/* * Copyright (C) 2007 by Alan Stern * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* this file is part of ehci-hcd.c */ /* Display the ports dedicated to the companion controller */ static ssize_t show_companion(struct device *dev, struct device_attribute *attr, char *buf) { struct ehci_hcd *ehci; int nports, index, n; int count = PAGE_SIZE; char *ptr = buf; ehci = hcd_to_ehci(dev_get_drvdata(dev)); nports = HCS_N_PORTS(ehci->hcs_params); for (index = 0; index < nports; ++index) { if (test_bit(index, &ehci->companion_ports)) { n = scnprintf(ptr, count, "%d\n", index + 1); ptr += n; count -= n; } } return ptr - buf; } /* * Dedicate or undedicate a port to the companion controller. * Syntax is "[-]portnum", where a leading '-' sign means * return control of the port to the EHCI controller. */ static ssize_t store_companion(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct ehci_hcd *ehci; int portnum, new_owner; ehci = hcd_to_ehci(dev_get_drvdata(dev)); new_owner = PORT_OWNER; /* Owned by companion */ if (sscanf(buf, "%d", &portnum) != 1) return -EINVAL; if (portnum < 0) { portnum = - portnum; new_owner = 0; /* Owned by EHCI */ } if (portnum <= 0 || portnum > HCS_N_PORTS(ehci->hcs_params)) return -ENOENT; portnum--; if (new_owner) set_bit(portnum, &ehci->companion_ports); else clear_bit(portnum, &ehci->companion_ports); set_owner(ehci, portnum, new_owner); return count; } static DEVICE_ATTR(companion, 0644, show_companion, store_companion); /* * Display / Set uframe_periodic_max */ static ssize_t show_uframe_periodic_max(struct device *dev, struct device_attribute *attr, char *buf) { struct ehci_hcd *ehci; int n; ehci = hcd_to_ehci(dev_get_drvdata(dev)); n = scnprintf(buf, PAGE_SIZE, "%d\n", ehci->uframe_periodic_max); return n; } static ssize_t store_uframe_periodic_max(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct ehci_hcd *ehci; unsigned uframe_periodic_max; unsigned uframe; unsigned long flags; ssize_t ret; ehci = hcd_to_ehci(dev_get_drvdata(dev)); if (kstrtouint(buf, 0, &uframe_periodic_max) < 0) return -EINVAL; if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) { ehci_info(ehci, "rejecting invalid request for " "uframe_periodic_max=%u\n", uframe_periodic_max); return -EINVAL; } ret = -EINVAL; /* * lock, so that our checking does not race with possible periodic * bandwidth allocation through submitting new urbs. */ spin_lock_irqsave (&ehci->lock, flags); /* * for request to decrease max periodic bandwidth, we have to check * to see whether the decrease is possible. */ if (uframe_periodic_max < ehci->uframe_periodic_max) { u8 allocated_max = 0; for (uframe = 0; uframe < EHCI_BANDWIDTH_SIZE; ++uframe) allocated_max = max(allocated_max, ehci->bandwidth[uframe]); if (allocated_max > uframe_periodic_max) { ehci_info(ehci, "cannot decrease uframe_periodic_max because " "periodic bandwidth is already allocated " "(%u > %u)\n", allocated_max, uframe_periodic_max); goto out_unlock; } } /* increasing is always ok */ ehci_info(ehci, "setting max periodic bandwidth to %u%% " "(== %u usec/uframe)\n", 100*uframe_periodic_max/125, uframe_periodic_max); if (uframe_periodic_max != 100) ehci_warn(ehci, "max periodic bandwidth set is non-standard\n"); ehci->uframe_periodic_max = uframe_periodic_max; ret = count; out_unlock: spin_unlock_irqrestore (&ehci->lock, flags); return ret; } static DEVICE_ATTR(uframe_periodic_max, 0644, show_uframe_periodic_max, store_uframe_periodic_max); static inline int create_sysfs_files(struct ehci_hcd *ehci) { struct device *controller = ehci_to_hcd(ehci)->self.controller; int i = 0; /* with integrated TT there is no companion! */ if (!ehci_is_TDI(ehci)) i = device_create_file(controller, &dev_attr_companion); if (i) goto out; i = device_create_file(controller, &dev_attr_uframe_periodic_max); out: return i; } static inline void remove_sysfs_files(struct ehci_hcd *ehci) { struct device *controller = ehci_to_hcd(ehci)->self.controller; /* with integrated TT there is no companion! */ if (!ehci_is_TDI(ehci)) device_remove_file(controller, &dev_attr_companion); device_remove_file(controller, &dev_attr_uframe_periodic_max); } 5e92'>c8f325a59cfc718d13a50fbc746ed9b415c25e92 (patch) treed53fbdac9d0781e39a13b2ac6b2bd258cf3b4140 /kernel/pid.c parentbf29bddf0417a4783da3b24e8c9e017ac649326f (diff)
efi/fdt: Avoid FDT manipulation after ExitBootServices()
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/pid.c')