/******************************************************************************
 * features.c
 *
 * Xen feature flags.
 *
 * Copyright (c) 2006, Ian Campbell, XenSource Inc.
 */
#include <linux/types.h>
#include <linux/cache.h>
#include <linux/module.h>
#include <asm/hypervisor.h>
#include <xen/features.h>

#ifndef __read_mostly
#define __read_mostly __cacheline_aligned
#endif

//#define DEBUG

u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly;
EXPORT_SYMBOL(xen_features);

#ifdef DEBUG
static const char *feature_names[XENFEAT_NR_SUBMAPS*32] = {
    [XENFEAT_writable_page_tables]       = "writable_page_tables",
    [XENFEAT_writable_descriptor_tables] = "writable_descriptor_tables",
    [XENFEAT_auto_translated_physmap]    = "auto_translated_physmap",
    [XENFEAT_supervisor_mode_kernel]     = "supervisor_mode_kernel",
    [XENFEAT_pae_pgdir_above_4gb]        = "pae_pgdir_above_4gb"
};
#endif

void setup_xen_features(void)
{
	xen_feature_info_t fi;
	int i, j;

	for (i = 0; i < XENFEAT_NR_SUBMAPS; i++) {
		fi.submap_idx = i;
		if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0)
			break;
		for (j=0; j<32; j++)
			xen_features[i*32+j] = !!(fi.submap & 1<<j);
	}
#ifdef DEBUG
	for (i = 0; i < XENFEAT_NR_SUBMAPS; i++) {
		for (j=0; j<32; j++) {
			if (feature_names[j])
				printk("xen_features[%d].%s = %d\n", i,
					feature_names[j], xen_features[i*32+j]);
		}
	}
#endif
}
EXPORT_SYMBOL(setup_xen_features);