ARC fixes for 4.18-rc6

- Fix CONFIG_SWAP [Alexey]
 
  - Robistify cmpxchg emulation for systems w/o atomics [Alexey / PeterZ]
 
  - Allow mprotext(PROT_EXEC) for stack mappings [Vineet]
 
  - HSDK platform enable PCIe, APG GPIO [Gustavo]
 
  - miscll other fixes, config updates etc
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Merge tag 'arc-4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC fixes from Vineet Gupta:
 "ARC is back after radio silence in 4.17:

   - Fix CONFIG_SWAP [Alexey]

   - Robustify cmpxchg emulation for systems w/o atomics [Alexey /
     PeterZ]

   - Allow mprotext(PROT_EXEC) for stack mappings [Vineet]

   - HSDK platform enable PCIe, APG GPIO [Gustavo]

   - miscll other fixes, config updates etc"

* tag 'arc-4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARCv2: [plat-hsdk]: Save accl reg pair by default
  ARC: mm: allow mprotect to make stack mappings executable
  ARC: Fix CONFIG_SWAP
  ARC: [arcompact] entry.S: minor code movement
  ARC: configs: Remove CONFIG_INITRAMFS_SOURCE from defconfigs
  ARC: configs: remove no longer needed CONFIG_DEVPTS_MULTIPLE_INSTANCES
  ARC: Improve cmpxchg syscall implementation
  ARC: [plat-hsdk]: Configure APB GPIO controller on ARC HSDK platform
  ARC: [plat-hsdk] Add PCIe support
  ARC: Enable machine_desc->init_per_cpu for !CONFIG_SMP
  ARC: Explicitly add -mmedium-calls to CFLAGS

arch/arc/Kconfig

@@ -413,7 +413,7 @@ config ARC_HAS_DIV_REM
 
 config ARC_HAS_ACCL_REGS
 	bool "Reg Pair ACCL:ACCH (FPU and/or MPY > 6)"
-	default n
+	default y
 	help
 	  Depending on the configuration, CPU can contain accumulator reg-pair
 	  (also referred to as r58:r59). These can also be used by gcc as GPR so

arch/arc/Makefile

@@ -16,7 +16,7 @@ endif
 
 KBUILD_DEFCONFIG := nsim_700_defconfig
 
-cflags-y	+= -fno-common -pipe -fno-builtin -D__linux__
+cflags-y	+= -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__
 cflags-$(CONFIG_ISA_ARCOMPACT)	+= -mA7
 cflags-$(CONFIG_ISA_ARCV2)	+= -mcpu=archs
 
@@ -140,16 +140,3 @@ dtbs: scripts
 
 archclean:
 	$(Q)$(MAKE) $(clean)=$(boot)
-
-# Hacks to enable final link due to absence of link-time branch relexation
-# and gcc choosing optimal(shorter) branches at -O3
-#
-# vineetg Feb 2010: -mlong-calls switched off for overall kernel build
-# However lib/decompress_inflate.o (.init.text) calls
-# zlib_inflate_workspacesize (.text) causing relocation errors.
-# Thus forcing all exten calls in this file to be long calls
-export CFLAGS_decompress_inflate.o = -mmedium-calls
-export CFLAGS_initramfs.o = -mmedium-calls
-ifdef CONFIG_SMP
-export CFLAGS_core.o = -mmedium-calls
-endif

arch/arc/configs/axs101_defconfig

@@ -11,7 +11,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../arc_initramfs/"
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

arch/arc/configs/axs103_defconfig

@@ -11,7 +11,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../../arc_initramfs_hs/"
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

arch/arc/configs/axs103_smp_defconfig

@@ -11,7 +11,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../../arc_initramfs_hs/"
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

arch/arc/configs/haps_hs_defconfig

@@ -11,7 +11,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../../arc_initramfs_hs/"
 CONFIG_EXPERT=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_COMPAT_BRK is not set

arch/arc/configs/haps_hs_smp_defconfig

@@ -11,7 +11,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../../arc_initramfs_hs/"
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

arch/arc/configs/hsdk_defconfig

@@ -9,7 +9,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../../arc_initramfs_hs/"
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 # CONFIG_VM_EVENT_COUNTERS is not set

arch/arc/configs/nsim_700_defconfig

@@ -11,7 +11,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../arc_initramfs/"
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

arch/arc/configs/nsim_hs_defconfig

@@ -11,7 +11,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../../arc_initramfs_hs/"
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

arch/arc/configs/nsim_hs_smp_defconfig

@@ -9,7 +9,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../arc_initramfs_hs/"
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

arch/arc/configs/nsimosci_defconfig

@@ -11,7 +11,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../arc_initramfs/"
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

arch/arc/configs/nsimosci_hs_defconfig

@@ -11,7 +11,6 @@ CONFIG_NAMESPACES=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../arc_initramfs_hs/"
 CONFIG_KALLSYMS_ALL=y
 CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y

