[PATCH v4 00/16] mm: ioremap: Convert architectures to take GENERIC_IOREMAP way

[PATCH v4 00/16] mm: ioremap: Convert architectures to take GENERIC_IOREMAP way

[Baoquan He]

Motivation and implementation:
==============================
Currently, many architecutres have't taken the standard GENERIC_IOREMAP
way to implement ioremap_prot(), iounmap(), and ioremap_xx(), but make
these functions specifically under each arch's folder. Those cause many
duplicated codes of ioremap() and iounmap().

In this patchset, firstly introduce generic_ioremap_prot() and
generic_iounmap() to extract the generic codes for GENERIC_IOREMAP.
By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic version if there's
arch specific handling in its corresponding ioremap_prot(), ioremap()
or iounmap(). With these changes, duplicated ioremap/iounmap() code uder
ARCH-es are removed, and the equivalent functioality is kept as before.

Background info:
================
1)
The converting more architectures to take GENERIC_IOREMAP way is
suggested by Christoph in below discussion:
https://lore.kernel.org/all/Yp7h0Jv6vpgt6xdZ@infradead.org/T/#u

2)
In the previous v1 to v3, it's basically further action after arm64
has converted to GENERIC_IOREMAP way in below patchset. It's done by
adding hook ioremap_allowed() and iounmap_allowed() in ARCH to add
ARCH specific handling the middle of ioremap_prot() and iounmap().

[PATCH v5 0/6] arm64: Cleanup ioremap() and support ioremap_prot()
https://lore.kernel.org/all/20220607125027.44946-1-wangkefeng.wang@huawei.com/T/#u

Later, during v3 reviewing, Christophe Leroy suggested to introduce
generic_ioremap_prot() and generic_iounmap() to generic codes, and ARCH
can provide wrapper function ioremap_prot(), ioremap() or iounmap() if
needed. Christophe made a RFC patchset as below to specially demonstrate
his idea. This is what v4 is doing.

[RFC PATCH 0/8] mm: ioremap: Convert architectures to take GENERIC_IOREMAP way
https://lore.kernel.org/all/cover.1665568707.git.christophe.leroy@csgroup.eu/T/#u

Testing:
========
- It's running well on arm64, s390x, ppc64le with this patchset applied
  on the latest upstream kernel 6.2-rc8+.
- Cross compiling passed on arc, ia64, parisc, sh, xtensa.
- cross compiling is not tried on hexagon, openrisc and powerpc 32bit
  because:
  - Didn't find cross compiling tools for hexagon, ppc 32bit;
  - there's error with openrisc compiling, while I have no idea how to
    fix it. Please see below pasted log:
    ---------------------------------------------------------------------
    [root@intel-knightslanding-lb-02 linux]# make ARCH=openrisc defconfig
    *** Default configuration is based on 'or1ksim_defconfig'
    #
    # configuration written to .config
    #
    [root@intel-knightslanding-lb-02 linux]# make ARCH=openrisc -j320 CROSS_COMPILE=/usr/bin/openrisc-linux-gnu-
      SYNC    include/config/auto.conf.cmd
      CC      scripts/mod/empty.o
    ./scripts/check-local-export: /usr/bin/openrisc-linux-gnu-nm failed
    make[1]: *** [scripts/Makefile.build:250: scripts/mod/empty.o] Error 1
    make[1]: *** Deleting file 'scripts/mod/empty.o'
    make: *** [Makefile:1275: prepare0] Error 2
    ----------------------------------------------------------------------

History:
=======
v3->v4:
- Change to contain arch specific handling in wrapper function
  ioremap(), ioremap_prot() or iounmap() to replace the old hook
  ioremap|iounmap_allowed() hook way for each arch.
- Add two patches to convert powerpc to GENERIC_IOREMAP. They are
  picked from above Christophe's RFC patchset, I made some changes
  to make them formal.

v2->v3:
- Rewrite log of all patches to add more details as Christoph suggested.

- Merge the old patch 1 and 2 which adjusts return values and
  parameters of arch_ioremap() into one patch, namely the current
  patch 3. Christoph suggested this.

- Change the return value of arch_iounmap() to bool type since we only
  do arch specific address filtering or address checking, bool value
  can reflect the checking better. This is pointed out by Niklas when
  he reviewed the s390 patch.

- Put hexagon patch at the beginning of patchset since hexagon has the
  same ioremap() and iounmap() as standard ones, no arch_ioremap() and
  arch_iounmap() hooks need be introduced. So the later arch_ioremap
  and arch_iounmap() adjustment are not related in hexagon. Christophe
  suggested this.

- Remove the early ioremap code from openrisc ioremap() firstly since
  openrisc doesn't have early ioremap handling in openrisc arch code.
  This simplifies the later converting to GENERIC_IOREMAP method.
  Christoph and Stafford suggersted this.

- Fix compiling erorrs reported by lkp in parisc and sh patches.
  Adding macro defintions for those port|mem io functions in
  <asm/io.h> to avoid repeated definition in <asm-generic/io.h>.

v1->v2:
- Rename io[re|un]map_allowed() to arch_io[re|un]map() and made
  some minor changes in patch 1~2 as per Alexander and Kefeng's
  suggestions. Accordingly, adjust patches~4~11 because of the renaming
  arch_io[re|un]map().

Baoquan He (13):
  hexagon: mm: Convert to GENERIC_IOREMAP
  openrisc: mm: remove unneeded early ioremap code
  mm: ioremap: allow ARCH to have its own ioremap method definition
  mm/ioremap: add slab availability checking in ioremap_prot
  arc: mm: Convert to GENERIC_IOREMAP
  ia64: mm: Convert to GENERIC_IOREMAP
  openrisc: mm: Convert to GENERIC_IOREMAP
  s390: mm: Convert to GENERIC_IOREMAP
  sh: mm: Convert to GENERIC_IOREMAP
  xtensa: mm: Convert to GENERIC_IOREMAP
  parisc: mm: Convert to GENERIC_IOREMAP
  arm64 : mm: add wrapper function ioremap_prot()
  mm: ioremap: remove unneeded ioremap_allowed and iounmap_allowed

Christophe Leroy (3):
  mm/ioremap: Define generic_ioremap_prot() and generic_iounmap()
  mm/ioremap: Consider IOREMAP space in generic ioremap
  powerpc: mm: Convert to GENERIC_IOREMAP

 arch/arc/Kconfig                  |  1 +
 arch/arc/include/asm/io.h         |  7 ++--
 arch/arc/mm/ioremap.c             | 49 ++---------------------
 arch/arm64/include/asm/io.h       |  3 +-
 arch/arm64/mm/ioremap.c           | 10 +++--
 arch/hexagon/Kconfig              |  1 +
 arch/hexagon/include/asm/io.h     |  9 ++++-
 arch/hexagon/mm/ioremap.c         | 44 ---------------------
 arch/ia64/Kconfig                 |  1 +
 arch/ia64/include/asm/io.h        | 13 +++----
 arch/ia64/mm/ioremap.c            | 41 +++----------------
 arch/openrisc/Kconfig             |  1 +
 arch/openrisc/include/asm/io.h    | 11 ++++--
 arch/openrisc/mm/ioremap.c        | 58 +--------------------------
 arch/parisc/Kconfig               |  1 +
 arch/parisc/include/asm/io.h      | 17 +++++---
 arch/parisc/mm/ioremap.c          | 62 ++---------------------------
 arch/powerpc/Kconfig              |  1 +
 arch/powerpc/include/asm/io.h     |  8 ++--
 arch/powerpc/mm/ioremap.c         | 26 +------------
 arch/powerpc/mm/ioremap_32.c      | 19 +++++----
 arch/powerpc/mm/ioremap_64.c      | 12 +-----
 arch/s390/Kconfig                 |  1 +
 arch/s390/include/asm/io.h        | 21 +++++-----
 arch/s390/pci/pci.c               | 57 +++++----------------------
 arch/sh/Kconfig                   |  1 +
 arch/sh/include/asm/io.h          | 65 ++++++++++++++++---------------
 arch/sh/include/asm/io_noioport.h |  7 ++++
 arch/sh/mm/ioremap.c              | 65 ++++++-------------------------
 arch/xtensa/Kconfig               |  1 +
 arch/xtensa/include/asm/io.h      | 32 ++++++---------
 arch/xtensa/mm/ioremap.c          | 58 +++++++--------------------
 include/asm-generic/io.h          | 31 +++------------
 mm/ioremap.c                      | 41 +++++++++++++------
 34 files changed, 214 insertions(+), 561 deletions(-)
 delete mode 100644 arch/hexagon/mm/ioremap.c

-- 
2.34.1

[PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

By taking GENERIC_IOREMAP method, the generic ioremap_prot() and
iounmap() are visible and available to arch. This change will
simplify implementation by removing duplicated codes with generic
ioremap_prot() and iounmap(), and has the equivalent functioality.

For hexagon, the current ioremap() and iounmap() are the same as
generic version. After taking GENERIC_IOREMAP way, the old ioremap()
and iounmap() can be completely removed.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@quicinc.com>
Cc: linux-hexagon@vger.kernel.org
---
 arch/hexagon/Kconfig          |  1 +
 arch/hexagon/include/asm/io.h |  9 +++++--
 arch/hexagon/mm/ioremap.c     | 44 -----------------------------------
 3 files changed, 8 insertions(+), 46 deletions(-)
 delete mode 100644 arch/hexagon/mm/ioremap.c

diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 54eadf265178..17afffde1a7f 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -25,6 +25,7 @@ config HEXAGON
 	select NEED_SG_DMA_LENGTH
 	select NO_IOPORT_MAP
 	select GENERIC_IOMAP
+	select GENERIC_IOREMAP
 	select GENERIC_SMP_IDLE_THREAD
 	select STACKTRACE_SUPPORT
 	select GENERIC_CLOCKEVENTS_BROADCAST
diff --git a/arch/hexagon/include/asm/io.h b/arch/hexagon/include/asm/io.h
index 46a099de85b7..dcd9cbbf5934 100644
--- a/arch/hexagon/include/asm/io.h
+++ b/arch/hexagon/include/asm/io.h
@@ -170,8 +170,13 @@ static inline void writel(u32 data, volatile void __iomem *addr)
 #define writew_relaxed __raw_writew
 #define writel_relaxed __raw_writel
 
-void __iomem *ioremap(unsigned long phys_addr, unsigned long size);
-#define ioremap_uc(X, Y) ioremap((X), (Y))
+/*
+ * I/O memory mapping functions.
+ */
+#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
+		       (__HEXAGON_C_DEV << 6))
+
+#define ioremap_uc(addr, size) ioremap((addr), (size))
 
 
 #define __raw_writel writel
diff --git a/arch/hexagon/mm/ioremap.c b/arch/hexagon/mm/ioremap.c
deleted file mode 100644
index 255c5b1ee1a7..000000000000
--- a/arch/hexagon/mm/ioremap.c
+++ /dev/null
@@ -1,44 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * I/O remap functions for Hexagon
- *
- * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
- */
-
-#include <linux/io.h>
-#include <linux/vmalloc.h>
-#include <linux/mm.h>
-
-void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
-{
-	unsigned long last_addr, addr;
-	unsigned long offset = phys_addr & ~PAGE_MASK;
-	struct vm_struct *area;
-
-	pgprot_t prot = __pgprot(_PAGE_PRESENT|_PAGE_READ|_PAGE_WRITE
-					|(__HEXAGON_C_DEV << 6));
-
-	last_addr = phys_addr + size - 1;
-
-	/*  Wrapping not allowed  */
-	if (!size || (last_addr < phys_addr))
-		return NULL;
-
-	/*  Rounds up to next page size, including whole-page offset */
-	size = PAGE_ALIGN(offset + size);
-
-	area = get_vm_area(size, VM_IOREMAP);
-	addr = (unsigned long)area->addr;
-
-	if (ioremap_page_range(addr, addr+size, phys_addr, prot)) {
-		vunmap((void *)addr);
-		return NULL;
-	}
-
-	return (void __iomem *) (offset + addr);
-}
-
-void iounmap(const volatile void __iomem *addr)
-{
-	vunmap((void *) ((unsigned long) addr & PAGE_MASK));
-}
-- 
2.34.1

[PATCH v4 02/16] openrisc: mm: remove unneeded early ioremap code

[Baoquan He]

Under arch/openrisc, there isn't any place where ioremap() is called.
It means that there isn't early ioremap handling needed in openrisc,
So the early ioremap handling code in ioremap() of
arch/openrisc/mm/ioremap.c is unnecessary and can be removed.

