Merge tag 'mips_4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Pull MIPS updates from Paul Burton:
 "Here are the main MIPS changes for 4.19.

  An overview of the general architecture changes:

   - Massive DMA ops refactoring from Christoph Hellwig (huzzah for
     deleting crufty code!).

   - We introduce NT_MIPS_DSP & NT_MIPS_FP_MODE ELF notes &
     corresponding regsets to expose DSP ASE & floating point mode state
     respectively, both for live debugging & core dumps.

   - We better optimize our code by hard-coding cpu_has_* macros at
     compile time where their values are known due to the ISA revision
     that the kernel build is targeting.

   - The EJTAG exception handler now better handles SMP systems, where
     it was previously possible for CPUs to clobber a register value
     saved by another CPU.

   - Our implementation of memset() gained a couple of fixes for MIPSr6
     systems to return correct values in some cases where stores fault.

   - We now implement ioremap_wc() using the uncached-accelerated cache
     coherency attribute where supported, which is detected during boot,
     and fall back to plain uncached access where necessary. The
     MIPS-specific (and unused in tree) ioremap_uncached_accelerated() &
     ioremap_cacheable_cow() are removed.

   - The prctl(PR_SET_FP_MODE, ...) syscall is better supported for SMP
     systems by reworking the way we ensure remote CPUs that may be
     running threads within the affected process switch mode.

   - Systems using the MIPS Coherence Manager will now set the
     MIPS_IC_SNOOPS_REMOTE flag to avoid some unnecessary cache
     maintenance overhead when flushing the icache.

   - A few fixes were made for building with clang/LLVM, which now
     sucessfully builds kernels for many of our platforms.

   - Miscellaneous cleanups all over.

  And some platform-specific changes:

   - ar7 gained stubs for a few clock API functions to fix build
     failures for some drivers.

   - ath79 gained support for a few new SoCs, a few fixes & better
     gpio-keys support.

   - Ci20 now exposes its SPI bus using the spi-gpio driver.

   - The generic platform can now auto-detect a suitable value for
     PHYS_OFFSET based upon the memory map described by the device tree,
     allowing us to avoid wasting memory on page book-keeping for
     systems where RAM starts at a non-zero physical address.

   - Ingenic systems using the jz4740 platform code now link their
     vmlinuz higher to allow for kernels of a realistic size.

   - Loongson32 now builds the kernel targeting MIPSr1 rather than
     MIPSr2 to avoid CPU errata.

   - Loongson64 gains a couple of fixes, a workaround for a write
     buffering issue & support for the Loongson 3A R3.1 CPU.

   - Malta now uses the piix4-poweroff driver to handle powering down.

   - Microsemi Ocelot gained support for its SPI bus & NOR flash, its
     second MDIO bus and can now be supported by a FIT/.itb image.

   - Octeon saw a bunch of header cleanups which remove a lot of
     duplicate or unused code"

* tag 'mips_4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (123 commits)
  MIPS: Remove remnants of UASM_ISA
  MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send()
  MIPS: VDSO: Force link endianness
  MIPS: Always specify -EB or -EL when using clang
  MIPS: Use dins to simplify __write_64bit_c0_split()
  MIPS: Use read-write output operand in __write_64bit_c0_split()
  MIPS: Avoid using array as parameter to write_c0_kpgd()
  MIPS: vdso: Allow clang's --target flag in VDSO cflags
  MIPS: genvdso: Remove GOT checks
  MIPS: Remove obsolete MIPS checks for DST node "chosen@0"
  MIPS: generic: Remove input symbols from defconfig
  MIPS: Delete unused code in linux32.c
  MIPS: Remove unused sys_32_mmap2
  MIPS: Remove nabi_no_regargs
  mips: dts: mscc: enable spi and NOR flash support on ocelot PCB123
  mips: dts: mscc: Add spi on Ocelot
  MIPS: Loongson: Merge load addresses
  MIPS: Loongson: Set Loongson32 to MIPS32R1
  MIPS: mscc: ocelot: add interrupt controller properties to GPIO controller
  MIPS: generic: Select MIPS_AUTO_PFN_OFFSET
  ...

1 files changed, 26 insertions, 14 deletions

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index cea8ad864b3f..54c730aed327 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -12,6 +12,8 @@
 #ifndef _ASM_IO_H
 #define _ASM_IO_H
 
+#define ARCH_HAS_IOREMAP_WC
+
 #include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
@@ -141,14 +143,14 @@ static inline void * phys_to_virt(unsigned long address)
 /*
  * ISA I/O bus memory addresses are 1:1 with the physical address.
  */
-static inline unsigned long isa_virt_to_bus(volatile void * address)
+static inline unsigned long isa_virt_to_bus(volatile void *address)
 {
-	return (unsigned long)address - PAGE_OFFSET;
+	return virt_to_phys(address);
 }
 
-static inline void * isa_bus_to_virt(unsigned long address)
+static inline void *isa_bus_to_virt(unsigned long address)
 {
-	return (void *)(address + PAGE_OFFSET);
+	return phys_to_virt(address);
 }
 
 #define isa_page_to_bus page_to_phys
@@ -278,15 +280,25 @@ static inline void __iomem * __ioremap_mode(phys_addr_t offset, unsigned long si
 #define ioremap_cache ioremap_cachable
 
 /*
- * These two are MIPS specific ioremap variant.	 ioremap_cacheable_cow
- * requests a cachable mapping, ioremap_uncached_accelerated requests a
- * mapping using the uncached accelerated mode which isn't supported on
- * all processors.
+ * ioremap_wc     -   map bus memory into CPU space
+ * @offset:    bus address of the memory
+ * @size:      size of the resource to map
+ *
+ * ioremap_wc 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.
+ *
+ * This version of ioremap ensures that the memory is marked uncachable
+ * but accelerated by means of write-combining feature. It is specifically
+ * useful for PCIe prefetchable windows, which may vastly improve a
+ * communications performance. If it was determined on boot stage, what
+ * CPU CCA doesn't support UCA, the method shall fall-back to the
+ * _CACHE_UNCACHED option (see cpu_probe() method).
  */
-#define ioremap_cacheable_cow(offset, size)				\
-	__ioremap_mode((offset), (size), _CACHE_CACHABLE_COW)
-#define ioremap_uncached_accelerated(offset, size)			\
-	__ioremap_mode((offset), (size), _CACHE_UNCACHED_ACCELERATED)
+#define ioremap_wc(offset, size)					\
+	__ioremap_mode((offset), (size), boot_cpu_data.writecombine)
 
 static inline void iounmap(const volatile void __iomem *addr)
 {
@@ -590,7 +602,7 @@ static inline void memcpy_toio(volatile void __iomem *dst, const void *src, int
  *
  * This API used to be exported; it now is for arch code internal use only.
  */
-#if defined(CONFIG_DMA_NONCOHERENT) || defined(CONFIG_DMA_MAYBE_COHERENT)
+#ifdef CONFIG_DMA_NONCOHERENT
 
 extern void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
 extern void (*_dma_cache_wback)(unsigned long start, unsigned long size);
@@ -609,7 +621,7 @@ extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
 #define dma_cache_inv(start,size)	\
 	do { (void) (start); (void) (size); } while (0)
 
-#endif /* CONFIG_DMA_NONCOHERENT || CONFIG_DMA_MAYBE_COHERENT */
+#endif /* CONFIG_DMA_NONCOHERENT */
 
 /*
  * Read a 32-bit register that requires a 64-bit read cycle on the bus.