While reviewing Hongyan's "x86/vmap: handle superpages in
vmap_to_mfn()" it became apparent that the interaction of
xen/mm.h and asm/page.h is problematic. Therefore some basic
page size related definitions get moved out of the latter, and
the mfn_t et al ones out of the former, each into new headers.

While various configurations build fine for me with these
changes in place, it's relatively likely that this may break
some more exotic ones. Such breakage ought to be easy to
resolve, so I hope this risk isn't going to be a hindrance of
the changes here going in.

1: include: don't use asm/page.h from common headers
2: mm: split out mfn_t / gfn_t / pfn_t definitions and helpers

Jan

Doing so limits what can be done in (in particular included by) this per-
arch header. Abstract out page shift/size related #define-s, which is all
the respective headers care about. Extend the replacement / removal to
some x86 headers as well; some others now need to include page.h (and
they really should have before).

Arm's VADDR_BITS gets dropped altogether: Its current value is clearly
wrong for 64-bit, but the constant also isn't used anywhere right now.

While Arm used vaddr_t in PAGE_OFFSET(), this use is compatible with
that of unsigned long in the new common implementation.

Also drop the dead PAGE_FLAG_MASK at this occasion.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v2: Have just a single PAGE_OFFSET(). Rename per-arch headers to
    page-bits.h. Drop VADDR_BITS altogether for Arm.

--- a/xen/arch/arm/arm64/lib/clear_page.S
+++ b/xen/arch/arm/arm64/lib/clear_page.S
@@ -14,6 +14,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <xen/page-size.h>
+
 /*
  * Clear page @dest
  *
--- a/xen/include/asm-arm/config.h
+++ b/xen/include/asm-arm/config.h
@@ -176,11 +176,6 @@
 #define FIXMAP_ACPI_BEGIN  2  /* Start mappings of ACPI tables */
 #define FIXMAP_ACPI_END    (FIXMAP_ACPI_BEGIN + NUM_FIXMAP_ACPI_PAGES - 1)  /* End mappings of ACPI tables */
 
-#define PAGE_SHIFT              12
-#define PAGE_SIZE           (_AC(1,L) << PAGE_SHIFT)
-#define PAGE_MASK           (~(PAGE_SIZE-1))
-#define PAGE_FLAG_MASK      (~0)
-
 #define NR_hypercalls 64
 
 #define STACK_ORDER 3
--- a/xen/include/asm-arm/current.h
+++ b/xen/include/asm-arm/current.h
@@ -1,6 +1,7 @@
 #ifndef __ARM_CURRENT_H__
 #define __ARM_CURRENT_H__
 
+#include <xen/page-size.h>
 #include <xen/percpu.h>
 
 #include <asm/processor.h>
--- a/xen/include/asm-arm/page.h
+++ b/xen/include/asm-arm/page.h
@@ -2,21 +2,11 @@
 #define __ARM_PAGE_H__
 
 #include <public/xen.h>
+#include <xen/page-size.h>
 #include <asm/processor.h>
 #include <asm/lpae.h>
 #include <asm/sysregs.h>
 
-#ifdef CONFIG_ARM_64
-#define PADDR_BITS              48
-#else
-#define PADDR_BITS              40
-#endif
-#define PADDR_MASK              ((1ULL << PADDR_BITS)-1)
-#define PAGE_OFFSET(ptr)        ((vaddr_t)(ptr) & ~PAGE_MASK)
-
-#define VADDR_BITS              32
-#define VADDR_MASK              (~0UL)
-
 /* Shareability values for the LPAE entries */
 #define LPAE_SH_NON_SHAREABLE 0x0
 #define LPAE_SH_UNPREDICTALE  0x1
--- /dev/null
+++ b/xen/include/asm-arm/page-bits.h
@@ -0,0 +1,12 @@
+#ifndef __ARM_PAGE_SHIFT_H__
+#define __ARM_PAGE_SHIFT_H__
+
+#define PAGE_SHIFT              12
+
+#ifdef CONFIG_ARM_64
+#define PADDR_BITS              48
+#else
+#define PADDR_BITS              40
+#endif
+
+#endif /* __ARM_PAGE_SHIFT_H__ */
--- a/xen/include/asm-x86/current.h
+++ b/xen/include/asm-x86/current.h
@@ -8,8 +8,8 @@
 #define __X86_CURRENT_H__
 
 #include <xen/percpu.h>
+#include <xen/page-size.h>
 #include <public/xen.h>
-#include <asm/page.h>
 
 /*
  * Xen's cpu stacks are 8 pages (8-page aligned), arranged as:
--- a/xen/include/asm-x86/desc.h
+++ b/xen/include/asm-x86/desc.h
@@ -1,6 +1,8 @@
 #ifndef __ARCH_DESC_H
 #define __ARCH_DESC_H
 
+#include <asm/page.h>
+
 /*
  * Xen reserves a memory page of GDT entries.
  * No guest GDT entries exist beyond the Xen reserved area.
--- a/xen/include/asm-x86/fixmap.h
+++ b/xen/include/asm-x86/fixmap.h
@@ -12,7 +12,7 @@
 #ifndef _ASM_FIXMAP_H
 #define _ASM_FIXMAP_H
 
