[PATCH 2/2] arm,arm64/xen: move Xen initialization earlier
Julien Grall
julien.grall at linaro.org
Wed Feb 11 22:34:58 PST 2015
From: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
Currently, Xen is initialized/discovered in an initcall. This doesn't
allow us to support earlyprintk or choosing the preferred console when
running on Xen.
The current function xen_guest_init is now split in 2 parts:
- xen_early_init: Check if there is a Xen node in the device tree
and setup domain type
- xen_guest_init: Retrieve the information from the device node and
initialize Xen (grant table, shared page...)
The former is called in setup_arch, while the latter is an initcall.
Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
Signed-off-by: Julien Grall <julien.grall at linaro.org>
Cc: Russell King <linux at arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will.deacon at arm.com>
---
It's based on a patch sent by Stefano nearly 2 years ago [1].
[1] http://lists.xen.org/archives/html/xen-devel/2013-08/msg02960.html
---
arch/arm/include/asm/xen/hypervisor.h | 8 +++++
arch/arm/kernel/setup.c | 2 ++
arch/arm/xen/enlighten.c | 58 ++++++++++++++++++++---------------
arch/arm64/kernel/setup.c | 2 ++
4 files changed, 46 insertions(+), 24 deletions(-)
diff --git a/arch/arm/include/asm/xen/hypervisor.h b/arch/arm/include/asm/xen/hypervisor.h
index 1317ee4..04ff8e7 100644
--- a/arch/arm/include/asm/xen/hypervisor.h
+++ b/arch/arm/include/asm/xen/hypervisor.h
@@ -1,6 +1,8 @@
#ifndef _ASM_ARM_XEN_HYPERVISOR_H
#define _ASM_ARM_XEN_HYPERVISOR_H
+#include <linux/init.h>
+
extern struct shared_info *HYPERVISOR_shared_info;
extern struct start_info *xen_start_info;
@@ -18,4 +20,10 @@ static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
extern struct dma_map_ops *xen_dma_ops;
+#ifdef CONFIG_XEN
+void __init xen_early_init(void);
+#else
+static inline void xen_early_init(void) { return; }
+#endif
+
#endif /* _ASM_ARM_XEN_HYPERVISOR_H */
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index e55408e..8b59d0d 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -46,6 +46,7 @@
#include <asm/cacheflush.h>
#include <asm/cachetype.h>
#include <asm/tlbflush.h>
+#include <asm/xen/hypervisor.h>
#include <asm/prom.h>
#include <asm/mach/arch.h>
@@ -936,6 +937,7 @@ void __init setup_arch(char **cmdline_p)
arm_dt_init_cpu_maps();
psci_init();
+ xen_early_init();
#ifdef CONFIG_SMP
if (is_smp()) {
if (!mdesc->smp_init || !mdesc->smp_init()) {
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 90101c8..0abeefa 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -53,6 +53,8 @@ EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
static unsigned int xen_events_irq;
+static __initdata struct device_node *xen_node;
+
/* map fgmfn of domid to lpfn in the current domain */
static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn,
unsigned int domid)
@@ -222,42 +224,28 @@ static irqreturn_t xen_arm_callback(int irq, void *arg)
* documentation of the Xen Device Tree format.
*/
#define GRANT_TABLE_PHYSADDR 0
-static int __init xen_guest_init(void)
+void __init xen_early_init(void)
{
- struct xen_add_to_physmap xatp;
- static struct shared_info *shared_info_page = 0;
- struct device_node *node;
int len;
const char *s = NULL;
const char *version = NULL;
const char *xen_prefix = "xen,xen-";
- struct resource res;
- phys_addr_t grant_frames;
- node = of_find_compatible_node(NULL, NULL, "xen,xen");
- if (!node) {
+ xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
+ if (!xen_node) {
pr_debug("No Xen support\n");
- return 0;
+ return;
}
- s = of_get_property(node, "compatible", &len);
+ s = of_get_property(xen_node, "compatible", &len);
if (strlen(xen_prefix) + 3 < len &&
!strncmp(xen_prefix, s, strlen(xen_prefix)))
version = s + strlen(xen_prefix);
if (version == NULL) {
pr_debug("Xen version not found\n");
- return 0;
- }
- if (of_address_to_resource(node, GRANT_TABLE_PHYSADDR, &res))
- return 0;
- grant_frames = res.start;
- xen_events_irq = irq_of_parse_and_map(node, 0);
- if (!xen_events_irq) {
- pr_debug("Xen event channel interrupt not found\n");
- return -ENODEV;
+ return;
}
- pr_info("Xen %s support found, events_irq=%d gnttab_frame=%pa\n",
- version, xen_events_irq, &grant_frames);
+ pr_info("Xen %s support found\n", version);
xen_domain_type = XEN_HVM_DOMAIN;
@@ -267,10 +255,32 @@ static int __init xen_guest_init(void)
xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
else
xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
+}
+
+static int __init xen_guest_init(void)
+{
+ struct xen_add_to_physmap xatp;
+ struct shared_info *shared_info_page = NULL;
+ struct resource res;
+ phys_addr_t grant_frames;
+
+ if (!xen_domain())
+ return 0;
+
+ if (of_address_to_resource(xen_node, GRANT_TABLE_PHYSADDR, &res)) {
+ pr_err("Xen grant table base address not found\n");
+ return -ENODEV;
+ }
+ grant_frames = res.start;
+
+ xen_events_irq = irq_of_parse_and_map(xen_node, 0);
+ if (!xen_events_irq) {
+ pr_err("Xen event channel interrupt not found\n");
+ return -ENODEV;
+ }
+
+ shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
- if (!shared_info_page)
- shared_info_page = (struct shared_info *)
- get_zeroed_page(GFP_KERNEL);
if (!shared_info_page) {
pr_err("not enough memory\n");
return -ENOMEM;
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index e8420f6..c00ae01 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -62,6 +62,7 @@
#include <asm/memblock.h>
#include <asm/psci.h>
#include <asm/efi.h>
+#include <asm/xen/hypervisor.h>
unsigned int processor_id;
EXPORT_SYMBOL(processor_id);
@@ -388,6 +389,7 @@ void __init setup_arch(char **cmdline_p)
unflatten_device_tree();
psci_init();
+ xen_early_init();
cpu_read_bootcpu_ops();
#ifdef CONFIG_SMP
--
2.1.0
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