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authorLinus Torvalds <torvalds@linux-foundation.org>2019-11-26 08:40:20 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-11-26 08:40:20 -0800
commit85fbf15bc9ac458f014fe70b38fa5773ee6aca9d (patch)
tree4fe817597e007ea0647ac4d9af84979cfba2f700
parentMerge branches 'core-objtool-for-linus', 'x86-cleanups-for-linus' and 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff)
parentx86/boot: Introduce setup_indirect (diff)
downloadlinux-dev-85fbf15bc9ac458f014fe70b38fa5773ee6aca9d.tar.xz
linux-dev-85fbf15bc9ac458f014fe70b38fa5773ee6aca9d.zip
Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Ingo Molnar: "The main changes were: - Extend the boot protocol to allow future extensions without hitting the setup_header size limit. - Add quirk to devicetree systems to disable the RTC unless it's listed as a supported device. - Fix ld.lld linker pedantry" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Introduce setup_indirect x86/boot: Introduce kernel_info.setup_type_max x86/boot: Introduce kernel_info x86/init: Allow DT configured systems to disable RTC at boot time x86/realmode: Explicitly set entry point via ENTRY in linker script
-rw-r--r--Documentation/x86/boot.rst174
-rw-r--r--arch/x86/boot/Makefile2
-rw-r--r--arch/x86/boot/compressed/Makefile4
-rw-r--r--arch/x86/boot/compressed/kaslr.c12
-rw-r--r--arch/x86/boot/compressed/kernel_info.S22
-rw-r--r--arch/x86/boot/header.S3
-rw-r--r--arch/x86/boot/tools/build.c5
-rw-r--r--arch/x86/include/uapi/asm/bootparam.h16
-rw-r--r--arch/x86/kernel/e820.c11
-rw-r--r--arch/x86/kernel/kdebugfs.c21
-rw-r--r--arch/x86/kernel/ksysfs.c31
-rw-r--r--arch/x86/kernel/setup.c6
-rw-r--r--arch/x86/kernel/x86_init.c24
-rw-r--r--arch/x86/mm/ioremap.c11
-rw-r--r--arch/x86/realmode/rm/realmode.lds.S1
15 files changed, 326 insertions, 17 deletions
diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst
index 08a2f100c0e6..90bb8f5ab384 100644
--- a/Documentation/x86/boot.rst
+++ b/Documentation/x86/boot.rst
@@ -68,8 +68,25 @@ Protocol 2.12 (Kernel 3.8) Added the xloadflags field and extension fields
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: BURNT BY INCORRECT COMMIT ae7e1238e68f2a472a125673ab506d49158c1889
+ (x86/boot: Add ACPI RSDP address to setup_header)
+ DO NOT USE!!! ASSUME SAME AS 2.13.
+
+Protocol 2.15: (Kernel 5.5) Added the kernel_info and kernel_info.setup_type_max.
============= ============================================================
+.. note::
+ The protocol version number should be changed only if the setup header
+ is changed. There is no need to update the version number if boot_params
+ or kernel_info are changed. Additionally, it is recommended to use
+ xloadflags (in this case the protocol version number should not be
+ updated either) or kernel_info to communicate supported Linux kernel
+ features to the boot loader. Due to very limited space available in
+ the original setup header every update to it should be considered
+ with great care. Starting from the protocol 2.15 the primary way to
+ communicate things to the boot loader is the kernel_info.
+
Memory Layout
=============
@@ -207,6 +224,7 @@ Offset/Size 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
+0268/4 2.15+ kernel_info_offset Offset of the kernel_info
=========== ======== ===================== ============================================
.. note::
@@ -809,6 +827,47 @@ Protocol: 2.09+
sure to consider the case where the linked list already contains
entries.
+ The setup_data is a bit awkward to use for extremely large data objects,
+ both because the setup_data header has to be adjacent to the data object
+ and because it has a 32-bit length field. However, it is important that
+ intermediate stages of the boot process have a way to identify which
+ chunks of memory are occupied by kernel data.
+
+ Thus setup_indirect struct and SETUP_INDIRECT type were introduced in
+ protocol 2.15.
+
+ struct setup_indirect {
+ __u32 type;
+ __u32 reserved; /* Reserved, must be set to zero. */
+ __u64 len;
+ __u64 addr;
+ };
+
+ The type member is a SETUP_INDIRECT | SETUP_* type. However, it cannot be
+ SETUP_INDIRECT itself since making the setup_indirect a tree structure
+ could require a lot of stack space in something that needs to parse it
+ and stack space can be limited in boot contexts.