Link: https://lore.kernel.org/linux-mm/YwxfxKrTUtAuejKQ@oscomms1/
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: openrisc@lists.librecores.org
---
 arch/openrisc/mm/ioremap.c | 22 +++++-----------------
 1 file changed, 5 insertions(+), 17 deletions(-)

diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c
index 8ec0dafecf25..90b59bc53c8c 100644
--- a/arch/openrisc/mm/ioremap.c
+++ b/arch/openrisc/mm/ioremap.c
@@ -22,8 +22,6 @@
 
 extern int mem_init_done;
 
-static unsigned int fixmaps_used __initdata;
-
 /*
  * Remap an arbitrary physical address space into the kernel virtual
  * address space. Needed when the kernel wants to access high addresses
@@ -52,24 +50,14 @@ void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
 	p = addr & PAGE_MASK;
 	size = PAGE_ALIGN(last_addr + 1) - p;
 
-	if (likely(mem_init_done)) {
-		area = get_vm_area(size, VM_IOREMAP);
-		if (!area)
-			return NULL;
-		v = (unsigned long)area->addr;
-	} else {
-		if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS)
-			return NULL;
-		v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used);
-		fixmaps_used += (size >> PAGE_SHIFT);
-	}
+	area = get_vm_area(size, VM_IOREMAP);
+	if (!area)
+		return NULL;
+	v = (unsigned long)area->addr;
 
 	if (ioremap_page_range(v, v + size, p,
 			__pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) {
-		if (likely(mem_init_done))
-			vfree(area->addr);
-		else
-			fixmaps_used -= (size >> PAGE_SHIFT);
+		vfree(area->addr);
 		return NULL;
 	}
 
-- 
2.34.1

[PATCH v4 03/16] mm/ioremap: Define generic_ioremap_prot() and generic_iounmap()

[Baoquan He]

From: Christophe Leroy <christophe.leroy@csgroup.eu>

Define a generic version of ioremap_prot() and iounmap() that
architectures can call after they have performed the necessary
alteration to parameters and/or necessary verifications.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Baoquan He <bhe@redhat.com>
---
 include/asm-generic/io.h |  4 ++++
 mm/ioremap.c             | 22 ++++++++++++++++------
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 4c44a29b5e8e..5a9cf16ee0c2 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1073,9 +1073,13 @@ static inline bool iounmap_allowed(void *addr)
 }
 #endif
 
+void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
+				   pgprot_t prot);
+
 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 			   unsigned long prot);
 void iounmap(volatile void __iomem *addr);
+void generic_iounmap(volatile void __iomem *addr);
 
 static inline void __iomem *ioremap(phys_addr_t addr, size_t size)
 {
diff --git a/mm/ioremap.c b/mm/ioremap.c
index 8652426282cc..db6234b9db59 100644
--- a/mm/ioremap.c
+++ b/mm/ioremap.c
@@ -11,8 +11,8 @@
 #include <linux/io.h>
 #include <linux/export.h>
 
-void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
-			   unsigned long prot)
+void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
+				   pgprot_t prot)
 {
 	unsigned long offset, vaddr;
 	phys_addr_t last_addr;
@@ -28,7 +28,7 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 	phys_addr -= offset;
 	size = PAGE_ALIGN(size + offset);
 
-	if (!ioremap_allowed(phys_addr, size, prot))
+	if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
 		return NULL;
 
 	area = get_vm_area_caller(size, VM_IOREMAP,
@@ -38,17 +38,22 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 	vaddr = (unsigned long)area->addr;
 	area->phys_addr = phys_addr;
 
-	if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
-			       __pgprot(prot))) {
+	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
 		free_vm_area(area);
 		return NULL;
 	}
 
 	return (void __iomem *)(vaddr + offset);
 }
+
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
+{
+	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
+}
 EXPORT_SYMBOL(ioremap_prot);
 
-void iounmap(volatile void __iomem *addr)
+void generic_iounmap(volatile void __iomem *addr)
 {
 	void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
 
@@ -58,4 +63,9 @@ void iounmap(volatile void __iomem *addr)
 	if (is_vmalloc_addr(vaddr))
 		vunmap(vaddr);
 }
+
+void iounmap(volatile void __iomem *addr)
+{
+	generic_iounmap(addr);
+}
 EXPORT_SYMBOL(iounmap);
-- 
2.34.1

[PATCH v4 04/16] mm: ioremap: allow ARCH to have its own ioremap method definition

[Baoquan He]

Architectures can be converted to GENERIC_IOREMAP, to take standard
ioremap_xxx() and iounmap() way. But some ARCH-es could have specific
handling for ioremap_prot(), ioremap() and iounmap(), than standard
methods.

In oder to convert these ARCH-es to take GENERIC_IOREMAP, allow these
architecutres to have their own ioremap_prot(), ioremap() and iounmap()
definitions.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: linux-arch@vger.kernel.org
---
 include/asm-generic/io.h | 3 +++
 mm/ioremap.c             | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 5a9cf16ee0c2..29ee791164ac 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1081,11 +1081,14 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 void iounmap(volatile void __iomem *addr);
 void generic_iounmap(volatile void __iomem *addr);
 
+#ifndef ioremap
+#define ioremap ioremap
 static inline void __iomem *ioremap(phys_addr_t addr, size_t size)
 {
 	/* _PAGE_IOREMAP needs to be supplied by the architecture */
 	return ioremap_prot(addr, size, _PAGE_IOREMAP);
 }
+#endif
 #endif /* !CONFIG_MMU || CONFIG_GENERIC_IOREMAP */
 
 #ifndef ioremap_wc
diff --git a/mm/ioremap.c b/mm/ioremap.c
index db6234b9db59..9f34a8f90b58 100644
--- a/mm/ioremap.c
+++ b/mm/ioremap.c
@@ -46,12 +46,14 @@ void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
 	return (void __iomem *)(vaddr + offset);
 }
 
+#ifndef ioremap_prot
 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 			   unsigned long prot)
 {
 	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
 }
 EXPORT_SYMBOL(ioremap_prot);
+#endif
 
 void generic_iounmap(volatile void __iomem *addr)
 {
@@ -64,8 +66,10 @@ void generic_iounmap(volatile void __iomem *addr)
 		vunmap(vaddr);
 }
 
+#ifndef iounmap
 void iounmap(volatile void __iomem *addr)
 {
 	generic_iounmap(addr);
 }
 EXPORT_SYMBOL(iounmap);
+#endif
-- 
2.34.1

[PATCH v4 05/16] mm/ioremap: add slab availability checking in ioremap_prot

[Baoquan He]

Several architectures has done checking if slab if available in
ioremap_prot(). In fact it should be done in generic ioremap_prot()
since on any architecutre, slab allocator must be available before
get_vm_area_caller() and vunmap() are used.

Add the checking into generic_ioremap_prot().

Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Baoquan He <bhe@redhat.com>
---
 mm/ioremap.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mm/ioremap.c b/mm/ioremap.c
index 9f34a8f90b58..2fbe6b9bc50e 100644
--- a/mm/ioremap.c
+++ b/mm/ioremap.c
@@ -18,6 +18,10 @@ void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
 	phys_addr_t last_addr;
 	struct vm_struct *area;
 
+	/* An early platform driver might end up here */
+	if (!slab_is_available())
+		return NULL;
+
 	/* Disallow wrap-around or zero size */
 	last_addr = phys_addr + size - 1;
 	if (!size || last_addr < phys_addr)
-- 
2.34.1

[PATCH v4 06/16] arc: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic versions if there's
arch specific handling in its ioremap_prot(), ioremap() or iounmap().
This change will simplify implementation by removing duplicated codes
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

Here, add wrapper functions ioremap_prot() and iounmap() for arc's
special operation when ioremap_prot() and iounmap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/arc/Kconfig          |  1 +
 arch/arc/include/asm/io.h |  7 +++---
 arch/arc/mm/ioremap.c     | 49 ++++-----------------------------------
 3 files changed, 8 insertions(+), 49 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d9a13ccf89a3..37da34ac7abf 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -26,6 +26,7 @@ config ARC
 	select GENERIC_PENDING_IRQ if SMP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
+	select GENERIC_IOREMAP
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARC_MMU_V4
diff --git a/arch/arc/include/asm/io.h b/arch/arc/include/asm/io.h
index 80347382a380..4fdb7350636c 100644
--- a/arch/arc/include/asm/io.h
+++ b/arch/arc/include/asm/io.h
@@ -21,8 +21,9 @@
 #endif
 
 extern void __iomem *ioremap(phys_addr_t paddr, unsigned long size);
-extern void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
-				  unsigned long flags);
+#define ioremap ioremap
+#define ioremap_prot ioremap_prot
+#define iounmap iounmap
 static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
 {
 	return (void __iomem *)port;
@@ -32,8 +33,6 @@ static inline void ioport_unmap(void __iomem *addr)
 {
 }
 
-extern void iounmap(const volatile void __iomem *addr);
-
 /*
  * io{read,write}{16,32}be() macros
  */
diff --git a/arch/arc/mm/ioremap.c b/arch/arc/mm/ioremap.c
index 712c2311daef..b07004d53267 100644
--- a/arch/arc/mm/ioremap.c
+++ b/arch/arc/mm/ioremap.c
@@ -8,7 +8,6 @@
 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/mm.h>
-#include <linux/slab.h>
 #include <linux/cache.h>
 
 static inline bool arc_uncached_addr_space(phys_addr_t paddr)
@@ -25,13 +24,6 @@ static inline bool arc_uncached_addr_space(phys_addr_t paddr)
 
 void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
 {
-	phys_addr_t end;
-
-	/* Don't allow wraparound or zero size */
-	end = paddr + size - 1;
-	if (!size || (end < paddr))
-		return NULL;
-
 	/*
 	 * If the region is h/w uncached, MMU mapping can be elided as optim
 	 * The cast to u32 is fine as this region can only be inside 4GB
@@ -51,55 +43,22 @@ EXPORT_SYMBOL(ioremap);
  * ARC hardware uncached region, this one still goes thru the MMU as caller
  * might need finer access control (R/W/X)
  */
-void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
+void __iomem *ioremap_prot(phys_addr_t paddr, size_t size,
 			   unsigned long flags)
 {
-	unsigned int off;
-	unsigned long vaddr;
-	struct vm_struct *area;
-	phys_addr_t end;
 	pgprot_t prot = __pgprot(flags);
 
-	/* Don't allow wraparound, zero size */
-	end = paddr + size - 1;
-	if ((!size) || (end < paddr))
-		return NULL;
-
-	/* An early platform driver might end up here */
-	if (!slab_is_available())
-		return NULL;
-
 	/* force uncached */
-	prot = pgprot_noncached(prot);
-
-	/* Mappings have to be page-aligned */
-	off = paddr & ~PAGE_MASK;
-	paddr &= PAGE_MASK_PHYS;
-	size = PAGE_ALIGN(end + 1) - paddr;
-
-	/*
-	 * Ok, go for it..
-	 */
-	area = get_vm_area(size, VM_IOREMAP);
-	if (!area)
-		return NULL;
-	area->phys_addr = paddr;
-	vaddr = (unsigned long)area->addr;
-	if (ioremap_page_range(vaddr, vaddr + size, paddr, prot)) {
-		vunmap((void __force *)vaddr);
-		return NULL;
-	}
-	return (void __iomem *)(off + (char __iomem *)vaddr);
+	return generic_ioremap_prot(paddr, size, pgprot_noncached(prot));
 }
 EXPORT_SYMBOL(ioremap_prot);
 
-
-void iounmap(const volatile void __iomem *addr)
+void iounmap(volatile void __iomem *addr)
 {
 	/* weird double cast to handle phys_addr_t > 32 bits */
 	if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
 		return;
 
-	vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
+	generic_iounmap(addr);
 }
 EXPORT_SYMBOL(iounmap);
-- 
2.34.1

[PATCH v4 07/16] ia64: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic versions if there's
arch specific handling in its ioremap_prot(), ioremap() or iounmap().
This change will simplify implementation by removing duplicated codes
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

Here, add wrapper functions ioremap_prot() and iounmap() for ia64's
special operation when ioremap() and iounmap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: linux-ia64@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/ia64/Kconfig          |  1 +
 arch/ia64/include/asm/io.h | 13 +++++-------
 arch/ia64/mm/ioremap.c     | 41 ++++++--------------------------------
 3 files changed, 12 insertions(+), 43 deletions(-)

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index d7e4a24e8644..74568cb73d87 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -45,6 +45,7 @@ config IA64
 	select GENERIC_IRQ_LEGACY
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_IOMAP
+	select GENERIC_IOREMAP
 	select GENERIC_SMP_IDLE_THREAD
 	select ARCH_TASK_STRUCT_ON_STACK
 	select ARCH_TASK_STRUCT_ALLOCATOR
diff --git a/arch/ia64/include/asm/io.h b/arch/ia64/include/asm/io.h
index 83a492c8d298..eedc0afa8cad 100644
--- a/arch/ia64/include/asm/io.h
+++ b/arch/ia64/include/asm/io.h
@@ -243,15 +243,12 @@ static inline void outsl(unsigned long port, const void *src,
 
 # ifdef __KERNEL__
 
-extern void __iomem * ioremap(unsigned long offset, unsigned long size);
+#define _PAGE_IOREMAP pgprot_val(PAGE_KERNEL)
+
 extern void __iomem * ioremap_uc(unsigned long offset, unsigned long size);
-extern void iounmap (volatile void __iomem *addr);
-static inline void __iomem * ioremap_cache (unsigned long phys_addr, unsigned long size)
-{
-	return ioremap(phys_addr, size);
-}
-#define ioremap ioremap
-#define ioremap_cache ioremap_cache
+
+#define ioremap_prot ioremap_prot
+#define ioremap_cache ioremap
 #define ioremap_uc ioremap_uc
 #define iounmap iounmap
 
diff --git a/arch/ia64/mm/ioremap.c b/arch/ia64/mm/ioremap.c
index 55fd3eb753ff..35e75e9c878b 100644
--- a/arch/ia64/mm/ioremap.c
+++ b/arch/ia64/mm/ioremap.c
@@ -29,13 +29,9 @@ early_ioremap (unsigned long phys_addr, unsigned long size)
 	return __ioremap_uc(phys_addr);
 }
 