-#include <asm/page.h>
+#include <xen/page-size.h>
 
 #define FIXADDR_TOP (VMAP_VIRT_END - PAGE_SIZE)
 #define FIXADDR_X_TOP (XEN_VIRT_END - PAGE_SIZE)
--- a/xen/include/asm-x86/guest/hyperv-hcall.h
+++ b/xen/include/asm-x86/guest/hyperv-hcall.h
@@ -20,12 +20,12 @@
 #define __X86_HYPERV_HCALL_H__
 
 #include <xen/lib.h>
+#include <xen/page-size.h>
 #include <xen/types.h>
 
 #include <asm/asm_defns.h>
 #include <asm/fixmap.h>
 #include <asm/guest/hyperv-tlfs.h>
-#include <asm/page.h>
 
 static inline uint64_t hv_do_hypercall(uint64_t control, paddr_t input_addr,
                                        paddr_t output_addr)
--- a/xen/include/asm-x86/guest/hyperv-tlfs.h
+++ b/xen/include/asm-x86/guest/hyperv-tlfs.h
@@ -10,8 +10,8 @@
 #define _ASM_X86_HYPERV_TLFS_H
 
 #include <xen/bitops.h>
+#include <xen/page-size.h>
 #include <xen/types.h>
-#include <asm/page.h>
 
 /*
  * While not explicitly listed in the TLFS, Hyper-V always runs with a page size
--- a/xen/include/asm-x86/io.h
+++ b/xen/include/asm-x86/io.h
@@ -3,7 +3,6 @@
 
 #include <xen/vmap.h>
 #include <xen/types.h>
-#include <asm/page.h>
 
 #define readb(x) (*(volatile uint8_t  *)(x))
 #define readw(x) (*(volatile uint16_t *)(x))
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -6,6 +6,7 @@
 #include <xen/spinlock.h>
 #include <xen/rwlock.h>
 #include <asm/io.h>
+#include <asm/page.h>
 #include <asm/uaccess.h>
 #include <asm/x86_emulate.h>
 
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -2,15 +2,7 @@
 #define __X86_PAGE_H__
 
 #include <xen/const.h>
-
-/*
- * It is important that the masks are signed quantities. This ensures that
- * the compiler sign-extends a 32-bit mask to 64 bits if that is required.
- */
-#define PAGE_SIZE           (_AC(1,L) << PAGE_SHIFT)
-#define PAGE_MASK           (~(PAGE_SIZE-1))
-#define PAGE_FLAG_MASK      (~0)
-#define PAGE_OFFSET(ptr)    ((unsigned long)(ptr) & ~PAGE_MASK)
+#include <xen/page-size.h>
 
 #define PAGE_ORDER_4K       0
 #define PAGE_ORDER_2M       9
--- /dev/null
+++ b/xen/include/asm-x86/page-bits.h
@@ -0,0 +1,26 @@
+#ifndef __X86_PAGE_SHIFT_H__
+#define __X86_PAGE_SHIFT_H__
+
+#define L1_PAGETABLE_SHIFT      12
+#define L2_PAGETABLE_SHIFT      21
+#define L3_PAGETABLE_SHIFT      30
+#define L4_PAGETABLE_SHIFT      39
+#define PAGE_SHIFT              L1_PAGETABLE_SHIFT
+#define SUPERPAGE_SHIFT         L2_PAGETABLE_SHIFT
+#define ROOT_PAGETABLE_SHIFT    L4_PAGETABLE_SHIFT
+
+#define PAGETABLE_ORDER         9
+#define L1_PAGETABLE_ENTRIES    (1 << PAGETABLE_ORDER)
+#define L2_PAGETABLE_ENTRIES    (1 << PAGETABLE_ORDER)
+#define L3_PAGETABLE_ENTRIES    (1 << PAGETABLE_ORDER)
+#define L4_PAGETABLE_ENTRIES    (1 << PAGETABLE_ORDER)
+#define ROOT_PAGETABLE_ENTRIES  L4_PAGETABLE_ENTRIES
+
+#define SUPERPAGE_ORDER         PAGETABLE_ORDER
+#define SUPERPAGE_PAGES         (1 << SUPERPAGE_ORDER)
+
+/* These are architectural limits. */
+#define PADDR_BITS              52
+#define VADDR_BITS              48
+
+#endif /* __X86_PAGE_SHIFT_H__ */
--- a/xen/include/asm-x86/uaccess.h
+++ b/xen/include/asm-x86/uaccess.h
@@ -6,7 +6,6 @@
 #include <xen/errno.h>
 #include <xen/prefetch.h>
 #include <asm/asm_defns.h>
-#include <asm/page.h>
 
 #include <asm/x86_64/uaccess.h>
 
--- a/xen/include/asm-x86/x86_64/page.h
+++ b/xen/include/asm-x86/x86_64/page.h
@@ -2,31 +2,8 @@
 #ifndef __X86_64_PAGE_H__
 #define __X86_64_PAGE_H__
 
