diff mbox series

[PATCHv7,05/14] x86/boot: Add infrastructure required for unaccepted memory support

Message ID 20220614120231.48165-6-kirill.shutemov@linux.intel.com (mailing list archive)
State New
Headers show
Series mm, x86/cc: Implement support for unaccepted memory | expand

Commit Message

Kirill A. Shutemov June 14, 2022, 12:02 p.m. UTC
Pull functionality from the main kernel headers and lib/ that is
required for unaccepted memory support.

This is preparatory patch. The users for the functionality will come in
following patches.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/boot/bitops.h                   | 40 ++++++++++++
 arch/x86/boot/compressed/align.h         | 14 +++++
 arch/x86/boot/compressed/bitmap.c        | 43 +++++++++++++
 arch/x86/boot/compressed/bitmap.h        | 49 +++++++++++++++
 arch/x86/boot/compressed/bits.h          | 36 +++++++++++
 arch/x86/boot/compressed/compiler.h      |  9 +++
 arch/x86/boot/compressed/find.c          | 54 ++++++++++++++++
 arch/x86/boot/compressed/find.h          | 80 ++++++++++++++++++++++++
 arch/x86/boot/compressed/math.h          | 37 +++++++++++
 arch/x86/boot/compressed/minmax.h        | 61 ++++++++++++++++++
 arch/x86/boot/compressed/pgtable_types.h | 25 ++++++++
 11 files changed, 448 insertions(+)
 create mode 100644 arch/x86/boot/compressed/align.h
 create mode 100644 arch/x86/boot/compressed/bitmap.c
 create mode 100644 arch/x86/boot/compressed/bitmap.h
 create mode 100644 arch/x86/boot/compressed/bits.h
 create mode 100644 arch/x86/boot/compressed/compiler.h
 create mode 100644 arch/x86/boot/compressed/find.c
 create mode 100644 arch/x86/boot/compressed/find.h
 create mode 100644 arch/x86/boot/compressed/math.h
 create mode 100644 arch/x86/boot/compressed/minmax.h
 create mode 100644 arch/x86/boot/compressed/pgtable_types.h

Comments

Peter Zijlstra June 15, 2022, 10:19 a.m. UTC | #1
On Tue, Jun 14, 2022 at 03:02:22PM +0300, Kirill A. Shutemov wrote:
> Pull functionality from the main kernel headers and lib/ that is
> required for unaccepted memory support.
> 
> This is preparatory patch. The users for the functionality will come in
> following patches.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> ---
>  arch/x86/boot/bitops.h                   | 40 ++++++++++++
>  arch/x86/boot/compressed/align.h         | 14 +++++
>  arch/x86/boot/compressed/bitmap.c        | 43 +++++++++++++
>  arch/x86/boot/compressed/bitmap.h        | 49 +++++++++++++++
>  arch/x86/boot/compressed/bits.h          | 36 +++++++++++
>  arch/x86/boot/compressed/compiler.h      |  9 +++
>  arch/x86/boot/compressed/find.c          | 54 ++++++++++++++++
>  arch/x86/boot/compressed/find.h          | 80 ++++++++++++++++++++++++
>  arch/x86/boot/compressed/math.h          | 37 +++++++++++
>  arch/x86/boot/compressed/minmax.h        | 61 ++++++++++++++++++
>  arch/x86/boot/compressed/pgtable_types.h | 25 ++++++++

