From: Neil Horman <nhorman@redhat.com>
Subject: [RHEL5] Patch: allow HP ZX1 systems to initalize swiotlb in kdump
Date: Mon, 18 Dec 2006 14:03:42 -0500
Bugzilla: 220064
Message-Id: <20061218190342.GA18584@hmsendeavour.rdu.redhat.com>
Changelog: ia64: allow HP ZX1 systems to initalize swiotlb in kdump


Hey all-
	HP sent me this patch today and I wanted to get it posted ASAP.  This
patch will auto initalize the swiotlb on HP ZX1 systems.  Without this patch
these systems hang on kdump kernel boots.  We currently work around this via a
hack in kexec-tools, but we'd really like to remove that if we can.  This has
been tested successfully by Terry L. at HP and from my review is fairly well
isolated to HP code, and so is harmless to anyone else.  Fixes BZ 220064.
Please ACK. 

Neil


--- linux-2.6.18.noarch/arch/ia64/kernel/setup.c.orig	2006-11-15 13:46:24.000000000 -0500
+++ linux-2.6.18.noarch/arch/ia64/kernel/setup.c	2006-12-18 13:57:35.000000000 -0500
@@ -62,6 +62,7 @@
 #include <asm/system.h>
 #include <asm/unistd.h>
 #include <asm/system.h>
+#include <asm/kexec.h>
 #ifdef CONFIG_XEN
 #include <asm/hypervisor.h>
 #endif
@@ -131,6 +132,8 @@ EXPORT_SYMBOL(ia64_iobase);
 struct io_space io_space[MAX_IO_SPACES];
 EXPORT_SYMBOL(io_space);
 unsigned int num_io_spaces;
+int kdump_kernel;
+EXPORT_SYMBOL(kdump_kernel);
 
 /*
  * "flush_icache_range()" needs to know what processor dependent stride size to use
@@ -540,6 +543,8 @@ setup_arch (char **cmdline_p)
 	*cmdline_p = __va(ia64_boot_param->command_line);
 	strlcpy(saved_command_line, *cmdline_p, COMMAND_LINE_SIZE);
 
+	kdump_kernel = (strstr(saved_command_line, "elfcorehdr=") != NULL);
+
 	efi_init();
 	io_port_init();
 
--- linux-2.6.18.noarch/arch/ia64/hp/common/sba_iommu.c.orig	2006-09-19 23:42:06.000000000 -0400
+++ linux-2.6.18.noarch/arch/ia64/hp/common/sba_iommu.c	2006-12-18 13:57:35.000000000 -0500
@@ -40,9 +40,12 @@
 #include <asm/page.h>		/* PAGE_OFFSET */
 #include <asm/dma.h>
 #include <asm/system.h>		/* wmb() */
+#include <asm/kexec.h>
 
 #include <asm/acpi-ext.h>
 
+extern int swiotlb_late_init_with_default_size (size_t size);
+
 #define PFX "IOC: "
 
 /*
@@ -2030,11 +2033,22 @@ sba_init(void)
 	if (!ia64_platform_is("hpzx1") && !ia64_platform_is("hpzx1_swiotlb"))
 		return 0;
 
+    /* If we are booting a kdump kernel, the sba_iommu will
+	 * cause devices that were not shutdown properly to MCA
+     * as soon as they are turned back on.  Our only option for
+	 * a successful kdump kernel boot is to use the swiotlb:
+	 */
+	if (kdump_kernel) {
+		if (swiotlb_late_init_with_default_size(64 * (1<<20)) != 0)
+			panic("Unable to initialize software I/O TLB:"
+				" Try machvec=dig boot option");
+		machvec_init("dig");
+		return 0;
+	}
+
 	acpi_bus_register_driver(&acpi_sba_ioc_driver);
 	if (!ioc_list) {
 #ifdef CONFIG_IA64_GENERIC
-		extern int swiotlb_late_init_with_default_size (size_t size);
-
 		/*
 		 * If we didn't find something sba_iommu can claim, we
 		 * need to setup the swiotlb and switch to the dig machvec.
--- linux-2.6.18.noarch/include/asm-ia64/kexec.h.orig	2006-11-15 13:46:21.000000000 -0500
+++ linux-2.6.18.noarch/include/asm-ia64/kexec.h	2006-12-18 13:57:35.000000000 -0500
@@ -49,5 +49,6 @@ extern unsigned long kdump_find_rsvd_reg
 extern void kdump_cpu_freeze(struct unw_frame_info *info, void *arg);
 extern int kdump_status[];
 extern atomic_t kdump_cpu_freezed;
+extern int kdump_kernel;
 
 #endif /* _ASM_IA64_KEXEC_H */
-- 
/***************************************************
 *Neil Horman
 *Software Engineer
 *Red Hat, Inc.
 *nhorman@redhat.com
 *gpg keyid: 1024D / 0x92A74FA1
 *http://pgp.mit.edu
 ***************************************************/