sgi-xp: prepare xpc_rsvd_page to work on either sn2 or uv hardware

Prepare XPC's reserved page header to work for either sn2 or uv.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 111 insertions, 0 deletions

diff --git a/drivers/misc/sgi-xp/xpc_sn2.c b/drivers/misc/sgi-xp/xpc_sn2.c
new file mode 100644
index 000000000000..5a37348715c7
--- /dev/null
+++ b/drivers/misc/sgi-xp/xpc_sn2.c
@@ -0,0 +1,111 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+/*
+ * Cross Partition Communication (XPC) sn2-based functions.
+ *
+ *     Architecture specific implementation of common functions.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <asm/uncached.h>
+#include <asm/sn/sn_sal.h>
+#include "xpc.h"
+
+struct xpc_vars *xpc_vars;
+struct xpc_vars_part *xpc_vars_part;
+
+static enum xp_retval
+xpc_rsvd_page_init_sn2(struct xpc_rsvd_page *rp)
+{
+	AMO_t *amos_page;
+	u64 nasid_array = 0;
+	int i;
+	int ret;
+
+	xpc_vars = XPC_RP_VARS(rp);
+
+	rp->sn.vars_pa = __pa(xpc_vars);
+
+	xpc_vars_part = XPC_RP_VARS_PART(rp);
+
+	/*
+	 * Before clearing xpc_vars, see if a page of AMOs had been previously
+	 * allocated. If not we'll need to allocate one and set permissions
+	 * so that cross-partition AMOs are allowed.
+	 *
+	 * The allocated AMO page needs MCA reporting to remain disabled after
+	 * XPC has unloaded.  To make this work, we keep a copy of the pointer
+	 * to this page (i.e., amos_page) in the struct xpc_vars structure,
+	 * which is pointed to by the reserved page, and re-use that saved copy
+	 * on subsequent loads of XPC. This AMO page is never freed, and its
+	 * memory protections are never restricted.
+	 */
+	amos_page = xpc_vars->amos_page;
+	if (amos_page == NULL) {
+		amos_page = (AMO_t *)TO_AMO(uncached_alloc_page(0, 1));
+		if (amos_page == NULL) {
+			dev_err(xpc_part, "can't allocate page of AMOs\n");
+			return xpNoMemory;
+		}
+
+		/*
+		 * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
+		 * when xpc_allow_IPI_ops() is called via xpc_hb_init().
+		 */
+		if (!enable_shub_wars_1_1()) {
+			ret = sn_change_memprotect(ia64_tpa((u64)amos_page),
+						   PAGE_SIZE,
+						   SN_MEMPROT_ACCESS_CLASS_1,
+						   &nasid_array);
+			if (ret != 0) {
+				dev_err(xpc_part, "can't change memory "
+					"protections\n");
+				uncached_free_page(__IA64_UNCACHED_OFFSET |
+						   TO_PHYS((u64)amos_page), 1);
+				return xpSalError;
+			}
+		}
+	}
+
+	/* clear xpc_vars */
+	memset(xpc_vars, 0, sizeof(struct xpc_vars));
+
+	xpc_vars->version = XPC_V_VERSION;
+	xpc_vars->act_nasid = cpuid_to_nasid(0);
+	xpc_vars->act_phys_cpuid = cpu_physical_id(0);
+	xpc_vars->vars_part_pa = __pa(xpc_vars_part);
+	xpc_vars->amos_page_pa = ia64_tpa((u64)amos_page);
+	xpc_vars->amos_page = amos_page;	/* save for next load of XPC */
+
+	/* clear xpc_vars_part */
+	memset((u64 *)xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
+	       xp_max_npartitions);
+
+	/* initialize the activate IRQ related AMO variables */
+	for (i = 0; i < xp_nasid_mask_words; i++)
+		(void)xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
+
+	/* initialize the engaged remote partitions related AMO variables */
+	(void)xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
+	(void)xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
+
+	return xpSuccess;
+}
+
+void
+xpc_init_sn2(void)
+{
+	xpc_rsvd_page_init = xpc_rsvd_page_init_sn2;
+}
+
+void
+xpc_exit_sn2(void)
+{
+}