[PATCH 0/2] Make arm64 headers self-contained

[PATCH 0/2] Make arm64 headers self-contained

[Marc Zyngier]

Wookey recently reported that the arm64 headers are not
self-contained, making it impossible to build external kernel modules
using DKMS and a distribution kernel-headers package. I do not condone
the use of out of tree modules, but there is no reason to be more
awkward than strictly necessary, and having standalone headers seems
to be a reasonable requirement.

The offenders are asm/opcodes.h, which drags its 32bit counterpart
despite only requiring a handful of macros, and a bunch of Xen files
that directly include their 32bit equivalent.

This series solves the issue in two ways:

- asm/opcodes.h is killed, and the few required macros moved added at
  the required locations

- asm/xen/* are brutally copied oved. It'd be better if they were
  placed in a common location (include/xen/ ?), but at least that
  solves it for now

Patches on top of -rc6.

Marc Zyngier (2):
  arm64: Get rid of asm/opcodes.h
  arm64: xen: Split architecture-specific headers from 32bit ARM

 arch/arm64/include/asm/opcodes.h           |   5 --
 arch/arm64/include/asm/sysreg.h            |  16 ++--
 arch/arm64/include/asm/xen/hypercall.h     |  88 ++++++++++++++++++++-
 arch/arm64/include/asm/xen/hypervisor.h    |  40 +++++++++-
 arch/arm64/include/asm/xen/interface.h     |  86 +++++++++++++++++++-
 arch/arm64/include/asm/xen/page-coherent.h |  99 ++++++++++++++++++++++-
 arch/arm64/include/asm/xen/page.h          | 123 ++++++++++++++++++++++++++++-
 arch/arm64/kernel/armv8_deprecated.c       |   5 +-
 arch/arm64/kernel/insn.c                   |   1 -
 9 files changed, 445 insertions(+), 18 deletions(-)
 delete mode 100644 arch/arm64/include/asm/opcodes.h

-- 
2.1.4

[PATCH 1/2] arm64: Get rid of asm/opcodes.h

[Marc Zyngier]

The opcodes.h drags in a lot of definition from the 32bit port, most
of which is not required at all. Clean things up a bit by moving
the bare minimum of what is required next to the actual users,
and drop the include file.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm64/include/asm/opcodes.h     |  5 -----
 arch/arm64/include/asm/sysreg.h      | 16 ++++++++++------
 arch/arm64/kernel/armv8_deprecated.c |  5 ++++-
 arch/arm64/kernel/insn.c             |  1 -
 4 files changed, 14 insertions(+), 13 deletions(-)
 delete mode 100644 arch/arm64/include/asm/opcodes.h

diff --git a/arch/arm64/include/asm/opcodes.h b/arch/arm64/include/asm/opcodes.h
deleted file mode 100644
index 123f45d..0000000
--- a/arch/arm64/include/asm/opcodes.h
+++ /dev/null
@@ -1,5 +0,0 @@
-#ifdef CONFIG_CPU_BIG_ENDIAN
-#define CONFIG_CPU_ENDIAN_BE8 CONFIG_CPU_BIG_ENDIAN
-#endif
-
-#include <../../arm/include/asm/opcodes.h>
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 6c80b36..9e16a18 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -22,8 +22,6 @@
 
 #include <linux/stringify.h>
 
-#include <asm/opcodes.h>
-
 /*
  * ARMv8 ARM reserves the following encoding for system registers:
  * (Ref: ARMv8 ARM, Section: "System instruction class encoding overview",
@@ -37,6 +35,12 @@
 #define sys_reg(op0, op1, crn, crm, op2) \
 	((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5))
 
+#ifdef __ASSEMBLY__
+#define __emit_inst(x)			.inst (x)
+#else
+#define __emit_inst(x)			".inst " __stringify((x)) "\n\t"
+#endif
+
 #define SYS_MIDR_EL1			sys_reg(3, 0, 0, 0, 0)
 #define SYS_MPIDR_EL1			sys_reg(3, 0, 0, 0, 5)
 #define SYS_REVIDR_EL1			sys_reg(3, 0, 0, 0, 6)
@@ -81,10 +85,10 @@
 #define REG_PSTATE_PAN_IMM		sys_reg(0, 0, 4, 0, 4)
 #define REG_PSTATE_UAO_IMM		sys_reg(0, 0, 4, 0, 3)
 
-#define SET_PSTATE_PAN(x) __inst_arm(0xd5000000 | REG_PSTATE_PAN_IMM |\
-				     (!!x)<<8 | 0x1f)
-#define SET_PSTATE_UAO(x) __inst_arm(0xd5000000 | REG_PSTATE_UAO_IMM |\
-				     (!!x)<<8 | 0x1f)
+#define SET_PSTATE_PAN(x) __emit_inst(0xd5000000 | REG_PSTATE_PAN_IMM |	\
+				      (!!x)<<8 | 0x1f)
+#define SET_PSTATE_UAO(x) __emit_inst(0xd5000000 | REG_PSTATE_UAO_IMM |	\
+				      (!!x)<<8 | 0x1f)
 
 /* Common SCTLR_ELx flags. */
 #define SCTLR_ELx_EE    (1 << 25)
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index b0988bb..567c397 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -17,7 +17,6 @@
 #include <asm/alternative.h>
 #include <asm/cpufeature.h>
 #include <asm/insn.h>
-#include <asm/opcodes.h>
 #include <asm/sysreg.h>
 #include <asm/system_misc.h>
 #include <asm/traps.h>
@@ -352,6 +351,10 @@ static int emulate_swpX(unsigned int address, unsigned int *data,
 	return res;
 }
 