+
+ Let's give an example how to point to SETUP_E820_EXT data using setup_indirect.
+ In this case setup_data and setup_indirect will look like this:
+
+ struct setup_data {
+ __u64 next = 0 or <addr_of_next_setup_data_struct>;
+ __u32 type = SETUP_INDIRECT;
+ __u32 len = sizeof(setup_data);
+ __u8 data[sizeof(setup_indirect)] = struct setup_indirect {
+ __u32 type = SETUP_INDIRECT | SETUP_E820_EXT;
+ __u32 reserved = 0;
+ __u64 len = <len_of_SETUP_E820_EXT_data>;
+ __u64 addr = <addr_of_SETUP_E820_EXT_data>;
+ }
+ }
+
+.. note::
+ SETUP_INDIRECT | SETUP_NONE objects cannot be properly distinguished
+ from SETUP_INDIRECT itself. So, this kind of objects cannot be provided
+ by the bootloaders.
+
============ ============
Field name: pref_address
Type: read (reloc)
@@ -855,6 +914,121 @@ Offset/size: 0x264/4
See EFI HANDOVER PROTOCOL below for more details.
+============ ==================
+Field name: kernel_info_offset
+Type: read
+Offset/size: 0x268/4
+Protocol: 2.15+
+============ ==================
+
+ This field is the offset from the beginning of the kernel image to the
+ kernel_info. The kernel_info structure is embedded in the Linux image
+ in the uncompressed protected mode region.
+
+
+The kernel_info
+===============
+
+The relationships between the headers are analogous to the various data
+sections:
+
+ setup_header = .data
+ boot_params/setup_data = .bss
+
+What is missing from the above list? That's right:
+
+ kernel_info = .rodata
+
+We have been (ab)using .data for things that could go into .rodata or .bss for
+a long time, for lack of alternatives and -- especially early on -- inertia.
+Also, the BIOS stub is responsible for creating boot_params, so it isn't
+available to a BIOS-based loader (setup_data is, though).
+
+setup_header is permanently limited to 144 bytes due to the reach of the
+2-byte jump field, which doubles as a length field for the structure, combined
+with the size of the "hole" in struct boot_params that a protected-mode loader
+or the BIOS stub has to copy it into. It is currently 119 bytes long, which
+leaves us with 25 very precious bytes. This isn't something that can be fixed
+without revising the boot protocol entirely, breaking backwards compatibility.
+
+boot_params proper is limited to 4096 bytes, but can be arbitrarily extended
+by adding setup_data entries. It cannot be used to communicate properties of
+the kernel image, because it is .bss and has no image-provided content.
+
+kernel_info solves this by providing an extensible place for information about
+the kernel image. It is readonly, because the kernel cannot rely on a
+bootloader copying its contents anywhere, but that is OK; if it becomes
+necessary it can still contain data items that an enabled bootloader would be
+expected to copy into a setup_data chunk.
+
+All kernel_info data should be part of this structure. Fixed size data have to
+be put before kernel_info_var_len_data label. Variable size data have to be put
+after kernel_info_var_len_data label. Each chunk of variable size data has to
+be prefixed with header/magic and its size, e.g.:
+
+ kernel_info:
+ .ascii "LToP" /* Header, Linux top (structure). */
+ .long kernel_info_var_len_data - kernel_info
+ .long kernel_info_end - kernel_info
+ .long 0x01234567 /* Some fixed size data for the bootloaders. */
+ kernel_info_var_len_data:
+ example_struct: /* Some variable size data for the bootloaders. */
+ .ascii "0123" /* Header/Magic. */
+ .long example_struct_end - example_struct
+ .ascii "Struct"
+ .long 0x89012345
+ example_struct_end:
+ example_strings: /* Some variable size data for the bootloaders. */
+ .ascii "ABCD" /* Header/Magic. */
+ .long example_strings_end - example_strings
+ .asciz "String_0"
+ .asciz "String_1"
+ example_strings_end:
+ kernel_info_end:
+
+This way the kernel_info is self-contained blob.
+
+.. note::
+ Each variable size data header/magic can be any 4-character string,
+ without \0 at the end of the string, which does not collide with
+ existing variable length data headers/magics.
+
+
+Details of the kernel_info Fields
+=================================
+
+============ ========
+Field name: header
+Offset/size: 0x0000/4
+============ ========
+
+ Contains the magic number "LToP" (0x506f544c).
+
+============ ========
+Field name: size
+Offset/size: 0x0004/4
+============ ========
+
+ This field contains the size of the kernel_info including kernel_info.header.