-#define L1_PAGETABLE_SHIFT      12
-#define L2_PAGETABLE_SHIFT      21
-#define L3_PAGETABLE_SHIFT      30
-#define L4_PAGETABLE_SHIFT      39
-#define PAGE_SHIFT              L1_PAGETABLE_SHIFT
-#define SUPERPAGE_SHIFT         L2_PAGETABLE_SHIFT
-#define ROOT_PAGETABLE_SHIFT    L4_PAGETABLE_SHIFT
-
-#define PAGETABLE_ORDER         9
-#define L1_PAGETABLE_ENTRIES    (1<<PAGETABLE_ORDER)
-#define L2_PAGETABLE_ENTRIES    (1<<PAGETABLE_ORDER)
-#define L3_PAGETABLE_ENTRIES    (1<<PAGETABLE_ORDER)
-#define L4_PAGETABLE_ENTRIES    (1<<PAGETABLE_ORDER)
-#define ROOT_PAGETABLE_ENTRIES  L4_PAGETABLE_ENTRIES
-#define SUPERPAGE_ORDER         PAGETABLE_ORDER
-#define SUPERPAGE_PAGES         (1<<SUPERPAGE_ORDER)
-
 #define __XEN_VIRT_START        XEN_VIRT_START
 
-/* These are architectural limits. Current CPUs support only 40-bit phys. */
-#define PADDR_BITS              52
-#define VADDR_BITS              48
-#define PADDR_MASK              ((_AC(1,UL) << PADDR_BITS) - 1)
-#define VADDR_MASK              ((_AC(1,UL) << VADDR_BITS) - 1)
-
 #define VADDR_TOP_BIT           (1UL << (VADDR_BITS - 1))
 #define CANONICAL_MASK          (~0UL & ~VADDR_MASK)
 
--- a/xen/include/xen/gdbstub.h
+++ b/xen/include/xen/gdbstub.h
@@ -20,8 +20,8 @@
 #ifndef __XEN_GDBSTUB_H__
 #define __XEN_GDBSTUB_H__
 
+#include <xen/page-size.h>
 #include <asm/atomic.h>
-#include <asm/page.h>
 
 #ifdef CONFIG_CRASH_DEBUG
 
--- a/xen/include/xen/grant_table.h
+++ b/xen/include/xen/grant_table.h
@@ -26,7 +26,6 @@
 #include <xen/mm.h>
 #include <xen/rwlock.h>
 #include <public/grant_table.h>
-#include <asm/page.h>
 #include <asm/grant_table.h>
 
 #ifdef CONFIG_GRANT_TABLE
--- /dev/null
+++ b/xen/include/xen/page-size.h
@@ -0,0 +1,18 @@
+#ifndef __XEN_PAGE_SIZE_H__
+#define __XEN_PAGE_SIZE_H__
+
+#include <xen/const.h>
+#include <asm/page-bits.h>
+
+/*
+ * It is important that the masks are signed quantities. This ensures that
+ * the compiler sign-extends a 32-bit mask to 64 bits if that is required.
+ */
+#define PAGE_SIZE           (_AC(1,L) << PAGE_SHIFT)
+#define PAGE_MASK           (~(PAGE_SIZE-1))
+#define PAGE_OFFSET(ptr)   ((unsigned long)(ptr) & ~PAGE_MASK)
+
+#define PADDR_MASK          ((_AC(1,ULL) << PADDR_BITS) - 1)
+#define VADDR_MASK          (~_AC(0,UL) >> (BITS_PER_LONG - VADDR_BITS))
+
+#endif /* __XEN_PAGE_SIZE__ */
--- a/xen/include/xen/pfn.h
+++ b/xen/include/xen/pfn.h
@@ -1,7 +1,7 @@
 #ifndef __XEN_PFN_H__
 #define __XEN_PFN_H__
 
-#include <asm/page.h>
+#include <xen/page-size.h>
 
 #define PFN_DOWN(x)   ((x) >> PAGE_SHIFT)
 #define PFN_UP(x)     (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
--- a/xen/include/xen/vmap.h
+++ b/xen/include/xen/vmap.h
@@ -2,7 +2,7 @@
 #define __XEN_VMAP_H__
 
 #include <xen/mm.h>
-#include <asm/page.h>
+#include <xen/page-size.h>
 
 enum vmap_region {
     VMAP_DEFAULT,

Hi Jan,

On 05/01/2021 12:37, Jan Beulich wrote:
> Doing so limits what can be done in (in particular included by) this per-
> arch header. Abstract out page shift/size related #define-s, which is all
> the respective headers care about. Extend the replacement / removal to
> some x86 headers as well; some others now need to include page.h (and
> they really should have before).
> 
> Arm's VADDR_BITS gets dropped altogether: Its current value is clearly
> wrong for 64-bit, but the constant also isn't used anywhere right now.
> 
> While Arm used vaddr_t in PAGE_OFFSET(), this use is compatible with
> that of unsigned long in the new common implementation.
> 
> Also drop the dead PAGE_FLAG_MASK at this occasion.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Julien Grall <jgrall@amazon.com>