+#define ARM_OPCODE_CONDTEST_FAIL   0
+#define ARM_OPCODE_CONDTEST_PASS   1
+#define ARM_OPCODE_CONDTEST_UNCOND 2
+
 #define	ARM_OPCODE_CONDITION_UNCOND	0xf
 
 static unsigned int __kprobes aarch32_check_condition(u32 opcode, u32 psr)
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index 6f2ac4f..94b62c1 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -30,7 +30,6 @@
 #include <asm/cacheflush.h>
 #include <asm/debug-monitors.h>
 #include <asm/fixmap.h>
-#include <asm/opcodes.h>
 #include <asm/insn.h>
 
 #define AARCH64_INSN_SF_BIT	BIT(31)
-- 
2.1.4

[PATCH 1/2] arm64: Get rid of asm/opcodes.h

[Catalin Marinas]

On Thu, Dec 01, 2016 at 10:44:33AM +0000, Marc Zyngier wrote:
> The opcodes.h drags in a lot of definition from the 32bit port, most
> of which is not required at all. Clean things up a bit by moving
> the bare minimum of what is required next to the actual users,
> and drop the include file.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  arch/arm64/include/asm/opcodes.h     |  5 -----
>  arch/arm64/include/asm/sysreg.h      | 16 ++++++++++------
>  arch/arm64/kernel/armv8_deprecated.c |  5 ++++-
>  arch/arm64/kernel/insn.c             |  1 -

I applied the first patch. I assume the second one, once it gets into
its final shape, will be merged via the Xen tree.

Thanks.

-- 
Catalin

[PATCH 1/2] arm64: Get rid of asm/opcodes.h

[Stefano Stabellini]

On Fri, 2 Dec 2016, Catalin Marinas wrote:
> On Thu, Dec 01, 2016 at 10:44:33AM +0000, Marc Zyngier wrote:
> > The opcodes.h drags in a lot of definition from the 32bit port, most
> > of which is not required at all. Clean things up a bit by moving
> > the bare minimum of what is required next to the actual users,
> > and drop the include file.
> > 
> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> > ---
> >  arch/arm64/include/asm/opcodes.h     |  5 -----
> >  arch/arm64/include/asm/sysreg.h      | 16 ++++++++++------
> >  arch/arm64/kernel/armv8_deprecated.c |  5 ++++-
> >  arch/arm64/kernel/insn.c             |  1 -
> 
> I applied the first patch. I assume the second one, once it gets into
> its final shape, will be merged via the Xen tree.

Sure

[PATCH 2/2] arm64: xen: Split architecture-specific headers from 32bit ARM

[Marc Zyngier]

ARM and arm64 Xen ports share a number of headers, leading to
packaging issues when these headers needs to be exported, as it
breaks the reasonable requirement that an architecture port
is standalone.