arch/arc/configs/nsimosci_hs_smp_defconfig

@@ -9,7 +9,6 @@ CONFIG_IKCONFIG_PROC=y
 # CONFIG_UTS_NS is not set
 # CONFIG_PID_NS is not set
 CONFIG_BLK_DEV_INITRD=y
-CONFIG_INITRAMFS_SOURCE="../arc_initramfs_hs/"
 CONFIG_PERF_EVENTS=y
 # CONFIG_COMPAT_BRK is not set
 CONFIG_KPROBES=y

arch/arc/configs/tb10x_defconfig

@@ -56,7 +56,6 @@ CONFIG_STMMAC_ETH=y
 # CONFIG_INPUT is not set
 # CONFIG_SERIO is not set
 # CONFIG_VT is not set
-CONFIG_DEVPTS_MULTIPLE_INSTANCES=y
 # CONFIG_LEGACY_PTYS is not set
 # CONFIG_DEVKMEM is not set
 CONFIG_SERIAL_8250=y

arch/arc/include/asm/entry-compact.h

@@ -234,6 +234,9 @@
 	POP	gp
 	RESTORE_R12_TO_R0
 
+#ifdef CONFIG_ARC_CURR_IN_REG
+	ld	r25, [sp, 12]
+#endif
 	ld  sp, [sp] /* restore original sp */
 	/* orig_r0, ECR, user_r25 skipped automatically */
 .endm
@@ -315,6 +318,9 @@
 	POP	gp
 	RESTORE_R12_TO_R0
 
+#ifdef CONFIG_ARC_CURR_IN_REG
+	ld	r25, [sp, 12]
+#endif
 	ld  sp, [sp] /* restore original sp */
 	/* orig_r0, ECR, user_r25 skipped automatically */
 .endm

arch/arc/include/asm/entry.h

@@ -86,9 +86,6 @@
 	POP	r1
 	POP	r0
 
-#ifdef CONFIG_ARC_CURR_IN_REG
-	ld	r25, [sp, 12]
-#endif
 .endm
 
 /*--------------------------------------------------------------

arch/arc/include/asm/mach_desc.h

@@ -34,9 +34,7 @@ struct machine_desc {
 	const char		*name;
 	const char		**dt_compat;
 	void			(*init_early)(void);
-#ifdef CONFIG_SMP
 	void			(*init_per_cpu)(unsigned int);
-#endif
 	void			(*init_machine)(void);
 	void			(*init_late)(void);
 

arch/arc/include/asm/page.h

@@ -105,7 +105,7 @@ typedef pte_t * pgtable_t;
 #define virt_addr_valid(kaddr)  pfn_valid(virt_to_pfn(kaddr))
 
 /* Default Permissions for stack/heaps pages (Non Executable) */
-#define VM_DATA_DEFAULT_FLAGS   (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE)
+#define VM_DATA_DEFAULT_FLAGS   (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 
 #define WANT_PAGE_VIRTUAL   1
 

arch/arc/include/asm/pgtable.h

@@ -377,7 +377,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 
 /* Decode a PTE containing swap "identifier "into constituents */
 #define __swp_type(pte_lookalike)	(((pte_lookalike).val) & 0x1f)
-#define __swp_offset(pte_lookalike)	((pte_lookalike).val << 13)
+#define __swp_offset(pte_lookalike)	((pte_lookalike).val >> 13)
 
 /* NOPs, to keep generic kernel happy */
 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })

arch/arc/kernel/irq.c

@@ -31,10 +31,10 @@ void __init init_IRQ(void)
 	/* a SMP H/w block could do IPI IRQ request here */
 	if (plat_smp_ops.init_per_cpu)
 		plat_smp_ops.init_per_cpu(smp_processor_id());
+#endif
 
 	if (machine_desc->init_per_cpu)
 		machine_desc->init_per_cpu(smp_processor_id());
-#endif
 }
 
 /*

arch/arc/kernel/process.c

@@ -47,7 +47,8 @@ SYSCALL_DEFINE0(arc_gettls)
 SYSCALL_DEFINE3(arc_usr_cmpxchg, int *, uaddr, int, expected, int, new)
 {
 	struct pt_regs *regs = current_pt_regs();
-	int uval = -EFAULT;
+	u32 uval;
+	int ret;
 
 	/*
 	 * This is only for old cores lacking LLOCK/SCOND, which by defintion
@@ -60,23 +61,47 @@ SYSCALL_DEFINE3(arc_usr_cmpxchg, int *, uaddr, int, expected, int, new)
 	/* Z indicates to userspace if operation succeded */
 	regs->status32 &= ~STATUS_Z_MASK;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	ret = access_ok(VERIFY_WRITE, uaddr, sizeof(*uaddr));
-		return -EFAULT;
+	if (!ret)
+		 goto fail;
 
+again:
 	preempt_disable();
 
-	if (__get_user(uval, uaddr))
+	ret = __get_user(uval, uaddr);
-		goto done;
+	if (ret)
+		 goto fault;
 
-	if (uval == expected) {
+	if (uval != expected)
-		if (!__put_user(new, uaddr))
+		 goto out;
-			regs->status32 |= STATUS_Z_MASK;
-	}
 
-done:
+	ret = __put_user(new, uaddr);
+	if (ret)
+		 goto fault;
+
+	regs->status32 |= STATUS_Z_MASK;
+
+out:
+	preempt_enable();
+	return uval;
+
+fault:
 	preempt_enable();
 
