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authorShannon Zhao <shannon.zhao@linaro.org>2016-05-12 14:19:54 +0200
committerDavid Vrabel <david.vrabel@citrix.com>2016-07-06 11:34:47 +0200
commit0cac5c3018b32707b3bab40e4beb83f91c4204f1 (patch)
tree2782afbb0fd9f861df6d0af6aa3d1f9481145708
parentFDT: Add a helper to get the subnode by given name (diff)
downloadlinux-0cac5c3018b32707b3bab40e4beb83f91c4204f1.tar.xz
linux-0cac5c3018b32707b3bab40e4beb83f91c4204f1.zip
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>
-rw-r--r--arch/arm/xen/enlighten.c22
-rw-r--r--drivers/firmware/efi/arm-runtime.c5
-rw-r--r--drivers/firmware/efi/efi.c81
3 files changed, 92 insertions, 16 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) {
diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c
index 17ccf0a8787a..c394b81fe452 100644
--- a/drivers/firmware/efi/arm-runtime.c
+++ b/drivers/firmware/efi/arm-runtime.c
@@ -107,6 +107,11 @@ static int __init arm_enable_runtime_services(void)
return 0;
}
+ if (efi_enabled(EFI_RUNTIME_SERVICES)) {
+ pr_info("EFI runtime services access via paravirt.\n");
+ return 0;
+ }
+
pr_info("Remapping and enabling EFI services.\n");
mapsize = efi.memmap.map_end - efi.memmap.map;
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 05509f3aaee8..1c6f9dda3c3e 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -472,12 +472,14 @@ device_initcall(efi_load_efivars);
FIELD_SIZEOF(struct efi_fdt_params, field) \
}
-static __initdata struct {
+struct params {
const char name[32];
const char propname[32];
int offset;
int size;
-} dt_params[] = {
+};
+
+static __initdata struct params fdt_params[] = {
UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
@@ -485,44 +487,91 @@ static __initdata struct {
UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
};
+static __initdata struct params xen_fdt_params[] = {
+ UEFI_PARAM("System Table", "xen,uefi-system-table", system_table),
+ UEFI_PARAM("MemMap Address", "xen,uefi-mmap-start", mmap),
+ UEFI_PARAM("MemMap Size", "xen,uefi-mmap-size", mmap_size),
+ UEFI_PARAM("MemMap Desc. Size", "xen,uefi-mmap-desc-size", desc_size),
+ UEFI_PARAM("MemMap Desc. Version", "xen,uefi-mmap-desc-ver", desc_ver)
+};
+
+#define EFI_FDT_PARAMS_SIZE ARRAY_SIZE(fdt_params)
+
+static __initdata struct {
+ const char *uname;
+ const char *subnode;
+ struct params *params;
+} dt_params[] = {
+ { "hypervisor", "uefi", xen_fdt_params },
+ { "chosen", NULL, fdt_params },
+};
+
struct param_info {
int found;
void *params;
+ const char *missing;
};
-static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
- int depth, void *data)
+static int __init __find_uefi_params(unsigned long node,
+ struct param_info *info,
+ struct params *params)
{
- struct param_info *info = data;
const void *prop;
void *dest;
u64 val;
int i, len;
- if (depth != 1 || strcmp(uname, "chosen") != 0)
- return 0;
-
- for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
- prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
- if (!prop)
+ for (i = 0; i < EFI_FDT_PARAMS_SIZE; i++) {
+ prop = of_get_flat_dt_prop(node, params[i].propname, &len);
+ if (!prop) {
+ info->missing = params[i].name;
return 0;
- dest = info->params + dt_params[i].offset;
+ }
+
+ dest = info->params + params[i].offset;
info->found++;
val = of_read_number(prop, len / sizeof(u32));
- if (dt_params[i].size == sizeof(u32))
+ if (params[i].size == sizeof(u32))
*(u32 *)dest = val;
else
*(u64 *)dest = val;
if (efi_enabled(EFI_DBG))
- pr_info(" %s: 0x%0*llx\n", dt_params[i].name,
- dt_params[i].size * 2, val);
+ pr_info(" %s: 0x%0*llx\n", params[i].name,
+ params[i].size * 2, val);
}
+
return 1;
}
+static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ struct param_info *info = data;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
+ const char *subnode = dt_params[i].subnode;
+
+ if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {
+ info->missing = dt_params[i].params[0].name;
+ continue;
+ }
+
+ if (subnode) {
+ node = of_get_flat_dt_subnode_by_name(node, subnode);
+ if (node < 0)
+ return 0;
+ }
+
+ return __find_uefi_params(node, info, dt_params[i].params);
+ }
+
+ return 0;
+}
+
int __init efi_get_fdt_params(struct efi_fdt_params *params)
{
struct param_info info;
@@ -538,7 +587,7 @@ int __init efi_get_fdt_params(struct efi_fdt_params *params)
pr_info("UEFI not found.\n");
else if (!ret)
pr_err("Can't find '%s' in device tree!\n",
- dt_params[info.found].name);
+ info.missing);
return ret;
}