That's quite a lot of duplicated code; is there really no way so share
this?
Kirill A. Shutemov June 15, 2022, 3:05 p.m. UTC | #2
On Wed, Jun 15, 2022 at 12:19:45PM +0200, Peter Zijlstra wrote:
> On Tue, Jun 14, 2022 at 03:02:22PM +0300, Kirill A. Shutemov wrote:
> > Pull functionality from the main kernel headers and lib/ that is
> > required for unaccepted memory support.
> > 
> > This is preparatory patch. The users for the functionality will come in
> > following patches.
> > 
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > ---
> >  arch/x86/boot/bitops.h                   | 40 ++++++++++++
> >  arch/x86/boot/compressed/align.h         | 14 +++++
> >  arch/x86/boot/compressed/bitmap.c        | 43 +++++++++++++
> >  arch/x86/boot/compressed/bitmap.h        | 49 +++++++++++++++
> >  arch/x86/boot/compressed/bits.h          | 36 +++++++++++
> >  arch/x86/boot/compressed/compiler.h      |  9 +++
> >  arch/x86/boot/compressed/find.c          | 54 ++++++++++++++++
> >  arch/x86/boot/compressed/find.h          | 80 ++++++++++++++++++++++++
> >  arch/x86/boot/compressed/math.h          | 37 +++++++++++
> >  arch/x86/boot/compressed/minmax.h        | 61 ++++++++++++++++++
> >  arch/x86/boot/compressed/pgtable_types.h | 25 ++++++++
> 
> That's quite a lot of duplicated code; is there really no way so share
> this?

Code duplication also make me uncomfortable. But that what Borislav wanted
to see. efi.h in the boot stub which copies bulk of <linux/efi.h> also
sets the trend in the direction.

Alternative is creating a subset of headers that can be used in both in
main kernel and boot stub. It is more complex and doesn't allow for short
cuts that can be made on copy if you know the context it is used in.

It also sounds painfully similar to uapi/ project. I'm not sure we want to
go this path.
Borislav Petkov July 17, 2022, 5:16 p.m. UTC | #3
On Wed, Jun 15, 2022 at 06:05:34PM +0300, Kirill A. Shutemov wrote:
> It also sounds painfully similar to uapi/ project. I'm not sure we want to
> go this path.

It is the same path perf tool is taking - see first paragraph:

https://lore.kernel.org/r/YtQM40VmiLTkPND2@kernel.org

I don't want to deal with the regular breakages or hacks to
boot/compressed/ just because little duplication. We copy the header
once and that's it - it doesn't even have to get updated like perf tool
does from time to time.
Borislav Petkov July 25, 2022, 9:33 p.m. UTC | #4
On Tue, Jun 14, 2022 at 03:02:22PM +0300, Kirill A. Shutemov wrote:
> diff --git a/arch/x86/boot/compressed/compiler.h b/arch/x86/boot/compressed/compiler.h
> new file mode 100644
> index 000000000000..452c4c0844b9
> --- /dev/null
> +++ b/arch/x86/boot/compressed/compiler.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef BOOT_COMPILER_H
> +#define BOOT_COMPILER_H
> +#define __LINUX_COMPILER_H /* Inhibit inclusion of <linux/compiler.h> */
> +
> +# define likely(x)	__builtin_expect(!!(x), 1)
> +# define unlikely(x)	__builtin_expect(!!(x), 0)
> +
> +#endif

I guess that header is not really needed - simply drop the annotations
from the code too.
diff mbox series

Patch

diff --git a/arch/x86/boot/bitops.h b/arch/x86/boot/bitops.h
index 02e1dea11d94..61eb820ee402 100644
--- a/arch/x86/boot/bitops.h
+++ b/arch/x86/boot/bitops.h
@@ -41,4 +41,44 @@  static inline void set_bit(int nr, void *addr)
 	asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr));
 }
 
