1 files changed, 246 insertions, 0 deletions
diff --git a/arch/ia64/kernel/uncached.c b/arch/ia64/kernel/uncached.c
new file mode 100644
index 00000000000..490dfc9ab47
--- /dev/null
+++ b/arch/ia64/kernel/uncached.c
@@ -0,0 +1,246 @@
+/*
+ * 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 = nasid_to_cnodeid(NASID_GET(maddr));
+
+	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;
+	unsigned long vstart, vend;
+	int node;
+
+	length = end - start;
+	vstart = start + __IA64_UNCACHED_OFFSET;
+	vend = end + __IA64_UNCACHED_OFFSET;
+
+	dprintk(KERN_ERR "uncached_build_memmap(%lx %lx)\n", start, end);
+
+	memset((char *)vstart, 0, length);
+
+	node = nasid_to_cnodeid(NASID_GET(start));
+
+	for (; vstart < vend ; vstart += PAGE_SIZE) {
+		dprintk(KERN_INFO "sticking %lx into the pool!\n", vstart);
+		gen_pool_free(uncached_pool[node], vstart, 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);