+ It does not count kernel_info.kernel_info_var_len_data size. This field should be
+ used by the bootloaders to detect supported fixed size fields in the kernel_info
+ and beginning of kernel_info.kernel_info_var_len_data.
+
+============ ========
+Field name: size_total
+Offset/size: 0x0008/4
+============ ========
+
+ This field contains the size of the kernel_info including kernel_info.header
+ and kernel_info.kernel_info_var_len_data.
+
+============ ==============
+Field name: setup_type_max
+Offset/size: 0x000c/4
+============ ==============
+
+ This field contains maximal allowed type for setup_data and setup_indirect structs.
+
The Image Checksum
==================
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index e2839b5c246c..c30a9b642a86 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -87,7 +87,7 @@ $(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE
SETUP_OBJS = $(addprefix $(obj)/,$(setup-y))
-sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|input_data\|_end\|_ehead\|_text\|z_.*\)$$/\#define ZO_\2 0x\1/p'
+sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\|z_.*\)$$/\#define ZO_\2 0x\1/p'
quiet_cmd_zoffset = ZOFFSET $@
cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 6b84afdd7538..fad3b18e2cc3 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -72,8 +72,8 @@ $(obj)/../voffset.h: vmlinux FORCE
$(obj)/misc.o: $(obj)/../voffset.h
-vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
- $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
+vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/kernel_info.o $(obj)/head_$(BITS).o \
+ $(obj)/misc.o $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
$(obj)/piggy.o $(obj)/cpuflags.o
vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 2e53c056ba20..bb9bfef174ae 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -459,6 +459,18 @@ static bool mem_avoid_overlap(struct mem_vector *img,
is_overlapping = true;
}
+ if (ptr->type == SETUP_INDIRECT &&
+ ((struct setup_indirect *)ptr->data)->type != SETUP_INDIRECT) {
+ avoid.start = ((struct setup_indirect *)ptr->data)->addr;
+ avoid.size = ((struct setup_indirect *)ptr->data)->len;
+
+ if (mem_overlaps(img, &avoid) && (avoid.start < earliest)) {
+ *overlap = avoid;
+ earliest = overlap->start;
+ is_overlapping = true;
+ }
+ }
+
ptr = (struct setup_data *)(unsigned long)ptr->next;
}
diff --git a/arch/x86/boot/compressed/kernel_info.S b/arch/x86/boot/compressed/kernel_info.S
new file mode 100644
index 000000000000..f818ee8fba38
--- /dev/null
+++ b/arch/x86/boot/compressed/kernel_info.S
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <asm/bootparam.h>
+
+ .section ".rodata.kernel_info", "a"
+
+ .global kernel_info
+
+kernel_info:
+ /* Header, Linux top (structure). */
+ .ascii "LToP"
+ /* Size. */
+ .long kernel_info_var_len_data - kernel_info
+ /* Size total. */
+ .long kernel_info_end - kernel_info
+
+ /* Maximal allowed type for setup_data and setup_indirect structs. */
+ .long SETUP_TYPE_MAX
+
+kernel_info_var_len_data:
+ /* Empty for time being... */
+kernel_info_end:
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 2c11c0f45d49..97d9b6d6c1af 100644
--- 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 0x020f # header version number (>= 0x0105)
# or else old loadlin-1.5 will fail)
.globl realmode_swtch
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
@@ -567,6 +567,7 @@ 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
+kernel_info_offset: .long 0 # Filled in by build.c
# End of setup header #####################################################
diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c
index a93d44e58f9c..55e669d29e54 100644
--- a/arch/x86/boot/tools/build.c
+++ b/arch/x86/boot/tools/build.c
@@ -56,6 +56,7 @@ u8 buf[SETUP_SECT_MAX*512];
unsigned long efi32_stub_entry;
unsigned long efi64_stub_entry;
unsigned long efi_pe_entry;
+unsigned long kernel_info;
unsigned long startup_64;
/*----------------------------------------------------------------------*/
@@ -321,6 +322,7 @@ static void parse_zoffset(char *fname)
PARSE_ZOFS(p, efi32_stub_entry);
PARSE_ZOFS(p, efi64_stub_entry);