+static __always_inline void __set_bit(long nr, volatile unsigned long *addr)
+{
+	asm volatile(__ASM_SIZE(bts) " %1,%0" : : "m" (*(volatile long *) addr),
+		     "Ir" (nr) : "memory");
+}
+
+static __always_inline void __clear_bit(long nr, volatile unsigned long *addr)
+{
+	asm volatile(__ASM_SIZE(btr) " %1,%0" : : "m" (*(volatile long *) addr),
+		     "Ir" (nr) : "memory");
+}
+
+/**
+ * __ffs - find first set bit in word
+ * @word: The word to search
+ *
+ * Undefined if no bit exists, so code should check against 0 first.
+ */
+static __always_inline unsigned long __ffs(unsigned long word)
+{
+	asm("rep; bsf %1,%0"
+		: "=r" (word)
+		: "rm" (word));
+	return word;
+}
+
+/**
+ * ffz - find first zero bit in word
+ * @word: The word to search
+ *
+ * Undefined if no zero exists, so code should check against ~0UL first.
+ */
+static __always_inline unsigned long ffz(unsigned long word)
+{
+	asm("rep; bsf %1,%0"
+		: "=r" (word)
+		: "r" (~word));
+	return word;
+}
+
 #endif /* BOOT_BITOPS_H */
diff --git a/arch/x86/boot/compressed/align.h b/arch/x86/boot/compressed/align.h
new file mode 100644
index 000000000000..7ccabbc5d1b8
--- /dev/null
+++ b/arch/x86/boot/compressed/align.h
@@ -0,0 +1,14 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef BOOT_ALIGN_H
+#define BOOT_ALIGN_H
+#define _LINUX_ALIGN_H /* Inhibit inclusion of <linux/align.h> */
+
+/* @a is a power of 2 value */
+#define ALIGN(x, a)		__ALIGN_KERNEL((x), (a))
+#define ALIGN_DOWN(x, a)	__ALIGN_KERNEL((x) - ((a) - 1), (a))
+#define __ALIGN_MASK(x, mask)	__ALIGN_KERNEL_MASK((x), (mask))
+#define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
+#define PTR_ALIGN_DOWN(p, a)	((typeof(p))ALIGN_DOWN((unsigned long)(p), (a)))
+#define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
+
+#endif
diff --git a/arch/x86/boot/compressed/bitmap.c b/arch/x86/boot/compressed/bitmap.c
new file mode 100644
index 000000000000..789ecadeb521
--- /dev/null
+++ b/arch/x86/boot/compressed/bitmap.c
@@ -0,0 +1,43 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "bitmap.h"
+
+void __bitmap_set(unsigned long *map, unsigned int start, int len)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const unsigned int size = start + len;
+	int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
+
+	while (len - bits_to_set >= 0) {
+		*p |= mask_to_set;
+		len -= bits_to_set;
+		bits_to_set = BITS_PER_LONG;
+		mask_to_set = ~0UL;
+		p++;
+	}
+	if (len) {
+		mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+		*p |= mask_to_set;
+	}
+}
+
+void __bitmap_clear(unsigned long *map, unsigned int start, int len)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const unsigned int size = start + len;
+	int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
+
+	while (len - bits_to_clear >= 0) {
+		*p &= ~mask_to_clear;
+		len -= bits_to_clear;
+		bits_to_clear = BITS_PER_LONG;
+		mask_to_clear = ~0UL;
+		p++;
+	}
+	if (len) {
+		mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+		*p &= ~mask_to_clear;
+	}
+}
diff --git a/arch/x86/boot/compressed/bitmap.h b/arch/x86/boot/compressed/bitmap.h
new file mode 100644
index 000000000000..35357f5feda2
--- /dev/null
+++ b/arch/x86/boot/compressed/bitmap.h
@@ -0,0 +1,49 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef BOOT_BITMAP_H
+#define BOOT_BITMAP_H
+#define __LINUX_BITMAP_H /* Inhibit inclusion of <linux/bitmap.h> */
+
+#include "../bitops.h"
+#include "../string.h"
+#include "align.h"
+
+#define BITMAP_MEM_ALIGNMENT 8
+#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
+
+#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
+#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
+
+#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