Cheers,

> ---
> v2: Have just a single PAGE_OFFSET(). Rename per-arch headers to
>      page-bits.h. Drop VADDR_BITS altogether for Arm.
> 
> --- a/xen/arch/arm/arm64/lib/clear_page.S
> +++ b/xen/arch/arm/arm64/lib/clear_page.S
> @@ -14,6 +14,8 @@
>    * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>    */
>   
> +#include <xen/page-size.h>
> +
>   /*
>    * Clear page @dest
>    *
> --- a/xen/include/asm-arm/config.h
> +++ b/xen/include/asm-arm/config.h
> @@ -176,11 +176,6 @@
>   #define FIXMAP_ACPI_BEGIN  2  /* Start mappings of ACPI tables */
>   #define FIXMAP_ACPI_END    (FIXMAP_ACPI_BEGIN + NUM_FIXMAP_ACPI_PAGES - 1)  /* End mappings of ACPI tables */
>   
> -#define PAGE_SHIFT              12
> -#define PAGE_SIZE           (_AC(1,L) << PAGE_SHIFT)
> -#define PAGE_MASK           (~(PAGE_SIZE-1))
> -#define PAGE_FLAG_MASK      (~0)
> -
>   #define NR_hypercalls 64
>   
>   #define STACK_ORDER 3
> --- a/xen/include/asm-arm/current.h
> +++ b/xen/include/asm-arm/current.h
> @@ -1,6 +1,7 @@
>   #ifndef __ARM_CURRENT_H__
>   #define __ARM_CURRENT_H__
>   
> +#include <xen/page-size.h>
>   #include <xen/percpu.h>
>   
>   #include <asm/processor.h>
> --- a/xen/include/asm-arm/page.h
> +++ b/xen/include/asm-arm/page.h
> @@ -2,21 +2,11 @@
>   #define __ARM_PAGE_H__
>   
>   #include <public/xen.h>
> +#include <xen/page-size.h>
>   #include <asm/processor.h>
>   #include <asm/lpae.h>
>   #include <asm/sysregs.h>
>   
> -#ifdef CONFIG_ARM_64
> -#define PADDR_BITS              48
> -#else
> -#define PADDR_BITS              40
> -#endif
> -#define PADDR_MASK              ((1ULL << PADDR_BITS)-1)
> -#define PAGE_OFFSET(ptr)        ((vaddr_t)(ptr) & ~PAGE_MASK)
> -
> -#define VADDR_BITS              32
> -#define VADDR_MASK              (~0UL)
> -
>   /* Shareability values for the LPAE entries */
>   #define LPAE_SH_NON_SHAREABLE 0x0
>   #define LPAE_SH_UNPREDICTALE  0x1
> --- /dev/null
> +++ b/xen/include/asm-arm/page-bits.h
> @@ -0,0 +1,12 @@
> +#ifndef __ARM_PAGE_SHIFT_H__
> +#define __ARM_PAGE_SHIFT_H__
> +
> +#define PAGE_SHIFT              12
> +
> +#ifdef CONFIG_ARM_64
> +#define PADDR_BITS              48
> +#else
> +#define PADDR_BITS              40
> +#endif
> +
> +#endif /* __ARM_PAGE_SHIFT_H__ */
> --- a/xen/include/asm-x86/current.h
> +++ b/xen/include/asm-x86/current.h
> @@ -8,8 +8,8 @@
>   #define __X86_CURRENT_H__
>   
>   #include <xen/percpu.h>
> +#include <xen/page-size.h>
>   #include <public/xen.h>
> -#include <asm/page.h>
>   
>   /*
>    * Xen's cpu stacks are 8 pages (8-page aligned), arranged as:
> --- a/xen/include/asm-x86/desc.h
> +++ b/xen/include/asm-x86/desc.h
> @@ -1,6 +1,8 @@
>   #ifndef __ARCH_DESC_H
>   #define __ARCH_DESC_H
>   
> +#include <asm/page.h>
> +
>   /*
>    * Xen reserves a memory page of GDT entries.
>    * No guest GDT entries exist beyond the Xen reserved area.
> --- a/xen/include/asm-x86/fixmap.h
> +++ b/xen/include/asm-x86/fixmap.h
> @@ -12,7 +12,7 @@
>   #ifndef _ASM_FIXMAP_H
>   #define _ASM_FIXMAP_H
>   
> -#include <asm/page.h>
> +#include <xen/page-size.h>
>   
>   #define FIXADDR_TOP (VMAP_VIRT_END - PAGE_SIZE)
>   #define FIXADDR_X_TOP (XEN_VIRT_END - PAGE_SIZE)
> --- a/xen/include/asm-x86/guest/hyperv-hcall.h
> +++ b/xen/include/asm-x86/guest/hyperv-hcall.h
