kernel/arch/parisc, branch linux-4.2.y

parisc: Filter out spurious interrupts in PA-RISC irq handler

2015-09-29T17:33:32Z

commit b1b4e435e4ef7de77f07bf2a42c8380b960c2d44 upstream. When detecting a serial port on newer PA-RISC machines (with iosapic) we have a long way to go to find the right IRQ line, registering it, then registering the serial port and the irq handler for the serial port. During this phase spurious interrupts for the serial port may happen which then crashes the kernel because the action handler might not have been set up yet. So, basically it's a race condition between the serial port hardware and the CPU which sets up the necessary fields in the irq sructs. The main reason for this race is, that we unmask the serial port irqs too early without having set up everything properly before (which isn't easily possible because we need the IRQ number to register the serial ports). This patch is a work-around for this problem. It adds checks to the CPU irq handler to verify if the IRQ action field has been initialized already. If not, we just skip this interrupt (which isn't critical for a serial port at bootup). The real fix would probably involve rewriting all PA-RISC specific IRQ code (for CPU, IOSAPIC, GSC and EISA) to use IRQ domains with proper parenting of the irq chips and proper irq enabling along this line. This bug has been in the PA-RISC port since the beginning, but the crashes happened very rarely with currently used hardware. But on the latest machine which I bought (a C8000 workstation), which uses the fastest CPUs (4 x PA8900, 1GHz) and which has the largest possible L1 cache size (64MB each), the kernel crashed at every boot because of this race. So, without this patch the machine would currently be unuseable. For the record, here is the flow logic: 1. serial_init_chip() in 8250_gsc.c calls iosapic_serial_irq(). 2. iosapic_serial_irq() calls txn_alloc_irq() to find the irq. 3. iosapic_serial_irq() calls cpu_claim_irq() to register the CPU irq 4. cpu_claim_irq() unmasks the CPU irq (which it shouldn't!) 5. serial_init_chip() then registers the 8250 port. Problems: - In step 4 the CPU irq shouldn't have been registered yet, but after step 5 - If serial irq happens between 4 and 5 have finished, the kernel will crash Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: Use double word condition in 64bit CAS operation

2015-09-29T17:33:31Z

commit 1b59ddfcf1678de38a1f8ca9fb8ea5eebeff1843 upstream. The attached change fixes the condition used in the "sub" instruction. A double word comparison is needed. This fixes the 64-bit LWS CAS operation on 64-bit kernels. I can now enable 64-bit atomic support in GCC. Signed-off-by: John David Anglin Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

parisc: mm: Fix a memory leak related to pmd not attached to the pgd

2015-07-19T06:56:14Z

Commit 0e0da48dee8d ("parisc: mm: don't count preallocated pmds") introduced a memory leak. After this commit, the 'return' statement in pmd_free is executed in all cases. Even for pmd that are not attached to the pgd. So 'free_pages' can never be called anymore, leading to a memory leak. Signed-off-by: Christophe JAILLET Acked-by: Kirill A. Shutemov Acked-by: Mikulas Patocka Acked-by: Helge Deller Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Helge Deller

mm: clean up per architecture MM hook header files

2015-07-17T23:39:53Z

Commit 2ae416b142b6 ("mm: new mm hook framework") introduced an empty header file (mm-arch-hooks.h) for every architecture, even those which doesn't need to define mm hooks. As suggested by Geert Uytterhoeven, this could be cleaned through the use of a generic header file included via each per architecture asm/include/Kbuild file. The PowerPC architecture is not impacted here since this architecture has to defined the arch_remap MM hook. Signed-off-by: Laurent Dufour Suggested-by: Geert Uytterhoeven Acked-by: Geert Uytterhoeven Acked-by: Vineet Gupta Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

parisc: Fix some PTE/TLB race conditions and optimize __flush_tlb_range based on timing results

2015-07-10T19:47:47Z

The increased use of pdtlb/pitlb instructions seemed to increase the frequency of random segmentation faults building packages. Further, we had a number of cases where TLB inserts would repeatedly fail and all forward progress would stop. The Haskell ghc package caused a lot of trouble in this area. The final indication of a race in pte handling was this syslog entry on sibaris (C8000): swap_free: Unused swap offset entry 00000004 BUG: Bad page map in process mysqld pte:00000100 pmd:019bbec5 addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464 CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1 Backtrace: [<0000000040173eb0>] show_stack+0x20/0x38 [<0000000040444424>] dump_stack+0x9c/0x110 [<00000000402a0d38>] print_bad_pte+0x1a8/0x278 [<00000000402a28b8>] unmap_single_vma+0x3d8/0x770 [<00000000402a4090>] zap_page_range+0xf0/0x198 [<00000000402ba2a4>] SyS_madvise+0x404/0x8c0 Note that the pte value is 0 except for the accessed bit 0x100. This bit shouldn't be set without the present bit. It should be noted that the madvise system call is probably a trigger for many of the random segmentation faults. In looking at the kernel code, I found the following problems: 1) The pte_clear define didn't take TLB lock when clearing a pte. 2) We didn't test pte present bit inside lock in exception support. 3) The pte and tlb locks needed to merged in order to ensure consistency between page table and TLB. This also has the effect of serializing TLB broadcasts on SMP systems. The attached change implements the above and a few other tweaks to try to improve performance. Based on the timing code, TLB purges are very slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it beneficial to test the split_tlb variable to avoid duplicate purges. Probably, all PA 2.0 machines have combined TLBs. I dropped using __flush_tlb_range in flush_tlb_mm as I realized all applications and most threads have a stack size that is too large to make this useful. I added some comments to this effect. Since implementing 1 through 3, I haven't had any random segmentation faults on mx3210 (rp3440) in about one week of building code and running as a Debian buildd. Signed-off-by: John David Anglin Cc: stable@vger.kernel.org # v3.18+ Signed-off-by: Helge Deller