+
+void __bitmap_set(unsigned long *map, unsigned int start, int len);
+void __bitmap_clear(unsigned long *map, unsigned int start, int len);
+
+static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
+		unsigned int nbits)
+{
+	if (__builtin_constant_p(nbits) && nbits == 1)
+		__set_bit(start, map);
+	else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
+		 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
+		 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
+		 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
+		memset((char *)map + start / 8, 0xff, nbits / 8);
+	else
+		__bitmap_set(map, start, nbits);
+}
+
+static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
+		unsigned int nbits)
+{
+	if (__builtin_constant_p(nbits) && nbits == 1)
+		__clear_bit(start, map);
+	else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
+		 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
+		 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
+		 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
+		memset((char *)map + start / 8, 0, nbits / 8);
+	else
+		__bitmap_clear(map, start, nbits);
+}
+
+#endif
diff --git a/arch/x86/boot/compressed/bits.h b/arch/x86/boot/compressed/bits.h
new file mode 100644
index 000000000000..b0ffa007ee19
--- /dev/null
+++ b/arch/x86/boot/compressed/bits.h
@@ -0,0 +1,36 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef BOOT_BITS_H
+#define BOOT_BITS_H
+#define __LINUX_BITS_H /* Inhibit inclusion of <linux/bits.h> */
+
+#ifdef __ASSEMBLY__
+#define _AC(X,Y)	X
+#define _AT(T,X)	X
+#else
+#define __AC(X,Y)	(X##Y)
+#define _AC(X,Y)	__AC(X,Y)
+#define _AT(T,X)	((T)(X))
+#endif
+
+#define _UL(x)		(_AC(x, UL))
+#define _ULL(x)		(_AC(x, ULL))
+#define UL(x)		(_UL(x))
+#define ULL(x)		(_ULL(x))
+
+#define BIT(nr)			(UL(1) << (nr))
+#define BIT_ULL(nr)		(ULL(1) << (nr))
+#define BIT_MASK(nr)		(UL(1) << ((nr) % BITS_PER_LONG))
+#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
+#define BIT_ULL_MASK(nr)	(ULL(1) << ((nr) % BITS_PER_LONG_LONG))
+#define BIT_ULL_WORD(nr)	((nr) / BITS_PER_LONG_LONG)
+#define BITS_PER_BYTE		8
+
+#define GENMASK(h, l) \
+	(((~UL(0)) - (UL(1) << (l)) + 1) & \
+	 (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
+
+#define GENMASK_ULL(h, l) \
+	(((~ULL(0)) - (ULL(1) << (l)) + 1) & \
+	 (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
+
+#endif
diff --git a/arch/x86/boot/compressed/compiler.h b/arch/x86/boot/compressed/compiler.h
new file mode 100644
index 000000000000..452c4c0844b9
--- /dev/null
+++ b/arch/x86/boot/compressed/compiler.h
@@ -0,0 +1,9 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef BOOT_COMPILER_H
+#define BOOT_COMPILER_H
+#define __LINUX_COMPILER_H /* Inhibit inclusion of <linux/compiler.h> */
+
+# define likely(x)	__builtin_expect(!!(x), 1)
+# define unlikely(x)	__builtin_expect(!!(x), 0)
+
+#endif
diff --git a/arch/x86/boot/compressed/find.c b/arch/x86/boot/compressed/find.c
new file mode 100644
index 000000000000..839be91aae52
--- /dev/null
+++ b/arch/x86/boot/compressed/find.c
@@ -0,0 +1,54 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+#include "bitmap.h"
+#include "find.h"
+#include "math.h"
+#include "minmax.h"
+
+static __always_inline unsigned long swab(const unsigned long y)
+{
+#if __BITS_PER_LONG == 64
+	return __builtin_bswap32(y);
+#else /* __BITS_PER_LONG == 32 */
+	return __builtin_bswap64(y);
+#endif
+}
+
+unsigned long _find_next_bit(const unsigned long *addr1,
+		const unsigned long *addr2, unsigned long nbits,
+		unsigned long start, unsigned long invert, unsigned long le)
+{
+	unsigned long tmp, mask;
+
+	if (unlikely(start >= nbits))
+		return nbits;
+
+	tmp = addr1[start / BITS_PER_LONG];
