Re: [PATCH v3 17/17] Xen: EFI: Parse DT parameters for Xen specific UEFI

[Stefano Stabellini]

On Sat, 23 Jan 2016, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
> 
> Add a new function to parse DT parameters for Xen specific UEFI just
> like the way for normal UEFI. Then it could reuse the existing codes.
> 
> If Xen supports EFI, initialize runtime services.
> 
> Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>

Reviewed-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>


> CC: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
> ---
>  arch/arm/xen/enlighten.c   |  6 ++++++
>  arch/arm64/kernel/efi.c    | 17 ++++++++++++-----
>  drivers/firmware/efi/efi.c | 45 ++++++++++++++++++++++++++++++++++++++-------
>  3 files changed, 56 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index cdc0bd2..608d735 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -245,6 +245,12 @@ 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);
>  
> +	if (IS_ENABLED(CONFIG_XEN_EFI)) {
> +		/* Check if Xen supports EFI */
> +		if (of_get_flat_dt_subnode_by_name(node, "uefi") > 0)
> +			set_bit(EFI_PARAVIRT, &efi.flags);
> +	}
> +
>  	return 0;
>  }
>  
> diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
> index 4eeb171..3c46129 100644
> --- a/arch/arm64/kernel/efi.c
> +++ b/arch/arm64/kernel/efi.c
> @@ -33,6 +33,7 @@
>  #include <asm/mmu_context.h>
>  #include <asm/mmu.h>
>  #include <asm/pgtable.h>
> +#include <asm/xen/xen-ops.h>
>  
>  struct efi_memory_map memmap;
>  
> @@ -308,13 +309,19 @@ static int __init arm64_enable_runtime_services(void)
>  	}
>  	set_bit(EFI_SYSTEM_TABLES, &efi.flags);
>  
> -	if (!efi_virtmap_init()) {
> -		pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
> -		return -ENOMEM;
> +	if (IS_ENABLED(CONFIG_XEN_EFI) && efi_enabled(EFI_PARAVIRT)) {
> +		/* Set up runtime services function pointers for Xen Dom0 */
> +		xen_efi_runtime_setup();
> +	} else {
> +		if (!efi_virtmap_init()) {
> +			pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
> +			return -ENOMEM;
> +		}
> +
> +		/* Set up runtime services function pointers */
> +		efi_native_runtime_setup();
>  	}
>  
> -	/* Set up runtime services function pointers */
> -	efi_native_runtime_setup();
>  	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
>  
>  	efi.runtime_version = efi.systab->hdr.revision;
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 027ca21..bdcf6d7 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -498,12 +498,14 @@ 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 struct params fdt_params[] __initdata = {
>  	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),
> @@ -511,24 +513,45 @@ static __initdata struct {
>  	UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
>  };
>  
> +static struct params xen_fdt_params[] __initdata = {
> +	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)
> +};
> +
>  struct param_info {
>  	int found;
>  	void *params;
> +	struct params *dt_params;
> +	int size;
>  };
>  
>  static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
>  				       int depth, void *data)
>  {
>  	struct param_info *info = data;
> +	struct params *dt_params = info->dt_params;
>  	const void *prop;
>  	void *dest;
>  	u64 val;
> -	int i, len;
> +	int i, len, offset;
>  
> -	if (depth != 1 || strcmp(uname, "chosen") != 0)
> -		return 0;
> +	if (efi_enabled(EFI_PARAVIRT)) {
> +		if (depth != 1 || strcmp(uname, "hypervisor") != 0)
> +			return 0;
>  
> -	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
> +		offset = of_get_flat_dt_subnode_by_name(node, "uefi");
> +		if (offset < 0)
> +			return 0;
> +		node = offset;
> +	} else {
> +		if (depth != 1 || strcmp(uname, "chosen") != 0)
> +			return 0;
> +	}
> +
> +	for (i = 0; i < info->size; i++) {
>  		prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len);
>  		if (!prop)
>  			return 0;
> @@ -559,12 +582,20 @@ int __init efi_get_fdt_params(struct efi_fdt_params *params)
>  	info.found = 0;
>  	info.params = params;
>  
> +	if (efi_enabled(EFI_PARAVIRT)) {
> +		info.dt_params = xen_fdt_params;
> +		info.size = ARRAY_SIZE(xen_fdt_params);
> +	} else {
> +		info.dt_params = fdt_params;
> +		info.size = ARRAY_SIZE(fdt_params);
> +	}
> +
>  	ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
>  	if (!info.found)
>  		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.dt_params[info.found].name);
>  
>  	return ret;
>  }
> -- 
> 2.0.4
> 
>