-void __iomem *
-ioremap (unsigned long phys_addr, unsigned long size)
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long flags)
 {
-	void __iomem *addr;
-	struct vm_struct *area;
-	unsigned long offset;
-	pgprot_t prot;
 	u64 attr;
 	unsigned long gran_base, gran_size;
 	unsigned long page_base;
@@ -68,36 +64,12 @@ ioremap (unsigned long phys_addr, unsigned long size)
 	 */
 	page_base = phys_addr & PAGE_MASK;
 	size = PAGE_ALIGN(phys_addr + size) - page_base;
-	if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) {
-		prot = PAGE_KERNEL;
-
-		/*
-		 * Mappings have to be page-aligned
-		 */
-		offset = phys_addr & ~PAGE_MASK;
-		phys_addr &= PAGE_MASK;
-
-		/*
-		 * Ok, go for it..
-		 */
-		area = get_vm_area(size, VM_IOREMAP);
-		if (!area)
-			return NULL;
-
-		area->phys_addr = phys_addr;
-		addr = (void __iomem *) area->addr;
-		if (ioremap_page_range((unsigned long) addr,
-				(unsigned long) addr + size, phys_addr, prot)) {
-			vunmap((void __force *) addr);
-			return NULL;
-		}
-
-		return (void __iomem *) (offset + (char __iomem *)addr);
-	}
+	if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB)
+		return generic_ioremap_prot(phys_addr, size, __pgprot(flags));
 
 	return __ioremap_uc(phys_addr);
 }
-EXPORT_SYMBOL(ioremap);
+EXPORT_SYMBOL(ioremap_prot);
 
 void __iomem *
 ioremap_uc(unsigned long phys_addr, unsigned long size)
@@ -114,8 +86,7 @@ early_iounmap (volatile void __iomem *addr, unsigned long size)
 {
 }
 
-void
-iounmap (volatile void __iomem *addr)
+void iounmap(volatile void __iomem *addr)
 {
 	if (REGION_NUMBER(addr) == RGN_GATE)
 		vunmap((void *) ((unsigned long) addr & PAGE_MASK));
-- 
2.34.1

[PATCH v4 08/16] openrisc: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic versions if there's
arch specific handling in its ioremap_prot(), ioremap() or iounmap().
This change will simplify implementation by removing duplicated codes
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

Here, add wrapper function iounmap() for openrisc's special operation
when iounmap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: openrisc@lists.librecores.org
---
 arch/openrisc/Kconfig          |  1 +
 arch/openrisc/include/asm/io.h | 11 +++++---
 arch/openrisc/mm/ioremap.c     | 46 +---------------------------------
 3 files changed, 9 insertions(+), 49 deletions(-)

diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index c7f282f60f64..fd9bb76a610b 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -21,6 +21,7 @@ config OPENRISC
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PCI_IOMAP
+	select GENERIC_IOREMAP
 	select GENERIC_CPU_DEVICES
 	select HAVE_PCI
 	select HAVE_UID16
diff --git a/arch/openrisc/include/asm/io.h b/arch/openrisc/include/asm/io.h
index ee6043a03173..e640960c26c2 100644
--- a/arch/openrisc/include/asm/io.h
+++ b/arch/openrisc/include/asm/io.h
@@ -15,6 +15,8 @@
 #define __ASM_OPENRISC_IO_H
 
 #include <linux/types.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
 
 /*
  * PCI: We do not use IO ports in OpenRISC
@@ -27,11 +29,12 @@
 #define PIO_OFFSET		0
 #define PIO_MASK		0
 
-#define ioremap ioremap
-void __iomem *ioremap(phys_addr_t offset, unsigned long size);
-
+/*
+ * I/O memory mapping functions.
+ */
 #define iounmap iounmap
-extern void iounmap(volatile void __iomem *addr);
+
+#define _PAGE_IOREMAP (pgprot_val(PAGE_KERNEL) | _PAGE_CI)
 
 #include <asm-generic/io.h>
 
diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c
index 90b59bc53c8c..9f9941df7d4c 100644
--- a/arch/openrisc/mm/ioremap.c
+++ b/arch/openrisc/mm/ioremap.c
@@ -22,49 +22,6 @@
 
 extern int mem_init_done;
 
-/*
- * Remap an arbitrary physical address space into the kernel virtual
- * address space. Needed when the kernel wants to access high addresses
- * directly.
- *
- * NOTE! We need to allow non-page-aligned mappings too: we will obviously
- * have to convert them into an offset in a page-aligned mapping, but the
- * caller shouldn't need to know that small detail.
- */
-void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
-{
-	phys_addr_t p;
-	unsigned long v;
-	unsigned long offset, last_addr;
-	struct vm_struct *area = NULL;
-
-	/* Don't allow wraparound or zero size */
-	last_addr = addr + size - 1;
-	if (!size || last_addr < addr)
-		return NULL;
-
-	/*
-	 * Mappings have to be page-aligned
-	 */
-	offset = addr & ~PAGE_MASK;
-	p = addr & PAGE_MASK;
-	size = PAGE_ALIGN(last_addr + 1) - p;
-
-	area = get_vm_area(size, VM_IOREMAP);
-	if (!area)
-		return NULL;
-	v = (unsigned long)area->addr;
-
-	if (ioremap_page_range(v, v + size, p,
-			__pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) {
-		vfree(area->addr);
-		return NULL;
-	}
-
-	return (void __iomem *)(offset + (char *)v);
-}
-EXPORT_SYMBOL(ioremap);
-
 void iounmap(volatile void __iomem *addr)
 {
 	/* If the page is from the fixmap pool then we just clear out
@@ -88,9 +45,8 @@ void iounmap(volatile void __iomem *addr)
 		return;
 	}
 
-	return vfree((void *)(PAGE_MASK & (unsigned long)addr));
+	generic_iounmap(addr);
 }
-EXPORT_SYMBOL(iounmap);
 
 /**
  * OK, this one's a bit tricky... ioremap can get called before memory is
-- 
2.34.1

[PATCH v4 09/16] s390: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic versions if there's
arch specific handling in its ioremap_prot(), ioremap() or iounmap().
This change will simplify implementation by removing duplicated codes
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

Here, add wrapper functions ioremap_prot() and iounmap() for s390's
special operation when ioremap() and iounmap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
---
 arch/s390/Kconfig          |  1 +
 arch/s390/include/asm/io.h | 21 ++++++++------
 arch/s390/pci/pci.c        | 57 +++++++-------------------------------
 3 files changed, 23 insertions(+), 56 deletions(-)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 7fd08755a1f9..be600b299328 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -141,6 +141,7 @@ config S390
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_TIME_NS
+	select GENERIC_IOREMAP if PCI
 	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_JUMP_LABEL
diff --git a/arch/s390/include/asm/io.h b/arch/s390/include/asm/io.h
index e3882b012bfa..4453ad7c11ac 100644
--- a/arch/s390/include/asm/io.h
+++ b/arch/s390/include/asm/io.h
@@ -22,11 +22,18 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr);
 
 #define IO_SPACE_LIMIT 0
 
-void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot);
-void __iomem *ioremap(phys_addr_t addr, size_t size);
-void __iomem *ioremap_wc(phys_addr_t addr, size_t size);
-void __iomem *ioremap_wt(phys_addr_t addr, size_t size);
-void iounmap(volatile void __iomem *addr);
+/*
+ * I/O memory mapping functions.
+ */
+#define ioremap_prot ioremap_prot
+#define iounmap iounmap
+
+#define _PAGE_IOREMAP pgprot_val(PAGE_KERNEL)
+
+#define ioremap_wc(addr, size)  \
+	ioremap_prot((addr), (size), pgprot_val(pgprot_writecombine(PAGE_KERNEL)))
+#define ioremap_wt(addr, size)  \
+	ioremap_prot((addr), (size), pgprot_val(pgprot_writethrough(PAGE_KERNEL)))
 
 static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
 {
@@ -51,10 +58,6 @@ static inline void ioport_unmap(void __iomem *p)
 #define pci_iomap_wc pci_iomap_wc
 #define pci_iomap_wc_range pci_iomap_wc_range
 
-#define ioremap ioremap
-#define ioremap_wt ioremap_wt
-#define ioremap_wc ioremap_wc
-
 #define memcpy_fromio(dst, src, count)	zpci_memcpy_fromio(dst, src, count)
 #define memcpy_toio(dst, src, count)	zpci_memcpy_toio(dst, src, count)
 #define memset_io(dst, val, count)	zpci_memset_io(dst, val, count)
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index ef38b1514c77..9590bf2c0d88 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -244,62 +244,25 @@ void __iowrite64_copy(void __iomem *to, const void *from, size_t count)
        zpci_memcpy_toio(to, from, count);
 }
 
-static void __iomem *__ioremap(phys_addr_t addr, size_t size, pgprot_t prot)
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
 {
-	unsigned long offset, vaddr;
-	struct vm_struct *area;
-	phys_addr_t last_addr;
-
-	last_addr = addr + size - 1;
-	if (!size || last_addr < addr)
-		return NULL;
-
+	/*
+	 * When PCI MIO instructions are unavailable the "physical" address
+	 * encodes a hint for accessing the PCI memory space it represents.
+	 * Just pass it unchanged such that ioread/iowrite can decode it.
+	 */
 	if (!static_branch_unlikely(&have_mio))
-		return (void __iomem *) addr;
+		return (void __iomem *)phys_addr;
 
-	offset = addr & ~PAGE_MASK;
-	addr &= PAGE_MASK;
-	size = PAGE_ALIGN(size + offset);
-	area = get_vm_area(size, VM_IOREMAP);
-	if (!area)
-		return NULL;
-
-	vaddr = (unsigned long) area->addr;
-	if (ioremap_page_range(vaddr, vaddr + size, addr, prot)) {
-		free_vm_area(area);
-		return NULL;
-	}
-	return (void __iomem *) ((unsigned long) area->addr + offset);
-}
-
-void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot)
-{
-	return __ioremap(addr, size, __pgprot(prot));
+	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
 }
 EXPORT_SYMBOL(ioremap_prot);
 
-void __iomem *ioremap(phys_addr_t addr, size_t size)
-{
-	return __ioremap(addr, size, PAGE_KERNEL);
-}
-EXPORT_SYMBOL(ioremap);
-
-void __iomem *ioremap_wc(phys_addr_t addr, size_t size)
-{
-	return __ioremap(addr, size, pgprot_writecombine(PAGE_KERNEL));
-}
-EXPORT_SYMBOL(ioremap_wc);
-
-void __iomem *ioremap_wt(phys_addr_t addr, size_t size)
-{
-	return __ioremap(addr, size, pgprot_writethrough(PAGE_KERNEL));
-}
-EXPORT_SYMBOL(ioremap_wt);
-
 void iounmap(volatile void __iomem *addr)
 {
 	if (static_branch_likely(&have_mio))
-		vunmap((__force void *) ((unsigned long) addr & PAGE_MASK));
+		generic_iounmap(addr);
 }
 EXPORT_SYMBOL(iounmap);
 
-- 
2.34.1

[PATCH v4 10/16] sh: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic versions if there's
arch specific handling in its ioremap_prot(), ioremap() or iounmap().
This change will simplify implementation by removing duplicated codes
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

Here, add wrapper functions ioremap_prot() and iounmap() for SuperH's
special operation when ioremap() and iounmap().

Meanwhile, add macro definitions for port|mm io functions since SuperH
has its own implementation in arch/sh/kernel/iomap.c and
arch/sh/include/asm/io_noioport.h. These will conflict with the port|mm io
function definitions in include/asm-generic/io.h to cause compiling
errors like below:

====
  CC      arch/sh/kernel/asm-offsets.s
In file included from ./arch/sh/include/asm/io.h:294,
                 from ./include/linux/io.h:13,
                 ......
                 from arch/sh/kernel/asm-offsets.c:16:
./include/asm-generic/io.h:792:17: error: conflicting types for ‘ioread8’
  792 | #define ioread8 ioread8
      |                 ^~~~~~~
./include/asm-generic/io.h:793:18: note: in expansion of macro ‘ioread8’
  793 | static inline u8 ioread8(const volatile void __iomem *addr)
      |                  ^~~~~~~
In file included from ./arch/sh/include/asm/io.h:22,
                 from ./include/linux/io.h:13,
                 ......
                 from arch/sh/kernel/asm-offsets.c:16:
./include/asm-generic/iomap.h:29:21: note: previous declaration of ‘ioread8’ was here
   29 | extern unsigned int ioread8(const void __iomem *);
====

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
---
 arch/sh/Kconfig                   |  1 +
 arch/sh/include/asm/io.h          | 65 ++++++++++++++++---------------
 arch/sh/include/asm/io_noioport.h |  7 ++++
 arch/sh/mm/ioremap.c              | 65 ++++++-------------------------
 4 files changed, 52 insertions(+), 86 deletions(-)

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 0665ac0add0b..9ab627f97c4a 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -25,6 +25,7 @@ config SUPERH
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
 	select GUP_GET_PXX_LOW_HIGH if X2TLB
+	select GENERIC_IOREMAP if MMU
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_SECCOMP_FILTER
diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h
index fba90e670ed4..b3a26b405c8d 100644
--- a/arch/sh/include/asm/io.h
+++ b/arch/sh/include/asm/io.h
@@ -119,6 +119,26 @@ void __raw_readsl(const void __iomem *addr, void *data, int longlen);
 
