Commit c2a7e818 authored by Tejun Heo's avatar Tejun Heo
Browse files

powerpc64: convert to dynamic percpu allocator 



Now that percpu allows arbitrary embedding of the first chunk,
powerpc64 can easily be converted to dynamic percpu allocator.
Convert it.  powerpc supports several large page sizes.  Cap atom_size
at 1M.  There isn't much to gain by going above that anyway.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
parent bcb2107f

arch/powerpc/Kconfig

+2 −2
Original line number Diff line number Diff line
@@ -46,10 +46,10 @@ config GENERIC_HARDIRQS_NO__DO_IRQ 
	bool

	default y



config HAVE_LEGACY_PER_CPU_AREA

config HAVE_SETUP_PER_CPU_AREA

	def_bool PPC64



config HAVE_SETUP_PER_CPU_AREA

config NEED_PER_CPU_EMBED_FIRST_CHUNK

	def_bool PPC64



config IRQ_PER_CPU

arch/powerpc/kernel/setup_64.c

+45 −16
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ 
#include <asm/cache.h>

#include <asm/page.h>

#include <asm/mmu.h>

#include <asm/mmu-hash64.h>

#include <asm/firmware.h>

#include <asm/xmon.h>

#include <asm/udbg.h>
@@ -569,25 +570,53 @@ void cpu_die(void) 
}



#ifdef CONFIG_SMP

void __init setup_per_cpu_areas(void)

#define PCPU_DYN_SIZE		()



static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)

{

	int i;

	unsigned long size;

	char *ptr;



	/* Copy section for each CPU (we discard the original) */

	size = ALIGN(__per_cpu_end - __per_cpu_start, PAGE_SIZE);

#ifdef CONFIG_MODULES

	if (size < PERCPU_ENOUGH_ROOM)

		size = PERCPU_ENOUGH_ROOM;

#endif

	return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align,

				    __pa(MAX_DMA_ADDRESS));

}



	for_each_possible_cpu(i) {

		ptr = alloc_bootmem_pages_node(NODE_DATA(cpu_to_node(i)), size);

static void __init pcpu_fc_free(void *ptr, size_t size)

{

	free_bootmem(__pa(ptr), size);

}



		paca[i].data_offset = ptr - __per_cpu_start;

		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);

static int pcpu_cpu_distance(unsigned int from, unsigned int to)

{

	if (cpu_to_node(from) == cpu_to_node(to))

		return LOCAL_DISTANCE;

	else

		return REMOTE_DISTANCE;

}



void __init setup_per_cpu_areas(void)

{

	const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;

	size_t atom_size;

	unsigned long delta;

	unsigned int cpu;

	int rc;



	/*

	 * Linear mapping is one of 4K, 1M and 16M.  For 4K, no need

	 * to group units.  For larger mappings, use 1M atom which

	 * should be large enough to contain a number of units.

	 */

	if (mmu_linear_psize == MMU_PAGE_4K)

		atom_size = PAGE_SIZE;

	else

		atom_size = 1 << 20;



	rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,

				    pcpu_fc_alloc, pcpu_fc_free);

	if (rc < 0)

		panic("cannot initialize percpu area (err=%d)", rc);



	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;

	for_each_possible_cpu(cpu)

		paca[cpu].data_offset = delta + pcpu_unit_offsets[cpu];

}

#endif

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