-	return uval;
+	if (unlikely(ret != -EFAULT))
+		 goto fail;
+
+	down_read(&current->mm->mmap_sem);
+	ret = fixup_user_fault(current, current->mm, (unsigned long) uaddr,
+			       FAULT_FLAG_WRITE, NULL);
+	up_read(&current->mm->mmap_sem);
+
+	if (likely(!ret))
+		 goto again;
+
+fail:
+	force_sig(SIGSEGV, current);
+	return ret;
 }
 
 #ifdef CONFIG_ISA_ARCV2

arch/arc/plat-hsdk/Kconfig

@@ -7,5 +7,8 @@
 
 menuconfig ARC_SOC_HSDK
 	bool "ARC HS Development Kit SOC"
+	depends on ISA_ARCV2
+	select ARC_HAS_ACCL_REGS
 	select CLK_HSDK
 	select RESET_HSDK
+	select MIGHT_HAVE_PCI

arch/arc/plat-hsdk/platform.c

@@ -42,6 +42,66 @@ static void __init hsdk_init_per_cpu(unsigned int cpu)
 #define SDIO_UHS_REG_EXT	(SDIO_BASE + 0x108)
 #define SDIO_UHS_REG_EXT_DIV_2	(2 << 30)
 
+#define HSDK_GPIO_INTC          (ARC_PERIPHERAL_BASE + 0x3000)
+
+static void __init hsdk_enable_gpio_intc_wire(void)
+{
+	/*
+	 * Peripherals on CPU Card are wired to cpu intc via intermediate
+	 * DW APB GPIO blocks (mainly for debouncing)
+	 *
+	 *         ---------------------
+	 *        |  snps,archs-intc  |
+	 *        ---------------------
+	 *                  |
+	 *        ----------------------
+	 *        | snps,archs-idu-intc |
+	 *        ----------------------
+	 *         |   |     |   |    |
+	 *         | [eth] [USB]    [... other peripherals]
+	 *         |
+	 * -------------------
+	 * | snps,dw-apb-intc |
+	 * -------------------
+	 *  |      |   |   |
+	 * [Bt] [HAPS]   [... other peripherals]
+	 *
+	 * Current implementation of "irq-dw-apb-ictl" driver doesn't work well
+	 * with stacked INTCs. In particular problem happens if its master INTC
+	 * not yet instantiated. See discussion here -
+	 * https://lkml.org/lkml/2015/3/4/755
+	 *
+	 * So setup the first gpio block as a passive pass thru and hide it from
+	 * DT hardware topology - connect intc directly to cpu intc
+	 * The GPIO "wire" needs to be init nevertheless (here)
+	 *
+	 * One side adv is that peripheral interrupt handling avoids one nested
+	 * intc ISR hop
+	 *
+	 * According to HSDK User's Manual [1], "Table 2 Interrupt Mapping"
+	 * we have the following GPIO input lines used as sources of interrupt:
+	 * - GPIO[0] - Bluetooth interrupt of RS9113 module
+	 * - GPIO[2] - HAPS interrupt (on HapsTrak 3 connector)
+	 * - GPIO[3] - Audio codec (MAX9880A) interrupt
+	 * - GPIO[8-23] - Available on Arduino and PMOD_x headers
+	 * For now there's no use of Arduino and PMOD_x headers in Linux
+	 * use-case so we only enable lines 0, 2 and 3.
+	 *
+	 * [1] https://github.com/foss-for-synopsys-dwc-arc-processors/ARC-Development-Systems-Forum/wiki/docs/ARC_HSDK_User_Guide.pdf
+	 */
+#define GPIO_INTEN              (HSDK_GPIO_INTC + 0x30)
+#define GPIO_INTMASK            (HSDK_GPIO_INTC + 0x34)
+#define GPIO_INTTYPE_LEVEL      (HSDK_GPIO_INTC + 0x38)
+#define GPIO_INT_POLARITY       (HSDK_GPIO_INTC + 0x3c)
+#define GPIO_INT_CONNECTED_MASK	0x0d
+
+	iowrite32(0xffffffff, (void __iomem *) GPIO_INTMASK);
+	iowrite32(~GPIO_INT_CONNECTED_MASK, (void __iomem *) GPIO_INTMASK);
+	iowrite32(0x00000000, (void __iomem *) GPIO_INTTYPE_LEVEL);
+	iowrite32(0xffffffff, (void __iomem *) GPIO_INT_POLARITY);
+	iowrite32(GPIO_INT_CONNECTED_MASK, (void __iomem *) GPIO_INTEN);
+}
+
 static void __init hsdk_init_early(void)
 {
 	/*
@@ -62,6 +122,8 @@ static void __init hsdk_init_early(void)
 	 * minimum possible div-by-2.
 	 */
 	iowrite32(SDIO_UHS_REG_EXT_DIV_2, (void __iomem *) SDIO_UHS_REG_EXT);
+
+	hsdk_enable_gpio_intc_wire();
 }
 
 static const char *hsdk_compat[] __initconst = {