[PATCH v2 2/3] arm,arm64/xen: move Xen initialization earlier
Stefano Stabellini
stefano.stabellini at eu.citrix.com
Tue Apr 7 10:26:56 PDT 2015
Russell,
I think that this patch should go via the Xen tree, however as it
touches arch/arm/kernel/setup.c, I would like your Acked-by before
adding it to the Xen queue.
Thanks,
Stefano
On Wed, 18 Feb 2015, Julien Grall wrote:
> 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>
> Acked-by: Ian Campbell <ian.campbell at citrix.com>
> 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
>
> Changes in v2:
> - Add Ian's ack
> ---
> 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 c8d3a17..1660432 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 __read_mostly 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
> --
> 2.1.4
>
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