> @@ -20,12 +20,12 @@
>   #define __X86_HYPERV_HCALL_H__
>   
>   #include <xen/lib.h>
> +#include <xen/page-size.h>
>   #include <xen/types.h>
>   
>   #include <asm/asm_defns.h>
>   #include <asm/fixmap.h>
>   #include <asm/guest/hyperv-tlfs.h>
> -#include <asm/page.h>
>   
>   static inline uint64_t hv_do_hypercall(uint64_t control, paddr_t input_addr,
>                                          paddr_t output_addr)
> --- a/xen/include/asm-x86/guest/hyperv-tlfs.h
> +++ b/xen/include/asm-x86/guest/hyperv-tlfs.h
> @@ -10,8 +10,8 @@
>   #define _ASM_X86_HYPERV_TLFS_H
>   
>   #include <xen/bitops.h>
> +#include <xen/page-size.h>
>   #include <xen/types.h>
> -#include <asm/page.h>
>   
>   /*
>    * While not explicitly listed in the TLFS, Hyper-V always runs with a page size
> --- a/xen/include/asm-x86/io.h
> +++ b/xen/include/asm-x86/io.h
> @@ -3,7 +3,6 @@
>   
>   #include <xen/vmap.h>
>   #include <xen/types.h>
> -#include <asm/page.h>
>   
>   #define readb(x) (*(volatile uint8_t  *)(x))
>   #define readw(x) (*(volatile uint16_t *)(x))
> --- a/xen/include/asm-x86/mm.h
> +++ b/xen/include/asm-x86/mm.h
> @@ -6,6 +6,7 @@
>   #include <xen/spinlock.h>
>   #include <xen/rwlock.h>
>   #include <asm/io.h>
> +#include <asm/page.h>
>   #include <asm/uaccess.h>
>   #include <asm/x86_emulate.h>
>   
> --- a/xen/include/asm-x86/page.h
> +++ b/xen/include/asm-x86/page.h
> @@ -2,15 +2,7 @@
>   #define __X86_PAGE_H__
>   
>   #include <xen/const.h>
> -
> -/*
> - * It is important that the masks are signed quantities. This ensures that
> - * the compiler sign-extends a 32-bit mask to 64 bits if that is required.
> - */
> -#define PAGE_SIZE           (_AC(1,L) << PAGE_SHIFT)
> -#define PAGE_MASK           (~(PAGE_SIZE-1))
> -#define PAGE_FLAG_MASK      (~0)
> -#define PAGE_OFFSET(ptr)    ((unsigned long)(ptr) & ~PAGE_MASK)
> +#include <xen/page-size.h>
>   
>   #define PAGE_ORDER_4K       0
>   #define PAGE_ORDER_2M       9
> --- /dev/null
> +++ b/xen/include/asm-x86/page-bits.h
> @@ -0,0 +1,26 @@
> +#ifndef __X86_PAGE_SHIFT_H__
> +#define __X86_PAGE_SHIFT_H__
> +
> +#define L1_PAGETABLE_SHIFT      12
> +#define L2_PAGETABLE_SHIFT      21
> +#define L3_PAGETABLE_SHIFT      30
> +#define L4_PAGETABLE_SHIFT      39
> +#define PAGE_SHIFT              L1_PAGETABLE_SHIFT
> +#define SUPERPAGE_SHIFT         L2_PAGETABLE_SHIFT
> +#define ROOT_PAGETABLE_SHIFT    L4_PAGETABLE_SHIFT
> +
> +#define PAGETABLE_ORDER         9
> +#define L1_PAGETABLE_ENTRIES    (1 << PAGETABLE_ORDER)
> +#define L2_PAGETABLE_ENTRIES    (1 << PAGETABLE_ORDER)
> +#define L3_PAGETABLE_ENTRIES    (1 << PAGETABLE_ORDER)
> +#define L4_PAGETABLE_ENTRIES    (1 << PAGETABLE_ORDER)
> +#define ROOT_PAGETABLE_ENTRIES  L4_PAGETABLE_ENTRIES
> +
> +#define SUPERPAGE_ORDER         PAGETABLE_ORDER
> +#define SUPERPAGE_PAGES         (1 << SUPERPAGE_ORDER)
> +
> +/* These are architectural limits. */
> +#define PADDR_BITS              52
> +#define VADDR_BITS              48
> +
> +#endif /* __X86_PAGE_SHIFT_H__ */
> --- a/xen/include/asm-x86/uaccess.h
> +++ b/xen/include/asm-x86/uaccess.h
> @@ -6,7 +6,6 @@
>   #include <xen/errno.h>
>   #include <xen/prefetch.h>
>   #include <asm/asm_defns.h>
> -#include <asm/page.h>
>   
