/* * Copyright 2010 Tilera Corporation. All Rights Reserved. * * 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, version 2. * * 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, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for * more details. * * Tilera TILE Processor hypervisor console */ #include #include #include #include #include #include #include #include #include #include #include #include #include "hvc_console.h" static int use_sim_console; static int __init sim_console(char *str) { use_sim_console = 1; return 0; } early_param("sim_console", sim_console); int tile_console_write(const char *buf, int count) { if (unlikely(use_sim_console)) { int i; for (i = 0; i < count; ++i) __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PUTC | (buf[i] << _SIM_CONTROL_OPERATOR_BITS)); __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PUTC | (SIM_PUTC_FLUSH_BINARY << _SIM_CONTROL_OPERATOR_BITS)); return 0; } else { /* Translate 0 bytes written to EAGAIN for hvc_console_print. */ return hv_console_write((HV_VirtAddr)buf, count) ?: -EAGAIN; } } static int hvc_tile_put_chars(uint32_t vt, const char *buf, int count) { return tile_console_write(buf, count); } static int hvc_tile_get_chars(uint32_t vt, char *buf, int count) { int i, c; for (i = 0; i < count; ++i) { c = hv_console_read_if_ready(); if (c < 0) break; buf[i] = c; } return i; } #ifdef __tilegx__ /* * IRQ based callbacks. */ static int hvc_tile_notifier_add_irq(struct hvc_struct *hp, int irq) { int rc; int cpu = raw_smp_processor_id(); /* Choose an arbitrary cpu */ HV_Coord coord = { .x = cpu_x(cpu), .y = cpu_y(cpu) }; rc = notifier_add_irq(hp, irq); if (rc) return rc; /* * Request that the hypervisor start sending us interrupts. * If the hypervisor returns an error, we still return 0, so that * we can fall back to polling. */ if (hv_console_set_ipi(KERNEL_PL, irq, coord) < 0) notifier_del_irq(hp, irq); return 0; } static void hvc_tile_notifier_del_irq(struct hvc_struct *hp, int irq) { HV_Coord coord = { 0, 0 }; /* Tell the hypervisor to stop sending us interrupts. */ hv_console_set_ipi(KERNEL_PL, -1, coord); notifier_del_irq(hp, irq); } static void hvc_tile_notifier_hangup_irq(struct hvc_struct *hp, int irq) { hvc_tile_notifier_del_irq(hp, irq); } #endif static const struct hv_ops hvc_tile_get_put_ops = { .get_chars = hvc_tile_get_chars, .put_chars = hvc_tile_put_chars, #ifdef __tilegx__ .notifier_add = hvc_tile_notifier_add_irq, .notifier_del = hvc_tile_notifier_del_irq, .notifier_hangup = hvc_tile_notifier_hangup_irq, #endif }; #ifdef __tilegx__ static int hvc_tile_probe(struct platform_device *pdev) { struct hvc_struct *hp; int tile_hvc_irq; /* Create our IRQ and register it. */ tile_hvc_irq = irq_alloc_hwirq(-1); if (!tile_hvc_irq) return -ENXIO; tile_irq_activate(tile_hvc_irq, TILE_IRQ_PERCPU); hp = hvc_alloc(0, tile_hvc_irq, &hvc_tile_get_put_ops, 128); if (IS_ERR(hp)) { irq_free_hwirq(tile_hvc_irq); return PTR_ERR(hp); } dev_set_drvdata(&pdev->dev, hp); return 0; } static int hvc_tile_remove(struct platform_device *pdev) { int rc; struct hvc_struct *hp = dev_get_drvdata(&pdev->dev); rc = hvc_remove(hp); if (rc == 0) irq_free_hwirq(hp->data); return rc; } static void hvc_tile_shutdown(struct platform_device *pdev) { struct hvc_struct *hp = dev_get_drvdata(&pdev->dev); hvc_tile_notifier_del_irq(hp, hp->data); } static struct platform_device hvc_tile_pdev = { .name = "hvc-tile", .id = 0, }; static struct platform_driver hvc_tile_driver = { .probe = hvc_tile_probe, .remove = hvc_tile_remove, .shutdown = hvc_tile_shutdown, .driver = { .name = "hvc-tile", } }; #endif static int __init hvc_tile_console_init(void) { hvc_instantiate(0, 0, &hvc_tile_get_put_ops); add_preferred_console("hvc", 0, NULL); return 0; } console_initcall(hvc_tile_console_init); static int __init hvc_tile_init(void) { #ifndef __tilegx__ struct hvc_struct *hp; hp = hvc_alloc(0, 0, &hvc_tile_get_put_ops, 128); return PTR_ERR_OR_ZERO(hp); #else platform_device_register(&hvc_tile_pdev); return platform_driver_register(&hvc_tile_driver); #endif } device_initcall(hvc_tile_init); 45:02 +0000 committerIngo Molnar <mingo@kernel.org>2017-02-01 21:17:49 +0100 commitc8f325a59cfc718d13a50fbc746ed9b415c25e92 (patch) treed53fbdac9d0781e39a13b2ac6b2bd258cf3b4140 /tools/perf/util/evlist.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 'tools/perf/util/evlist.c')