 __BUILD_MEMORY_STRING(__raw_, q, u64)
 
+#define ioread8 ioread8
+#define ioread16 ioread16
+#define ioread16be ioread16be
+#define ioread32 ioread32
+#define ioread32be ioread32be
+
+#define iowrite8 iowrite8
+#define iowrite16 iowrite16
+#define iowrite16be iowrite16be
+#define iowrite32 iowrite32
+#define iowrite32be iowrite32be
+
+#define ioread8_rep ioread8_rep
+#define ioread16_rep ioread16_rep
+#define ioread32_rep ioread32_rep
+
+#define iowrite8_rep iowrite8_rep
+#define iowrite16_rep iowrite16_rep
+#define iowrite32_rep iowrite32_rep
+
 #ifdef CONFIG_HAS_IOPORT_MAP
 
 /*
@@ -225,6 +245,9 @@ __BUILD_IOPORT_STRING(q, u64)
 #define IO_SPACE_LIMIT 0xffffffff
 
 /* We really want to try and get these to memcpy etc */
+#define memset_io memset_io
+#define memcpy_fromio memcpy_fromio
+#define memcpy_toio memcpy_toio
 void memcpy_fromio(void *, const volatile void __iomem *, unsigned long);
 void memcpy_toio(volatile void __iomem *, const void *, unsigned long);
 void memset_io(volatile void __iomem *, int, unsigned long);
@@ -243,40 +266,16 @@ unsigned long long poke_real_address_q(unsigned long long addr,
 #endif
 
 #ifdef CONFIG_MMU
-void iounmap(void __iomem *addr);
-void __iomem *__ioremap_caller(phys_addr_t offset, unsigned long size,
-			       pgprot_t prot, void *caller);
-
-static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size)
-{
-	return __ioremap_caller(offset, size, PAGE_KERNEL_NOCACHE,
-			__builtin_return_address(0));
-}
-
-static inline void __iomem *
-ioremap_cache(phys_addr_t offset, unsigned long size)
-{
-	return __ioremap_caller(offset, size, PAGE_KERNEL,
-			__builtin_return_address(0));
-}
-#define ioremap_cache ioremap_cache
-
-#ifdef CONFIG_HAVE_IOREMAP_PROT
-static inline void __iomem *ioremap_prot(phys_addr_t offset, unsigned long size,
-		unsigned long flags)
-{
-	return __ioremap_caller(offset, size, __pgprot(flags),
-			__builtin_return_address(0));
-}
-#endif /* CONFIG_HAVE_IOREMAP_PROT */
+/*
+ * I/O memory mapping functions.
+ */
+#define ioremap_prot ioremap_prot
+#define iounmap iounmap
 
-#else /* CONFIG_MMU */
-static inline void __iomem *ioremap(phys_addr_t offset, size_t size)
-{
-	return (void __iomem *)(unsigned long)offset;
-}
+#define _PAGE_IOREMAP pgprot_val(PAGE_KERNEL_NOCACHE)
 
-static inline void iounmap(volatile void __iomem *addr) { }
+#define ioremap_cache(addr, size)  \
+	ioremap_prot((addr), (size), pgprot_val(PAGE_KERNEL))
 #endif /* CONFIG_MMU */
 
 #define ioremap_uc	ioremap
@@ -287,6 +286,8 @@ static inline void iounmap(volatile void __iomem *addr) { }
  */
 #define xlate_dev_mem_ptr(p)	__va(p)
 
+#include <asm-generic/io.h>
+
 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 int valid_phys_addr_range(phys_addr_t addr, size_t size);
 int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
diff --git a/arch/sh/include/asm/io_noioport.h b/arch/sh/include/asm/io_noioport.h
index f7938fe0f911..5ba4116b4265 100644
--- a/arch/sh/include/asm/io_noioport.h
+++ b/arch/sh/include/asm/io_noioport.h
@@ -53,6 +53,13 @@ static inline void ioport_unmap(void __iomem *addr)
 #define outw_p(x, addr)	outw((x), (addr))
 #define outl_p(x, addr)	outl((x), (addr))
 
+#define insb insb
+#define insw insw
+#define insl insl
+#define outsb outsb
+#define outsw outsw
+#define outsl outsl
+
 static inline void insb(unsigned long port, void *dst, unsigned long count)
 {
 	BUG();
diff --git a/arch/sh/mm/ioremap.c b/arch/sh/mm/ioremap.c
index 21342581144d..c33b3daa4ad1 100644
--- a/arch/sh/mm/ioremap.c
+++ b/arch/sh/mm/ioremap.c
@@ -72,22 +72,11 @@ __ioremap_29bit(phys_addr_t offset, unsigned long size, pgprot_t prot)
 #define __ioremap_29bit(offset, size, prot)		NULL
 #endif /* CONFIG_29BIT */
 
-/*
- * Remap an arbitrary physical address space into the kernel virtual
- * address space. Needed when the kernel wants to access high addresses
- * directly.
- *
- * NOTE! We need to allow non-page-aligned mappings too: we will obviously
- * have to convert them into an offset in a page-aligned mapping, but the
- * caller shouldn't need to know that small detail.
- */
-void __iomem * __ref
-__ioremap_caller(phys_addr_t phys_addr, unsigned long size,
-		 pgprot_t pgprot, void *caller)
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
 {
-	struct vm_struct *area;
-	unsigned long offset, last_addr, addr, orig_addr;
 	void __iomem *mapped;
+	pgprot_t pgprot = __pgprot(prot);
 
 	mapped = __ioremap_trapped(phys_addr, size);
 	if (mapped)
@@ -97,11 +86,6 @@ __ioremap_caller(phys_addr_t phys_addr, unsigned long size,
 	if (mapped)
 		return mapped;
 
-	/* Don't allow wraparound or zero size */
-	last_addr = phys_addr + size - 1;
-	if (!size || last_addr < phys_addr)
-		return NULL;
-
 	/*
 	 * If we can't yet use the regular approach, go the fixmap route.
 	 */
@@ -112,34 +96,14 @@ __ioremap_caller(phys_addr_t phys_addr, unsigned long size,
 	 * First try to remap through the PMB.
 	 * PMB entries are all pre-faulted.
 	 */
-	mapped = pmb_remap_caller(phys_addr, size, pgprot, caller);
+	mapped = pmb_remap_caller(phys_addr, size, pgprot,
+			__builtin_return_address(0));
 	if (mapped && !IS_ERR(mapped))
 		return mapped;
 
-	/*
-	 * Mappings have to be page-aligned
-	 */
-	offset = phys_addr & ~PAGE_MASK;
-	phys_addr &= PAGE_MASK;
-	size = PAGE_ALIGN(last_addr+1) - phys_addr;
-
-	/*
-	 * Ok, go for it..
-	 */
-	area = get_vm_area_caller(size, VM_IOREMAP, caller);
-	if (!area)
-		return NULL;
-	area->phys_addr = phys_addr;
-	orig_addr = addr = (unsigned long)area->addr;
-
-	if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
-		vunmap((void *)orig_addr);
-		return NULL;
-	}
-
-	return (void __iomem *)(offset + (char *)orig_addr);
+	return generic_ioremap_prot(phys_addr, size, pgprot);
 }
-EXPORT_SYMBOL(__ioremap_caller);
+EXPORT_SYMBOL(ioremap_prot);
 
 /*
  * Simple checks for non-translatable mappings.
@@ -158,10 +122,9 @@ static inline int iomapping_nontranslatable(unsigned long offset)
 	return 0;
 }
 
-void iounmap(void __iomem *addr)
+void iounmap(volatile void __iomem *addr)
 {
 	unsigned long vaddr = (unsigned long __force)addr;
-	struct vm_struct *p;
 
 	/*
 	 * Nothing to do if there is no translatable mapping.
@@ -172,21 +135,15 @@ void iounmap(void __iomem *addr)
 	/*
 	 * There's no VMA if it's from an early fixed mapping.
 	 */
-	if (iounmap_fixed(addr) == 0)
+	if (iounmap_fixed((void __iomem *)addr) == 0)
 		return;
 
 	/*
 	 * If the PMB handled it, there's nothing else to do.
 	 */
-	if (pmb_unmap(addr) == 0)
+	if (pmb_unmap((void __iomem *)addr) == 0)
 		return;
 
-	p = remove_vm_area((void *)(vaddr & PAGE_MASK));
-	if (!p) {
-		printk(KERN_ERR "%s: bad address %p\n", __func__, addr);
-		return;
-	}
-
-	kfree(p);
+	generic_iounmap(addr);
 }
 EXPORT_SYMBOL(iounmap);
-- 
2.34.1

[PATCH v4 11/16] xtensa: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic versions if there's
arch specific handling in its ioremap_prot(), ioremap() or iounmap().
This change will simplify implementation by removing duplicated codes
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

Here, add wrapper functions ioremap_prot(), ioremap() and iounmap() for
xtensa's special operation when ioremap() and iounmap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-xtensa@linux-xtensa.org
---
 arch/xtensa/Kconfig          |  1 +
 arch/xtensa/include/asm/io.h | 32 ++++++++------------
 arch/xtensa/mm/ioremap.c     | 58 +++++++++---------------------------
 3 files changed, 27 insertions(+), 64 deletions(-)

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index bcb0c5d2abc2..465d5981082a 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -29,6 +29,7 @@ config XTENSA
 	select GENERIC_LIB_UCMPDI2
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
+	select GENERIC_IOREMAP if MMU
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
 	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
diff --git a/arch/xtensa/include/asm/io.h b/arch/xtensa/include/asm/io.h
index a5b707e1c0f4..934e58399c8c 100644
--- a/arch/xtensa/include/asm/io.h
+++ b/arch/xtensa/include/asm/io.h
@@ -16,6 +16,7 @@
 #include <asm/vectors.h>
 #include <linux/bug.h>
 #include <linux/kernel.h>
+#include <linux/pgtable.h>
 
 #include <linux/types.h>
 
@@ -24,22 +25,24 @@
 #define PCI_IOBASE		((void __iomem *)XCHAL_KIO_BYPASS_VADDR)
 
 #ifdef CONFIG_MMU
-
-void __iomem *xtensa_ioremap_nocache(unsigned long addr, unsigned long size);
-void __iomem *xtensa_ioremap_cache(unsigned long addr, unsigned long size);
-void xtensa_iounmap(volatile void __iomem *addr);
-
 /*
- * Return the virtual address for the specified bus memory.
+ * I/O memory mapping functions.
  */
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot);
+#define ioremap_prot ioremap_prot
+#define iounmap iounmap
+
 static inline void __iomem *ioremap(unsigned long offset, unsigned long size)
 {
 	if (offset >= XCHAL_KIO_PADDR
 	    && offset - XCHAL_KIO_PADDR < XCHAL_KIO_SIZE)
 		return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_BYPASS_VADDR);
 	else
-		return xtensa_ioremap_nocache(offset, size);
+		return ioremap_prot(offset, size,
+			pgprot_val(pgprot_noncached(PAGE_KERNEL)));
 }
+#define ioremap ioremap
 
 static inline void __iomem *ioremap_cache(unsigned long offset,
 		unsigned long size)
@@ -48,21 +51,10 @@ static inline void __iomem *ioremap_cache(unsigned long offset,
 	    && offset - XCHAL_KIO_PADDR < XCHAL_KIO_SIZE)
 		return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_CACHED_VADDR);
 	else
-		return xtensa_ioremap_cache(offset, size);
-}
-#define ioremap_cache ioremap_cache
+		return ioremap_prot(offset, size, pgprot_val(PAGE_KERNEL));
 
-static inline void iounmap(volatile void __iomem *addr)
-{
-	unsigned long va = (unsigned long) addr;
-
-	if (!(va >= XCHAL_KIO_CACHED_VADDR &&
-	      va - XCHAL_KIO_CACHED_VADDR < XCHAL_KIO_SIZE) &&
-	    !(va >= XCHAL_KIO_BYPASS_VADDR &&
-	      va - XCHAL_KIO_BYPASS_VADDR < XCHAL_KIO_SIZE))
-		xtensa_iounmap(addr);
 }
-
+#define ioremap_cache ioremap_cache
 #endif /* CONFIG_MMU */
 
 #include <asm-generic/io.h>
diff --git a/arch/xtensa/mm/ioremap.c b/arch/xtensa/mm/ioremap.c
index a400188c16b9..8ca660b7ab49 100644
--- a/arch/xtensa/mm/ioremap.c
+++ b/arch/xtensa/mm/ioremap.c
@@ -6,60 +6,30 @@
  */
 
 #include <linux/io.h>
-#include <linux/vmalloc.h>
 #include <linux/pgtable.h>
 #include <asm/cacheflush.h>
 #include <asm/io.h>
 
-static void __iomem *xtensa_ioremap(unsigned long paddr, unsigned long size,
-				    pgprot_t prot)
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
 {
-	unsigned long offset = paddr & ~PAGE_MASK;
-	unsigned long pfn = __phys_to_pfn(paddr);
-	struct vm_struct *area;
-	unsigned long vaddr;
-	int err;
-
-	paddr &= PAGE_MASK;
-
+	unsigned long pfn = __phys_to_pfn((phys_addr));
 	WARN_ON(pfn_valid(pfn));
 
-	size = PAGE_ALIGN(offset + size);
-
-	area = get_vm_area(size, VM_IOREMAP);
-	if (!area)
-		return NULL;
-
-	vaddr = (unsigned long)area->addr;
-	area->phys_addr = paddr;
-
-	err = ioremap_page_range(vaddr, vaddr + size, paddr, prot);
-
-	if (err) {
-		vunmap((void *)vaddr);
-		return NULL;
-	}
-
-	flush_cache_vmap(vaddr, vaddr + size);
-	return (void __iomem *)(offset + vaddr);
-}
-
-void __iomem *xtensa_ioremap_nocache(unsigned long addr, unsigned long size)
-{
-	return xtensa_ioremap(addr, size, pgprot_noncached(PAGE_KERNEL));
+	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
 }
-EXPORT_SYMBOL(xtensa_ioremap_nocache);
+EXPORT_SYMBOL(ioremap_prot);
 
-void __iomem *xtensa_ioremap_cache(unsigned long addr, unsigned long size)
+void iounmap(volatile void __iomem *addr)
 {
-	return xtensa_ioremap(addr, size, PAGE_KERNEL);
-}
-EXPORT_SYMBOL(xtensa_ioremap_cache);
+	unsigned long va = (unsigned long) addr;
 
-void xtensa_iounmap(volatile void __iomem *io_addr)
-{
-	void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
+	if ((va >= XCHAL_KIO_CACHED_VADDR &&
+	      va - XCHAL_KIO_CACHED_VADDR < XCHAL_KIO_SIZE) ||
+	    (va >= XCHAL_KIO_BYPASS_VADDR &&
+	      va - XCHAL_KIO_BYPASS_VADDR < XCHAL_KIO_SIZE))
+		return;
 
-	vunmap(addr);
+	generic_iounmap(addr);
 }
-EXPORT_SYMBOL(xtensa_iounmap);
+EXPORT_SYMBOL(iounmap);
-- 
2.34.1

[PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic versions if there's
arch specific handling in its ioremap_prot(), ioremap() or iounmap().
This change will simplify implementation by removing duplicated codes
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

Here, add wrapper function ioremap_prot() for parisc's special operation
when iounmap().

