[PATCH v7 11/17] ARM: XEN: Move xen_early_init() before efi_init()

Shannon Zhao
2016-03-24T14:48:20Z

Move xen_early_init() before efi_init(), then when calling efi_init()
could initialize Xen specific UEFI.

Check if it runs on Xen hypervisor through the flat dts.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
arch/arm/xen/enlighten.c | 56 ++++++++++++++++++++++++++++++++++-------------
arch/arm64/kernel/setup.c | 2 +-
2 files changed, 42 insertions(+), 16 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 680aae0..c43617f 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -20,6 +20,7 @@
#include <linux/irqreturn.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_fdt.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/cpuidle.h>
@@ -53,8 +54,6 @@ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;

static __read_mostly unsigned int xen_events_irq;

-static __initdata struct device_node *xen_node;
-
int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
unsigned long addr,
xen_pfn_t *gfn, int nr,
@@ -238,6 +237,33 @@ static irqreturn_t xen_arm_callback(int irq, void *arg)
return IRQ_HANDLED;
}

+static __initdata struct {
+ const char *compat;
+ const char *prefix;
+ const char *version;
+ bool found;
+} hyper_node = {"xen,xen", "xen,xen-", NULL, false};
+
+static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ const void *s = NULL;
+ int len;
+
+ if (depth != 1 || strcmp(uname, "hypervisor") != 0)
+ return 0;
+
+ if (of_flat_dt_is_compatible(node, hyper_node.compat))
+ hyper_node.found = true;
+
+ s = of_get_flat_dt_prop(node, "compatible", &len);
+ if (strlen(hyper_node.prefix) + 3 < len &&
+ !strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
+ hyper_node.version = s + strlen(hyper_node.prefix);
+
+ return 0;
+}
+
/*
* see Documentation/devicetree/bindings/arm/xen.txt for the
* documentation of the Xen Device Tree format.
@@ -245,26 +271,18 @@ static irqreturn_t xen_arm_callback(int irq, void *arg)
#define GRANT_TABLE_PHYSADDR 0
void __init xen_early_init(void)
{
- int len;
- const char *s = NULL;
- const char *version = NULL;
- const char *xen_prefix = "xen,xen-";
-
- xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
- if (!xen_node) {
+ of_scan_flat_dt(fdt_find_hyper_node, NULL);
+ if (!hyper_node.found) {
pr_debug("No Xen support\n");
return;
}
- 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) {
+
+ if (hyper_node.version == NULL) {
pr_debug("Xen version not found\n");
return;
}

- pr_info("Xen %s support found\n", version);
+ pr_info("Xen %s support found\n", hyper_node.version);

xen_domain_type = XEN_HVM_DOMAIN;

@@ -305,6 +323,14 @@ static void __init xen_acpi_guest_init(void)

static void __init xen_dt_guest_init(void)
{
+ struct device_node *xen_node;
+
+ xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
+ if (!xen_node) {
+ pr_err("Xen support was detected before, but it has disappeared\n");
+ return;
+ }
+
xen_events_irq = irq_of_parse_and_map(xen_node, 0);
}

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 450987d..6cf5051 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -313,6 +313,7 @@ void __init setup_arch(char **cmdline_p)
*/
local_async_enable();

+ xen_early_init();
efi_init();
arm64_memblock_init();

@@ -334,7 +335,6 @@ void __init setup_arch(char **cmdline_p)
} else {
psci_acpi_init();
}
- xen_early_init();

cpu_read_bootcpu_ops();
smp_init_cpus();
--
2.1.4