Solve the issue by copying the 5 header files over the arch
barrier.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm64/include/asm/xen/hypercall.h     |  88 ++++++++++++++++++++-
 arch/arm64/include/asm/xen/hypervisor.h    |  40 +++++++++-
 arch/arm64/include/asm/xen/interface.h     |  86 +++++++++++++++++++-
 arch/arm64/include/asm/xen/page-coherent.h |  99 ++++++++++++++++++++++-
 arch/arm64/include/asm/xen/page.h          | 123 ++++++++++++++++++++++++++++-
 5 files changed, 431 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/xen/hypercall.h b/arch/arm64/include/asm/xen/hypercall.h
index 74b0c42..9d874db 100644
--- a/arch/arm64/include/asm/xen/hypercall.h
+++ b/arch/arm64/include/asm/xen/hypercall.h
@@ -1 +1,87 @@
-#include <../../arm/include/asm/xen/hypercall.h>
+/******************************************************************************
+ * hypercall.h
+ *
+ * Linux-specific hypervisor handling.
+ *
+ * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef _ASM_ARM_XEN_HYPERCALL_H
+#define _ASM_ARM_XEN_HYPERCALL_H
+
+#include <linux/bug.h>
+
+#include <xen/interface/xen.h>
+#include <xen/interface/sched.h>
+#include <xen/interface/platform.h>
+
+long privcmd_call(unsigned call, unsigned long a1,
+		unsigned long a2, unsigned long a3,
+		unsigned long a4, unsigned long a5);
+int HYPERVISOR_xen_version(int cmd, void *arg);
+int HYPERVISOR_console_io(int cmd, int count, char *str);
+int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count);
+int HYPERVISOR_sched_op(int cmd, void *arg);
+int HYPERVISOR_event_channel_op(int cmd, void *arg);
+unsigned long HYPERVISOR_hvm_op(int op, void *arg);
+int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
+int HYPERVISOR_physdev_op(int cmd, void *arg);
+int HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args);
+int HYPERVISOR_tmem_op(void *arg);
+int HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type);
+int HYPERVISOR_platform_op_raw(void *arg);
+static inline int HYPERVISOR_platform_op(struct xen_platform_op *op)
+{
+	op->interface_version = XENPF_INTERFACE_VERSION;
+	return HYPERVISOR_platform_op_raw(op);
+}
+int HYPERVISOR_multicall(struct multicall_entry *calls, uint32_t nr);
+
+static inline int
+HYPERVISOR_suspend(unsigned long start_info_mfn)
+{
+	struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
+
+	/* start_info_mfn is unused on ARM */
+	return HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
+}
+
+static inline void
+MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
+			unsigned int new_val, unsigned long flags)
+{
+	BUG();
+}
+
+static inline void
+MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
+		 int count, int *success_count, domid_t domid)
+{
+	BUG();
+}
+
+#endif /* _ASM_ARM_XEN_HYPERCALL_H */
diff --git a/arch/arm64/include/asm/xen/hypervisor.h b/arch/arm64/include/asm/xen/hypervisor.h
index f263da8..9525151 100644
--- a/arch/arm64/include/asm/xen/hypervisor.h
+++ b/arch/arm64/include/asm/xen/hypervisor.h
@@ -1 +1,39 @@
-#include <../../arm/include/asm/xen/hypervisor.h>
+#ifndef _ASM_ARM_XEN_HYPERVISOR_H
+#define _ASM_ARM_XEN_HYPERVISOR_H
+
+#include <linux/init.h>
+
+extern struct shared_info *HYPERVISOR_shared_info;
+extern struct start_info *xen_start_info;
+
+/* Lazy mode for batching updates / context switch */
+enum paravirt_lazy_mode {
+	PARAVIRT_LAZY_NONE,
+	PARAVIRT_LAZY_MMU,
+	PARAVIRT_LAZY_CPU,
+};
+
+static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
+{
+	return PARAVIRT_LAZY_NONE;
+}
+
+extern struct dma_map_ops *xen_dma_ops;
+
+#ifdef CONFIG_XEN
+void __init xen_early_init(void);
+#else
+static inline void xen_early_init(void) { return; }
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+static inline void xen_arch_register_cpu(int num)
+{
+}
+
+static inline void xen_arch_unregister_cpu(int num)
+{
+}
+#endif
+
+#endif /* _ASM_ARM_XEN_HYPERVISOR_H */
diff --git a/arch/arm64/include/asm/xen/interface.h b/arch/arm64/include/asm/xen/interface.h
index 44457ae..75d5968 100644
--- a/arch/arm64/include/asm/xen/interface.h
+++ b/arch/arm64/include/asm/xen/interface.h
@@ -1 +1,85 @@
-#include <../../arm/include/asm/xen/interface.h>
+/******************************************************************************
+ * Guest OS interface to ARM Xen.
+ *
+ * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012
+ */
+
+#ifndef _ASM_ARM_XEN_INTERFACE_H
+#define _ASM_ARM_XEN_INTERFACE_H
+
+#include <linux/types.h>
+
+#define uint64_aligned_t uint64_t __attribute__((aligned(8)))
+
+#define __DEFINE_GUEST_HANDLE(name, type) \
+	typedef struct { union { type *p; uint64_aligned_t q; }; }  \
+        __guest_handle_ ## name
+
+#define DEFINE_GUEST_HANDLE_STRUCT(name) \
+	__DEFINE_GUEST_HANDLE(name, struct name)
+#define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
+#define GUEST_HANDLE(name)        __guest_handle_ ## name
+
+#define set_xen_guest_handle(hnd, val)			\
+	do {						\
+		if (sizeof(hnd) == 8)			\
+			*(uint64_t *)&(hnd) = 0;	\
+		(hnd).p = val;				\
+	} while (0)
+
+#define __HYPERVISOR_platform_op_raw __HYPERVISOR_platform_op
+
+#ifndef __ASSEMBLY__
+/* Explicitly size integers that represent pfns in the interface with
+ * Xen so that we can have one ABI that works for 32 and 64 bit guests.
+ * Note that this means that the xen_pfn_t type may be capable of
+ * representing pfn's which the guest cannot represent in its own pfn
+ * type. However since pfn space is controlled by the guest this is
+ * fine since it simply wouldn't be able to create any sure pfns in
+ * the first place.
+ */
+typedef uint64_t xen_pfn_t;
+#define PRI_xen_pfn "llx"
+typedef uint64_t xen_ulong_t;
+#define PRI_xen_ulong "llx"
+typedef int64_t xen_long_t;
+#define PRI_xen_long "llx"
+/* Guest handles for primitive C types. */
+__DEFINE_GUEST_HANDLE(uchar, unsigned char);
+__DEFINE_GUEST_HANDLE(uint,  unsigned int);
+DEFINE_GUEST_HANDLE(char);
+DEFINE_GUEST_HANDLE(int);
+DEFINE_GUEST_HANDLE(void);
+DEFINE_GUEST_HANDLE(uint64_t);
+DEFINE_GUEST_HANDLE(uint32_t);
+DEFINE_GUEST_HANDLE(xen_pfn_t);
+DEFINE_GUEST_HANDLE(xen_ulong_t);
+
+/* Maximum number of virtual CPUs in multi-processor guests. */
+#define MAX_VIRT_CPUS 1
+
+struct arch_vcpu_info { };
+struct arch_shared_info { };
+
+/* TODO: Move pvclock definitions some place arch independent */
+struct pvclock_vcpu_time_info {
+	u32   version;
+	u32   pad0;
+	u64   tsc_timestamp;
+	u64   system_time;
+	u32   tsc_to_system_mul;
+	s8    tsc_shift;
+	u8    flags;
+	u8    pad[2];
+} __attribute__((__packed__)); /* 32 bytes */
+
+/* It is OK to have a 12 bytes struct with no padding because it is packed */
+struct pvclock_wall_clock {
+	u32   version;
+	u32   sec;
+	u32   nsec;
+	u32   sec_hi;
+} __attribute__((__packed__));
+#endif
+
+#endif /* _ASM_ARM_XEN_INTERFACE_H */
diff --git a/arch/arm64/include/asm/xen/page-coherent.h b/arch/arm64/include/asm/xen/page-coherent.h
index 2052102..95ce6ac 100644
--- a/arch/arm64/include/asm/xen/page-coherent.h
+++ b/arch/arm64/include/asm/xen/page-coherent.h
@@ -1 +1,98 @@
-#include <../../arm/include/asm/xen/page-coherent.h>
+#ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
