @@ 
#define H_VMEMMAP_SIZE		H_KERN_MAP_SIZE

#define H_VMEMMAP_END		(H_VMEMMAP_START + H_VMEMMAP_SIZE)



#define NON_LINEAR_REGION_ID(ea)	((((unsigned long)ea - H_KERN_VIRT_START) >> REGION_SHIFT) + 2)



/*

 * Region IDs

 */

#define USER_REGION_ID		1

#define KERNEL_REGION_ID	2

#define VMALLOC_REGION_ID	3

#define IO_REGION_ID		4

#define VMEMMAP_REGION_ID	5

#define USER_REGION_ID		0

#define KERNEL_REGION_ID	1

#define VMALLOC_REGION_ID	NON_LINEAR_REGION_ID(H_VMALLOC_START)

#define IO_REGION_ID		NON_LINEAR_REGION_ID(H_KERN_IO_START)

#define VMEMMAP_REGION_ID	NON_LINEAR_REGION_ID(H_VMEMMAP_START)



/*

 * Defines the address of the vmemap area, in its own region on

 * hash table CPUs.

 */



#ifdef CONFIG_PPC_MM_SLICES

#define HAVE_ARCH_UNMAPPED_AREA

#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN

#endif /* CONFIG_PPC_MM_SLICES */





/* PTEIDX nibble */

#define _PTEIDX_SECONDARY	0x8

#define _PTEIDX_GROUP_IX	0x7
@@ -113,22 +113,21 @@ 
#ifndef __ASSEMBLY__

static inline int get_region_id(unsigned long ea)

{

	int region_id;

	int id = (ea >> 60UL);



	if (id == 0)

		return USER_REGION_ID;



	VM_BUG_ON(id != 0xc);

	VM_BUG_ON(ea >= H_VMEMMAP_END);

	if (ea < H_KERN_VIRT_START)

		return KERNEL_REGION_ID;



	if (ea >= H_VMEMMAP_START)

		return VMEMMAP_REGION_ID;

	else if (ea >= H_KERN_IO_START)

		return IO_REGION_ID;

	else if (ea >= H_VMALLOC_START)

		return VMALLOC_REGION_ID;

	VM_BUG_ON(id != 0xc);

	BUILD_BUG_ON(NON_LINEAR_REGION_ID(H_VMALLOC_START) != 2);



	return KERNEL_REGION_ID;

	region_id = NON_LINEAR_REGION_ID(ea);

	VM_BUG_ON(region_id > VMEMMAP_REGION_ID);

	return region_id;

}



#define	hash__pmd_bad(pmd)		(pmd_val(pmd) & H_PMD_BAD_BITS)

arch/powerpc/include/asm/book3s/64/mmu-hash.h

+1 −1
Original line number Diff line number Diff line
@@ -823,7 +823,7 @@ static inline unsigned long get_kernel_context(unsigned long ea) 
		 */

		ctx =  1 + ((ea & EA_MASK) >> MAX_EA_BITS_PER_CONTEXT);

	} else

		ctx = region_id + MAX_KERNEL_CTX_CNT - 2;

		ctx = region_id + MAX_KERNEL_CTX_CNT - 1;

	return ctx;

}