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commit ac73e08eda885a6723593c45d634b59c63365986
parent fec98069fb72fb656304a3e52265e0c2fc9adf87
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Tue, 23 Oct 2018 16:31:33 +0100

Merge branch 'x86-grub2-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 grub2 updates from Ingo Molnar:
 "This extends the x86 boot protocol to include an address for the RSDP
  table - utilized by Xen currently.

  Matching Grub2 patches are pending as well. (Juergen Gross)"

* 'x86-grub2-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/acpi, x86/boot: Take RSDP address for boot params if available
  x86/boot: Add ACPI RSDP address to setup_header
  x86/xen: Fix boot loader version reported for PVH guests

Diffstat:
MDocumentation/x86/boot.txt | 32+++++++++++++++++++++++++++++++-
March/x86/boot/header.S | 6+++++-
March/x86/include/asm/acpi.h | 7+++++++
March/x86/include/asm/x86_init.h | 2++
March/x86/include/uapi/asm/bootparam.h | 4++++
March/x86/kernel/acpi/boot.c | 6++++++
March/x86/kernel/head32.c | 1+
March/x86/kernel/head64.c | 2++
March/x86/kernel/setup.c | 17+++++++++++++++++
March/x86/kernel/x86_init.c | 3+--
March/x86/xen/enlighten_pvh.c | 2+-
11 files changed, 77 insertions(+), 5 deletions(-)

diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt @@ -61,6 +61,18 @@ Protocol 2.12: (Kernel 3.8) Added the xloadflags field and extension fields to struct boot_params for loading bzImage and ramdisk above 4G in 64bit. +Protocol 2.13: (Kernel 3.14) Support 32- and 64-bit flags being set in + xloadflags to support booting a 64-bit kernel from 32-bit + EFI + +Protocol 2.14: (Kernel 4.20) Added acpi_rsdp_addr holding the physical + address of the ACPI RSDP table. + The bootloader updates version with: + 0x8000 | min(kernel-version, bootloader-version) + kernel-version being the protocol version supported by + the kernel and bootloader-version the protocol version + supported by the bootloader. + **** MEMORY LAYOUT The traditional memory map for the kernel loader, used for Image or @@ -197,6 +209,7 @@ Offset Proto Name Meaning 0258/8 2.10+ pref_address Preferred loading address 0260/4 2.10+ init_size Linear memory required during initialization 0264/4 2.11+ handover_offset Offset of handover entry point +0268/8 2.14+ acpi_rsdp_addr Physical address of RSDP table (1) For backwards compatibility, if the setup_sects field contains 0, the real value is 4. @@ -309,7 +322,7 @@ Protocol: 2.00+ Contains the magic number "HdrS" (0x53726448). Field name: version -Type: read +Type: modify Offset/size: 0x206/2 Protocol: 2.00+ @@ -317,6 +330,12 @@ Protocol: 2.00+ e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version 10.17. + Up to protocol version 2.13 this information is only read by the + bootloader. From protocol version 2.14 onwards the bootloader will + write the used protocol version or-ed with 0x8000 to the field. The + used protocol version will be the minimum of the supported protocol + versions of the bootloader and the kernel. + Field name: realmode_swtch Type: modify (optional) Offset/size: 0x208/4 @@ -744,6 +763,17 @@ Offset/size: 0x264/4 See EFI HANDOVER PROTOCOL below for more details. +Field name: acpi_rsdp_addr +Type: write +Offset/size: 0x268/8 +Protocol: 2.14+ + + This field can be set by the boot loader to tell the kernel the + physical address of the ACPI RSDP table. + + A value of 0 indicates the kernel should fall back to the standard + methods to locate the RSDP. + **** THE IMAGE CHECKSUM diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S @@ -300,7 +300,7 @@ _start: # Part 2 of the header, from the old setup.S .ascii "HdrS" # header signature - .word 0x020d # header version number (>= 0x0105) + .word 0x020e # header version number (>= 0x0105) # or else old loadlin-1.5 will fail) .globl realmode_swtch realmode_swtch: .word 0, 0 # default_switch, SETUPSEG @@ -558,6 +558,10 @@ pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr init_size: .long INIT_SIZE # kernel initialization size handover_offset: .long 0 # Filled in by build.c +acpi_rsdp_addr: .quad 0 # 64-bit physical pointer to the + # ACPI RSDP table, added with + # version 2.14 + # End of setup header ##################################################### .section ".entrytext", "ax" diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h @@ -142,6 +142,8 @@ static inline u64 acpi_arch_get_root_pointer(void) void acpi_generic_reduced_hw_init(void); +u64 x86_default_get_root_pointer(void); + #else /* !CONFIG_ACPI */ #define acpi_lapic 0 @@ -153,6 +155,11 @@ static inline void disable_acpi(void) { } static inline void acpi_generic_reduced_hw_init(void) { } +static inline u64 x86_default_get_root_pointer(void) +{ + return 0; +} + #endif /* !CONFIG_ACPI */ #define ARCH_HAS_POWER_INIT 1 diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h @@ -303,4 +303,6 @@ extern void x86_init_noop(void); extern void x86_init_uint_noop(unsigned int unused); extern bool x86_pnpbios_disabled(void); +void x86_verify_bootdata_version(void); + #endif diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h @@ -16,6 +16,9 @@ #define RAMDISK_PROMPT_FLAG 0x8000 #define RAMDISK_LOAD_FLAG 0x4000 +/* version flags */ +#define VERSION_WRITTEN 0x8000 + /* loadflags */ #define LOADED_HIGH (1<<0) #define KASLR_FLAG (1<<1) @@ -86,6 +89,7 @@ struct setup_header { __u64 pref_address; __u32 init_size; __u32 handover_offset; + __u64 acpi_rsdp_addr; } __attribute__((packed)); struct sys_desc_table { diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c @@ -48,6 +48,7 @@ #include <asm/mpspec.h> #include <asm/smp.h> #include <asm/i8259.h> +#include <asm/setup.h> #include "sleep.h" /* To include x86_acpi_suspend_lowlevel */ static int __initdata acpi_force = 0; @@ -1771,3 +1772,8 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size) e820__range_add(addr, size, E820_TYPE_ACPI); e820__update_table_print(); } + +u64 x86_default_get_root_pointer(void) +{ + return boot_params.hdr.acpi_rsdp_addr; +} diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c @@ -37,6 +37,7 @@ asmlinkage __visible void __init i386_start_kernel(void) cr4_init_shadow(); sanitize_boot_params(&boot_params); + x86_verify_bootdata_version(); x86_early_init_platform_quirks(); diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c @@ -457,6 +457,8 @@ void __init x86_64_start_reservations(char *real_mode_data) if (!boot_params.hdr.version) copy_bootdata(__va(real_mode_data)); + x86_verify_bootdata_version(); + x86_early_init_platform_quirks(); switch (boot_params.hdr.hardware_subarch) { diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c @@ -1281,6 +1281,23 @@ void __init setup_arch(char **cmdline_p) unwind_init(); } +/* + * From boot protocol 2.14 onwards we expect the bootloader to set the + * version to "0x8000 | <used version>". In case we find a version >= 2.14 + * without the 0x8000 we assume the boot loader supports 2.13 only and + * reset the version accordingly. The 0x8000 flag is removed in any case. + */ +void __init x86_verify_bootdata_version(void) +{ + if (boot_params.hdr.version & VERSION_WRITTEN) + boot_params.hdr.version &= ~VERSION_WRITTEN; + else if (boot_params.hdr.version >= 0x020e) + boot_params.hdr.version = 0x020d; + + if (boot_params.hdr.version < 0x020e) + boot_params.hdr.acpi_rsdp_addr = 0; +} + #ifdef CONFIG_X86_32 static struct resource video_ram_resource = { diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c @@ -31,7 +31,6 @@ static int __init iommu_init_noop(void) { return 0; } static void iommu_shutdown_noop(void) { } static bool __init bool_x86_init_noop(void) { return false; } static void x86_op_int_noop(int cpu) { } -static u64 u64_x86_init_noop(void) { return 0; } /* * The platform setup functions are preset with the default functions @@ -96,7 +95,7 @@ struct x86_init_ops x86_init __initdata = { }, .acpi = { - .get_root_pointer = u64_x86_init_noop, + .get_root_pointer = x86_default_get_root_pointer, .reduced_hw_early_init = acpi_generic_reduced_hw_init, }, }; diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c @@ -76,7 +76,7 @@ static void __init init_pvh_bootparams(void) * Version 2.12 supports Xen entry point but we will use default x86/PC * environment (i.e. hardware_subarch 0). */ - pvh_bootparams.hdr.version = 0x212; + pvh_bootparams.hdr.version = (2 << 8) | 12; pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */ x86_init.acpi.get_root_pointer = pvh_get_root_pointer;