+#define _ASM_ARM_XEN_PAGE_COHERENT_H
+
+#include <asm/page.h>
+#include <linux/dma-mapping.h>
+
+void __xen_dma_map_page(struct device *hwdev, struct page *page,
+	     dma_addr_t dev_addr, unsigned long offset, size_t size,
+	     enum dma_data_direction dir, unsigned long attrs);
+void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+		size_t size, enum dma_data_direction dir,
+		unsigned long attrs);
+void __xen_dma_sync_single_for_cpu(struct device *hwdev,
+		dma_addr_t handle, size_t size, enum dma_data_direction dir);
+
+void __xen_dma_sync_single_for_device(struct device *hwdev,
+		dma_addr_t handle, size_t size, enum dma_data_direction dir);
+
+static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
+		dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
+{
+	return __generic_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
+}
+
+static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
+		void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
+{
+	__generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
+}
+
+static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
+	     dma_addr_t dev_addr, unsigned long offset, size_t size,
+	     enum dma_data_direction dir, unsigned long attrs)
+{
+	unsigned long page_pfn = page_to_xen_pfn(page);
+	unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
+	unsigned long compound_pages =
+		(1<<compound_order(page)) * XEN_PFN_PER_PAGE;
+	bool local = (page_pfn <= dev_pfn) &&
+		(dev_pfn - page_pfn < compound_pages);
+
+	/*
+	 * Dom0 is mapped 1:1, while the Linux page can span across
+	 * multiple Xen pages, it's not possible for it to contain a
+	 * mix of local and foreign Xen pages. So if the first xen_pfn
+	 * == mfn the page is local otherwise it's a foreign page
+	 * grant-mapped in dom0. If the page is local we can safely
+	 * call the native dma_ops function, otherwise we call the xen
+	 * specific function.
+	 */
+	if (local)
+		__generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
+	else
+		__xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
+}
+
+static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+		size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+	unsigned long pfn = PFN_DOWN(handle);
+	/*
+	 * Dom0 is mapped 1:1, while the Linux page can be spanned accross
+	 * multiple Xen page, it's not possible to have a mix of local and
+	 * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
+	 * foreign mfn will always return false. If the page is local we can
+	 * safely call the native dma_ops function, otherwise we call the xen
+	 * specific function.
+	 */
+	if (pfn_valid(pfn)) {
+		if (__generic_dma_ops(hwdev)->unmap_page)
+			__generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
+	} else
+		__xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
+}
+
+static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
+		dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+	unsigned long pfn = PFN_DOWN(handle);
+	if (pfn_valid(pfn)) {
+		if (__generic_dma_ops(hwdev)->sync_single_for_cpu)
+			__generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
+	} else
+		__xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
+}
+
+static inline void xen_dma_sync_single_for_device(struct device *hwdev,
+		dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+	unsigned long pfn = PFN_DOWN(handle);
+	if (pfn_valid(pfn)) {
+		if (__generic_dma_ops(hwdev)->sync_single_for_device)
+			__generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
+	} else
+		__xen_dma_sync_single_for_device(hwdev, handle, size, dir);
+}
+
+#endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */
diff --git a/arch/arm64/include/asm/xen/page.h b/arch/arm64/include/asm/xen/page.h
index bed87ec..415dbc6 100644
--- a/arch/arm64/include/asm/xen/page.h
+++ b/arch/arm64/include/asm/xen/page.h
@@ -1 +1,122 @@
-#include <../../arm/include/asm/xen/page.h>
+#ifndef _ASM_ARM_XEN_PAGE_H
+#define _ASM_ARM_XEN_PAGE_H
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+#include <linux/pfn.h>
+#include <linux/types.h>
+#include <linux/dma-mapping.h>
+
+#include <xen/xen.h>
+#include <xen/interface/grant_table.h>
+
+#define phys_to_machine_mapping_valid(pfn) (1)
+
+/* Xen machine address */
+typedef struct xmaddr {
+	phys_addr_t maddr;
+} xmaddr_t;
+
+/* Xen pseudo-physical address */
+typedef struct xpaddr {
+	phys_addr_t paddr;
+} xpaddr_t;
+
+#define XMADDR(x)	((xmaddr_t) { .maddr = (x) })
+#define XPADDR(x)	((xpaddr_t) { .paddr = (x) })
+
+#define INVALID_P2M_ENTRY      (~0UL)
+
+/*
+ * The pseudo-physical frame (pfn) used in all the helpers is always based
+ * on Xen page granularity (i.e 4KB).
+ *
+ * A Linux page may be split across multiple non-contiguous Xen page so we
+ * have to keep track with frame based on 4KB page granularity.
+ *
+ * PV drivers should never make a direct usage of those helpers (particularly
+ * pfn_to_gfn and gfn_to_pfn).
+ */
+
+unsigned long __pfn_to_mfn(unsigned long pfn);
+extern struct rb_root phys_to_mach;
+
+/* Pseudo-physical <-> Guest conversion */
+static inline unsigned long pfn_to_gfn(unsigned long pfn)
+{
+	return pfn;
+}
+
+static inline unsigned long gfn_to_pfn(unsigned long gfn)
+{
+	return gfn;
+}
+
+/* Pseudo-physical <-> BUS conversion */
+static inline unsigned long pfn_to_bfn(unsigned long pfn)
+{
+	unsigned long mfn;
+
+	if (phys_to_mach.rb_node != NULL) {
+		mfn = __pfn_to_mfn(pfn);
+		if (mfn != INVALID_P2M_ENTRY)
+			return mfn;
+	}
+
+	return pfn;
+}
+
+static inline unsigned long bfn_to_pfn(unsigned long bfn)
+{
+	return bfn;
+}
+
+#define bfn_to_local_pfn(bfn)	bfn_to_pfn(bfn)
+
+/* VIRT <-> GUEST conversion */
+#define virt_to_gfn(v)		(pfn_to_gfn(virt_to_phys(v) >> XEN_PAGE_SHIFT))
+#define gfn_to_virt(m)		(__va(gfn_to_pfn(m) << XEN_PAGE_SHIFT))
+
+/* Only used in PV code. But ARM guests are always HVM. */
+static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr)
+{
+	BUG();
+}
+
+/* TODO: this shouldn't be here but it is because the frontend drivers
+ * are using it (its rolled in headers) even though we won't hit the code path.
+ * So for right now just punt with this.
+ */
+static inline pte_t *lookup_address(unsigned long address, unsigned int *level)
+{
+	BUG();
+	return NULL;
+}
+
+extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
+				   struct gnttab_map_grant_ref *kmap_ops,
+				   struct page **pages, unsigned int count);
+
+extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
+				     struct gnttab_unmap_grant_ref *kunmap_ops,
+				     struct page **pages, unsigned int count);
+
+bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
+bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn,
+		unsigned long nr_pages);
+
+static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
+{
+	return __set_phys_to_machine(pfn, mfn);
+}
+
+#define xen_remap(cookie, size) ioremap_cache((cookie), (size))
+#define xen_unmap(cookie) iounmap((cookie))
+
+bool xen_arch_need_swiotlb(struct device *dev,
+			   phys_addr_t phys,
+			   dma_addr_t dev_addr);
+unsigned long xen_get_swiotlb_free_pages(unsigned int order);
+
+#endif /* _ASM_ARM_XEN_PAGE_H */
-- 
2.1.4