>   #include <asm/x86_64/uaccess.h>
>   
> --- a/xen/include/asm-x86/x86_64/page.h
> +++ b/xen/include/asm-x86/x86_64/page.h
> @@ -2,31 +2,8 @@
>   #ifndef __X86_64_PAGE_H__
>   #define __X86_64_PAGE_H__
>   
> -#define L1_PAGETABLE_SHIFT      12
> -#define L2_PAGETABLE_SHIFT      21
> -#define L3_PAGETABLE_SHIFT      30
> -#define L4_PAGETABLE_SHIFT      39
> -#define PAGE_SHIFT              L1_PAGETABLE_SHIFT
> -#define SUPERPAGE_SHIFT         L2_PAGETABLE_SHIFT
> -#define ROOT_PAGETABLE_SHIFT    L4_PAGETABLE_SHIFT
> -
> -#define PAGETABLE_ORDER         9
> -#define L1_PAGETABLE_ENTRIES    (1<<PAGETABLE_ORDER)
> -#define L2_PAGETABLE_ENTRIES    (1<<PAGETABLE_ORDER)
> -#define L3_PAGETABLE_ENTRIES    (1<<PAGETABLE_ORDER)
> -#define L4_PAGETABLE_ENTRIES    (1<<PAGETABLE_ORDER)
> -#define ROOT_PAGETABLE_ENTRIES  L4_PAGETABLE_ENTRIES
> -#define SUPERPAGE_ORDER         PAGETABLE_ORDER
> -#define SUPERPAGE_PAGES         (1<<SUPERPAGE_ORDER)
> -
>   #define __XEN_VIRT_START        XEN_VIRT_START
>   
> -/* These are architectural limits. Current CPUs support only 40-bit phys. */
> -#define PADDR_BITS              52
> -#define VADDR_BITS              48
> -#define PADDR_MASK              ((_AC(1,UL) << PADDR_BITS) - 1)
> -#define VADDR_MASK              ((_AC(1,UL) << VADDR_BITS) - 1)
> -
>   #define VADDR_TOP_BIT           (1UL << (VADDR_BITS - 1))
>   #define CANONICAL_MASK          (~0UL & ~VADDR_MASK)
>   
> --- a/xen/include/xen/gdbstub.h
> +++ b/xen/include/xen/gdbstub.h
> @@ -20,8 +20,8 @@
>   #ifndef __XEN_GDBSTUB_H__
>   #define __XEN_GDBSTUB_H__
>   
> +#include <xen/page-size.h>
>   #include <asm/atomic.h>
> -#include <asm/page.h>
>   
>   #ifdef CONFIG_CRASH_DEBUG
>   
> --- a/xen/include/xen/grant_table.h
> +++ b/xen/include/xen/grant_table.h
> @@ -26,7 +26,6 @@
>   #include <xen/mm.h>
>   #include <xen/rwlock.h>
>   #include <public/grant_table.h>
> -#include <asm/page.h>
>   #include <asm/grant_table.h>
>   
>   #ifdef CONFIG_GRANT_TABLE
> --- /dev/null
> +++ b/xen/include/xen/page-size.h
> @@ -0,0 +1,18 @@
> +#ifndef __XEN_PAGE_SIZE_H__
> +#define __XEN_PAGE_SIZE_H__
> +
> +#include <xen/const.h>
> +#include <asm/page-bits.h>
> +
> +/*
> + * It is important that the masks are signed quantities. This ensures that
> + * the compiler sign-extends a 32-bit mask to 64 bits if that is required.
> + */
> +#define PAGE_SIZE           (_AC(1,L) << PAGE_SHIFT)
> +#define PAGE_MASK           (~(PAGE_SIZE-1))
> +#define PAGE_OFFSET(ptr)   ((unsigned long)(ptr) & ~PAGE_MASK)
> +
> +#define PADDR_MASK          ((_AC(1,ULL) << PADDR_BITS) - 1)
> +#define VADDR_MASK          (~_AC(0,UL) >> (BITS_PER_LONG - VADDR_BITS))
> +
> +#endif /* __XEN_PAGE_SIZE__ */
> --- a/xen/include/xen/pfn.h
> +++ b/xen/include/xen/pfn.h
> @@ -1,7 +1,7 @@
>   #ifndef __XEN_PFN_H__
>   #define __XEN_PFN_H__
>   
> -#include <asm/page.h>
> +#include <xen/page-size.h>
>   
>   #define PFN_DOWN(x)   ((x) >> PAGE_SHIFT)
>   #define PFN_UP(x)     (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
> --- a/xen/include/xen/vmap.h
> +++ b/xen/include/xen/vmap.h
> @@ -2,7 +2,7 @@
>   #define __XEN_VMAP_H__
>   
>   #include <xen/mm.h>
> -#include <asm/page.h>
> +#include <xen/page-size.h>
>   
>   enum vmap_region {
>       VMAP_DEFAULT,
> 