Meanwhile, add macro ARCH_HAS_IOREMAP_WC since the added ioremap_wc()
will conflict with the one in include/asm-generic/iomap.h, then an
compiling error is seen:

./include/asm-generic/iomap.h:97: warning: "ioremap_wc" redefined
   97 | #define ioremap_wc ioremap

And benefit from the commit 437b6b35362b ("parisc: Use the generic
IO helpers"), those macros don't need be added any more.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
---
 arch/parisc/Kconfig          |  1 +
 arch/parisc/include/asm/io.h | 17 +++++++---
 arch/parisc/mm/ioremap.c     | 62 +++---------------------------------
 3 files changed, 17 insertions(+), 63 deletions(-)

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index a98940e64243..0ed18e673aba 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -36,6 +36,7 @@ config PARISC
 	select GENERIC_ATOMIC64 if !64BIT
 	select GENERIC_IRQ_PROBE
 	select GENERIC_PCI_IOMAP
+	select GENERIC_IOREMAP
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_ARCH_TOPOLOGY if SMP
diff --git a/arch/parisc/include/asm/io.h b/arch/parisc/include/asm/io.h
index c05e781be2f5..4c386b0cee08 100644
--- a/arch/parisc/include/asm/io.h
+++ b/arch/parisc/include/asm/io.h
@@ -2,6 +2,8 @@
 #ifndef _ASM_IO_H
 #define _ASM_IO_H
 
+#define ARCH_HAS_IOREMAP_WC
+
 #include <linux/types.h>
 #include <linux/pgtable.h>
 
@@ -125,12 +127,17 @@ static inline void gsc_writeq(unsigned long long val, unsigned long addr)
 /*
  * The standard PCI ioremap interfaces
  */
-void __iomem *ioremap(unsigned long offset, unsigned long size);
-#define ioremap_wc			ioremap
-#define ioremap_uc			ioremap
-#define pci_iounmap			pci_iounmap
+#define ioremap_prot ioremap_prot
+
+#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | \
+		       _PAGE_ACCESSED | _PAGE_NO_CACHE)
 
-extern void iounmap(const volatile void __iomem *addr);
+#define ioremap_wc(addr, size)  \
+	ioremap_prot((addr), (size), _PAGE_IOREMAP)
+#define ioremap_uc(addr, size)  \
+	ioremap_prot((addr), (size), _PAGE_IOREMAP)
+
+#define pci_iounmap			pci_iounmap
 
 void memset_io(volatile void __iomem *addr, unsigned char val, int count);
 void memcpy_fromio(void *dst, const volatile void __iomem *src, int count);
diff --git a/arch/parisc/mm/ioremap.c b/arch/parisc/mm/ioremap.c
index 345ff0b66499..fd996472dfe7 100644
--- a/arch/parisc/mm/ioremap.c
+++ b/arch/parisc/mm/ioremap.c
@@ -13,25 +13,9 @@
 #include <linux/io.h>
 #include <linux/mm.h>
 
-/*
- * Generic mapping function (not visible outside):
- */
-
-/*
- * Remap an arbitrary physical address space into the kernel virtual
- * address space.
- *
- * NOTE! We need to allow non-page-aligned mappings too: we will obviously
- * have to convert them into an offset in a page-aligned mapping, but the
- * caller shouldn't need to know that small detail.
- */
-void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
 {
-	void __iomem *addr;
-	struct vm_struct *area;
-	unsigned long offset, last_addr;
-	pgprot_t pgprot;
-
 #ifdef CONFIG_EISA
 	unsigned long end = phys_addr + size - 1;
 	/* Support EISA addresses */
@@ -40,11 +24,6 @@ void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
 		phys_addr |= F_EXTEND(0xfc000000);
 #endif
 
-	/* Don't allow wraparound or zero size */
-	last_addr = phys_addr + size - 1;
-	if (!size || last_addr < phys_addr)
-		return NULL;
-
 	/*
 	 * Don't allow anybody to remap normal RAM that we're using..
 	 */
@@ -62,39 +41,6 @@ void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
 		}
 	}
 
-	pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
-			  _PAGE_ACCESSED | _PAGE_NO_CACHE);
-
-	/*
-	 * Mappings have to be page-aligned
-	 */
-	offset = phys_addr & ~PAGE_MASK;
-	phys_addr &= PAGE_MASK;
-	size = PAGE_ALIGN(last_addr + 1) - phys_addr;
-
-	/*
-	 * Ok, go for it..
-	 */
-	area = get_vm_area(size, VM_IOREMAP);
-	if (!area)
-		return NULL;
-
-	addr = (void __iomem *) area->addr;
-	if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
-			       phys_addr, pgprot)) {
-		vunmap(addr);
-		return NULL;
-	}
-
-	return (void __iomem *) (offset + (char __iomem *)addr);
-}
-EXPORT_SYMBOL(ioremap);
-
-void iounmap(const volatile void __iomem *io_addr)
-{
-	unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
-
-	if (is_vmalloc_addr((void *)addr))
-		vunmap((void *)addr);
+	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
 }
-EXPORT_SYMBOL(iounmap);
+EXPORT_SYMBOL(ioremap_prot);
-- 
2.34.1

[PATCH v4 13/16] mm/ioremap: Consider IOREMAP space in generic ioremap

[Baoquan He]

From: Christophe Leroy <christophe.leroy@csgroup.eu>

Architectures like powerpc have a dedicated space for IOREMAP mappings.

If so, use it in generic_ioremap_pro().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Baoquan He <bhe@redhat.com>
---
 mm/ioremap.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/mm/ioremap.c b/mm/ioremap.c
index 2fbe6b9bc50e..4a7749d85044 100644
--- a/mm/ioremap.c
+++ b/mm/ioremap.c
@@ -35,8 +35,13 @@ void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
 	if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
 		return NULL;
 
+#ifdef IOREMAP_START
+	area = __get_vm_area_caller(size, VM_IOREMAP, IOREMAP_START,
+				    IOREMAP_END, __builtin_return_address(0));
+#else
 	area = get_vm_area_caller(size, VM_IOREMAP,
 			__builtin_return_address(0));
+#endif
 	if (!area)
 		return NULL;
 	vaddr = (unsigned long)area->addr;
@@ -66,7 +71,7 @@ void generic_iounmap(volatile void __iomem *addr)
 	if (!iounmap_allowed(vaddr))
 		return;
 
-	if (is_vmalloc_addr(vaddr))
+	if (is_ioremap_addr(vaddr))
 		vunmap(vaddr);
 }
 
-- 
2.34.1

[PATCH v4 14/16] powerpc: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

From: Christophe Leroy <christophe.leroy@csgroup.eu>

By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic versions if there's
arch specific handling in its ioremap_prot(), ioremap() or iounmap().
This change will simplify implementation by removing duplicated codes
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

Here, add wrapper functions ioremap_prot() and iounmap() for powerpc's
special operation when ioremap() and iounmap().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/Kconfig          |  1 +
 arch/powerpc/include/asm/io.h |  8 +++-----
 arch/powerpc/mm/ioremap.c     | 26 +-------------------------
 arch/powerpc/mm/ioremap_32.c  | 19 +++++++++----------
 arch/powerpc/mm/ioremap_64.c  | 12 ++----------
 5 files changed, 16 insertions(+), 50 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 7a5f8dbfbdd0..02ae9e6afed6 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -181,6 +181,7 @@ config PPC
 	select GENERIC_CPU_VULNERABILITIES	if PPC_BARRIER_NOSPEC
 	select GENERIC_EARLY_IOREMAP
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_IOREMAP
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
 	select GENERIC_PCI_IOMAP		if PCI
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index fc112a91d0c2..127d8300b40b 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -859,8 +859,8 @@ static inline void iosync(void)
  *
  */
 extern void __iomem *ioremap(phys_addr_t address, unsigned long size);
-extern void __iomem *ioremap_prot(phys_addr_t address, unsigned long size,
-				  unsigned long flags);
+#define ioremap ioremap
+#define ioremap_prot ioremap_prot
 extern void __iomem *ioremap_wc(phys_addr_t address, unsigned long size);
 #define ioremap_wc ioremap_wc
 
@@ -874,14 +874,12 @@ void __iomem *ioremap_coherent(phys_addr_t address, unsigned long size);
 #define ioremap_cache(addr, size) \
 	ioremap_prot((addr), (size), pgprot_val(PAGE_KERNEL))
 
-extern void iounmap(volatile void __iomem *addr);
+#define iounmap iounmap
 
 void __iomem *ioremap_phb(phys_addr_t paddr, unsigned long size);
 
 int early_ioremap_range(unsigned long ea, phys_addr_t pa,
 			unsigned long size, pgprot_t prot);
-void __iomem *do_ioremap(phys_addr_t pa, phys_addr_t offset, unsigned long size,
-			 pgprot_t prot, void *caller);
 
 extern void __iomem *__ioremap_caller(phys_addr_t, unsigned long size,
 				      pgprot_t prot, void *caller);
diff --git a/arch/powerpc/mm/ioremap.c b/arch/powerpc/mm/ioremap.c
index 4f12504fb405..705e8e8ffde4 100644
--- a/arch/powerpc/mm/ioremap.c
+++ b/arch/powerpc/mm/ioremap.c
@@ -41,7 +41,7 @@ void __iomem *ioremap_coherent(phys_addr_t addr, unsigned long size)
 	return __ioremap_caller(addr, size, prot, caller);
 }
 
-void __iomem *ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
+void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long flags)
 {
 	pte_t pte = __pte(flags);
 	void *caller = __builtin_return_address(0);
@@ -74,27 +74,3 @@ int early_ioremap_range(unsigned long ea, phys_addr_t pa,
 
 	return 0;
 }
-
-void __iomem *do_ioremap(phys_addr_t pa, phys_addr_t offset, unsigned long size,
-			 pgprot_t prot, void *caller)
-{
-	struct vm_struct *area;
-	int ret;
-	unsigned long va;
-
-	area = __get_vm_area_caller(size, VM_IOREMAP, IOREMAP_START, IOREMAP_END, caller);
-	if (area == NULL)
-		return NULL;
-
-	area->phys_addr = pa;
-	va = (unsigned long)area->addr;
-
-	ret = ioremap_page_range(va, va + size, pa, prot);
-	if (!ret)
-		return (void __iomem *)area->addr + offset;
-
-	vunmap_range(va, va + size);
-	free_vm_area(area);
-
-	return NULL;
-}
diff --git a/arch/powerpc/mm/ioremap_32.c b/arch/powerpc/mm/ioremap_32.c
index 9d13143b8be4..ca5bc6be3e6f 100644
--- a/arch/powerpc/mm/ioremap_32.c
+++ b/arch/powerpc/mm/ioremap_32.c
@@ -21,6 +21,13 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *call
 	phys_addr_t p, offset;
 	int err;
 
+	/*
+	 * If the address lies within the first 16 MB, assume it's in ISA
+	 * memory space
+	 */
+	if (addr < SZ_16M)
+		addr += _ISA_MEM_BASE;
+
 	/*
 	 * Choose an address to map it to.
 	 * Once the vmalloc system is running, we use it.
@@ -31,13 +38,6 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *call
 	offset = addr & ~PAGE_MASK;
 	size = PAGE_ALIGN(addr + size) - p;
 
-	/*
-	 * If the address lies within the first 16 MB, assume it's in ISA
-	 * memory space
-	 */
-	if (p < 16 * 1024 * 1024)
-		p += _ISA_MEM_BASE;
-
 #ifndef CONFIG_CRASH_DUMP
 	/*
 	 * Don't allow anybody to remap normal RAM that we're using.
@@ -63,7 +63,7 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *call
 		return (void __iomem *)v + offset;
 
 	if (slab_is_available())
-		return do_ioremap(p, offset, size, prot, caller);
+		return generic_ioremap_prot(addr, size, prot);
 
 	/*
 	 * Should check if it is a candidate for a BAT mapping
@@ -87,7 +87,6 @@ void iounmap(volatile void __iomem *addr)
 	if (v_block_mapped((unsigned long)addr))
 		return;
 
