Merge tag 'soc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC platform changes from Olof Johansson:
 "This branch contains mostly additions and changes to platform
  enablement and SoC-level drivers.  Since there's sometimes a
  dependency on device-tree changes, there's also a fair amount of
  those in this branch.

  Pieces worth mentioning are:

   - Mbus driver for Marvell platforms, allowing kernel configuration
     and resource allocation of on-chip peripherals.
   - Enablement of the mbus infrastructure from Marvell PCI-e drivers.
   - Preparation of MSI support for Marvell platforms.
   - Addition of new PCI-e host controller driver for Tegra platforms
   - Some churn caused by sharing of macro names between i.MX 6Q and 6DL
     platforms in the device tree sources and header files.
   - Various suspend/PM updates for Tegra, including LP1 support.
   - Versatile Express support for MCPM, part of big little support.
   - Allwinner platform support for A20 and A31 SoCs (dual and quad
     Cortex-A7)
   - OMAP2+ support for DRA7, a new Cortex-A15-based SoC.

  The code that touches other architectures are patches moving MSI
  arch-specific functions over to weak symbols and removal of
  ARCH_SUPPORTS_MSI, acked by PCI maintainers"

* tag 'soc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (266 commits)
  tegra-cpuidle: provide stub when !CONFIG_CPU_IDLE
  PCI: tegra: replace devm_request_and_ioremap by devm_ioremap_resource
  ARM: tegra: Drop ARCH_SUPPORTS_MSI and sort list
  ARM: dts: vf610-twr: enable i2c0 device
  ARM: dts: i.MX51: Add one more I2C2 pinmux entry
  ARM: dts: i.MX51: Move pins configuration under "iomuxc" label
  ARM: dtsi: imx6qdl-sabresd: Add USB OTG vbus pin to pinctrl_hog
  ARM: dtsi: imx6qdl-sabresd: Add USB host 1 VBUS regulator
  ARM: dts: imx27-phytec-phycore-som: Enable AUDMUX
  ARM: dts: i.MX27: Disable AUDMUX in the template
  ARM: dts: wandboard: Add support for SDIO bcm4329
  ARM: i.MX5 clocks: Remove optional clock setup (CKIH1) from i.MX51 template
  ARM: dts: imx53-qsb: Make USBH1 functional
  ARM i.MX6Q: dts: Enable I2C1 with EEPROM and PMIC on Phytec phyFLEX-i.MX6 Ouad module
  ARM i.MX6Q: dts: Enable SPI NOR flash on Phytec phyFLEX-i.MX6 Ouad module
  ARM: dts: imx6qdl-sabresd: Add touchscreen support
  ARM: imx: add ocram clock for imx53
  ARM: dts: imx: ocram size is different between imx6q and imx6dl
  ARM: dts: imx27-phytec-phycore-som: Fix regulator settings
  ARM: dts: i.MX27: Remove clock name from CPU node
  ...

1 files changed, 45 insertions, 21 deletions

diff --git a/arch/arm/mach-vexpress/dcscb.c b/arch/arm/mach-vexpress/dcscb.c
index 16d57a8a9d5a..3a6384c6c435 100644
--- a/arch/arm/mach-vexpress/dcscb.c
+++ b/arch/arm/mach-vexpress/dcscb.c
@@ -136,14 +136,35 @@ static void dcscb_power_down(void)
 		/*
 		 * Flush all cache levels for this cluster.
 		 *
-		 * A15/A7 can hit in the cache with SCTLR.C=0, so we don't need
-		 * a preliminary flush here for those CPUs.  At least, that's
-		 * the theory -- without the extra flush, Linux explodes on
-		 * RTSM (to be investigated).
+		 * To do so we do:
+		 * - Clear the SCTLR.C bit to prevent further cache allocations
+		 * - Flush the whole cache
+		 * - Clear the ACTLR "SMP" bit to disable local coherency
+		 *
+		 * Let's do it in the safest possible way i.e. with
+		 * no memory access within the following sequence
+		 * including to the stack.
+		 *
+		 * Note: fp is preserved to the stack explicitly prior doing
+		 * this since adding it to the clobber list is incompatible
+		 * with having CONFIG_FRAME_POINTER=y.
 		 */
-		flush_cache_all();
-		set_cr(get_cr() & ~CR_C);
-		flush_cache_all();
+		asm volatile(
+		"str	fp, [sp, #-4]! \n\t"
+		"mrc	p15, 0, r0, c1, c0, 0	@ get CR \n\t"
+		"bic	r0, r0, #"__stringify(CR_C)" \n\t"
+		"mcr	p15, 0, r0, c1, c0, 0	@ set CR \n\t"
+		"isb	\n\t"
+		"bl	v7_flush_dcache_all \n\t"
+		"clrex	\n\t"
+		"mrc	p15, 0, r0, c1, c0, 1	@ get AUXCR \n\t"
+		"bic	r0, r0, #(1 << 6)	@ disable local coherency \n\t"
+		"mcr	p15, 0, r0, c1, c0, 1	@ set AUXCR \n\t"
+		"isb	\n\t"
+		"dsb	\n\t"
+		"ldr	fp, [sp], #4"
+		: : : "r0","r1","r2","r3","r4","r5","r6","r7",
+		      "r9","r10","lr","memory");
 
 		/*
 		 * This is a harmless no-op.  On platforms with a real
@@ -152,9 +173,6 @@ static void dcscb_power_down(void)
 		 */
 		outer_flush_all();
 
-		/* Disable local coherency by clearing the ACTLR "SMP" bit: */
-		set_auxcr(get_auxcr() & ~(1 << 6));
-
 		/*
 		 * Disable cluster-level coherency by masking
 		 * incoming snoops and DVM messages:
@@ -167,18 +185,24 @@ static void dcscb_power_down(void)
 
 		/*
 		 * Flush the local CPU cache.
-		 *
-		 * A15/A7 can hit in the cache with SCTLR.C=0, so we don't need
-		 * a preliminary flush here for those CPUs.  At least, that's
-		 * the theory -- without the extra flush, Linux explodes on
-		 * RTSM (to be investigated).
+		 * Let's do it in the safest possible way as above.
 		 */
-		flush_cache_louis();
-		set_cr(get_cr() & ~CR_C);
-		flush_cache_louis();
-
-		/* Disable local coherency by clearing the ACTLR "SMP" bit: */
-		set_auxcr(get_auxcr() & ~(1 << 6));
+		asm volatile(
+		"str	fp, [sp, #-4]! \n\t"
+		"mrc	p15, 0, r0, c1, c0, 0	@ get CR \n\t"
+		"bic	r0, r0, #"__stringify(CR_C)" \n\t"
+		"mcr	p15, 0, r0, c1, c0, 0	@ set CR \n\t"
+		"isb	\n\t"
+		"bl	v7_flush_dcache_louis \n\t"
+		"clrex	\n\t"
+		"mrc	p15, 0, r0, c1, c0, 1	@ get AUXCR \n\t"
+		"bic	r0, r0, #(1 << 6)	@ disable local coherency \n\t"
+		"mcr	p15, 0, r0, c1, c0, 1	@ set AUXCR \n\t"
+		"isb	\n\t"
+		"dsb	\n\t"
+		"ldr	fp, [sp], #4"
+		: : : "r0","r1","r2","r3","r4","r5","r6","r7",
+		      "r9","r10","lr","memory");
 	}
 
 	__mcpm_cpu_down(cpu, cluster);