-- 
Julien Grall

xen/mm.h has heavy dependencies, while in a number of cases only these
type definitions are needed. This separation then also allows pulling in
these definitions when including xen/mm.h would cause cyclic
dependencies.

Replace xen/mm.h inclusion where possible in include/xen/. (In
xen/iommu.h also take the opportunity and correct the few remaining
sorting issues.)

While the change could be dropped, remove an unnecessary asm/io.h
inclusion from xen/arch/x86/acpi/power.c. This was the initial attempt
to address build issues with it, until it became clear that the header
itself needs adjustment.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v2: Rename header to mm-frame.h.

--- a/xen/arch/x86/acpi/power.c
+++ b/xen/arch/x86/acpi/power.c
@@ -10,7 +10,6 @@
  * Slimmed with Xen specific support.
  */
 
-#include <asm/io.h>
 #include <xen/acpi.h>
 #include <xen/errno.h>
 #include <xen/iocap.h>
--- a/xen/drivers/char/meson-uart.c
+++ b/xen/drivers/char/meson-uart.c
@@ -18,7 +18,9 @@
  * License along with this program; If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <xen/errno.h>
 #include <xen/irq.h>
+#include <xen/mm.h>
 #include <xen/serial.h>
 #include <xen/vmap.h>
 #include <asm/io.h>
--- a/xen/drivers/char/mvebu-uart.c
+++ b/xen/drivers/char/mvebu-uart.c
@@ -18,7 +18,9 @@
  * License along with this program; If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <xen/errno.h>
 #include <xen/irq.h>
+#include <xen/mm.h>
 #include <xen/serial.h>
 #include <xen/vmap.h>
 #include <asm/io.h>
--- a/xen/include/asm-x86/io.h
+++ b/xen/include/asm-x86/io.h
@@ -49,6 +49,7 @@ __OUT(l,,int)
 
 /* Function pointer used to handle platform specific I/O port emulation. */
 #define IOEMUL_QUIRK_STUB_BYTES 9
+struct cpu_user_regs;
 extern unsigned int (*ioemul_handle_quirk)(
     u8 opcode, char *io_emul_stub, struct cpu_user_regs *regs);
 
--- a/xen/include/xen/grant_table.h
+++ b/xen/include/xen/grant_table.h
@@ -23,7 +23,7 @@
 #ifndef __XEN_GRANT_TABLE_H__
 #define __XEN_GRANT_TABLE_H__
 
-#include <xen/mm.h>
+#include <xen/mm-frame.h>
 #include <xen/rwlock.h>
 #include <public/grant_table.h>
 #include <asm/grant_table.h>
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -19,14 +19,13 @@
 #ifndef _IOMMU_H_
 #define _IOMMU_H_
 
+#include <xen/mm-frame.h>
 #include <xen/init.h>
 #include <xen/page-defs.h>
-#include <xen/spinlock.h>
 #include <xen/pci.h>
-#include <xen/typesafe.h>
-#include <xen/mm.h>
-#include <public/hvm/ioreq.h>
+#include <xen/spinlock.h>
 #include <public/domctl.h>
+#include <public/hvm/ioreq.h>
 #include <asm/device.h>
 
 TYPE_SAFE(uint64_t, dfn);
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -51,103 +51,13 @@
 #define __XEN_MM_H__
 
 #include <xen/compiler.h>
+#include <xen/mm-frame.h>
 #include <xen/types.h>
 #include <xen/list.h>
 #include <xen/spinlock.h>
-#include <xen/typesafe.h>
-#include <xen/kernel.h>
 #include <xen/perfc.h>
 #include <public/memory.h>
 
-TYPE_SAFE(unsigned long, mfn);
-#define PRI_mfn          "05lx"
-#define INVALID_MFN      _mfn(~0UL)
-/*
- * To be used for global variable initialization. This workaround a bug
- * in GCC < 5.0.
- */
-#define INVALID_MFN_INITIALIZER { ~0UL }
-
-#ifndef mfn_t
-#define mfn_t /* Grep fodder: mfn_t, _mfn() and mfn_x() are defined above */
-#define _mfn
-#define mfn_x
-#undef mfn_t
-#undef _mfn
-#undef mfn_x
-#endif
-
-static inline mfn_t mfn_add(mfn_t mfn, unsigned long i)
-{
-    return _mfn(mfn_x(mfn) + i);
-}
-
-static inline mfn_t mfn_max(mfn_t x, mfn_t y)
-{
-    return _mfn(max(mfn_x(x), mfn_x(y)));
-}
-
-static inline mfn_t mfn_min(mfn_t x, mfn_t y)
-{
-    return _mfn(min(mfn_x(x), mfn_x(y)));
-}
-
-static inline bool_t mfn_eq(mfn_t x, mfn_t y)
-{
-    return mfn_x(x) == mfn_x(y);
-}
-
-TYPE_SAFE(unsigned long, gfn);
-#define PRI_gfn          "05lx"
-#define INVALID_GFN      _gfn(~0UL)
-/*
- * To be used for global variable initialization. This workaround a bug
- * in GCC < 5.0 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64856
- */
-#define INVALID_GFN_INITIALIZER { ~0UL }
-
-#ifndef gfn_t
-#define gfn_t /* Grep fodder: gfn_t, _gfn() and gfn_x() are defined above */
-#define _gfn
-#define gfn_x
-#undef gfn_t
-#undef _gfn
-#undef gfn_x
-#endif
-
-static inline gfn_t gfn_add(gfn_t gfn, unsigned long i)
-{
-    return _gfn(gfn_x(gfn) + i);
-}
-
-static inline gfn_t gfn_max(gfn_t x, gfn_t y)
-{
-    return _gfn(max(gfn_x(x), gfn_x(y)));
-}
-
-static inline gfn_t gfn_min(gfn_t x, gfn_t y)
-{
-    return _gfn(min(gfn_x(x), gfn_x(y)));
-}
-
-static inline bool_t gfn_eq(gfn_t x, gfn_t y)
-{
-    return gfn_x(x) == gfn_x(y);
-}
-
-TYPE_SAFE(unsigned long, pfn);
-#define PRI_pfn          "05lx"
-#define INVALID_PFN      (~0UL)
-
-#ifndef pfn_t
-#define pfn_t /* Grep fodder: pfn_t, _pfn() and pfn_x() are defined above */
-#define _pfn
-#define pfn_x
-#undef pfn_t
-#undef _pfn
-#undef pfn_x
-#endif
-
 struct page_info;
 