-	if (addr > high_memory && (unsigned long)addr < ioremap_bot)
-		vunmap((void *)(PAGE_MASK & (unsigned long)addr));
+	generic_iounmap(addr);
 }
 EXPORT_SYMBOL(iounmap);
diff --git a/arch/powerpc/mm/ioremap_64.c b/arch/powerpc/mm/ioremap_64.c
index 3acece00b33e..d24e5f166723 100644
--- a/arch/powerpc/mm/ioremap_64.c
+++ b/arch/powerpc/mm/ioremap_64.c
@@ -29,7 +29,7 @@ void __iomem *__ioremap_caller(phys_addr_t addr, unsigned long size,
 		return NULL;
 
 	if (slab_is_available())
-		return do_ioremap(paligned, offset, size, prot, caller);
+		return generic_ioremap_prot(addr, size, prot);
 
 	pr_warn("ioremap() called early from %pS. Use early_ioremap() instead\n", caller);
 
@@ -49,17 +49,9 @@ void __iomem *__ioremap_caller(phys_addr_t addr, unsigned long size,
  */
 void iounmap(volatile void __iomem *token)
 {
-	void *addr;
-
 	if (!slab_is_available())
 		return;
 
-	addr = (void *)((unsigned long __force)PCI_FIX_ADDR(token) & PAGE_MASK);
-
-	if ((unsigned long)addr < ioremap_bot) {
-		pr_warn("Attempt to iounmap early bolted mapping at 0x%p\n", addr);
-		return;
-	}
-	vunmap(addr);
+	generic_iounmap(PCI_FIX_ADDR(token));
 }
 EXPORT_SYMBOL(iounmap);
-- 
2.34.1

[PATCH v4 15/16] arm64 : mm: add wrapper function ioremap_prot()

[Baoquan He]

Since hook functions ioremap_allowed() and iounmap_allowed() will be
obsoleted, add wrapper function ioremap_prot() to contain the
the specific handling in addition to generic_ioremap_prot() invocation.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-kernel@lists.infradead.org
---
 arch/arm64/include/asm/io.h |  3 +--
 arch/arm64/mm/ioremap.c     | 10 ++++++----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 877495a0fd0c..97dd4ff1253b 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -139,8 +139,7 @@ extern void __memset_io(volatile void __iomem *, int, size_t);
  * I/O memory mapping functions.
  */
 
-bool ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot);
-#define ioremap_allowed ioremap_allowed
+#define ioremap_prot ioremap_prot
 
 #define _PAGE_IOREMAP PROT_DEVICE_nGnRE
 
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
index c5af103d4ad4..269f2f63ab7d 100644
--- a/arch/arm64/mm/ioremap.c
+++ b/arch/arm64/mm/ioremap.c
@@ -3,20 +3,22 @@
 #include <linux/mm.h>
 #include <linux/io.h>
 
-bool ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot)
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
 {
 	unsigned long last_addr = phys_addr + size - 1;
 
 	/* Don't allow outside PHYS_MASK */
 	if (last_addr & ~PHYS_MASK)
-		return false;
+		return NULL;
 
 	/* Don't allow RAM to be mapped. */
 	if (WARN_ON(pfn_is_map_memory(__phys_to_pfn(phys_addr))))
-		return false;
+		return NULL;
 
-	return true;
+	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
 }
+EXPORT_SYMBOL(ioremap_prot);
 
 /*
  * Must be called after early_fixmap_init
-- 
2.34.1

[PATCH v4 16/16] mm: ioremap: remove unneeded ioremap_allowed and iounmap_allowed

[Baoquan He]

Now there are no users of ioremap_allowed and iounmap_allowed, clean
them up.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
 include/asm-generic/io.h | 26 --------------------------
 mm/ioremap.c             |  6 ------
 2 files changed, 32 deletions(-)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 29ee791164ac..c13109d17dcb 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1047,32 +1047,6 @@ static inline void iounmap(volatile void __iomem *addr)
 #elif defined(CONFIG_GENERIC_IOREMAP)
 #include <linux/pgtable.h>
 
-/*
- * Arch code can implement the following two hooks when using GENERIC_IOREMAP
- * ioremap_allowed() return a bool,
- *   - true means continue to remap
- *   - false means skip remap and return directly
- * iounmap_allowed() return a bool,
- *   - true means continue to vunmap
- *   - false means skip vunmap and return directly
- */
-#ifndef ioremap_allowed
-#define ioremap_allowed ioremap_allowed
-static inline bool ioremap_allowed(phys_addr_t phys_addr, size_t size,
-				   unsigned long prot)
-{
-	return true;
-}
-#endif
-
-#ifndef iounmap_allowed
-#define iounmap_allowed iounmap_allowed
-static inline bool iounmap_allowed(void *addr)
-{
-	return true;
-}
-#endif
-
 void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
 				   pgprot_t prot);
 
diff --git a/mm/ioremap.c b/mm/ioremap.c
index 4a7749d85044..8cb337446bba 100644
--- a/mm/ioremap.c
+++ b/mm/ioremap.c
@@ -32,9 +32,6 @@ void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
 	phys_addr -= offset;
 	size = PAGE_ALIGN(size + offset);
 
-	if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
-		return NULL;
-
 #ifdef IOREMAP_START
 	area = __get_vm_area_caller(size, VM_IOREMAP, IOREMAP_START,
 				    IOREMAP_END, __builtin_return_address(0));
@@ -68,9 +65,6 @@ void generic_iounmap(volatile void __iomem *addr)
 {
 	void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
 
-	if (!iounmap_allowed(vaddr))
-		return;
-
 	if (is_ioremap_addr(vaddr))
 		vunmap(vaddr);
 }
-- 
2.34.1

Re: [PATCH v4 04/16] mm: ioremap: allow ARCH to have its own ioremap method definition

[Arnd Bergmann]

On Thu, Feb 16, 2023, at 13:34, Baoquan He wrote:
> Architectures can be converted to GENERIC_IOREMAP, to take standard
> ioremap_xxx() and iounmap() way. But some ARCH-es could have specific
> handling for ioremap_prot(), ioremap() and iounmap(), than standard
> methods.
>
> In oder to convert these ARCH-es to take GENERIC_IOREMAP, allow these
> architecutres to have their own ioremap_prot(), ioremap() and iounmap()
> definitions.
>
> Signed-off-by: Baoquan He <bhe@redhat.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
> Cc: linux-arch@vger.kernel.org

Acked-by: Arnd Bergmann <arnd@arndb.de>

Re: [PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Arnd Bergmann]

On Thu, Feb 16, 2023, at 13:34, Baoquan He wrote:
> diff --git a/arch/hexagon/include/asm/io.h 
> b/arch/hexagon/include/asm/io.h
> index 46a099de85b7..dcd9cbbf5934 100644
> --- a/arch/hexagon/include/asm/io.h
> +++ b/arch/hexagon/include/asm/io.h
> @@ -170,8 +170,13 @@ static inline void writel(u32 data, volatile void 
> __iomem *addr)
>  #define writew_relaxed __raw_writew
>  #define writel_relaxed __raw_writel
> 
> -void __iomem *ioremap(unsigned long phys_addr, unsigned long size);
> -#define ioremap_uc(X, Y) ioremap((X), (Y))
> +/*
> + * I/O memory mapping functions.
> + */
> +#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
> +		       (__HEXAGON_C_DEV << 6))
> +
> +#define ioremap_uc(addr, size) ioremap((addr), (size))

I think we probably want to kill off ioremap_uc() here, and use
the generic version that just returns NULL.

I see that there are only two callers of {devm_,}ioremap_uc() left in the
tree, so maybe we can even take that final step and remove it from
the interface. Maybe we can revisit [1] as part of this series.

     Arnd

[1] https://lore.kernel.org/all/20191111192258.2234502-1-arnd@arndb.de/

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Matthew Wilcox]

On Thu, Feb 16, 2023 at 08:34:15PM +0800, Baoquan He wrote:
> Meanwhile, add macro ARCH_HAS_IOREMAP_WC since the added ioremap_wc()
> will conflict with the one in include/asm-generic/iomap.h, then an
> compiling error is seen:

Huh?  ARCH_HAS_IOREMAP_WC comes up nowhere else in this patchset, and
the current definition of ioremap_wc() is guarded by an ifndef ioremap_wc

> +#define ioremap_wc(addr, size)  \
> +	ioremap_prot((addr), (size), _PAGE_IOREMAP)

This should be enough all by itself.

Re: [PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/16/23 at 01:53pm, Arnd Bergmann wrote:
> On Thu, Feb 16, 2023, at 13:34, Baoquan He wrote:
> > diff --git a/arch/hexagon/include/asm/io.h 
> > b/arch/hexagon/include/asm/io.h
> > index 46a099de85b7..dcd9cbbf5934 100644
> > --- a/arch/hexagon/include/asm/io.h
> > +++ b/arch/hexagon/include/asm/io.h
> > @@ -170,8 +170,13 @@ static inline void writel(u32 data, volatile void 
> > __iomem *addr)
> >  #define writew_relaxed __raw_writew
> >  #define writel_relaxed __raw_writel
> > 
> > -void __iomem *ioremap(unsigned long phys_addr, unsigned long size);
> > -#define ioremap_uc(X, Y) ioremap((X), (Y))
> > +/*
> > + * I/O memory mapping functions.
> > + */
> > +#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
> > +		       (__HEXAGON_C_DEV << 6))
> > +

Thanks for reviewing.

> > +#define ioremap_uc(addr, size) ioremap((addr), (size))
> 
> I think we probably want to kill off ioremap_uc() here, and use
> the generic version that just returns NULL.


-#define ioremap_uc(X, Y) ioremap((X), (Y))
+#define ioremap_uc(addr, size) ioremap((addr), (size))

Here, in fact the ioremap_uc() definition is not related. I just
improve the old definition passingly. And similar for other
ioremap_uc() adaptation.

> 
> I see that there are only two callers of {devm_,}ioremap_uc() left in the
> tree, so maybe we can even take that final step and remove it from
> the interface. Maybe we can revisit [1] as part of this series.

I see now. Christoph Hellwig ever mentioned in v2 reviewing, I
didn't get why. Thanks for the details. 
https://lore.kernel.org/all/YwHX98KBEnZw9t6e@infradead.org/T/#u

I am not sure if it's OK to do the change in this patchset, maybe
another patch?

Thanks
Baoquan

Re: [PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Arnd Bergmann]

On Thu, Feb 16, 2023, at 15:47, Baoquan He wrote:
> On 02/16/23 at 01:53pm, Arnd Bergmann wrote:
>> On Thu, Feb 16, 2023, at 13:34, Baoquan He wrote:
>> I see that there are only two callers of {devm_,}ioremap_uc() left in the
>> tree, so maybe we can even take that final step and remove it from
>> the interface. Maybe we can revisit [1] as part of this series.
>
> I see now. Christoph Hellwig ever mentioned in v2 reviewing, I
> didn't get why. Thanks for the details. 
> https://lore.kernel.org/all/YwHX98KBEnZw9t6e@infradead.org/T/#u
>
> I am not sure if it's OK to do the change in this patchset, maybe
> another patch?

Yes, a separate patch would be ideal. If you do the same change in
more than one architecture (other than ia64 and x86), you can combine
those into one patch.

    Arnd

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/16/23 at 01:50pm, Matthew Wilcox wrote:
> On Thu, Feb 16, 2023 at 08:34:15PM +0800, Baoquan He wrote:
> > Meanwhile, add macro ARCH_HAS_IOREMAP_WC since the added ioremap_wc()
> > will conflict with the one in include/asm-generic/iomap.h, then an
> > compiling error is seen:
> 

Thanks for reviewing.

> Huh?  ARCH_HAS_IOREMAP_WC comes up nowhere else in this patchset, and
> the current definition of ioremap_wc() is guarded by an ifndef ioremap_wc

Because another patch of powerpc has got ARCH_HAS_IOREMAP_WC in the
existed code.

> 
> > +#define ioremap_wc(addr, size)  \
> > +	ioremap_prot((addr), (size), _PAGE_IOREMAP)
> 
> This should be enough all by itself.

It's not if including asm-generic/iomap.h. The ARCH_HAS_IOREMAP_xx is to
avoid redefinition there.

include/asm-generic/iomap.h:
----
#ifndef ARCH_HAS_IOREMAP_WC
#define ioremap_wc ioremap
#endif

> 

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Arnd Bergmann]

On Thu, Feb 16, 2023, at 16:02, Baoquan He wrote:
> On 02/16/23 at 01:50pm, Matthew Wilcox wrote:
> It's not if including asm-generic/iomap.h. The ARCH_HAS_IOREMAP_xx is to
> avoid redefinition there.
>
> include/asm-generic/iomap.h:
> ----
> #ifndef ARCH_HAS_IOREMAP_WC
> #define ioremap_wc ioremap
> #endif

I'd change that to the usual '#ifndef ioremap_wc' in that case.