Merge tag 'module_init-device_initcall-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2015-07-02T17:30:48Z

Pull module_init replacement part one from Paul Gortmaker: "Replace module_init with equivalent device_initcall in non modules. This series of commits converts non-modular code that is using the module_init() call to hook itself into the system to instead use device_initcall(). The conversion is a runtime no-op, since module_init actually becomes __initcall in the non-modular case, and that in turn gets mapped onto device_initcall. A couple files show a larger negative diffstat, representing ones that had a module_exit function that we remove here vs previously relying on the linker to dispose of it. We make this conversion now, so that we can relocate module_init from init.h into module.h in the future. The files changed here are just limited to those that would otherwise have to add module.h to obviously non-modular code, in order to avoid a compile fail, as testing has shown" * tag 'module_init-device_initcall-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: MIPS: don't use module_init in non-modular cobalt/mtd.c file drivers/leds: don't use module_init in non-modular leds-cobalt-raq.c cris: don't use module_init for non-modular core eeprom.c code tty/metag_da: Avoid module_init/module_exit in non-modular code drivers/clk: don't use module_init in clk-nomadik.c which is non-modular xtensa: don't use module_init for non-modular core network.c code sh: don't use module_init in non-modular psw.c code mn10300: don't use module_init in non-modular flash.c code parisc64: don't use module_init for non-modular core perf code parisc: don't use module_init for non-modular core pdc_cons code cris: don't use module_init for non-modular core intmem.c code ia64: don't use module_init in non-modular sim/simscsi.c code ia64: don't use module_init for non-modular core kernel/mca.c code arm: don't use module_init in non-modular mach-vexpress/spc.c code powerpc: don't use module_init in non-modular 83xx suspend code powerpc: use device_initcall for registering rtc devices x86: don't use module_init in non-modular devicetree.c code x86: don't use module_init in non-modular intel_mid_vrtc.c

Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block

2015-06-25T22:22:36Z

Pull asm/scatterlist.h removal from Jens Axboe: "We don't have any specific arch scatterlist anymore, since parisc finally switched over. Kill the include" * 'for-4.2/sg' of git://git.kernel.dk/linux-block: remove scatterlist.h generation from arch Kbuild files remove

mm: new mm hook framework

2015-06-25T00:49:41Z

CRIU is recreating the process memory layout by remapping the checkpointee memory area on top of the current process (criu). This includes remapping the vDSO to the place it has at checkpoint time. However some architectures like powerpc are keeping a reference to the vDSO base address to build the signal return stack frame by calling the vDSO sigreturn service. So once the vDSO has been moved, this reference is no more valid and the signal frame built later are not usable. This patch serie is introducing a new mm hook framework, and a new arch_remap hook which is called when mremap is done and the mm lock still hold. The next patch is adding the vDSO remap and unmap tracking to the powerpc architecture. This patch (of 3): This patch introduces a new set of header file to manage mm hooks: - per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h) - a generic header (include/linux/mm-arch-hooks.h) The architecture which need to overwrite a hook as to redefine it in its header file, while architecture which doesn't need have nothing to do. The default hooks are defined in the generic header and are used in the case the architecture is not defining it. In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should be moved here. Signed-off-by: Laurent Dufour Suggested-by: Andrew Morton Cc: "Kirill A. Shutemov" Cc: Hugh Dickins Cc: Rik van Riel Cc: Mel Gorman Cc: Pavel Emelyanov Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

parisc: use for_each_sg()

2015-06-25T00:49:40Z

This replaces the plain loop over the sglist array with for_each_sg() macro which consists of sg_next() function calls. Since parisc doesn't select ARCH_HAS_SG_CHAIN, it is not necessary to use for_each_sg() in order to loop over each sg element. But this can help find problems with drivers that do not properly initialize their sg tables when CONFIG_DEBUG_SG is enabled. Signed-off-by: Akinobu Mita Cc: "James E.J. Bottomley" Cc: Helge Deller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'pci-v4.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2015-06-23T20:41:24Z

