Re: [PATCH 1/3] x86: unify asm/io.h: IO_SPACE_LIMIT

[Jeremy Fitzhardinge]

H. Peter Anvin wrote:
> Hi Jeremy,
>
> I applied patch #1 to tip:x86/cleanups, however, patch #2 and #3 are
> identical... did you mean to do something different here?
>
> Furthermore, please provide an actual description (and preferrably an
> Impact: line) with your patches.  In particular, when unifying code that
> is identical between 32 and 64 bits, please specify this in the
> description (e.g. "unified functions X and Y which were already
> identical between 32 and 64 bits"), so we know why there isn't a
> preceeding patch to remove the remaining differences.

Oops.  Here they are.  The order is:

x86-unify-io.h-virt-phys.patch
x86-unify-io.h-ioremap-proto.patch

   J

Subject: x86: asm/io.h: unify virt_to_phys/phys_to_virt

Impact: unify identical code

asm/io_32.h and _64.h has functionally identical definitions for
virt_to_phys, phys_to_virt, page_to_phys, and the isa_* variants, so
just unify them.

The only slightly functional change is using phys_addr_t for the
physical address argument and return val.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 arch/x86/include/asm/io.h    |   59 ++++++++++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/io_32.h |   57 ----------------------------------------
 arch/x86/include/asm/io_64.h |   37 --------------------------
 3 files changed, 59 insertions(+), 94 deletions(-)

===================================================================
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -5,6 +5,7 @@
 
 #include <linux/compiler.h>
 #include <asm-generic/int-ll64.h>
+#include <asm/page.h>
 
 #define build_mmio_read(name, size, type, reg, barrier) \
 static inline type name(const volatile void __iomem *addr) \
@@ -80,6 +81,64 @@
 #define readq			readq
 #define writeq			writeq
 
+/**
+ *	virt_to_phys	-	map virtual addresses to physical
+ *	@address: address to remap
+ *
+ *	The returned physical address is the physical (CPU) mapping for
+ *	the memory address given. It is only valid to use this function on
+ *	addresses directly mapped or allocated via kmalloc.
+ *
+ *	This function does not give bus mappings for DMA transfers. In
+ *	almost all conceivable cases a device driver should not be using
+ *	this function
+ */
+
+static inline phys_addr_t virt_to_phys(volatile void *address)
+{
+	return __pa(address);
+}
+
+/**
+ *	phys_to_virt	-	map physical address to virtual
+ *	@address: address to remap
+ *
+ *	The returned virtual address is a current CPU mapping for
+ *	the memory address given. It is only valid to use this function on
+ *	addresses that have a kernel mapping
+ *
+ *	This function does not handle bus mappings for DMA transfers. In
+ *	almost all conceivable cases a device driver should not be using
+ *	this function
+ */
+
+static inline void *phys_to_virt(phys_addr_t address)
+{
+	return __va(address);
+}
+
+/*
+ * Change "struct page" to physical address.
+ */
+#define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
+
+/*
+ * ISA I/O bus memory addresses are 1:1 with the physical address.
+ */
+#define isa_virt_to_bus virt_to_phys
+#define isa_page_to_bus page_to_phys
+#define isa_bus_to_virt phys_to_virt
+
+/*
+ * However PCI ones are not necessarily 1:1 and therefore these interfaces
+ * are forbidden in portable PCI drivers.
+ *
+ * Allow them on x86 for legacy drivers, though.
+ */
+#define virt_to_bus virt_to_phys
+#define bus_to_virt phys_to_virt
+
+
 #ifdef CONFIG_X86_32
 # include "io_32.h"
 #else
===================================================================
--- a/arch/x86/include/asm/io_32.h
+++ b/arch/x86/include/asm/io_32.h
@@ -52,47 +52,6 @@
 #define xlate_dev_kmem_ptr(p)	p
 
 /**
- *	virt_to_phys	-	map virtual addresses to physical
- *	@address: address to remap
- *
- *	The returned physical address is the physical (CPU) mapping for
- *	the memory address given. It is only valid to use this function on
- *	addresses directly mapped or allocated via kmalloc.
- *
- *	This function does not give bus mappings for DMA transfers. In
- *	almost all conceivable cases a device driver should not be using
- *	this function
- */
-
-static inline unsigned long virt_to_phys(volatile void *address)
-{
-	return __pa(address);
-}
-
-/**
- *	phys_to_virt	-	map physical address to virtual
- *	@address: address to remap
- *
- *	The returned virtual address is a current CPU mapping for
- *	the memory address given. It is only valid to use this function on
- *	addresses that have a kernel mapping
- *
- *	This function does not handle bus mappings for DMA transfers. In
- *	almost all conceivable cases a device driver should not be using
- *	this function
- */
-
-static inline void *phys_to_virt(unsigned long address)
-{
-	return __va(address);
-}
-
-/*
- * Change "struct page" to physical address.
- */
-#define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
-
-/**
  * ioremap     -   map bus memory into CPU space
  * @offset:    bus address of the memory
  * @size:      size of the resource to map
@@ -121,22 +80,6 @@
 
 extern void iounmap(volatile void __iomem *addr);
 
