[PATCH 09/16] xen/arm: Move fixmap definitions in a separate header

[Julien Grall <julien@xxxxxxx>]

From: Julien Grall <jgrall@xxxxxxxxxx>

To use properly the fixmap definitions, their user would need
also new to include <xen/acpi.h>. This is not very great when
the user itself is not meant to directly use ACPI definitions.

Including <xen/acpi.h> in <asm/config.h> is not option because
the latter header is included by everyone. So move out the fixmap
entries definition in a new header.

Take the opportunity to also move {set, clear}_fixmap() prototypes
in the new header.

Note that most of the definitions in <xen/acpi.h> now need to be
surrounded with #ifndef __ASSEMBLY__ because <asm/fixmap.h> will
be used in assembly (see EARLY_UART_VIRTUAL_ADDRESS).

The split will become more helpful in a follow-up patch where new
fixmap entries will be defined.

Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>

---
    There was some disagreement with Stefano on whether fixmap.h
    should include acpi.h or this should be the other way around.

    I chose the former because each components should decide how
    much entries in the fixmap they need and also because this is
    the current behavior on x86. We should stay consitent
    between arch to avoid any headers mess.

    Jan acked this patch, so I am assuming he is happy with this
    approach. I would be OK to rework it if others agree with
    Stefano's view.

    Changes in v4:
        - Add Jan's acked-by
        - Record Stefano's disagreement on the approach

    Changes in v3:
        - Patch added
---
 xen/arch/arm/acpi/lib.c                 |  2 ++
 xen/arch/arm/include/asm/config.h       |  6 ------
 xen/arch/arm/include/asm/early_printk.h |  1 +
 xen/arch/arm/include/asm/fixmap.h       | 24 ++++++++++++++++++++++++
 xen/arch/arm/include/asm/mm.h           |  4 ----
 xen/arch/arm/kernel.c                   |  1 +
 xen/arch/arm/mm.c                       |  1 +
 xen/include/xen/acpi.h                  | 18 +++++++++++-------
 8 files changed, 40 insertions(+), 17 deletions(-)
 create mode 100644 xen/arch/arm/include/asm/fixmap.h

diff --git a/xen/arch/arm/acpi/lib.c b/xen/arch/arm/acpi/lib.c
index a59cc4074cfb..41d521f720ac 100644
--- a/xen/arch/arm/acpi/lib.c
+++ b/xen/arch/arm/acpi/lib.c
@@ -25,6 +25,8 @@
 #include <xen/init.h>
 #include <xen/mm.h>
 
+#include <asm/fixmap.h>
+
 static bool fixmap_inuse;
 
 char *__acpi_map_table(paddr_t phys, unsigned long size)
diff --git a/xen/arch/arm/include/asm/config.h 
b/xen/arch/arm/include/asm/config.h
index b25c9d39bb32..3e2a55a91058 100644
--- a/xen/arch/arm/include/asm/config.h
+++ b/xen/arch/arm/include/asm/config.h
@@ -169,12 +169,6 @@
 
 #endif
 
-/* Fixmap slots */
-#define FIXMAP_CONSOLE  0  /* The primary UART */
-#define FIXMAP_MISC     1  /* Ephemeral mappings of hardware */
-#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 NR_hypercalls 64
 
 #define STACK_ORDER 3
diff --git a/xen/arch/arm/include/asm/early_printk.h 
b/xen/arch/arm/include/asm/early_printk.h
index 8dc911cf48a3..c5149b2976da 100644
--- a/xen/arch/arm/include/asm/early_printk.h
+++ b/xen/arch/arm/include/asm/early_printk.h
@@ -11,6 +11,7 @@
 #define __ARM_EARLY_PRINTK_H__
 
