/*
* Copyright (C) 2001-2005 Silicon Graphics, Inc. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License
* as published by the Free Software Foundation.
*
* A simple uncached page allocator using the generic allocator. This
* allocator first utilizes the spare (spill) pages found in the EFI
* memmap and will then start converting cached pages to uncached ones
* at a granule at a time. Node awareness is implemented by having a
* pool of pages per node.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/efi.h>
#include <linux/genalloc.h>
#include <asm/page.h>
#include <asm/pal.h>
#include <asm/system.h>
#include <asm/pgtable.h>
#include <asm/atomic.h>
#include <asm/tlbflush.h>
#include <asm/sn/arch.h>
#define DEBUG 0
#if DEBUG
#define dprintk printk
#else
#define dprintk(x...) do { } while (0)
#endif
void __init efi_memmap_walk_uc (efi_freemem_callback_t callback);
#define MAX_UNCACHED_GRANULES 5
static int allocated_granules;
struct gen_pool *uncached_pool[MAX_NUMNODES];
static void uncached_ipi_visibility(void *data)
{
int status;
status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
if ((status != PAL_VISIBILITY_OK) &&
(status != PAL_VISIBILITY_OK_REMOTE_NEEDED))
printk(KERN_DEBUG "pal_prefetch_visibility() returns %i on "
"CPU %i\n", status, get_cpu());
}
static void uncached_ipi_mc_drain(void *data)
{
int status;
status = ia64_pal_mc_drain();
if (status)
printk(KERN_WARNING "ia64_pal_mc_drain() failed with %i on "
"CPU %i\n", status, get_cpu());
}
static unsigned long
uncached_get_new_chunk(struct gen_pool *poolp)
{
struct page *page;
void *tmp;
int status, i;
unsigned long addr, node;
if (allocated_granules >= MAX_UNCACHED_GRANULES)
return 0;
node = poolp->private;
page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO,
IA64_GRANULE_SHIFT-PAGE_SHIFT);
dprintk(KERN_INFO "get_new_chunk page %p, addr %lx\n",
page, (unsigned long)(page-vmem_map) << PAGE_SHIFT);
/*
* Do magic if no mem on local node! XXX
*/
if (!page)
return 0;
tmp = page_address(page);
/*
* There's a small race here where it's possible for someone to
* access the page through /dev/mem halfway through the conversion
* to uncached - not sure it's really worth bothering about
*/
for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++)
SetPageUncached(&page[i]);
flush_tlb_kernel_range(tmp, tmp + IA64_GRANULE_SIZE);
status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
dprintk(KERN_INFO "pal_prefetch_visibility() returns %i on cpu %i\n",
status, get_cpu());
if (!status) {
status = smp_call_function(uncached_ipi_visibility, NULL, 0, 1);
if (status)
printk(KERN_WARNING "smp_call_function failed for "
"uncached_ipi_visibility! (%i)\n", status);
}
if (ia64_platform_is("sn2"))
sn_flush_all_caches((unsigned long)tmp, IA64_GRANULE_SIZE);
else
flush_icache_range((unsigned long)tmp,
(unsigned long)tmp+IA64_GRANULE_SIZE);
ia64_pal_mc_drain();
status = smp_call_function(uncached_ipi_mc_drain, NULL, 0, 1);
if (status)
printk(KERN_WARNING "smp_call_function failed for "
"uncached_ipi_mc_drain! (%i)\n", status);
addr = (unsigned long)tmp - PAGE_OFFSET + __IA64_UNCACHED_OFFSET;
allocated_granules++;
return addr;
}
/*
* uncached_alloc_page
*
* Allocate 1 uncached page. Allocates on the requested node. If no
* uncached pages are available on the requested node, roundrobin starting
* with higher nodes.
*/
unsigned long
uncached_alloc_page(int nid)
{
unsigned long maddr;
maddr = gen_pool_alloc(uncached_pool[nid], PAGE_SIZE);
dprintk(KERN_DEBUG "uncached_alloc_page returns %lx on node %i\n",
maddr, nid);
/*
* If no memory is availble on our local node, try the
* remaining nodes in the system.
*/
if (!maddr) {
int i;
for (i = MAX_NUMNODES - 1; i >= 0; i--) {
if (i == nid || !node_online(i))
continue;
maddr = gen_pool_alloc(uncached_pool[i], PAGE_SIZE);
dprintk(KERN_DEBUG "uncached_alloc_page alternate search "
"returns %lx on node %i\n", maddr, i);
if (maddr) {
break;
}
}
}
return maddr;
}
EXPORT_SYMBOL(uncached_alloc_page);
/*
* uncached_free_page
*
* Free a single uncached page.
*/
void
uncached_free_page(unsigned long maddr)
{
int node;
node = paddr_to_nid(maddr - __IA64_UNCACHED_OFFSET);
dprintk(KERN_DEBUG "uncached_free_page(%lx) on node %i\n", maddr, node);
if ((maddr & (0XFUL << 60)) != __IA64_UNCACHED_OFFSET)
panic("uncached_free_page invalid address %lx\n", maddr);
gen_pool_free(uncached_pool[node], maddr, PAGE_SIZE);
}
EXPORT_SYMBOL(uncached_free_page);
/*
* uncached_build_memmap,
*
* Called at boot time to build a map of pages that can be used for
* memory special operations.
*/
static int __init
uncached_build_memmap(unsigned long start, unsigned long end, void *arg)
{
long length = end - start;
int node;
dprintk(KERN_ERR "uncached_build_memmap(%lx %lx)\n", start, end);
memset((char *)start, 0, length);
node = paddr_to_nid(start - __IA64_UNCACHED_OFFSET);
for (; start < end ; start += PAGE_SIZE) {
dprintk(KERN_INFO "sticking %lx into the pool!\n", start);
gen_pool_free(uncached_pool[node], start, PAGE_SIZE);
}
return 0;
}
static int __init uncached_init(void) {
int i;
for (i = 0; i < MAX_NUMNODES; i++) {
if (!node_online(i))
continue;
uncached_pool[i] = gen_pool_create(0, IA64_GRANULE_SHIFT,
&uncached_get_new_chunk, i);
}
efi_memmap_walk_uc(uncached_build_memmap);
return 0;
}
__initcall(uncached_init);