+	if (addr2)
+		tmp &= addr2[start / BITS_PER_LONG];
+	tmp ^= invert;
+
+	/* Handle 1st word. */
+	mask = BITMAP_FIRST_WORD_MASK(start);
+	if (le)
+		mask = swab(mask);
+
+	tmp &= mask;
+
+	start = round_down(start, BITS_PER_LONG);
+
+	while (!tmp) {
+		start += BITS_PER_LONG;
+		if (start >= nbits)
+			return nbits;
+
+		tmp = addr1[start / BITS_PER_LONG];
+		if (addr2)
+			tmp &= addr2[start / BITS_PER_LONG];
+		tmp ^= invert;
+	}
+
+	if (le)
+		tmp = swab(tmp);
+
+	return min(start + __ffs(tmp), nbits);
+}
diff --git a/arch/x86/boot/compressed/find.h b/arch/x86/boot/compressed/find.h
new file mode 100644
index 000000000000..799176972ebc
--- /dev/null
+++ b/arch/x86/boot/compressed/find.h
@@ -0,0 +1,80 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef BOOT_FIND_H
+#define BOOT_FIND_H
+#define __LINUX_FIND_H /* Inhibit inclusion of <linux/find.h> */
+
+#include "../bitops.h"
+#include "align.h"
+#include "bits.h"
+#include "compiler.h"
+
+unsigned long _find_next_bit(const unsigned long *addr1,
+		const unsigned long *addr2, unsigned long nbits,
+		unsigned long start, unsigned long invert, unsigned long le);
+
+/**
+ * find_next_bit - find the next set bit in a memory region
+ * @addr: The address to base the search on
+ * @offset: The bitnumber to start searching at
+ * @size: The bitmap size in bits
+ *
+ * Returns the bit number for the next set bit
+ * If no bits are set, returns @size.
+ */
+static inline
+unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
+			    unsigned long offset)
+{
+	if (small_const_nbits(size)) {
+		unsigned long val;
+
+		if (unlikely(offset >= size))
+			return size;
+
+		val = *addr & GENMASK(size - 1, offset);
+		return val ? __ffs(val) : size;
+	}
+
+	return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
+}
+
+/**
+ * find_next_zero_bit - find the next cleared bit in a memory region
+ * @addr: The address to base the search on
+ * @offset: The bitnumber to start searching at
+ * @size: The bitmap size in bits
+ *
+ * Returns the bit number of the next zero bit
+ * If no bits are zero, returns @size.
+ */
+static inline
+unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
+				 unsigned long offset)
+{
+	if (small_const_nbits(size)) {
+		unsigned long val;
+
+		if (unlikely(offset >= size))
+			return size;
+
+		val = *addr | ~GENMASK(size - 1, offset);
+		return val == ~0UL ? size : ffz(val);
+	}
+
+	return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
+}
+
+/**
+ * for_each_set_bitrange_from - iterate over all set bit ranges [b; e)
+ * @b: bit offset of start of current bitrange (first set bit); must be initialized
+ * @e: bit offset of end of current bitrange (first unset bit)
+ * @addr: bitmap address to base the search on
+ * @size: bitmap size in number of bits
+ */
+#define for_each_set_bitrange_from(b, e, addr, size)		\
+	for ((b) = find_next_bit((addr), (size), (b)),		\
+	     (e) = find_next_zero_bit((addr), (size), (b) + 1);	\
+	     (b) < (size);					\
+	     (b) = find_next_bit((addr), (size), (e) + 1),	\
+	     (e) = find_next_zero_bit((addr), (size), (b) + 1))
+#endif
diff --git a/arch/x86/boot/compressed/math.h b/arch/x86/boot/compressed/math.h
new file mode 100644
index 000000000000..f7eede84bbc2
--- /dev/null
+++ b/arch/x86/boot/compressed/math.h
@@ -0,0 +1,37 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef BOOT_MATH_H
+#define BOOT_MATH_H
+#define __LINUX_MATH_H /* Inhibit inclusion of <linux/math.h> */
+
+/*
+ *
+ * This looks more complex than it should be. But we need to
+ * get the type for the ~ right in round_down (it needs to be
+ * as wide as the result!), and we want to evaluate the macro
+ * arguments just once each.
+ */