      Arnd

Re: [PATCH v4 09/16] s390: mm: Convert to GENERIC_IOREMAP

[Niklas Schnelle]

On Thu, 2023-02-16 at 20:34 +0800, Baoquan He wrote:
> By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
> generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
> and iounmap() are all visible and available to arch. Arch needs to
> provide wrapper functions to override the generic versions if there's
> arch specific handling in its ioremap_prot(), ioremap() or iounmap().
> This change will simplify implementation by removing duplicated codes
> with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
> functioality as before.
> 
> Here, add wrapper functions ioremap_prot() and iounmap() for s390's
> special operation when ioremap() and iounmap().
> 
> Signed-off-by: Baoquan He <bhe@redhat.com>
> Cc: Niklas Schnelle <schnelle@linux.ibm.com>
> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
> Cc: Heiko Carstens <hca@linux.ibm.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Alexander Gordeev <agordeev@linux.ibm.com>
> Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> Cc: Sven Schnelle <svens@linux.ibm.com>
> Cc: linux-s390@vger.kernel.org
> ---
>  arch/s390/Kconfig          |  1 +
>  arch/s390/include/asm/io.h | 21 ++++++++------
>  arch/s390/pci/pci.c        | 57 +++++++-------------------------------
>  3 files changed, 23 insertions(+), 56 deletions(-)

Thanks for the patch. This is a very clear improvement for us! I tested
this series with s390 systems with and without the PCI memory-I/O (MIO)
support and everything works as expected.

One thing I did stumble upon but which is independent from this patch
is that I think memremap(…, MEMREMAP_WB) on system RAM outside the
direct map is broken for us. At least on systems without PCI memory-I/O
support. I think with this series it would be much easier to fix
though. Basically I think we would have to define arch_memremap_wb() to
generic_ioremap_prot(…, PAGE_KERNEL) and then have iounmap() check
is_ioremap_addr() to see if it is an actual mapping or an address
cookie. But again this is independent of this patch which doesn't
change the behavior in this area.

So feel free to add my:

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>

Re: [PATCH v4 01/16] hexagon: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/16/23 at 03:51pm, Arnd Bergmann wrote:
> On Thu, Feb 16, 2023, at 15:47, Baoquan He wrote:
> > On 02/16/23 at 01:53pm, Arnd Bergmann wrote:
> >> On Thu, Feb 16, 2023, at 13:34, Baoquan He wrote:
> >> I see that there are only two callers of {devm_,}ioremap_uc() left in the
> >> tree, so maybe we can even take that final step and remove it from
> >> the interface. Maybe we can revisit [1] as part of this series.
> >
> > I see now. Christoph Hellwig ever mentioned in v2 reviewing, I
> > didn't get why. Thanks for the details. 
> > https://lore.kernel.org/all/YwHX98KBEnZw9t6e@infradead.org/T/#u
> >
> > I am not sure if it's OK to do the change in this patchset, maybe
> > another patch?
> 
> Yes, a separate patch would be ideal. If you do the same change in
> more than one architecture (other than ia64 and x86), you can combine
> those into one patch.

I am making a patch to achieve this. There's trouble in mips since it
hasn't had <asm-generic/io.h> in <asm/io.h>, and adding that will cuase
build error. I will post the patch for reviewing.

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/16/23 at 04:18pm, Arnd Bergmann wrote:
> On Thu, Feb 16, 2023, at 16:02, Baoquan He wrote:
> > On 02/16/23 at 01:50pm, Matthew Wilcox wrote:
> > It's not if including asm-generic/iomap.h. The ARCH_HAS_IOREMAP_xx is to
> > avoid redefinition there.
> >
> > include/asm-generic/iomap.h:
> > ----
> > #ifndef ARCH_HAS_IOREMAP_WC
> > #define ioremap_wc ioremap
> > #endif
> 
> I'd change that to the usual '#ifndef ioremap_wc' in that case.

Not sure if I got you. Kill all ARCH_HAS_IOREMAP_xxx in kernel? If yes,
sounds like a good idea.

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Christophe Leroy]

Le 17/02/2023 à 14:31, Baoquan He a écrit :
> On 02/16/23 at 04:18pm, Arnd Bergmann wrote:
>> On Thu, Feb 16, 2023, at 16:02, Baoquan He wrote:
>>> On 02/16/23 at 01:50pm, Matthew Wilcox wrote:
>>> It's not if including asm-generic/iomap.h. The ARCH_HAS_IOREMAP_xx is to
>>> avoid redefinition there.
>>>
>>> include/asm-generic/iomap.h:
>>> ----
>>> #ifndef ARCH_HAS_IOREMAP_WC
>>> #define ioremap_wc ioremap
>>> #endif
>>
>> I'd change that to the usual '#ifndef ioremap_wc' in that case.
> 
> Not sure if I got you. Kill all ARCH_HAS_IOREMAP_xxx in kernel? If yes,
> sounds like a good idea.
> 

At least kill that one at the first place in your series, and then the 
other ones in a follow-up series maybe.

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/17/23 at 01:46pm, Christophe Leroy wrote:
> 
> 
> Le 17/02/2023 à 14:31, Baoquan He a écrit :
> > On 02/16/23 at 04:18pm, Arnd Bergmann wrote:
> >> On Thu, Feb 16, 2023, at 16:02, Baoquan He wrote:
> >>> On 02/16/23 at 01:50pm, Matthew Wilcox wrote:
> >>> It's not if including asm-generic/iomap.h. The ARCH_HAS_IOREMAP_xx is to
> >>> avoid redefinition there.
> >>>
> >>> include/asm-generic/iomap.h:
> >>> ----
> >>> #ifndef ARCH_HAS_IOREMAP_WC
> >>> #define ioremap_wc ioremap
> >>> #endif
> >>
> >> I'd change that to the usual '#ifndef ioremap_wc' in that case.
> > 
> > Not sure if I got you. Kill all ARCH_HAS_IOREMAP_xxx in kernel? If yes,
> > sounds like a good idea.
> > 
> 
> At least kill that one at the first place in your series, and then the 
> other ones in a follow-up series maybe.

Then we can make a preparation patch to change that in iomap.h, then
remove all ARCH_HAS_IOREMAP_WC definition in arch. I thought to let this
patch as is,  then get rid of all ARCH_HAS_IOREMAP_xxx in a follow-up
series. While the former is also fine to me. Thanks, Christophe.

diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h
index 08237ae8b840..5fa1e9ca951c 100644
--- a/include/asm-generic/iomap.h
+++ b/include/asm-generic/iomap.h
@@ -93,7 +93,7 @@ extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
 extern void ioport_unmap(void __iomem *);
 #endif
 
-#ifndef ARCH_HAS_IOREMAP_WC
+#ifndef ioremap_wc
 #define ioremap_wc ioremap
 #endif

[~]$ git grep ARCH_HAS_IOREMAP_WC
arch/loongarch/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/mips/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
drivers/net/ethernet/sfc/io.h:#ifdef ARCH_HAS_IOREMAP_WC
drivers/net/ethernet/sfc/siena/io.h:#ifdef ARCH_HAS_IOREMAP_WC
include/asm-generic/iomap.h:#ifndef ARCH_HAS_IOREMAP_WC

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Christophe Leroy]

Le 17/02/2023 à 15:21, Baoquan He a écrit :
> On 02/17/23 at 01:46pm, Christophe Leroy wrote:
>>
>>
>> Le 17/02/2023 à 14:31, Baoquan He a écrit :
>>> On 02/16/23 at 04:18pm, Arnd Bergmann wrote:
>>>> On Thu, Feb 16, 2023, at 16:02, Baoquan He wrote:
>>>>> On 02/16/23 at 01:50pm, Matthew Wilcox wrote:
>>>>> It's not if including asm-generic/iomap.h. The ARCH_HAS_IOREMAP_xx is to
>>>>> avoid redefinition there.
>>>>>
>>>>> include/asm-generic/iomap.h:
>>>>> ----
>>>>> #ifndef ARCH_HAS_IOREMAP_WC
>>>>> #define ioremap_wc ioremap
>>>>> #endif
>>>>
>>>> I'd change that to the usual '#ifndef ioremap_wc' in that case.
>>>
>>> Not sure if I got you. Kill all ARCH_HAS_IOREMAP_xxx in kernel? If yes,
>>> sounds like a good idea.
>>>
>>
>> At least kill that one at the first place in your series, and then the
>> other ones in a follow-up series maybe.
> 
> Then we can make a preparation patch to change that in iomap.h, then
> remove all ARCH_HAS_IOREMAP_WC definition in arch. I thought to let this
> patch as is,  then get rid of all ARCH_HAS_IOREMAP_xxx in a follow-up
> series. While the former is also fine to me. Thanks, Christophe.
> 
> diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h
> index 08237ae8b840..5fa1e9ca951c 100644
> --- a/include/asm-generic/iomap.h
> +++ b/include/asm-generic/iomap.h
> @@ -93,7 +93,7 @@ extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
>   extern void ioport_unmap(void __iomem *);
>   #endif
>   
> -#ifndef ARCH_HAS_IOREMAP_WC
> +#ifndef ioremap_wc
>   #define ioremap_wc ioremap
>   #endif
> 
> [~]$ git grep ARCH_HAS_IOREMAP_WC
> arch/loongarch/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/mips/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> drivers/net/ethernet/sfc/io.h:#ifdef ARCH_HAS_IOREMAP_WC
> drivers/net/ethernet/sfc/siena/io.h:#ifdef ARCH_HAS_IOREMAP_WC
> include/asm-generic/iomap.h:#ifndef ARCH_HAS_IOREMAP_WC
> 
> 

Not so many:

$ git grep ARCH_HAS_IOREMAP_WC  | grep define
arch/loongarch/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/mips/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC

And also make sure they define ioremap_wc :

$ git grep "define ioremap_wc" `git grep -l "define ARCH_HAS_IOREMAP_WC"`
arch/loongarch/include/asm/io.h:#define ioremap_wc(offset, size)        \
arch/mips/include/asm/io.h:#define ioremap_wc(offset, size) 
                        \
arch/powerpc/include/asm/io.h:#define ioremap_wc ioremap_wc
arch/x86/include/asm/io.h:#define ioremap_wc ioremap_wc


Christophe

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Christophe Leroy]

Le 17/02/2023 à 15:33, Christophe Leroy a écrit :
> 
> 
> Le 17/02/2023 à 15:21, Baoquan He a écrit :
>> On 02/17/23 at 01:46pm, Christophe Leroy wrote:
>>>
>>>
>>> Le 17/02/2023 à 14:31, Baoquan He a écrit :
>>>> On 02/16/23 at 04:18pm, Arnd Bergmann wrote:
>>>>> On Thu, Feb 16, 2023, at 16:02, Baoquan He wrote:
>>>>>> On 02/16/23 at 01:50pm, Matthew Wilcox wrote:
>>>>>> It's not if including asm-generic/iomap.h. The ARCH_HAS_IOREMAP_xx 
>>>>>> is to
>>>>>> avoid redefinition there.
>>>>>>
>>>>>> include/asm-generic/iomap.h:
>>>>>> ----
>>>>>> #ifndef ARCH_HAS_IOREMAP_WC
>>>>>> #define ioremap_wc ioremap
>>>>>> #endif
>>>>>
>>>>> I'd change that to the usual '#ifndef ioremap_wc' in that case.
>>>>
>>>> Not sure if I got you. Kill all ARCH_HAS_IOREMAP_xxx in kernel? If yes,
>>>> sounds like a good idea.
>>>>
>>>
>>> At least kill that one at the first place in your series, and then the
>>> other ones in a follow-up series maybe.
>>
>> Then we can make a preparation patch to change that in iomap.h, then
>> remove all ARCH_HAS_IOREMAP_WC definition in arch. I thought to let this
>> patch as is,  then get rid of all ARCH_HAS_IOREMAP_xxx in a follow-up
>> series. While the former is also fine to me. Thanks, Christophe.
>>
>> diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h
>> index 08237ae8b840..5fa1e9ca951c 100644
>> --- a/include/asm-generic/iomap.h
>> +++ b/include/asm-generic/iomap.h
>> @@ -93,7 +93,7 @@ extern void __iomem *ioport_map(unsigned long port, 
>> unsigned int nr);
>>   extern void ioport_unmap(void __iomem *);
>>   #endif
>> -#ifndef ARCH_HAS_IOREMAP_WC
>> +#ifndef ioremap_wc
>>   #define ioremap_wc ioremap
>>   #endif
>>
>> [~]$ git grep ARCH_HAS_IOREMAP_WC
>> arch/loongarch/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
>> arch/mips/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
>> arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
>> arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
>> drivers/net/ethernet/sfc/io.h:#ifdef ARCH_HAS_IOREMAP_WC
>> drivers/net/ethernet/sfc/siena/io.h:#ifdef ARCH_HAS_IOREMAP_WC
>> include/asm-generic/iomap.h:#ifndef ARCH_HAS_IOREMAP_WC
>>
>>
> 
> Not so many:
> 
> $ git grep ARCH_HAS_IOREMAP_WC  | grep define
> arch/loongarch/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/mips/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> 
> And also make sure they define ioremap_wc :
> 
> $ git grep "define ioremap_wc" `git grep -l "define ARCH_HAS_IOREMAP_WC"`
> arch/loongarch/include/asm/io.h:#define ioremap_wc(offset, size)        \
> arch/mips/include/asm/io.h:#define ioremap_wc(offset, size) 
>                         \
> arch/powerpc/include/asm/io.h:#define ioremap_wc ioremap_wc
> arch/x86/include/asm/io.h:#define ioremap_wc ioremap_wc
> 


By the way there are so few, you can make all at once:

$ git grep ARCH_HAS_IOREMAP_ | grep define
arch/loongarch/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/m68k/include/asm/kmap.h:#define ARCH_HAS_IOREMAP_WT
arch/mips/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WT
arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WT

Christophe

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/17/23 at 02:35pm, Christophe Leroy wrote:
...... 
> > Not so many:
> > 
> > $ git grep ARCH_HAS_IOREMAP_WC  | grep define
> > arch/loongarch/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> > arch/mips/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> > arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> > arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> > 
> > And also make sure they define ioremap_wc :
> > 
> > $ git grep "define ioremap_wc" `git grep -l "define ARCH_HAS_IOREMAP_WC"`
> > arch/loongarch/include/asm/io.h:#define ioremap_wc(offset, size)        \
> > arch/mips/include/asm/io.h:#define ioremap_wc(offset, size) 
> >                         \
> > arch/powerpc/include/asm/io.h:#define ioremap_wc ioremap_wc
> > arch/x86/include/asm/io.h:#define ioremap_wc ioremap_wc
> > 
> 
> 
> By the way there are so few, you can make all at once:

OK, I will try to pack this into one preparation patch. Thanks.

