sh: Ensure active regions have a backing PMB entry.

In the NUMA or memory hot-add case where system memory has been
partitioned up, we immediately run in to a situation where the existing
PMB entry doesn't cover the new range (primarily as a result of the entry
size being shrunk to match the node size early in the initialization). In
order to fix this up it's necessary to preload a PMB mapping for the new
range prior to activation in order to circumvent reset by MMU.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index 61404ed014491012213aa1456db5e25ba1586d24..57bd93838f150189352cfba2524c091f7e7747f5 100644 (file)
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -191,13 +191,18 @@ void __init __add_active_range(unsigned int nid, unsigned long start_pfn,
                                                unsigned long end_pfn)
 {
        struct resource *res = &mem_resources[nid];
+       unsigned long start, end;
 
        WARN_ON(res->name); /* max one active range per node for now */
 
+       start = start_pfn << PAGE_SHIFT;
+       end = end_pfn << PAGE_SHIFT;
+
        res->name = "System RAM";
-       res->start = start_pfn << PAGE_SHIFT;
-       res->end = (end_pfn << PAGE_SHIFT) - 1;
+       res->start = start;
+       res->end = end - 1;
        res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+
        if (request_resource(&iomem_resource, res)) {
                pr_err("unable to request memory_resource 0x%lx 0x%lx\n",
                       start_pfn, end_pfn);
@@ -213,6 +218,14 @@ void __init __add_active_range(unsigned int nid, unsigned long start_pfn,
        request_resource(res, &data_resource);
        request_resource(res, &bss_resource);
 
+       /*
+        * Also make sure that there is a PMB mapping that covers this
+        * range before we attempt to activate it, to avoid reset by MMU.
+        * We can hit this path with NUMA or memory hot-add.
+        */
+       pmb_bolt_mapping((unsigned long)__va(start), start, end - start,
+                        PAGE_KERNEL);
+
        add_active_range(nid, start_pfn, end_pfn);
 }