[POWERPC] cell: enable RTAS-based PTCAL for Cell XDR memory

Enable Periodic Recalibration (PTCAL) support for Cell XDR memory,
using the new ibm,cbe-start-ptcal and ibm,cbe-stop-ptcal RTAS calls.

Tested on QS20 and QS21 (by Thomas Huth). It seems that SLOF has
problems disabling, at least on QS20; this patch should only be
used once these problems have been addressed.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

diff --git a/arch/powerpc/platforms/cell/ras.c b/arch/powerpc/platforms/cell/ras.c
index 0984c70..b5ebc91 100644 (file)
--- a/arch/powerpc/platforms/cell/ras.c
+++ b/arch/powerpc/platforms/cell/ras.c
@@ -3,11 +3,13 @@
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/smp.h>
+#include <linux/reboot.h>
 
 #include <asm/reg.h>
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/machdep.h>
+#include <asm/rtas.h>
 
 #include "ras.h"
 #include "cbe_regs.h"
@@ -82,6 +84,164 @@ static int cbe_machine_check_handler(struct pt_regs *regs)
        return 0;
 }
 
+struct ptcal_area {
+       struct list_head list;
+       int nid;
+       int order;
+       struct page *pages;
+};
+
+static LIST_HEAD(ptcal_list);
+
+static int ptcal_start_tok, ptcal_stop_tok;
+
+static int __init cbe_ptcal_enable_on_node(int nid, int order)
+{
+       struct ptcal_area *area;
+       int ret = -ENOMEM;
+       unsigned long addr;
+
+#ifdef CONFIG_CRASH_DUMP
+       rtas_call(ptcal_stop_tok, 1, 1, NULL, nid);
+#endif
+
+       area = kmalloc(sizeof(*area), GFP_KERNEL);
+       if (!area)
+               goto out_err;
+
+       area->nid = nid;
+       area->order = order;
+       area->pages = alloc_pages_node(area->nid, GFP_KERNEL, area->order);
+
+       if (!area->pages)
+               goto out_free_area;
+
+       addr = __pa(page_address(area->pages));
+
+       ret = -EIO;
+       if (rtas_call(ptcal_start_tok, 3, 1, NULL, area->nid,
+                               (unsigned int)(addr >> 32),
+                               (unsigned int)(addr & 0xffffffff))) {
+               printk(KERN_ERR "%s: error enabling PTCAL on node %d!\n",
+                               __FUNCTION__, nid);
+               goto out_free_pages;
+       }
+
+       list_add(&area->list, &ptcal_list);
+
+       return 0;
+
+out_free_pages:
+       __free_pages(area->pages, area->order);
+out_free_area:
+       kfree(area);
+out_err:
+       return ret;
+}
+
+static int __init cbe_ptcal_enable(void)
+{
+       const u32 *size;
+       struct device_node *np;
+       int order, found_mic = 0;
+
+       np = of_find_node_by_path("/rtas");
+       if (!np)
+               return -ENODEV;
+
+       size = get_property(np, "ibm,cbe-ptcal-size", NULL);
+       if (!size)
+               return -ENODEV;
+
+       pr_debug("%s: enabling PTCAL, size = 0x%x\n", __FUNCTION__, *size);
+       order = get_order(*size);
+       of_node_put(np);
+
+       /* support for malta device trees, with be@/mic@ nodes */
+       for_each_node_by_type(np, "mic-tm") {
+               cbe_ptcal_enable_on_node(of_node_to_nid(np), order);
+               found_mic = 1;
+       }
+
+       if (found_mic)
+               return 0;
+
+       /* support for older device tree - use cpu nodes */
+       for_each_node_by_type(np, "cpu") {
+               const u32 *nid = get_property(np, "node-id", NULL);
+               if (!nid) {
+                       printk(KERN_ERR "%s: node %s is missing node-id?\n",
+                                       __FUNCTION__, np->full_name);
+                       continue;
+               }
+               cbe_ptcal_enable_on_node(*nid, order);
+               found_mic = 1;
+       }
+
+       return found_mic ? 0 : -ENODEV;
+}
+
+static int cbe_ptcal_disable(void)
+{
+       struct ptcal_area *area, *tmp;
+       int ret = 0;
+
+       pr_debug("%s: disabling PTCAL\n", __FUNCTION__);
+
+       list_for_each_entry_safe(area, tmp, &ptcal_list, list) {
+               /* disable ptcal on this node */
+               if (rtas_call(ptcal_stop_tok, 1, 1, NULL, area->nid)) {
+                       printk(KERN_ERR "%s: error disabling PTCAL "
+                                       "on node %d!\n", __FUNCTION__,
+                                       area->nid);
+                       ret = -EIO;
+                       continue;
+               }
+
+               /* ensure we can access the PTCAL area */
+               memset(page_address(area->pages), 0,
+                               1 << (area->order + PAGE_SHIFT));
+
+               /* clean up */
+               list_del(&area->list);
+               __free_pages(area->pages, area->order);
+               kfree(area);
+       }
+
+       return ret;
+}
+
+static int cbe_ptcal_notify_reboot(struct notifier_block *nb,
+               unsigned long code, void *data)
+{
+       return cbe_ptcal_disable();
+}
+
+static struct notifier_block cbe_ptcal_reboot_notifier = {
+       .notifier_call = cbe_ptcal_notify_reboot
+};
+
+int __init cbe_ptcal_init(void)
+{
+       int ret;
+       ptcal_start_tok = rtas_token("ibm,cbe-start-ptcal");
+       ptcal_stop_tok = rtas_token("ibm,cbe-stop-ptcal");
+
+       if (ptcal_start_tok == RTAS_UNKNOWN_SERVICE
+                       || ptcal_stop_tok == RTAS_UNKNOWN_SERVICE)
+               return -ENODEV;
+
+       ret = register_reboot_notifier(&cbe_ptcal_reboot_notifier);
+       if (ret) {
+               printk(KERN_ERR "Can't disable PTCAL, so not enabling\n");
+               return ret;
+       }
+
+       return cbe_ptcal_enable();
+}
+
+arch_initcall(cbe_ptcal_init);
+
 void __init cbe_ras_init(void)
 {
        unsigned long hid0;