Revision 8bc086899816214fbc6047c9c7e15fcab49552bf authored by Ben Hutchings on 17 March 2019, 01:17:56 UTC, committed by Michael Ellerman on 20 March 2019, 13:16:45 UTC
MAX_PHYSMEM_BITS only needs to be defined if CONFIG_SPARSEMEM is
enabled, and that was the case before commit 4ffe713b7587
("powerpc/mm: Increase the max addressable memory to 2PB").

On 32-bit systems, where CONFIG_SPARSEMEM is not enabled, we now
define it as 46.  That is larger than the real number of physical
address bits, and breaks calculations in zsmalloc:

  mm/zsmalloc.c:130:49: warning: right shift count is negative
    MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
                                                   ^~
  ...
  mm/zsmalloc.c:253:21: error: variably modified 'size_class' at file scope
    struct size_class *size_class[ZS_SIZE_CLASSES];
                       ^~~~~~~~~~

Fixes: 4ffe713b7587 ("powerpc/mm: Increase the max addressable memory to 2PB")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
1 parent 4622a2d
Raw File
hweight.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/export.h>
#include <linux/bitops.h>
#include <asm/types.h>

/**
 * hweightN - returns the hamming weight of a N-bit word
 * @x: the word to weigh
 *
 * The Hamming Weight of a number is the total number of bits set in it.
 */

#ifndef __HAVE_ARCH_SW_HWEIGHT
unsigned int __sw_hweight32(unsigned int w)
{
#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
	w -= (w >> 1) & 0x55555555;
	w =  (w & 0x33333333) + ((w >> 2) & 0x33333333);
	w =  (w + (w >> 4)) & 0x0f0f0f0f;
	return (w * 0x01010101) >> 24;
#else
	unsigned int res = w - ((w >> 1) & 0x55555555);
	res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
	res = (res + (res >> 4)) & 0x0F0F0F0F;
	res = res + (res >> 8);
	return (res + (res >> 16)) & 0x000000FF;
#endif
}
EXPORT_SYMBOL(__sw_hweight32);
#endif

unsigned int __sw_hweight16(unsigned int w)
{
	unsigned int res = w - ((w >> 1) & 0x5555);
	res = (res & 0x3333) + ((res >> 2) & 0x3333);
	res = (res + (res >> 4)) & 0x0F0F;
	return (res + (res >> 8)) & 0x00FF;
}
EXPORT_SYMBOL(__sw_hweight16);

unsigned int __sw_hweight8(unsigned int w)
{
	unsigned int res = w - ((w >> 1) & 0x55);
	res = (res & 0x33) + ((res >> 2) & 0x33);
	return (res + (res >> 4)) & 0x0F;
}
EXPORT_SYMBOL(__sw_hweight8);

#ifndef __HAVE_ARCH_SW_HWEIGHT
unsigned long __sw_hweight64(__u64 w)
{
#if BITS_PER_LONG == 32
	return __sw_hweight32((unsigned int)(w >> 32)) +
	       __sw_hweight32((unsigned int)w);
#elif BITS_PER_LONG == 64
#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
	w -= (w >> 1) & 0x5555555555555555ul;
	w =  (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul);
	w =  (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful;
	return (w * 0x0101010101010101ul) >> 56;
#else
	__u64 res = w - ((w >> 1) & 0x5555555555555555ul);
	res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
	res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
	res = res + (res >> 8);
	res = res + (res >> 16);
	return (res + (res >> 32)) & 0x00000000000000FFul;
#endif
#endif
}
EXPORT_SYMBOL(__sw_hweight64);
#endif
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