+#define __round_mask(x, y) ((__typeof__(x))((y)-1))
+
+/**
+ * round_up - round up to next specified power of 2
+ * @x: the value to round
+ * @y: multiple to round up to (must be a power of 2)
+ *
+ * Rounds @x up to next multiple of @y (which must be a power of 2).
+ * To perform arbitrary rounding up, use roundup() below.
+ */
+#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
+
+/**
+ * round_down - round down to next specified power of 2
+ * @x: the value to round
+ * @y: multiple to round down to (must be a power of 2)
+ *
+ * Rounds @x down to next multiple of @y (which must be a power of 2).
+ * To perform arbitrary rounding down, use rounddown() below.
+ */
+#define round_down(x, y) ((x) & ~__round_mask(x, y))
+
+#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
+
+#endif
diff --git a/arch/x86/boot/compressed/minmax.h b/arch/x86/boot/compressed/minmax.h
new file mode 100644
index 000000000000..4efd05673260
--- /dev/null
+++ b/arch/x86/boot/compressed/minmax.h
@@ -0,0 +1,61 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef BOOT_MINMAX_H
+#define BOOT_MINMAX_H
+#define __LINUX_MINMAX_H /* Inhibit inclusion of <linux/minmax.h> */
+
+/*
+ * This returns a constant expression while determining if an argument is
+ * a constant expression, most importantly without evaluating the argument.
+ * Glory to Martin Uecker <Martin.Uecker@med.uni-goettingen.de>
+ */
+#define __is_constexpr(x) \
+	(sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
+
+/*
+ * min()/max()/clamp() macros must accomplish three things:
+ *
+ * - avoid multiple evaluations of the arguments (so side-effects like
+ *   "x++" happen only once) when non-constant.
+ * - perform strict type-checking (to generate warnings instead of
+ *   nasty runtime surprises). See the "unnecessary" pointer comparison
+ *   in __typecheck().
+ * - retain result as a constant expressions when called with only
+ *   constant expressions (to avoid tripping VLA warnings in stack
+ *   allocation usage).
+ */
+#define __typecheck(x, y) \
+	(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
+
+#define __no_side_effects(x, y) \
+		(__is_constexpr(x) && __is_constexpr(y))
+
+#define __safe_cmp(x, y) \
+		(__typecheck(x, y) && __no_side_effects(x, y))
+
+#define __cmp(x, y, op)	((x) op (y) ? (x) : (y))
+
+#define __cmp_once(x, y, unique_x, unique_y, op) ({	\
+		typeof(x) unique_x = (x);		\
+		typeof(y) unique_y = (y);		\
+		__cmp(unique_x, unique_y, op); })
+
+#define __careful_cmp(x, y, op) \
+	__builtin_choose_expr(__safe_cmp(x, y), \
+		__cmp(x, y, op), \
+		__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
+
+/**
+ * min - return minimum of two values of the same or compatible types
+ * @x: first value
+ * @y: second value
+ */
+#define min(x, y)	__careful_cmp(x, y, <)
+
+/**
+ * max - return maximum of two values of the same or compatible types
+ * @x: first value
+ * @y: second value
+ */
+#define max(x, y)	__careful_cmp(x, y, >)
+
+#endif
diff --git a/arch/x86/boot/compressed/pgtable_types.h b/arch/x86/boot/compressed/pgtable_types.h
new file mode 100644
index 000000000000..8f1d87a69efc
--- /dev/null
+++ b/arch/x86/boot/compressed/pgtable_types.h
@@ -0,0 +1,25 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BOOT_COMPRESSED_PGTABLE_TYPES_H
+#define BOOT_COMPRESSED_PGTABLE_TYPES_H
+#define _ASM_X86_PGTABLE_DEFS_H /* Inhibit inclusion of <asm/pgtable_types.h> */
+
+#define PAGE_SHIFT	12
+
+#ifdef CONFIG_X86_64
+#define PTE_SHIFT	9
+#elif defined CONFIG_X86_PAE
+#define PTE_SHIFT	9
+#else /* 2-level */
+#define PTE_SHIFT	10
+#endif
+
+enum pg_level {
+	PG_LEVEL_NONE,
+	PG_LEVEL_4K,
+	PG_LEVEL_2M,
+	PG_LEVEL_1G,
+	PG_LEVEL_512G,
+	PG_LEVEL_NUM
+};
+
+#endif