[PATCH 2/2] arm64: xen: Split architecture-specific headers from 32bit ARM

[Stefano Stabellini]

On Thu, 1 Dec 2016, Marc Zyngier wrote:
> ARM and arm64 Xen ports share a number of headers, leading to
> packaging issues when these headers needs to be exported, as it
> breaks the reasonable requirement that an architecture port
> is standalone.
> 
> Solve the issue by copying the 5 header files over the arch
> barrier.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

I might be unhappy about making life more difficult for people building
out of tree modules (not really, but I can pretend), but copying the
headers over is not a solution. I really don't want two copies of them.

What does "standalone" mean in this context? What is the failure exactly?

If moving the headers out of arch/arm is necessary, then please move
them to another shared directory, maybe include/xen/arm.



>  arch/arm64/include/asm/xen/hypercall.h     |  88 ++++++++++++++++++++-
>  arch/arm64/include/asm/xen/hypervisor.h    |  40 +++++++++-
>  arch/arm64/include/asm/xen/interface.h     |  86 +++++++++++++++++++-
>  arch/arm64/include/asm/xen/page-coherent.h |  99 ++++++++++++++++++++++-
>  arch/arm64/include/asm/xen/page.h          | 123 ++++++++++++++++++++++++++++-
>  5 files changed, 431 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/xen/hypercall.h b/arch/arm64/include/asm/xen/hypercall.h
> index 74b0c42..9d874db 100644
> --- a/arch/arm64/include/asm/xen/hypercall.h
> +++ b/arch/arm64/include/asm/xen/hypercall.h
> @@ -1 +1,87 @@
> -#include <../../arm/include/asm/xen/hypercall.h>
> +/******************************************************************************
> + * hypercall.h
> + *
> + * Linux-specific hypervisor handling.
> + *
> + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation; or, when distributed
> + * separately from the Linux kernel or incorporated into other
> + * software packages, subject to the following license:
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this source file (the "Software"), to deal in the Software without
> + * restriction, including without limitation the rights to use, copy, modify,
> + * merge, publish, distribute, sublicense, and/or sell copies of the Software,
> + * and to permit persons to whom the Software is furnished to do so, subject to
> + * the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#ifndef _ASM_ARM_XEN_HYPERCALL_H
> +#define _ASM_ARM_XEN_HYPERCALL_H
> +
> +#include <linux/bug.h>
> +
> +#include <xen/interface/xen.h>
> +#include <xen/interface/sched.h>
> +#include <xen/interface/platform.h>
> +
> +long privcmd_call(unsigned call, unsigned long a1,
> +		unsigned long a2, unsigned long a3,
> +		unsigned long a4, unsigned long a5);
> +int HYPERVISOR_xen_version(int cmd, void *arg);
> +int HYPERVISOR_console_io(int cmd, int count, char *str);
> +int HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count);
> +int HYPERVISOR_sched_op(int cmd, void *arg);
> +int HYPERVISOR_event_channel_op(int cmd, void *arg);
> +unsigned long HYPERVISOR_hvm_op(int op, void *arg);
> +int HYPERVISOR_memory_op(unsigned int cmd, void *arg);
> +int HYPERVISOR_physdev_op(int cmd, void *arg);
> +int HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args);
> +int HYPERVISOR_tmem_op(void *arg);
> +int HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type);
> +int HYPERVISOR_platform_op_raw(void *arg);
> +static inline int HYPERVISOR_platform_op(struct xen_platform_op *op)
> +{
> +	op->interface_version = XENPF_INTERFACE_VERSION;
> +	return HYPERVISOR_platform_op_raw(op);
> +}
> +int HYPERVISOR_multicall(struct multicall_entry *calls, uint32_t nr);
> +
> +static inline int
> +HYPERVISOR_suspend(unsigned long start_info_mfn)
> +{
> +	struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
> +
> +	/* start_info_mfn is unused on ARM */
> +	return HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
> +}
> +
> +static inline void
> +MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
> +			unsigned int new_val, unsigned long flags)
> +{
> +	BUG();
> +}
> +
> +static inline void
> +MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
> +		 int count, int *success_count, domid_t domid)
> +{
> +	BUG();
> +}
> +
> +#endif /* _ASM_ARM_XEN_HYPERCALL_H */
> diff --git a/arch/arm64/include/asm/xen/hypervisor.h b/arch/arm64/include/asm/xen/hypervisor.h
> index f263da8..9525151 100644
> --- a/arch/arm64/include/asm/xen/hypervisor.h
> +++ b/arch/arm64/include/asm/xen/hypervisor.h
> @@ -1 +1,39 @@
> -#include <../../arm/include/asm/xen/hypervisor.h>
> +#ifndef _ASM_ARM_XEN_HYPERVISOR_H
> +#define _ASM_ARM_XEN_HYPERVISOR_H
> +
> +#include <linux/init.h>
> +
> +extern struct shared_info *HYPERVISOR_shared_info;
> +extern struct start_info *xen_start_info;
> +
> +/* Lazy mode for batching updates / context switch */
> +enum paravirt_lazy_mode {
> +	PARAVIRT_LAZY_NONE,
> +	PARAVIRT_LAZY_MMU,
> +	PARAVIRT_LAZY_CPU,
> +};
> +
> +static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
> +{
> +	return PARAVIRT_LAZY_NONE;
> +}
> +
> +extern struct dma_map_ops *xen_dma_ops;
> +
> +#ifdef CONFIG_XEN
> +void __init xen_early_init(void);
> +#else
> +static inline void xen_early_init(void) { return; }
> +#endif
> +
> +#ifdef CONFIG_HOTPLUG_CPU
> +static inline void xen_arch_register_cpu(int num)
> +{
> +}
> +
> +static inline void xen_arch_unregister_cpu(int num)
> +{
> +}
> +#endif
> +
> +#endif /* _ASM_ARM_XEN_HYPERVISOR_H */
> diff --git a/arch/arm64/include/asm/xen/interface.h b/arch/arm64/include/asm/xen/interface.h