 #include <xen/page-size.h>
+#include <asm/fixmap.h>
 
 #ifdef CONFIG_EARLY_PRINTK
 
diff --git a/xen/arch/arm/include/asm/fixmap.h 
b/xen/arch/arm/include/asm/fixmap.h
new file mode 100644
index 000000000000..1cee51e52ab9
--- /dev/null
+++ b/xen/arch/arm/include/asm/fixmap.h
@@ -0,0 +1,24 @@
+/*
+ * fixmap.h: compile-time virtual memory allocation
+ */
+#ifndef __ASM_FIXMAP_H
+#define __ASM_FIXMAP_H
+
+#include <xen/acpi.h>
+
+/* Fixmap slots */
+#define FIXMAP_CONSOLE  0  /* The primary UART */
+#define FIXMAP_MISC     1  /* Ephemeral mappings of hardware */
+#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 */
+
+#ifndef __ASSEMBLY__
+
+/* Map a page in a fixmap entry */
+extern void set_fixmap(unsigned map, mfn_t mfn, unsigned attributes);
+/* Remove a mapping from a fixmap entry */
+extern void clear_fixmap(unsigned map);
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_FIXMAP_H */
diff --git a/xen/arch/arm/include/asm/mm.h b/xen/arch/arm/include/asm/mm.h
index 424aaf28230b..045a8ba4bb63 100644
--- a/xen/arch/arm/include/asm/mm.h
+++ b/xen/arch/arm/include/asm/mm.h
@@ -191,10 +191,6 @@ extern void mmu_init_secondary_cpu(void);
 extern void setup_xenheap_mappings(unsigned long base_mfn, unsigned long 
nr_mfns);
 /* Map a frame table to cover physical addresses ps through pe */
 extern void setup_frametable_mappings(paddr_t ps, paddr_t pe);
-/* Map a 4k page in a fixmap entry */
-extern void set_fixmap(unsigned map, mfn_t mfn, unsigned attributes);
-/* Remove a mapping from a fixmap entry */
-extern void clear_fixmap(unsigned map);
 /* map a physical range in virtual memory */
 void __iomem *ioremap_attr(paddr_t start, size_t len, unsigned attributes);
 
diff --git a/xen/arch/arm/kernel.c b/xen/arch/arm/kernel.c
index 8f43caa1866d..25ded1c056d9 100644
--- a/xen/arch/arm/kernel.c
+++ b/xen/arch/arm/kernel.c
@@ -15,6 +15,7 @@
 #include <xen/vmap.h>
 
 #include <asm/byteorder.h>
+#include <asm/fixmap.h>
 #include <asm/kernel.h>
 #include <asm/setup.h>
 
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 6b7b72de27fe..52b2a0394047 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -41,6 +41,7 @@
 #include <xen/sizes.h>
 #include <xen/libfdt/libfdt.h>
 
+#include <asm/fixmap.h>
 #include <asm/setup.h>
 
 /* Override macros from asm/page.h to make them work with mfn_t */
diff --git a/xen/include/xen/acpi.h b/xen/include/xen/acpi.h
index 39d51fcd01dd..1b9c75e68fc4 100644
--- a/xen/include/xen/acpi.h
+++ b/xen/include/xen/acpi.h
@@ -28,6 +28,15 @@
 #define _LINUX
 #endif
 
+/*
+ * Fixmap pages to reserve for ACPI boot-time tables (see
+ * arch/x86/include/asm/fixmap.h or arch/arm/include/asm/fixmap.h),
+ * 64 pages(256KB) is large enough for most cases.)
+ */
+#define NUM_FIXMAP_ACPI_PAGES  64
+
+#ifndef __ASSEMBLY__
+
 #include <xen/list.h>
 
 #include <acpi/acpi.h>
@@ -39,13 +48,6 @@
 #define ACPI_MADT_GET_POLARITY(inti)   ACPI_MADT_GET_(POLARITY, inti)
 #define ACPI_MADT_GET_TRIGGER(inti)    ACPI_MADT_GET_(TRIGGER, inti)
 
-/*
- * Fixmap pages to reserve for ACPI boot-time tables (see
- * arch/x86/include/asm/fixmap.h or arch/arm/include/asm/config.h,
- * 64 pages(256KB) is large enough for most cases.)
- */
-#define NUM_FIXMAP_ACPI_PAGES  64
-
 #define BAD_MADT_ENTRY(entry, end) (                                        \
                 (!(entry)) || (unsigned long)(entry) + sizeof(*(entry)) > 
(end) ||  \
                 (entry)->header.length < sizeof(*(entry)))
@@ -207,4 +209,6 @@ void acpi_reboot(void);
 void acpi_dmar_zap(void);
 void acpi_dmar_reinstate(void);
 
+#endif /* __ASSEMBLY__ */
+
 #endif /*_LINUX_ACPI_H*/
-- 
2.32.0