PARSE_ZOFS(p, efi_pe_entry);
+ PARSE_ZOFS(p, kernel_info);
PARSE_ZOFS(p, startup_64);
p = strchr(p, '\n');
@@ -410,6 +412,9 @@ int main(int argc, char ** argv)
efi_stub_entry_update();
+ /* Update kernel_info offset. */
+ put_unaligned_le32(kernel_info, &buf[0x268]);
+
crc = partial_crc32(buf, i, crc);
if (fwrite(buf, 1, i, dest) != i)
die("Writing setup failed");
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index c895df5482c5..949066b5398a 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -2,7 +2,7 @@
#ifndef _ASM_X86_BOOTPARAM_H
#define _ASM_X86_BOOTPARAM_H
-/* setup_data types */
+/* setup_data/setup_indirect types */
#define SETUP_NONE 0
#define SETUP_E820_EXT 1
#define SETUP_DTB 2
@@ -11,6 +11,11 @@
#define SETUP_APPLE_PROPERTIES 5
#define SETUP_JAILHOUSE 6
+#define SETUP_INDIRECT (1<<31)
+
+/* SETUP_INDIRECT | max(SETUP_*) */
+#define SETUP_TYPE_MAX (SETUP_INDIRECT | SETUP_JAILHOUSE)
+
/* ram_size flags */
#define RAMDISK_IMAGE_START_MASK 0x07FF
#define RAMDISK_PROMPT_FLAG 0x8000
@@ -49,6 +54,14 @@ struct setup_data {
__u8 data[0];
};
+/* extensible setup indirect data node */
+struct setup_indirect {
+ __u32 type;
+ __u32 reserved; /* Reserved, must be set to zero. */
+ __u64 len;
+ __u64 addr;
+};
+
struct setup_header {
__u8 setup_sects;
__u16 root_flags;
@@ -88,6 +101,7 @@ struct setup_header {
__u64 pref_address;
__u32 init_size;
__u32 handover_offset;
+ __u32 kernel_info_offset;
} __attribute__((packed));
struct sys_desc_table {
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 7da2bcd2b8eb..0bfe9a685b3b 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -999,6 +999,17 @@ void __init e820__reserve_setup_data(void)
data = early_memremap(pa_data, sizeof(*data));
e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
e820__range_update_kexec(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+
+ if (data->type == SETUP_INDIRECT &&
+ ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
+ e820__range_update(((struct setup_indirect *)data->data)->addr,
+ ((struct setup_indirect *)data->data)->len,
+ E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+ e820__range_update_kexec(((struct setup_indirect *)data->data)->addr,
+ ((struct setup_indirect *)data->data)->len,
+ E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+ }
+
pa_data = data->next;
early_memunmap(data, sizeof(*data));
}
diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c
index edaa30b20841..64b6da95af98 100644
--- a/arch/x86/kernel/kdebugfs.c
+++ b/arch/x86/kernel/kdebugfs.c
@@ -44,7 +44,12 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf,
if (count > node->len - pos)
count = node->len - pos;
- pa = node->paddr + sizeof(struct setup_data) + pos;
+ pa = node->paddr + pos;
+
+ /* Is it direct data or invalid indirect one? */
+ if (!(node->type & SETUP_INDIRECT) || node->type == SETUP_INDIRECT)
+ pa += sizeof(struct setup_data);
+
p = memremap(pa, count, MEMREMAP_WB);
if (!p)
return -ENOMEM;
@@ -108,9 +113,17 @@ static int __init create_setup_data_nodes(struct dentry *parent)
goto err_dir;
}
- node->paddr = pa_data;
- node->type = data->type;
- node->len = data->len;
+ if (data->type == SETUP_INDIRECT &&
+ ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
+ node->paddr = ((struct setup_indirect *)data->data)->addr;
+ node->type = ((struct setup_indirect *)data->data)->type;
+ node->len = ((struct setup_indirect *)data->data)->len;
+ } else {
+ node->paddr = pa_data;
+ node->type = data->type;
+ node->len = data->len;
+ }
+
create_setup_data_node(d, no, node);
pa_data = data->next;
diff --git a/arch/x86/kernel/ksysfs.c b/arch/x86/kernel/ksysfs.c
index 7969da939213..d0a19121c6a4 100644
--- a/arch/x86/kernel/ksysfs.c
+++ b/arch/x86/kernel/ksysfs.c
@@ -100,7 +100,12 @@ static int __init get_setup_data_size(int nr, size_t *size)
if (!data)
return -ENOMEM;
if (nr == i) {
- *size = data->len;
+ if (data->type == SETUP_INDIRECT &&
+ ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT)
+ *size = ((struct setup_indirect *)data->data)->len;
+ else
+ *size = data->len;
+
memunmap(data);
return 0;
}
