mips: drop GENERIC_IOMAP wrapper

All PIO on MIPS platforms is memory mapped, so there is no benefit in
the lib/iomap.c wrappers that switch between inb/outb and readb/writeb
style accessses.

In fact, the '#define PIO_RESERVED 0' setting completely disables
the GENERIC_IOMAP functionality, and the '#define PIO_OFFSET
mips_io_port_base' setting is based on a misunderstanding of what the
offset is meant to do.

MIPS started using GENERIC_IOMAP in 2018 with commit b962aeb02205 ("MIPS:
Use GENERIC_IOMAP") replacing a simple custom implementation of the same
interfaces, but at the time the asm-generic/io.h version was not usable
yet. Since the header is now always included, it's now possible to go
back to the even simpler version.

Use the normal GENERIC_PCI_IOMAP functionality for all mips platforms
without the hacky GENERIC_IOMAP, and provide a custom pci_iounmap()
for the CONFIG_PCI_DRIVERS_LEGACY case to ensure the I/O port base never
gets unmapped.

The readsl() prototype needs an extra 'const' keyword to make it
compatible with the generic ioread32_rep() alias.

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

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 1924f2d839323243e378e32ef7d12640560a7be3..2a2120a6d8520bf4ce18f11c8433ef33a40a0e78 100644 (file)
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -38,7 +38,6 @@ config MIPS
        select GENERIC_CMOS_UPDATE
        select GENERIC_CPU_AUTOPROBE
        select GENERIC_GETTIMEOFDAY
-       select GENERIC_IOMAP
        select GENERIC_IRQ_PROBE
        select GENERIC_IRQ_SHOW
        select GENERIC_ISA_DMA if EISA
@@ -47,6 +46,7 @@ config MIPS
        select GENERIC_LIB_CMPDI2
        select GENERIC_LIB_LSHRDI3
        select GENERIC_LIB_UCMPDI2
+       select GENERIC_PCI_IOMAP
        select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
        select GENERIC_SMP_IDLE_THREAD
        select GENERIC_IDLE_POLL_SETUP

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 0bddb568af7c1cce9761bcb0face5de993cebc57..1fe56d1870a688f3d68b638d74888ba2165b4717 100644 (file)
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -66,17 +66,6 @@ static inline void set_io_port_base(unsigned long base)
        mips_io_port_base = base;
 }
 
-/*
- * Provide the necessary definitions for generic iomap. We make use of
- * mips_io_port_base for iomap(), but we don't reserve any low addresses for
- * use with I/O ports.
- */
-
-#define HAVE_ARCH_PIO_SIZE
-#define PIO_OFFSET     mips_io_port_base
-#define PIO_MASK       IO_SPACE_LIMIT
-#define PIO_RESERVED   0x0UL
-
 /*
  * Enforce in-order execution of data I/O.  In the MIPS architecture
  * these are equivalent to corresponding platform-specific memory
@@ -397,8 +386,8 @@ static inline void writes##bwlq(volatile void __iomem *mem,         \
        }                                                               \
 }                                                                      \
                                                                        \
-static inline void reads##bwlq(volatile void __iomem *mem, void *addr, \
-                              unsigned int count)                      \
+static inline void reads##bwlq(const volatile void __iomem *mem,       \
+                              void *addr, unsigned int count)          \
 {                                                                      \
        volatile type *__addr = addr;                                   \
                                                                        \
@@ -555,6 +544,12 @@ extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
 
 void __ioread64_copy(void *to, const void __iomem *from, size_t count);
 
+#ifdef CONFIG_PCI_DRIVERS_LEGACY
+struct pci_dev;
+void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
+#define pci_iounmap pci_iounmap
+#endif
+
 #include <asm-generic/io.h>
 
 static inline void *isa_bus_to_virt(unsigned long address)

diff --git a/arch/mips/lib/iomap-pci.c b/arch/mips/lib/iomap-pci.c
index a9cb28813f0bc3ebee5be26d6f48f87e824a1fd9..2f82c776c6d0a88e0957996e04e4703bc964388c 100644 (file)
--- a/arch/mips/lib/iomap-pci.c
+++ b/arch/mips/lib/iomap-pci.c
@@ -43,4 +43,13 @@ void __iomem *__pci_ioport_map(struct pci_dev *dev,
        return (void __iomem *) (ctrl->io_map_base + port);
 }
 
+void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
+{
+       struct pci_controller *ctrl = dev->bus->sysdata;
+       void __iomem *base = (void __iomem *)ctrl->io_map_base;
+
+       if (addr < base || addr > (base + resource_size(ctrl->io_resource)))
+               iounmap(addr);
+}
+
 #endif /* CONFIG_PCI_DRIVERS_LEGACY */