> 
> $ git grep ARCH_HAS_IOREMAP_ | grep define
> arch/loongarch/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/m68k/include/asm/kmap.h:#define ARCH_HAS_IOREMAP_WT
> arch/mips/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/powerpc/include/asm/io.h:#define ARCH_HAS_IOREMAP_WT
> arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WC
> arch/x86/include/asm/io.h:#define ARCH_HAS_IOREMAP_WT
> 
> Christophe

Re: [PATCH v4 09/16] s390: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/16/23 at 05:21pm, Niklas Schnelle wrote:
> On Thu, 2023-02-16 at 20:34 +0800, Baoquan He wrote:
> > By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
> > generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
> > and iounmap() are all visible and available to arch. Arch needs to
> > provide wrapper functions to override the generic versions if there's
> > arch specific handling in its ioremap_prot(), ioremap() or iounmap().
> > This change will simplify implementation by removing duplicated codes
> > with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
> > functioality as before.
> > 
> > Here, add wrapper functions ioremap_prot() and iounmap() for s390's
> > special operation when ioremap() and iounmap().
> > 
> > Signed-off-by: Baoquan He <bhe@redhat.com>
> > Cc: Niklas Schnelle <schnelle@linux.ibm.com>
> > Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
> > Cc: Heiko Carstens <hca@linux.ibm.com>
> > Cc: Vasily Gorbik <gor@linux.ibm.com>
> > Cc: Alexander Gordeev <agordeev@linux.ibm.com>
> > Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> > Cc: Sven Schnelle <svens@linux.ibm.com>
> > Cc: linux-s390@vger.kernel.org
> > ---
> >  arch/s390/Kconfig          |  1 +
> >  arch/s390/include/asm/io.h | 21 ++++++++------
> >  arch/s390/pci/pci.c        | 57 +++++++-------------------------------
> >  3 files changed, 23 insertions(+), 56 deletions(-)
> 
> Thanks for the patch. This is a very clear improvement for us! I tested
> this series with s390 systems with and without the PCI memory-I/O (MIO)
> support and everything works as expected.
> 
> One thing I did stumble upon but which is independent from this patch
> is that I think memremap(…, MEMREMAP_WB) on system RAM outside the
> direct map is broken for us. At least on systems without PCI memory-I/O
> support. I think with this series it would be much easier to fix
> though. Basically I think we would have to define arch_memremap_wb() to
> generic_ioremap_prot(…, PAGE_KERNEL) and then have iounmap() check
> is_ioremap_addr() to see if it is an actual mapping or an address
> cookie. But again this is independent of this patch which doesn't
> change the behavior in this area.

OK, I can check this after this patchset done.

> 
> So feel free to add my:
> 
> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
> Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>

Thanks a lot, will add these when repost.

Re: [PATCH v4 09/16] s390: mm: Convert to GENERIC_IOREMAP

[Niklas Schnelle]

On Tue, 2023-02-21 at 19:48 +0800, Baoquan He wrote:
> On 02/16/23 at 05:21pm, Niklas Schnelle wrote:
> > On Thu, 2023-02-16 at 20:34 +0800, Baoquan He wrote:
> > > By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
> > > generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
> > > and iounmap() are all visible and available to arch. Arch needs to
> > > provide wrapper functions to override the generic versions if there's
> > > arch specific handling in its ioremap_prot(), ioremap() or iounmap().
> > > This change will simplify implementation by removing duplicated codes
> > > with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
> > > functioality as before.
> > > 
> > > Here, add wrapper functions ioremap_prot() and iounmap() for s390's
> > > special operation when ioremap() and iounmap().
> > > 
> > > Signed-off-by: Baoquan He <bhe@redhat.com>
> > > Cc: Niklas Schnelle <schnelle@linux.ibm.com>
> > > Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
> > > Cc: Heiko Carstens <hca@linux.ibm.com>
> > > Cc: Vasily Gorbik <gor@linux.ibm.com>
> > > Cc: Alexander Gordeev <agordeev@linux.ibm.com>
> > > Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> > > Cc: Sven Schnelle <svens@linux.ibm.com>
> > > Cc: linux-s390@vger.kernel.org
> > > ---
> > >  arch/s390/Kconfig          |  1 +
> > >  arch/s390/include/asm/io.h | 21 ++++++++------
> > >  arch/s390/pci/pci.c        | 57 +++++++-------------------------------
> > >  3 files changed, 23 insertions(+), 56 deletions(-)
> > 
> > Thanks for the patch. This is a very clear improvement for us! I tested
> > this series with s390 systems with and without the PCI memory-I/O (MIO)
> > support and everything works as expected.
> > 
> > One thing I did stumble upon but which is independent from this patch
> > is that I think memremap(…, MEMREMAP_WB) on system RAM outside the
> > direct map is broken for us. At least on systems without PCI memory-I/O
> > support. I think with this series it would be much easier to fix
> > though. Basically I think we would have to define arch_memremap_wb() to
> > generic_ioremap_prot(…, PAGE_KERNEL) and then have iounmap() check
> > is_ioremap_addr() to see if it is an actual mapping or an address
> > cookie. But again this is independent of this patch which doesn't
> > change the behavior in this area.
> 
> OK, I can check this after this patchset done.

Oh this wasn't meant as adding a task for you just a FYI. I'm already
experimenting with this and plan to possibly send a patch that fixes
the case of remapping system RAM once your series has landed. The thing
is that memremap() is quite tricky for us whichever way you look at
it. 

We don't have real MMIO on s390x and thus using memremap() for PCI MMIO
spaces doesn't really work as the void* returned can still only be
accessed using ioread()/iowrite() because only our special PCI access
instructions work on the pseudo-MMIO addresses (with PCI MIO)
respectively the address cookies. Obviously void* and memremap() really
isn't the right tool if you need to use ioread()/iowrite() to access it
and can't treat it as memory though.

Thanks,
Niklas

Re: [PATCH v4 09/16] s390: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

On 02/21/23 at 01:26pm, Niklas Schnelle wrote:
> On Tue, 2023-02-21 at 19:48 +0800, Baoquan He wrote:
> > On 02/16/23 at 05:21pm, Niklas Schnelle wrote:
> > > On Thu, 2023-02-16 at 20:34 +0800, Baoquan He wrote:
> > > > By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
> > > > generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
> > > > and iounmap() are all visible and available to arch. Arch needs to
> > > > provide wrapper functions to override the generic versions if there's
> > > > arch specific handling in its ioremap_prot(), ioremap() or iounmap().
> > > > This change will simplify implementation by removing duplicated codes
> > > > with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
> > > > functioality as before.
> > > > 
> > > > Here, add wrapper functions ioremap_prot() and iounmap() for s390's
> > > > special operation when ioremap() and iounmap().
> > > > 
> > > > Signed-off-by: Baoquan He <bhe@redhat.com>
> > > > Cc: Niklas Schnelle <schnelle@linux.ibm.com>
> > > > Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
> > > > Cc: Heiko Carstens <hca@linux.ibm.com>
> > > > Cc: Vasily Gorbik <gor@linux.ibm.com>
> > > > Cc: Alexander Gordeev <agordeev@linux.ibm.com>
> > > > Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> > > > Cc: Sven Schnelle <svens@linux.ibm.com>
> > > > Cc: linux-s390@vger.kernel.org
> > > > ---
> > > >  arch/s390/Kconfig          |  1 +
> > > >  arch/s390/include/asm/io.h | 21 ++++++++------
> > > >  arch/s390/pci/pci.c        | 57 +++++++-------------------------------
> > > >  3 files changed, 23 insertions(+), 56 deletions(-)
> > > 
> > > Thanks for the patch. This is a very clear improvement for us! I tested
> > > this series with s390 systems with and without the PCI memory-I/O (MIO)
> > > support and everything works as expected.
> > > 
> > > One thing I did stumble upon but which is independent from this patch
> > > is that I think memremap(…, MEMREMAP_WB) on system RAM outside the
> > > direct map is broken for us. At least on systems without PCI memory-I/O
> > > support. I think with this series it would be much easier to fix
> > > though. Basically I think we would have to define arch_memremap_wb() to
> > > generic_ioremap_prot(…, PAGE_KERNEL) and then have iounmap() check
> > > is_ioremap_addr() to see if it is an actual mapping or an address
> > > cookie. But again this is independent of this patch which doesn't
> > > change the behavior in this area.
> > 
> > OK, I can check this after this patchset done.
> 
> Oh this wasn't meant as adding a task for you just a FYI. I'm already
> experimenting with this and plan to possibly send a patch that fixes
> the case of remapping system RAM once your series has landed. The thing
> is that memremap() is quite tricky for us whichever way you look at
> it. 
> 
> We don't have real MMIO on s390x and thus using memremap() for PCI MMIO
> spaces doesn't really work as the void* returned can still only be
> accessed using ioread()/iowrite() because only our special PCI access
> instructions work on the pseudo-MMIO addresses (with PCI MIO)
> respectively the address cookies. Obviously void* and memremap() really
> isn't the right tool if you need to use ioread()/iowrite() to access it
> and can't treat it as memory though.

Ah, I misunderstood it. Thanks for sharing and expect to see your post.

Re: [PATCH v4 12/16] parisc: mm: Convert to GENERIC_IOREMAP

[Baoquan He]

Hi Christophe, Arnd,

On 02/17/23 at 01:46pm, Christophe Leroy wrote:
> 
> 
> Le 17/02/2023 à 14:31, Baoquan He a écrit :
> > On 02/16/23 at 04:18pm, Arnd Bergmann wrote:
> >> On Thu, Feb 16, 2023, at 16:02, Baoquan He wrote:
> >>> On 02/16/23 at 01:50pm, Matthew Wilcox wrote:
> >>> It's not if including asm-generic/iomap.h. The ARCH_HAS_IOREMAP_xx is to
> >>> avoid redefinition there.
> >>>
> >>> include/asm-generic/iomap.h:
> >>> ----
> >>> #ifndef ARCH_HAS_IOREMAP_WC
> >>> #define ioremap_wc ioremap
> >>> #endif
> >>
> >> I'd change that to the usual '#ifndef ioremap_wc' in that case.
> > 
> > Not sure if I got you. Kill all ARCH_HAS_IOREMAP_xxx in kernel? If yes,
> > sounds like a good idea.
> > 
> 
> At least kill that one at the first place in your series, and then the 
> other ones in a follow-up series maybe.

I made a patch to remove all ARCH_HAS_IOREMAP_xx macros in architectures
and the ifdeffery of ARCH_HAS_IOREMAP_xx in asm-generic/iomap.h.
But the change will cause building error as below. Becuase we usually
have '#include <asm-generic/iomap.h>' at the beginning of
arch/xx/include/asm/io.h, and have '#include <asm-generic/io.h>' at the
end of arch/xx/include/asm/io.h. For architecutres which has
ARCH_HAS_IOREMAP_xx defining, we need move ''#include <asm-generic/iomap.h>
dowe to below '#include <asm-generic/io.h>'. Please help check if it's
still worth doing.


***move '#include <asm-generic/iomap.h>' below '#include <asm-generic/io.h>' 
***
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 8ab68cde1f13..a8d55fc62959 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -209,8 +209,6 @@ void memset_io(volatile void __iomem *, int, size_t);
 #define memcpy_toio memcpy_toio
 #define memset_io memset_io
 
-#include <asm-generic/iomap.h>
-
 /*
  * ISA space is 'always mapped' on a typical x86 system, no need to
  * explicitly ioremap() it. The fact that the ISA IO space is mapped
@@ -329,6 +327,8 @@ extern bool is_early_ioremap_ptep(pte_t *ptep);
 #include <asm-generic/io.h>
 #undef PCI_IOBASE
 
+#include <asm-generic/iomap.h>
+
 #ifdef CONFIG_MTRR
 extern int __must_check arch_phys_wc_index(int handle);
 #define arch_phys_wc_index arch_phys_wc_index


***Building error after removing ARCH_HAS_IOREMAP_xx
***
In file included from ./include/linux/io.h:13,
                 from ./include/linux/irq.h:20,
                 from ./include/xen/events.h:6,
                 from arch/x86/entry/common.c:25:
./arch/x86/include/asm/io.h:321: warning: "ioremap_wc" redefined
  321 | #define ioremap_wc ioremap_wc
      | 
In file included from ./arch/x86/include/asm/io.h:212:
./include/asm-generic/iomap.h:97: note: this is the location of the previous definition
   97 | #define ioremap_wc ioremap
      | 
./arch/x86/include/asm/io.h:323: warning: "ioremap_wt" redefined
  323 | #define ioremap_wt ioremap_wt
      | 
./include/asm-generic/iomap.h:101: note: this is the location of the previous definition
  101 | #define ioremap_wt ioremap