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 000000000000..490dfc9ab47f
--- /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);