@@ -130,7 +135,10 @@ static ssize_t type_show(struct kobject *kobj,
if (!data)
return -ENOMEM;
- ret = sprintf(buf, "0x%x\n", data->type);
+ if (data->type == SETUP_INDIRECT)
+ ret = sprintf(buf, "0x%x\n", ((struct setup_indirect *)data->data)->type);
+ else
+ ret = sprintf(buf, "0x%x\n", data->type);
memunmap(data);
return ret;
}
@@ -142,7 +150,7 @@ static ssize_t setup_data_data_read(struct file *fp,
loff_t off, size_t count)
{
int nr, ret = 0;
- u64 paddr;
+ u64 paddr, len;
struct setup_data *data;
void *p;
@@ -157,19 +165,28 @@ static ssize_t setup_data_data_read(struct file *fp,
if (!data)
return -ENOMEM;
- if (off > data->len) {
+ if (data->type == SETUP_INDIRECT &&
+ ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
+ paddr = ((struct setup_indirect *)data->data)->addr;
+ len = ((struct setup_indirect *)data->data)->len;
+ } else {
+ paddr += sizeof(*data);
+ len = data->len;
+ }
+
+ if (off > len) {
ret = -EINVAL;
goto out;
}
- if (count > data->len - off)
- count = data->len - off;
+ if (count > len - off)
+ count = len - off;
if (!count)
goto out;
ret = count;
- p = memremap(paddr + sizeof(*data), data->len, MEMREMAP_WB);
+ p = memremap(paddr, len, MEMREMAP_WB);
if (!p) {
ret = -ENOMEM;
goto out;
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 35b3f3a976dc..7f4dae49cc49 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -438,6 +438,12 @@ static void __init memblock_x86_reserve_range_setup_data(void)
while (pa_data) {
data = early_memremap(pa_data, sizeof(*data));
memblock_reserve(pa_data, sizeof(*data) + data->len);
+
+ if (data->type == SETUP_INDIRECT &&
+ ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT)
+ memblock_reserve(((struct setup_indirect *)data->data)->addr,
+ ((struct setup_indirect *)data->data)->len);
+
pa_data = data->next;
early_memunmap(data, sizeof(*data));
}
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index 18a799c8fa28..ce89430a7f80 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -31,6 +31,28 @@ static int __init iommu_init_noop(void) { return 0; }
static void iommu_shutdown_noop(void) { }
bool __init bool_x86_init_noop(void) { return false; }
void x86_op_int_noop(int cpu) { }
+static __init int set_rtc_noop(const struct timespec64 *now) { return -EINVAL; }
+static __init void get_rtc_noop(struct timespec64 *now) { }
+
+static __initconst const struct of_device_id of_cmos_match[] = {
+ { .compatible = "motorola,mc146818" },
+ {}
+};
+
+/*
+ * Allow devicetree configured systems to disable the RTC by setting the
+ * corresponding DT node's status property to disabled. Code is optimized
+ * out for CONFIG_OF=n builds.
+ */
+static __init void x86_wallclock_init(void)
+{
+ struct device_node *node = of_find_matching_node(NULL, of_cmos_match);
+
+ if (node && !of_device_is_available(node)) {
+ x86_platform.get_wallclock = get_rtc_noop;
+ x86_platform.set_wallclock = set_rtc_noop;
+ }
+}
/*
* The platform setup functions are preset with the default functions
@@ -73,7 +95,7 @@ struct x86_init_ops x86_init __initdata = {
.timers = {
.setup_percpu_clockev = setup_boot_APIC_clock,
.timer_init = hpet_time_init,
- .wallclock_init = x86_init_noop,
+ .wallclock_init = x86_wallclock_init,
},
.iommu = {
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index a39dcdb5ae34..1ff9c2030b4f 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -626,6 +626,17 @@ static bool memremap_is_setup_data(resource_size_t phys_addr,
paddr_next = data->next;
len = data->len;
+ if ((phys_addr > paddr) && (phys_addr < (paddr + len))) {
+ memunmap(data);
+ return true;
+ }
+
+ if (data->type == SETUP_INDIRECT &&
+ ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
+ paddr = ((struct setup_indirect *)data->data)->addr;
+ len = ((struct setup_indirect *)data->data)->len;
+ }
+
memunmap(data);
if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
diff --git a/arch/x86/realmode/rm/realmode.lds.S b/arch/x86/realmode/rm/realmode.lds.S
index 3bb980800c58..64d135d1ee63 100644
--- a/arch/x86/realmode/rm/realmode.lds.S
+++ b/arch/x86/realmode/rm/realmode.lds.S
@@ -11,6 +11,7 @@
OUTPUT_FORMAT("elf32-i386")
OUTPUT_ARCH(i386)
+ENTRY(pa_text_start)
SECTIONS
{