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, 36 insertions, 2 deletions

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 2c96c0c68116..c71d1eb7da59 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -36,6 +36,7 @@
 #include <asm/cdmm.h>
 #include <asm/cpu.h>
 #include <asm/debug.h>
+#include <asm/dma-coherence.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
 #include <asm/smp-ops.h>
@@ -84,6 +85,11 @@ static struct resource bss_resource = { .name = "Kernel bss", };
 
 static void *detect_magic __initdata = detect_memory_region;
 
+#ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
+unsigned long ARCH_PFN_OFFSET;
+EXPORT_SYMBOL(ARCH_PFN_OFFSET);
+#endif
+
 void __init add_memory_region(phys_addr_t start, phys_addr_t size, long type)
 {
 	int x = boot_mem_map.nr_map;
@@ -441,6 +447,12 @@ static void __init bootmem_init(void)
 		mapstart = max(reserved_end, start);
 	}
 
+	if (min_low_pfn >= max_low_pfn)
+		panic("Incorrect memory mapping !!!");
+
+#ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
+	ARCH_PFN_OFFSET = PFN_UP(ramstart);
+#else
 	/*
 	 * Reserve any memory between the start of RAM and PHYS_OFFSET
 	 */
@@ -448,8 +460,6 @@ static void __init bootmem_init(void)
 		add_memory_region(PHYS_OFFSET, ramstart - PHYS_OFFSET,
 				  BOOT_MEM_RESERVED);
 
-	if (min_low_pfn >= max_low_pfn)
-		panic("Incorrect memory mapping !!!");
 	if (min_low_pfn > ARCH_PFN_OFFSET) {
 		pr_info("Wasting %lu bytes for tracking %lu unused pages\n",
 			(min_low_pfn - ARCH_PFN_OFFSET) * sizeof(struct page),
@@ -459,6 +469,7 @@ static void __init bootmem_init(void)
 			ARCH_PFN_OFFSET - min_low_pfn);
 	}
 	min_low_pfn = ARCH_PFN_OFFSET;
+#endif
 
 	/*
 	 * Determine low and high memory ranges
@@ -1055,3 +1066,26 @@ static int __init debugfs_mips(void)
 }
 arch_initcall(debugfs_mips);
 #endif
+
+#if defined(CONFIG_DMA_MAYBE_COHERENT) && !defined(CONFIG_DMA_PERDEV_COHERENT)
+/* User defined DMA coherency from command line. */
+enum coherent_io_user_state coherentio = IO_COHERENCE_DEFAULT;
+EXPORT_SYMBOL_GPL(coherentio);
+int hw_coherentio = 0;	/* Actual hardware supported DMA coherency setting. */
+
+static int __init setcoherentio(char *str)
+{
+	coherentio = IO_COHERENCE_ENABLED;
+	pr_info("Hardware DMA cache coherency (command line)\n");
+	return 0;
+}
+early_param("coherentio", setcoherentio);
+
+static int __init setnocoherentio(char *str)
+{
+	coherentio = IO_COHERENCE_DISABLED;
+	pr_info("Software DMA cache coherency (command line)\n");
+	return 0;
+}
+early_param("nocoherentio", setnocoherentio);
+#endif