Revision f32393c943e297b8ae180c8f83d81a156c7d0412 authored by Nathan Fontenot on 30 April 2015, 01:42:06 UTC, committed by Michael Ellerman on 01 May 2015, 03:47:24 UTC
The incorrect ordering of operations during cpu dlpar add results in invalid
affinity for the cpu being added. The ibm,associativity property in the
device tree is populated with all zeroes for the added cpu which results in
invalid affinity mappings and all cpus appear to belong to node 0.

This occurs because rtas configure-connector is called prior to making the
rtas set-indicator calls. Phyp does not assign affinity information
for a cpu until the rtas set-indicator calls are made to set the isolation
and allocation state.

Correct the order of operations to make the rtas set-indicator
calls (done in dlpar_acquire_drc) before calling rtas configure-connector.

Fixes: 1a8061c46c46 ("powerpc/pseries: Add kernel based CPU DLPAR handling")

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
1 parent 2fa30fe
Raw File
maccess.c
/*
 * Access kernel memory without faulting.
 */
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/uaccess.h>

/**
 * probe_kernel_read(): safely attempt to read from a location
 * @dst: pointer to the buffer that shall take the data
 * @src: address to read from
 * @size: size of the data chunk
 *
 * Safely read from address @src to the buffer at @dst.  If a kernel fault
 * happens, handle that and return -EFAULT.
 */

long __weak probe_kernel_read(void *dst, const void *src, size_t size)
    __attribute__((alias("__probe_kernel_read")));

long __probe_kernel_read(void *dst, const void *src, size_t size)
{
	long ret;
	mm_segment_t old_fs = get_fs();

	set_fs(KERNEL_DS);
	pagefault_disable();
	ret = __copy_from_user_inatomic(dst,
			(__force const void __user *)src, size);
	pagefault_enable();
	set_fs(old_fs);

	return ret ? -EFAULT : 0;
}
EXPORT_SYMBOL_GPL(probe_kernel_read);

/**
 * probe_kernel_write(): safely attempt to write to a location
 * @dst: address to write to
 * @src: pointer to the data that shall be written
 * @size: size of the data chunk
 *
 * Safely write to address @dst from the buffer at @src.  If a kernel fault
 * happens, handle that and return -EFAULT.
 */
long __weak probe_kernel_write(void *dst, const void *src, size_t size)
    __attribute__((alias("__probe_kernel_write")));

long __probe_kernel_write(void *dst, const void *src, size_t size)
{
	long ret;
	mm_segment_t old_fs = get_fs();

	set_fs(KERNEL_DS);
	pagefault_disable();
	ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
	pagefault_enable();
	set_fs(old_fs);

	return ret ? -EFAULT : 0;
}
EXPORT_SYMBOL_GPL(probe_kernel_write);
back to top