-/*
- * ISA I/O bus memory addresses are 1:1 with the physical address.
- */
-#define isa_virt_to_bus virt_to_phys
-#define isa_page_to_bus page_to_phys
-#define isa_bus_to_virt phys_to_virt
-
-/*
- * However PCI ones are not necessarily 1:1 and therefore these interfaces
- * are forbidden in portable PCI drivers.
- *
- * Allow them on x86 for legacy drivers, though.
- */
-#define virt_to_bus virt_to_phys
-#define bus_to_virt phys_to_virt
-
 static inline void
 memset_io(volatile void __iomem *addr, unsigned char val, int count)
 {
===================================================================
--- a/arch/x86/include/asm/io_64.h
+++ b/arch/x86/include/asm/io_64.h
@@ -140,27 +140,6 @@
 
 #include <linux/vmalloc.h>
 
-#ifndef __i386__
-/*
- * Change virtual addresses to physical addresses and vv.
- * These are pretty trivial
- */
-static inline unsigned long virt_to_phys(volatile void *address)
-{
-	return __pa(address);
-}
-
-static inline void *phys_to_virt(unsigned long address)
-{
-	return __va(address);
-}
-#endif
-
-/*
- * Change "struct page" to physical address.
- */
-#define page_to_phys(page)    ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
-
 #include <asm-generic/iomap.h>
 
 /*
@@ -185,22 +164,6 @@
 
 extern void __iomem *fix_ioremap(unsigned idx, unsigned long phys);
 
-/*
- * ISA I/O bus memory addresses are 1:1 with the physical address.
- */
-#define isa_virt_to_bus virt_to_phys
-#define isa_page_to_bus page_to_phys
-#define isa_bus_to_virt phys_to_virt
-
-/*
- * However PCI ones are not necessarily 1:1 and therefore these interfaces
- * are forbidden in portable PCI drivers.
- *
- * Allow them on x86 for legacy drivers, though.
- */
-#define virt_to_bus virt_to_phys
-#define bus_to_virt phys_to_virt
-
 void __memcpy_fromio(void *, unsigned long, unsigned);
 void __memcpy_toio(unsigned long, const void *, unsigned);
 
Subject: x86: asm/io.h: unify ioremap prototypes

Impact: unify identical code

asm/io_32.h and _64.h have identical prototypes for the ioremap family
of functions.  The 32-bit header had a more descriptive comment.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 arch/x86/include/asm/io.h    |   31 +++++++++++++++++++++++++++++++
 arch/x86/include/asm/io_32.h |   29 -----------------------------
 arch/x86/include/asm/io_64.h |   22 ----------------------
 3 files changed, 31 insertions(+), 51 deletions(-)

===================================================================
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -118,6 +118,37 @@
 #define virt_to_bus virt_to_phys
 #define bus_to_virt phys_to_virt
 
+/**
+ * ioremap     -   map bus memory into CPU space
+ * @offset:    bus address of the memory
+ * @size:      size of the resource to map
+ *
+ * ioremap performs a platform specific sequence of operations to
+ * make bus memory CPU accessible via the readb/readw/readl/writeb/
+ * writew/writel functions and the other mmio helpers. The returned
+ * address is not guaranteed to be usable directly as a virtual
+ * address.
+ *
+ * If the area you are trying to map is a PCI BAR you should have a
+ * look at pci_iomap().
+ */
+extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
+extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
+extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
+				unsigned long prot_val);
+
+/*
+ * The default ioremap() behavior is non-cached:
+ */
+static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
+{
+	return ioremap_nocache(offset, size);
+}
+
+extern void iounmap(volatile void __iomem *addr);
+
+extern void __iomem *fix_ioremap(unsigned idx, unsigned long phys);
+
 
 #ifdef CONFIG_X86_32
 # include "io_32.h"
===================================================================
--- a/arch/x86/include/asm/io_32.h
+++ b/arch/x86/include/asm/io_32.h
@@ -52,35 +52,6 @@
  * Convert a virtual cached pointer to an uncached pointer
  */
 #define xlate_dev_kmem_ptr(p)	p
-
-/**
- * ioremap     -   map bus memory into CPU space
- * @offset:    bus address of the memory
- * @size:      size of the resource to map
- *
- * ioremap performs a platform specific sequence of operations to
- * make bus memory CPU accessible via the readb/readw/readl/writeb/
- * writew/writel functions and the other mmio helpers. The returned
- * address is not guaranteed to be usable directly as a virtual
- * address.
- *
- * If the area you are trying to map is a PCI BAR you should have a
- * look at pci_iomap().
- */
-extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
-extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
-extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
-				unsigned long prot_val);
-
-/*
- * The default ioremap() behavior is non-cached:
- */
-static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
-{
-	return ioremap_nocache(offset, size);
-}
-
-extern void iounmap(volatile void __iomem *addr);
 
 static inline void
 memset_io(volatile void __iomem *addr, unsigned char val, int count)
===================================================================
--- a/arch/x86/include/asm/io_64.h
+++ b/arch/x86/include/asm/io_64.h
@@ -144,28 +144,6 @@
 
 #include <asm-generic/iomap.h>
 
-/*
- * This one maps high address device memory and turns off caching for that area.
- * it's useful if some control registers are in such an area and write combining
- * or read caching is not desirable:
- */
-extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size);
-extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size);
-extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size,
-				unsigned long prot_val);
-
-/*
- * The default ioremap() behavior is non-cached:
- */
-static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
-{
-	return ioremap_nocache(offset, size);
-}
-
-extern void iounmap(volatile void __iomem *addr);
-
-extern void __iomem *fix_ioremap(unsigned idx, unsigned long phys);
-
 void __memcpy_fromio(void *, unsigned long, unsigned);
 void __memcpy_toio(unsigned long, const void *, unsigned);