 void put_page(struct page_info *);
--- /dev/null
+++ b/xen/include/xen/mm-frame.h
@@ -0,0 +1,96 @@
+#ifndef __XEN_FRAME_NUM_H__
+#define __XEN_FRAME_NUM_H__
+
+#include <xen/kernel.h>
+#include <xen/typesafe.h>
+
+TYPE_SAFE(unsigned long, mfn);
+#define PRI_mfn          "05lx"
+#define INVALID_MFN      _mfn(~0UL)
+/*
+ * To be used for global variable initialization. This workaround a bug
+ * in GCC < 5.0.
+ */
+#define INVALID_MFN_INITIALIZER { ~0UL }
+
+#ifndef mfn_t
+#define mfn_t /* Grep fodder: mfn_t, _mfn() and mfn_x() are defined above */
+#define _mfn
+#define mfn_x
+#undef mfn_t
+#undef _mfn
+#undef mfn_x
+#endif
+
+static inline mfn_t mfn_add(mfn_t mfn, unsigned long i)
+{
+    return _mfn(mfn_x(mfn) + i);
+}
+
+static inline mfn_t mfn_max(mfn_t x, mfn_t y)
+{
+    return _mfn(max(mfn_x(x), mfn_x(y)));
+}
+
+static inline mfn_t mfn_min(mfn_t x, mfn_t y)
+{
+    return _mfn(min(mfn_x(x), mfn_x(y)));
+}
+
+static inline bool_t mfn_eq(mfn_t x, mfn_t y)
+{
+    return mfn_x(x) == mfn_x(y);
+}
+
+TYPE_SAFE(unsigned long, gfn);
+#define PRI_gfn          "05lx"
+#define INVALID_GFN      _gfn(~0UL)
+/*
+ * To be used for global variable initialization. This workaround a bug
+ * in GCC < 5.0 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64856
+ */
+#define INVALID_GFN_INITIALIZER { ~0UL }
+
+#ifndef gfn_t
+#define gfn_t /* Grep fodder: gfn_t, _gfn() and gfn_x() are defined above */
+#define _gfn
+#define gfn_x
+#undef gfn_t
+#undef _gfn
+#undef gfn_x
+#endif
+
+static inline gfn_t gfn_add(gfn_t gfn, unsigned long i)
+{
+    return _gfn(gfn_x(gfn) + i);
+}
+
+static inline gfn_t gfn_max(gfn_t x, gfn_t y)
+{
+    return _gfn(max(gfn_x(x), gfn_x(y)));
+}
+
+static inline gfn_t gfn_min(gfn_t x, gfn_t y)
+{
+    return _gfn(min(gfn_x(x), gfn_x(y)));
+}
+
+static inline bool_t gfn_eq(gfn_t x, gfn_t y)
+{
+    return gfn_x(x) == gfn_x(y);
+}
+
+TYPE_SAFE(unsigned long, pfn);
+#define PRI_pfn          "05lx"
+#define INVALID_PFN      (~0UL)
+
+#ifndef pfn_t
+#define pfn_t /* Grep fodder: pfn_t, _pfn() and pfn_x() are defined above */
+#define _pfn
+#define pfn_x
+#undef pfn_t
+#undef _pfn
+#undef pfn_x
+#endif
+
+#endif /* __XEN_FRAME_NUM_H__ */
--- a/xen/include/xen/p2m-common.h
+++ b/xen/include/xen/p2m-common.h
@@ -1,7 +1,7 @@
 #ifndef _XEN_P2M_COMMON_H
 #define _XEN_P2M_COMMON_H
 
-#include <xen/mm.h>
+#include <xen/mm-frame.h>
 
 /* Remove a page from a domain's p2m table */
 int __must_check
--- a/xen/include/xen/vmap.h
+++ b/xen/include/xen/vmap.h
@@ -1,7 +1,7 @@
 #if !defined(__XEN_VMAP_H__) && defined(VMAP_VIRT_START)
 #define __XEN_VMAP_H__
 
-#include <xen/mm.h>
+#include <xen/mm-frame.h>
 #include <xen/page-size.h>
 
 enum vmap_region {

Hi Jan,

On 05/01/2021 12:38, Jan Beulich wrote:
> xen/mm.h has heavy dependencies, while in a number of cases only these
> type definitions are needed. This separation then also allows pulling in
> these definitions when including xen/mm.h would cause cyclic
> dependencies.
> 
> Replace xen/mm.h inclusion where possible in include/xen/. (In
> xen/iommu.h also take the opportunity and correct the few remaining
> sorting issues.)
> 
> While the change could be dropped, remove an unnecessary asm/io.h
> inclusion from xen/arch/x86/acpi/power.c. This was the initial attempt
> to address build issues with it, until it became clear that the header
> itself needs adjustment.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Julien Grall <jgrall@amazon.com>

Cheers,

-- 
Julien Grall