> index 44457ae..75d5968 100644
> --- a/arch/arm64/include/asm/xen/interface.h
> +++ b/arch/arm64/include/asm/xen/interface.h
> @@ -1 +1,85 @@
> -#include <../../arm/include/asm/xen/interface.h>
> +/******************************************************************************
> + * Guest OS interface to ARM Xen.
> + *
> + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012
> + */
> +
> +#ifndef _ASM_ARM_XEN_INTERFACE_H
> +#define _ASM_ARM_XEN_INTERFACE_H
> +
> +#include <linux/types.h>
> +
> +#define uint64_aligned_t uint64_t __attribute__((aligned(8)))
> +
> +#define __DEFINE_GUEST_HANDLE(name, type) \
> +	typedef struct { union { type *p; uint64_aligned_t q; }; }  \
> +        __guest_handle_ ## name
> +
> +#define DEFINE_GUEST_HANDLE_STRUCT(name) \
> +	__DEFINE_GUEST_HANDLE(name, struct name)
> +#define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
> +#define GUEST_HANDLE(name)        __guest_handle_ ## name
> +
> +#define set_xen_guest_handle(hnd, val)			\
> +	do {						\
> +		if (sizeof(hnd) == 8)			\
> +			*(uint64_t *)&(hnd) = 0;	\
> +		(hnd).p = val;				\
> +	} while (0)
> +
> +#define __HYPERVISOR_platform_op_raw __HYPERVISOR_platform_op
> +
> +#ifndef __ASSEMBLY__
> +/* Explicitly size integers that represent pfns in the interface with
> + * Xen so that we can have one ABI that works for 32 and 64 bit guests.
> + * Note that this means that the xen_pfn_t type may be capable of
> + * representing pfn's which the guest cannot represent in its own pfn
> + * type. However since pfn space is controlled by the guest this is
> + * fine since it simply wouldn't be able to create any sure pfns in
> + * the first place.
> + */
> +typedef uint64_t xen_pfn_t;
> +#define PRI_xen_pfn "llx"
> +typedef uint64_t xen_ulong_t;
> +#define PRI_xen_ulong "llx"
> +typedef int64_t xen_long_t;
> +#define PRI_xen_long "llx"
> +/* Guest handles for primitive C types. */
> +__DEFINE_GUEST_HANDLE(uchar, unsigned char);
> +__DEFINE_GUEST_HANDLE(uint,  unsigned int);
> +DEFINE_GUEST_HANDLE(char);
> +DEFINE_GUEST_HANDLE(int);
> +DEFINE_GUEST_HANDLE(void);
> +DEFINE_GUEST_HANDLE(uint64_t);
> +DEFINE_GUEST_HANDLE(uint32_t);
> +DEFINE_GUEST_HANDLE(xen_pfn_t);
> +DEFINE_GUEST_HANDLE(xen_ulong_t);
> +
> +/* Maximum number of virtual CPUs in multi-processor guests. */
> +#define MAX_VIRT_CPUS 1
> +
> +struct arch_vcpu_info { };
> +struct arch_shared_info { };
> +
> +/* TODO: Move pvclock definitions some place arch independent */
> +struct pvclock_vcpu_time_info {
> +	u32   version;
> +	u32   pad0;
> +	u64   tsc_timestamp;
> +	u64   system_time;
> +	u32   tsc_to_system_mul;
> +	s8    tsc_shift;
> +	u8    flags;
> +	u8    pad[2];
> +} __attribute__((__packed__)); /* 32 bytes */
> +
> +/* It is OK to have a 12 bytes struct with no padding because it is packed */
> +struct pvclock_wall_clock {
> +	u32   version;
> +	u32   sec;
> +	u32   nsec;
> +	u32   sec_hi;
> +} __attribute__((__packed__));
> +#endif
> +
> +#endif /* _ASM_ARM_XEN_INTERFACE_H */
> diff --git a/arch/arm64/include/asm/xen/page-coherent.h b/arch/arm64/include/asm/xen/page-coherent.h
> index 2052102..95ce6ac 100644
> --- a/arch/arm64/include/asm/xen/page-coherent.h
> +++ b/arch/arm64/include/asm/xen/page-coherent.h
> @@ -1 +1,98 @@
> -#include <../../arm/include/asm/xen/page-coherent.h>
> +#ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
> +#define _ASM_ARM_XEN_PAGE_COHERENT_H
> +
> +#include <asm/page.h>
> +#include <linux/dma-mapping.h>
> +
> +void __xen_dma_map_page(struct device *hwdev, struct page *page,
> +	     dma_addr_t dev_addr, unsigned long offset, size_t size,
> +	     enum dma_data_direction dir, unsigned long attrs);
> +void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
> +		size_t size, enum dma_data_direction dir,
> +		unsigned long attrs);
> +void __xen_dma_sync_single_for_cpu(struct device *hwdev,
> +		dma_addr_t handle, size_t size, enum dma_data_direction dir);
> +
> +void __xen_dma_sync_single_for_device(struct device *hwdev,
> +		dma_addr_t handle, size_t size, enum dma_data_direction dir);
> +
> +static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
> +		dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
> +{
> +	return __generic_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
> +}
> +
> +static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
> +		void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
> +{
> +	__generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
> +}
> +
> +static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
> +	     dma_addr_t dev_addr, unsigned long offset, size_t size,
> +	     enum dma_data_direction dir, unsigned long attrs)
> +{
> +	unsigned long page_pfn = page_to_xen_pfn(page);
> +	unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
> +	unsigned long compound_pages =
> +		(1<<compound_order(page)) * XEN_PFN_PER_PAGE;
> +	bool local = (page_pfn <= dev_pfn) &&
> +		(dev_pfn - page_pfn < compound_pages);
> +
> +	/*
> +	 * Dom0 is mapped 1:1, while the Linux page can span across
> +	 * multiple Xen pages, it's not possible for it to contain a
> +	 * mix of local and foreign Xen pages. So if the first xen_pfn
> +	 * == mfn the page is local otherwise it's a foreign page
> +	 * grant-mapped in dom0. If the page is local we can safely
> +	 * call the native dma_ops function, otherwise we call the xen
> +	 * specific function.
> +	 */
> +	if (local)
> +		__generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
> +	else
