powerpc: Better split CONFIG_PPC_INDIRECT_PIO and CONFIG_PPC_INDIRECT_MMIO

Remove the generic PPC_INDIRECT_IO and ensure we only add overhead
to the right accessors. IE. If only CONFIG_PPC_INDIRECT_PIO is set,
we don't add overhead to all MMIO accessors.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/io.h

@@ -69,8 +69,10 @@ extern unsigned long pci_dram_offset;
 
 extern resource_size_t isa_mem_base;
 
-#if defined(CONFIG_PPC32) && defined(CONFIG_PPC_INDIRECT_IO)
-#error CONFIG_PPC_INDIRECT_IO is not yet supported on 32 bits
+#ifdef CONFIG_PPC32
+#if defined(CONFIG_PPC_INDIRECT_PIO) || defined(CONFIG_PPC_INDIRECT_MMIO)
+#error CONFIG_PPC_INDIRECT_{PIO,MMIO} are not yet supported on 32 bits
+#endif
 #endif
 
 /*
@@ -222,9 +224,9 @@ extern void _memcpy_toio(volatile void __iomem *dest, const void *src,
  * for PowerPC is as close as possible to the x86 version of these, and thus
  * provides fairly heavy weight barriers for the non-raw versions
  *
- * In addition, they support a hook mechanism when CONFIG_PPC_INDIRECT_IO
- * allowing the platform to provide its own implementation of some or all
- * of the accessors.
+ * In addition, they support a hook mechanism when CONFIG_PPC_INDIRECT_MMIO
+ * or CONFIG_PPC_INDIRECT_PIO are set allowing the platform to provide its
+ * own implementation of some or all of the accessors.
  */
 
 /*
@@ -240,8 +242,8 @@ extern void _memcpy_toio(volatile void __iomem *dest, const void *src,
 
 /* Indirect IO address tokens:
  *
- * When CONFIG_PPC_INDIRECT_IO is set, the platform can provide hooks
- * on all IOs. (Note that this is all 64 bits only for now)
+ * When CONFIG_PPC_INDIRECT_MMIO is set, the platform can provide hooks
+ * on all MMIOs. (Note that this is all 64 bits only for now)
  *
  * To help platforms who may need to differenciate MMIO addresses in
  * their hooks, a bitfield is reserved for use by the platform near the
@@ -263,11 +265,14 @@ extern void _memcpy_toio(volatile void __iomem *dest, const void *src,
  *
  * The direct IO mapping operations will then mask off those bits
  * before doing the actual access, though that only happen when
- * CONFIG_PPC_INDIRECT_IO is set, thus be careful when you use that
+ * CONFIG_PPC_INDIRECT_MMIO is set, thus be careful when you use that
  * mechanism
+ *
+ * For PIO, there is a separate CONFIG_PPC_INDIRECT_PIO which makes
+ * all PIO functions call through a hook.
  */
 
-#ifdef CONFIG_PPC_INDIRECT_IO
+#ifdef CONFIG_PPC_INDIRECT_MMIO
 #define PCI_IO_IND_TOKEN_MASK	0x0fff000000000000ul
 #define PCI_IO_IND_TOKEN_SHIFT	48
 #define PCI_FIX_ADDR(addr)						\
@@ -672,7 +677,7 @@ extern void __iomem * __ioremap_at(phys_addr_t pa, void *ea,
 extern void __iounmap_at(void *ea, unsigned long size);
 
 /*
- * When CONFIG_PPC_INDIRECT_IO is set, we use the generic iomap implementation
+ * When CONFIG_PPC_INDIRECT_PIO is set, we use the generic iomap implementation
  * which needs some additional definitions here. They basically allow PIO
  * space overall to be 1GB. This will work as long as we never try to use
  * iomap to map MMIO below 1GB which should be fine on ppc64

arch/powerpc/kernel/Makefile

@@ -119,7 +119,7 @@ obj-$(CONFIG_FTRACE_SYSCALLS)	+= ftrace.o
 
 obj-$(CONFIG_8XX_MINIMAL_FPEMU) += softemu8xx.o
 
-ifneq ($(CONFIG_PPC_INDIRECT_IO),y)
+ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
 obj-y				+= iomap.o
 endif
 

arch/powerpc/kernel/io-workarounds.c

@@ -53,6 +53,7 @@ static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
 	return NULL;
 }
 
+#ifdef CONFIG_PPC_INDIRECT_MMIO
 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
 {
 	unsigned hugepage_shift;
@@ -90,13 +91,25 @@ struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
 
 	return bus;
 }
+#else /* CONFIG_PPC_INDIRECT_MMIO */
+struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
+{
+	return NULL;
+}
+#endif /* !CONFIG_PPC_INDIRECT_MMIO */
 
+#ifdef CONFIG_PPC_INDIRECT_PIO
 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
 {
 	unsigned long vaddr = (unsigned long)pci_io_base + port;
 	return iowa_pci_find(vaddr, 0);
 }
-
+#else
+struct iowa_bus *iowa_pio_find_bus(unsigned long port)
+{
+	return NULL;
+}
+#endif
 
 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)		\
 static ret iowa_##name at					\
@@ -137,6 +150,7 @@ static const struct ppc_pci_io iowa_pci_io = {
 
 };
 
+#ifdef CONFIG_PPC_INDIRECT_MMIO
 static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
 				  unsigned long flags, void *caller)
 {
@@ -151,6 +165,9 @@ static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
 	}
 	return res;
 }
+#else /* CONFIG_PPC_INDIRECT_MMIO */
+#define iowa_ioremap NULL
+#endif /* !CONFIG_PPC_INDIRECT_MMIO */
 
 /* Enable IO workaround */
 static void io_workaround_init(void)

arch/powerpc/kernel/setup_64.c

@@ -716,8 +716,7 @@ void __init setup_per_cpu_areas(void)
 #endif
 
 
-#ifdef CONFIG_PPC_INDIRECT_IO
+#if defined(CONFIG_PPC_INDIRECT_PIO) || defined(CONFIG_PPC_INDIRECT_MMIO)
 struct ppc_pci_io ppc_pci_io;
 EXPORT_SYMBOL(ppc_pci_io);
-#endif /* CONFIG_PPC_INDIRECT_IO */
-
+#endif

arch/powerpc/platforms/Kconfig

@@ -202,17 +202,12 @@ config PPC_P7_NAP
 	bool
 	default n
 
-config PPC_INDIRECT_IO
+config PPC_INDIRECT_PIO
 	bool
 	select GENERIC_IOMAP
 
-config PPC_INDIRECT_PIO
-	bool
-	select PPC_INDIRECT_IO
-
 config PPC_INDIRECT_MMIO
 	bool
-	select PPC_INDIRECT_IO
 
 config PPC_IO_WORKAROUNDS
 	bool