[PATCH v2] Xen: EFI: Parse DT parameters for Xen specific UEFI
Matt Fleming
matt at codeblueprint.co.uk
Fri May 13 15:09:23 PDT 2016
(Including more folks, quoting entire patch)
On Thu, 12 May, at 08:19:54PM, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao at linaro.org>
>
> 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.
>
> CC: Matt Fleming <matt at codeblueprint.co.uk>
> Signed-off-by: Shannon Zhao <shannon.zhao at linaro.org>
> ---
> v2: rebase it on top of EFI and Xen next branch, add some comments to
> explain the codes.
> ---
> arch/arm/xen/enlighten.c | 22 +++++++++++
> drivers/firmware/efi/arm-runtime.c | 5 +++
> drivers/firmware/efi/efi.c | 81 ++++++++++++++++++++++++++++++--------
> 3 files changed, 92 insertions(+), 16 deletions(-)
This looks good to me. Thanks for all the work Shannon.
Stefan, OK, let's figure out how to deal with this.
What I've done is merge xen/linux-next into the 'efi/xen-arm' topic
branch and applied this patch here,
https://git.kernel.org/cgit/linux/kernel/git/mfleming/efi.git/log/?h=efi/arm-xen
Yes, the merge includes some Xen patches that are not actually needed
for any of the EFI patches, but Linus has complained about picking
random commits of a tree to merge. At least this way this is all the
Xen linux-next material.
If you're OK with this, and assuming no one else has any preferred
methods, I'll send out a pull request to tip over the weekend.
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 13e3e9f..d4f36eb 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 17ccf0a..c394b81 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 05509f3..1c6f9dd 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;
> }
> --
> 2.0.4
>
>
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