> +		__xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
> +}
> +
> +static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
> +		size_t size, enum dma_data_direction dir, unsigned long attrs)
> +{
> +	unsigned long pfn = PFN_DOWN(handle);
> +	/*
> +	 * Dom0 is mapped 1:1, while the Linux page can be spanned accross
> +	 * multiple Xen page, it's not possible to have a mix of local and
> +	 * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
> +	 * foreign mfn will always return false. If the page is local we can
> +	 * safely call the native dma_ops function, otherwise we call the xen
> +	 * specific function.
> +	 */
> +	if (pfn_valid(pfn)) {
> +		if (__generic_dma_ops(hwdev)->unmap_page)
> +			__generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
> +	} else
> +		__xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
> +}
> +
> +static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
> +		dma_addr_t handle, size_t size, enum dma_data_direction dir)
> +{
> +	unsigned long pfn = PFN_DOWN(handle);
> +	if (pfn_valid(pfn)) {
> +		if (__generic_dma_ops(hwdev)->sync_single_for_cpu)
> +			__generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
> +	} else
> +		__xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
> +}
> +
> +static inline void xen_dma_sync_single_for_device(struct device *hwdev,
> +		dma_addr_t handle, size_t size, enum dma_data_direction dir)
> +{
> +	unsigned long pfn = PFN_DOWN(handle);
> +	if (pfn_valid(pfn)) {
> +		if (__generic_dma_ops(hwdev)->sync_single_for_device)
> +			__generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
> +	} else
> +		__xen_dma_sync_single_for_device(hwdev, handle, size, dir);
> +}
> +
> +#endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */
> diff --git a/arch/arm64/include/asm/xen/page.h b/arch/arm64/include/asm/xen/page.h
> index bed87ec..415dbc6 100644
> --- a/arch/arm64/include/asm/xen/page.h
> +++ b/arch/arm64/include/asm/xen/page.h
> @@ -1 +1,122 @@
> -#include <../../arm/include/asm/xen/page.h>
> +#ifndef _ASM_ARM_XEN_PAGE_H
> +#define _ASM_ARM_XEN_PAGE_H
> +
> +#include <asm/page.h>
> +#include <asm/pgtable.h>
> +
> +#include <linux/pfn.h>
> +#include <linux/types.h>
> +#include <linux/dma-mapping.h>
> +
> +#include <xen/xen.h>
> +#include <xen/interface/grant_table.h>
> +
> +#define phys_to_machine_mapping_valid(pfn) (1)
> +
> +/* Xen machine address */
> +typedef struct xmaddr {
> +	phys_addr_t maddr;
> +} xmaddr_t;
> +
> +/* Xen pseudo-physical address */
> +typedef struct xpaddr {
> +	phys_addr_t paddr;
> +} xpaddr_t;
> +
> +#define XMADDR(x)	((xmaddr_t) { .maddr = (x) })
> +#define XPADDR(x)	((xpaddr_t) { .paddr = (x) })
> +
> +#define INVALID_P2M_ENTRY      (~0UL)
> +
> +/*
> + * The pseudo-physical frame (pfn) used in all the helpers is always based
> + * on Xen page granularity (i.e 4KB).
> + *
> + * A Linux page may be split across multiple non-contiguous Xen page so we
> + * have to keep track with frame based on 4KB page granularity.
> + *
> + * PV drivers should never make a direct usage of those helpers (particularly
> + * pfn_to_gfn and gfn_to_pfn).
> + */
> +
> +unsigned long __pfn_to_mfn(unsigned long pfn);
> +extern struct rb_root phys_to_mach;
> +
> +/* Pseudo-physical <-> Guest conversion */
> +static inline unsigned long pfn_to_gfn(unsigned long pfn)
> +{
> +	return pfn;
> +}
> +
> +static inline unsigned long gfn_to_pfn(unsigned long gfn)
> +{
> +	return gfn;
> +}
> +
> +/* Pseudo-physical <-> BUS conversion */
> +static inline unsigned long pfn_to_bfn(unsigned long pfn)
> +{
> +	unsigned long mfn;
> +
> +	if (phys_to_mach.rb_node != NULL) {
> +		mfn = __pfn_to_mfn(pfn);
> +		if (mfn != INVALID_P2M_ENTRY)
> +			return mfn;
> +	}
> +
> +	return pfn;
> +}
> +
> +static inline unsigned long bfn_to_pfn(unsigned long bfn)
> +{
> +	return bfn;
> +}
> +
> +#define bfn_to_local_pfn(bfn)	bfn_to_pfn(bfn)
> +
> +/* VIRT <-> GUEST conversion */
> +#define virt_to_gfn(v)		(pfn_to_gfn(virt_to_phys(v) >> XEN_PAGE_SHIFT))
> +#define gfn_to_virt(m)		(__va(gfn_to_pfn(m) << XEN_PAGE_SHIFT))
> +
> +/* Only used in PV code. But ARM guests are always HVM. */
> +static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr)
> +{
> +	BUG();
> +}
> +
> +/* TODO: this shouldn't be here but it is because the frontend drivers
> + * are using it (its rolled in headers) even though we won't hit the code path.
> + * So for right now just punt with this.
> + */
> +static inline pte_t *lookup_address(unsigned long address, unsigned int *level)
> +{
> +	BUG();
> +	return NULL;
> +}
> +
> +extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
> +				   struct gnttab_map_grant_ref *kmap_ops,
> +				   struct page **pages, unsigned int count);
> +
> +extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
> +				     struct gnttab_unmap_grant_ref *kunmap_ops,
> +				     struct page **pages, unsigned int count);
> +
> +bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
> +bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn,
> +		unsigned long nr_pages);
> +
> +static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
> +{
> +	return __set_phys_to_machine(pfn, mfn);
> +}
> +
> +#define xen_remap(cookie, size) ioremap_cache((cookie), (size))
> +#define xen_unmap(cookie) iounmap((cookie))
> +
> +bool xen_arch_need_swiotlb(struct device *dev,
> +			   phys_addr_t phys,
> +			   dma_addr_t dev_addr);
> +unsigned long xen_get_swiotlb_free_pages(unsigned int order);
> +
> +#endif /* _ASM_ARM_XEN_PAGE_H */
> -- 
> 2.1.4
> 