Pull PCI updates from Bjorn Helgaas: "PCI changes for the v4.2 merge window: Enumeration - Move pci_ari_enabled() to global header (Alex Williamson) - Account for ARI in _PRT lookups (Alex Williamson) - Remove unused pci_scan_bus_parented() (Yijing Wang) Resource management - Use host bridge _CRS info on systems with >32 bit addressing (Bjorn Helgaas) - Use host bridge _CRS info on Foxconn K8M890-8237A (Bjorn Helgaas) - Fix pci_address_to_pio() conversion of CPU address to I/O port (Zhichang Yuan) - Add pci_bus_addr_t (Yinghai Lu) PCI device hotplug - Wait for pciehp command completion where necessary (Alex Williamson) - Drop pointless ACPI-based "slot detection" check (Rafael J. Wysocki) - Check ignore_hotplug for all downstream devices (Rafael J. Wysocki) - Propagate the "ignore hotplug" setting to parent (Rafael J. Wysocki) - Inline pciehp "handle event" functions into the ISR (Bjorn Helgaas) - Clean up pciehp debug logging (Bjorn Helgaas) Power management - Remove redundant PCIe port type checking (Yijing Wang) - Add dev->has_secondary_link to track downstream PCIe links (Yijing Wang) - Use dev->has_secondary_link to find downstream links for ASPM (Yijing Wang) - Drop __pci_disable_link_state() useless "force" parameter (Bjorn Helgaas) - Simplify Clock Power Management setting (Bjorn Helgaas) Virtualization - Add ACS quirks for Intel 9-series PCH root ports (Alex Williamson) - Add function 1 DMA alias quirk for Marvell 9120 (Sakari Ailus) MSI - Disable MSI at enumeration even if kernel doesn't support MSI (Michael S. Tsirkin) - Remove unused pci_msi_off() (Bjorn Helgaas) - Rename msi_set_enable(), msix_clear_and_set_ctrl() (Michael S. Tsirkin) - Export pci_msi_set_enable(), pci_msix_clear_and_set_ctrl() (Michael S. Tsirkin) - Drop pci_msi_off() calls during probe (Michael S. Tsirkin) APM X-Gene host bridge driver - Add APM X-Gene v1 PCIe MSI/MSIX termination driver (Duc Dang) - Add APM X-Gene PCIe MSI DTS nodes (Duc Dang) - Disable Configuration Request Retry Status for v1 silicon (Duc Dang) - Allow config access to Root Port even when link is down (Duc Dang) Broadcom iProc host bridge driver - Allow override of device tree IRQ mapping function (Hauke Mehrtens) - Add BCMA PCIe driver (Hauke Mehrtens) - Directly add PCI resources (Hauke Mehrtens) - Free resource list after registration (Hauke Mehrtens) Freescale i.MX6 host bridge driver - Add speed change timeout message (Troy Kisky) - Rename imx6_pcie_start_link() to imx6_pcie_establish_link() (Bjorn Helgaas) Freescale Layerscape host bridge driver - Use dw_pcie_link_up() consistently (Bjorn Helgaas) - Factor out ls_pcie_establish_link() (Bjorn Helgaas) Marvell MVEBU host bridge driver - Remove mvebu_pcie_scan_bus() (Yijing Wang) NVIDIA Tegra host bridge driver - Remove tegra_pcie_scan_bus() (Yijing Wang) Synopsys DesignWare host bridge driver - Consolidate outbound iATU programming functions (Jisheng Zhang) - Use iATU0 for cfg and IO, iATU1 for MEM (Jisheng Zhang) - Add support for x8 links (Zhou Wang) - Wait for link to come up with consistent style (Bjorn Helgaas) - Use pci_scan_root_bus() for simplicity (Yijing Wang) TI DRA7xx host bridge driver - Use dw_pcie_link_up() consistently (Bjorn Helgaas) Miscellaneous - Include , not (Bjorn Helgaas) - Remove unnecessary #includes of (Bjorn Helgaas) - Remove unused pcibios_select_root() (again) (Bjorn Helgaas) - Remove unused pci_dma_burst_advice() (Bjorn Helgaas) - xen/pcifront: Don't use deprecated function pci_scan_bus_parented() (Arnd Bergmann)" * tag 'pci-v4.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (58 commits) PCI: pciehp: Inline the "handle event" functions into the ISR PCI: pciehp: Rename queue_interrupt_event() to pciehp_queue_interrupt_event() PCI: pciehp: Make queue_interrupt_event() void PCI: xgene: Allow config access to Root Port even when link is down PCI: xgene: Disable Configuration Request Retry Status for v1 silicon PCI: pciehp: Clean up debug logging x86/PCI: Use host bridge _CRS info on systems with >32 bit addressing PCI: imx6: Add #define PCIE_RC_LCSR PCI: imx6: Use "u32", not "uint32_t" PCI: Remove unused pci_scan_bus_parented() xen/pcifront: Don't use deprecated function pci_scan_bus_parented() PCI: imx6: Add speed change timeout message PCI/ASPM: Simplify Clock Power Management setting PCI: designware: Wait for link to come up with consistent style PCI: layerscape: Factor out ls_pcie_establish_link() PCI: layerscape: Use dw_pcie_link_up() consistently PCI: dra7xx: Use dw_pcie_link_up() consistently x86/PCI: Use host bridge _CRS info on Foxconn K8M890-8237A PCI: pciehp: Wait for hotplug command completion where necessary PCI: Remove unused pci_dma_burst_advice() ...