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Revision 435faf5c218a47fd6258187f62d9bb1009717896 authored by Linus Torvalds on 05 June 2020, 03:14:18 UTC, committed by Linus Torvalds on 05 June 2020, 03:14:18 UTC 
Merge tag 'riscv-for-linus-5.8-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
 
Pull RISC-V updates from Palmer Dabbelt:

 - The remainder of the code necessary to support the Kendryte K210:

     * Support for building device trees into the kernel, as the K210
       doesn't have a bootloader that provides one

     * A K210 device tree and the associated defconfig update

     * Support for skipping PMP initialization on systems that trap on
       PMP accesses rather than treating them as WARL

 - Support for KGDB

 - Improvements to text patching

 - Some cleanups to the SiFive L2 cache driver

* tag 'riscv-for-linus-5.8-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  soc: sifive: l2 cache: Mark l2_get_priv_group as static
  soc: sifive: l2 cache: Eliminate an unsigned zero compare warning
  riscv: Add support to determine no. of L2 cache way enabled
  riscv: cacheinfo: Implement cache_get_priv_group with a generic ops structure
  riscv: Use text_mutex instead of patch_lock
  riscv: Use NOKPROBE_SYMBOL() instead of __krpobes annotation
  riscv: Remove the 'riscv_' prefix of function name
  riscv: Add SW single-step support for KDB
  riscv: Use the XML target descriptions to report 3 system registers
  riscv: Add KGDB support
  kgdb: Add kgdb_has_hit_break function
  RISC-V: Skip setting up PMPs on traps
  riscv: K210: Update defconfig
  riscv: K210: Add a built-in device tree
  riscv: Allow device trees to be built into the kernel
2 parent s 571d54e + 09c0533
Raw File
memweight.c 
// SPDX-License-Identifier: GPL-2.0
#include <linux/export.h>
#include <linux/bug.h>
#include <linux/bitmap.h>

/**
 * memweight - count the total number of bits set in memory area
 * @ptr: pointer to the start of the area
 * @bytes: the size of the area
 */
size_t memweight(const void *ptr, size_t bytes)
{
	size_t ret = 0;
	size_t longs;
	const unsigned char *bitmap = ptr;

	for (; bytes > 0 && ((unsigned long)bitmap) % sizeof(long);
			bytes--, bitmap++)
		ret += hweight8(*bitmap);

	longs = bytes / sizeof(long);
	if (longs) {
		BUG_ON(longs >= INT_MAX / BITS_PER_LONG);
		ret += bitmap_weight((unsigned long *)bitmap,
				longs * BITS_PER_LONG);
		bytes -= longs * sizeof(long);
		bitmap += longs * sizeof(long);
	}
	/*
	 * The reason that this last loop is distinct from the preceding
	 * bitmap_weight() call is to compute 1-bits in the last region smaller
	 * than sizeof(long) properly on big-endian systems.
	 */
	for (; bytes > 0; bytes--, bitmap++)
		ret += hweight8(*bitmap);

	return ret;
}
EXPORT_SYMBOL(memweight);
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