[PATCH 2/2] arm64: xen: Split architecture-specific headers from 32bit ARM

[Marc Zyngier]

On 01/12/16 22:17, Stefano Stabellini wrote:
> On Thu, 1 Dec 2016, Marc Zyngier wrote:
>> ARM and arm64 Xen ports share a number of headers, leading to
>> packaging issues when these headers needs to be exported, as it
>> breaks the reasonable requirement that an architecture port
>> is standalone.
>>
>> Solve the issue by copying the 5 header files over the arch
>> barrier.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> 
> I might be unhappy about making life more difficult for people building
> out of tree modules (not really, but I can pretend), but copying the
> headers over is not a solution. I really don't want two copies of them.
> 
> What does "standalone" mean in this context? What is the failure exactly?

Standalone means exactly that. You don't need any include file from
another architecture, and arch/arm64/include/* together with include/*
should be enough to build any odd piece of out of tree code, like on any
other architecture. For example, here's an extract from Wookey's
(internal) report trying to build the *cough* mali driver *cough*:

$ sudo make -C /usr/src/linux-headers-4.8.0-1-arm64
M=/usr/src/midgard-0.r2p0/ EXTRA_CFLAGS="-I
/usr/src/linux-headers-4.8.0-1-common/include/ -Wall -Werror
-DCONFIG_MALI_MIDGARD=m -DCONFIG_MALI_BACKEND=gpu" CONFIG_MALI_MIDGARD=m
CONFIG_MALI_BACKEND=gpu modules
make: Entering directory '/usr/src/linux-headers-4.8.0-1-arm64'
   CC [M]  /usr/src/midgard-0.r2p0//mali_kbase_device.o
In file included from
/usr/src/linux-headers-4.8.0-1-common/arch/arm64/include/asm/sysreg.h:25:0,
                  from
/usr/src/linux-headers-4.8.0-1-common/arch/arm64/include/asm/cputype.h:94,
                  from
/usr/src/linux-headers-4.8.0-1-common/arch/arm64/include/asm/cachetype.h:19,
                  from
/usr/src/linux-headers-4.8.0-1-common/arch/arm64/include/asm/cache.h:19,
                  from
/usr/src/linux-headers-4.8.0-1-common/include/linux/cache.h:5,
                  from
/usr/src/linux-headers-4.8.0-1-common/include/linux/printk.h:8,
                  from
/usr/src/linux-headers-4.8.0-1-common/include/linux/kernel.h:13,
                  from
/usr/src/linux-headers-4.8.0-1-common/include/linux/list.h:8,
                  from
/usr/src/linux-headers-4.8.0-1-common/include/linux/wait.h:6,
                  from
/usr/src/linux-headers-4.8.0-1-common/include/linux/fs.h:5,
                  from
/usr/src/linux-headers-4.8.0-1-common/include/linux/debugfs.h:18,
                  from
/usr/src/midgard-0.r2p0//mali_kbase_device.c:24:/usr/src/linux-headers-4.8.0-1-common/arch/arm64/include/asm/opcodes.h:5:43:

fatal error: ../../arm/include/asm/opcodes.h: No such file or directory
compilation terminated.

As I said in the cover letter, I don't care much for out of tree code
either. However, there is strictly no need for arm64 to break the
reasonable expectation that header files can be packaged using the
method that "just works" on all other architectures. Distributions do
depend on this, and breaking these expectations is not something that I
find acceptable. YMMV.

> If moving the headers out of arch/arm is necessary, then please move
> them to another shared directory, maybe include/xen/arm.

Works for me, I'll respin this patch.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...