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authorShannon Zhao <shannon.zhao@linaro.org>2016-05-12 20:19:54 +0800
committerDavid Vrabel <david.vrabel@citrix.com>2016-07-06 10:34:47 +0100
commit0cac5c3018b32707b3bab40e4beb83f91c4204f1 (patch)
tree2782afbb0fd9f861df6d0af6aa3d1f9481145708 /arch/arm/xen
parent9c6098685a1d5df72da61ff7838ebb1524796869 (diff)
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Xen: EFI: Parse DT parameters for Xen specific UEFI
The EFI DT parameters for bare metal are located under /chosen node, while for Xen Dom0 they are located under /hyperviosr/uefi node. These parameters under /chosen and /hyperviosr/uefi are not expected to appear at the same time. Parse these EFI parameters and initialize EFI like the way for bare metal except the runtime services because the runtime services for Xen Dom0 are available through hypercalls and they are always enabled. So it sets the EFI_RUNTIME_SERVICES flag if it finds /hyperviosr/uefi node and bails out in arm_enable_runtime_services() when EFI_RUNTIME_SERVICES flag is set already. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Diffstat (limited to 'arch/arm/xen')
-rw-r--r--arch/arm/xen/enlighten.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 13e3e9f9b094..d4f36eba3499 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -15,7 +15,9 @@
#include <asm/paravirt.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
+#include <asm/xen/xen-ops.h>
#include <asm/system_misc.h>
+#include <asm/efi.h>
#include <linux/interrupt.h>
#include <linux/irqreturn.h>
#include <linux/module.h>
@@ -261,6 +263,19 @@ static int __init fdt_find_hyper_node(unsigned long node, const char *uname,
!strncmp(hyper_node.prefix, s, strlen(hyper_node.prefix)))
hyper_node.version = s + strlen(hyper_node.prefix);
+ /*
+ * Check if Xen supports EFI by checking whether there is the
+ * "/hypervisor/uefi" node in DT. If so, runtime services are available
+ * through proxy functions (e.g. in case of Xen dom0 EFI implementation
+ * they call special hypercall which executes relevant EFI functions)
+ * and that is why they are always enabled.
+ */
+ if (IS_ENABLED(CONFIG_XEN_EFI)) {
+ if ((of_get_flat_dt_subnode_by_name(node, "uefi") > 0) &&
+ !efi_runtime_disabled())
+ set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+ }
+
return 0;
}
@@ -352,6 +367,13 @@ static int __init xen_guest_init(void)
return -ENODEV;
}
+ /*
+ * The fdt parsing codes have set EFI_RUNTIME_SERVICES if Xen EFI
+ * parameters are found. Force enable runtime services.
+ */
+ if (efi_enabled(EFI_RUNTIME_SERVICES))
+ xen_efi_runtime_setup();
+
shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
if (!shared_info_page) {