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Commit 0c243ad8 authored by David S. Miller's avatar David S. Miller
Browse files

sparc64: Only allocate per-cpu areas for possible cpus. 



This gets us real close to the generic implementation of
setup_per_cpu_areas() except:

1) We store the per-cpu offset into the trap_block[], whereas
   the generic code has it's own static array.

2) We have to initialize the %g5 register to hold the boot cpu's
   per-cpu area offset.

3) The OBP/MDESC cpu info scan is performed at the end.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 73fffc03

arch/sparc/kernel/smp_64.c

+6 −16
Original line number Diff line number Diff line
@@ -1373,27 +1373,17 @@ void smp_send_stop(void) 


void __init setup_per_cpu_areas(void)

{

	unsigned long base, shift, goal, size, i;

	unsigned long size, i, nr_possible_cpus = num_possible_cpus();

	char *ptr;



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

	goal = PERCPU_ENOUGH_ROOM;

	size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);

	ptr = alloc_bootmem_pages(size * nr_possible_cpus);



	shift = PAGE_SHIFT;

	for (size = PAGE_SIZE; size < goal; size <<= 1UL)

		shift++;



	ptr = __alloc_bootmem(size * NR_CPUS, PAGE_SIZE, 0);

	if (!ptr) {

		prom_printf("Cannot allocate per-cpu memory.\n");

		prom_halt();

	}



	base = ptr - __per_cpu_start;



	for (i = 0; i < NR_CPUS; i++, ptr += size) {

		__per_cpu_offset(i) = base + (i * size);

	for_each_possible_cpu(i) {

		__per_cpu_offset(i) = ptr - __per_cpu_start;

		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);

		ptr += size;

	}



	/* Setup %g5 for the boot cpu.  */