![Alexey Dobriyan](/assets/img/avatar_default.png)
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1102 lines
30 KiB
C
1102 lines
30 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#include <linux/fs.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/rwsem.h>
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#include <linux/kprobes.h>
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#include <linux/sched.h>
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#include <linux/hardirq.h>
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#include <linux/uaccess.h>
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#include <linux/smp.h>
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#include <linux/cdev.h>
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#include <linux/compat.h>
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#include <asm/hardwall.h>
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#include <asm/traps.h>
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#include <asm/siginfo.h>
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#include <asm/irq_regs.h>
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#include <arch/interrupts.h>
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#include <arch/spr_def.h>
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/*
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* Implement a per-cpu "hardwall" resource class such as UDN or IPI.
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* We use "hardwall" nomenclature throughout for historical reasons.
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* The lock here controls access to the list data structure as well as
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* to the items on the list.
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*/
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struct hardwall_type {
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int index;
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int is_xdn;
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int is_idn;
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int disabled;
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const char *name;
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struct list_head list;
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spinlock_t lock;
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struct proc_dir_entry *proc_dir;
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};
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enum hardwall_index {
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HARDWALL_UDN = 0,
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#ifndef __tilepro__
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HARDWALL_IDN = 1,
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HARDWALL_IPI = 2,
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#endif
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_HARDWALL_TYPES
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};
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static struct hardwall_type hardwall_types[] = {
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{ /* user-space access to UDN */
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0,
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1,
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0,
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0,
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"udn",
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LIST_HEAD_INIT(hardwall_types[HARDWALL_UDN].list),
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__SPIN_LOCK_UNLOCKED(hardwall_types[HARDWALL_UDN].lock),
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NULL
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},
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#ifndef __tilepro__
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{ /* user-space access to IDN */
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1,
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1,
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1,
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1, /* disabled pending hypervisor support */
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"idn",
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LIST_HEAD_INIT(hardwall_types[HARDWALL_IDN].list),
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__SPIN_LOCK_UNLOCKED(hardwall_types[HARDWALL_IDN].lock),
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NULL
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},
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{ /* access to user-space IPI */
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2,
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0,
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0,
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0,
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"ipi",
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LIST_HEAD_INIT(hardwall_types[HARDWALL_IPI].list),
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__SPIN_LOCK_UNLOCKED(hardwall_types[HARDWALL_IPI].lock),
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NULL
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},
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#endif
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};
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/*
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* This data structure tracks the cpu data, etc., associated
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* one-to-one with a "struct file *" from opening a hardwall device file.
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* Note that the file's private data points back to this structure.
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*/
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struct hardwall_info {
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struct list_head list; /* for hardwall_types.list */
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struct list_head task_head; /* head of tasks in this hardwall */
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struct hardwall_type *type; /* type of this resource */
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struct cpumask cpumask; /* cpus reserved */
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int id; /* integer id for this hardwall */
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int teardown_in_progress; /* are we tearing this one down? */
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/* Remaining fields only valid for user-network resources. */
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int ulhc_x; /* upper left hand corner x coord */
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int ulhc_y; /* upper left hand corner y coord */
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int width; /* rectangle width */
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int height; /* rectangle height */
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#if CHIP_HAS_REV1_XDN()
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atomic_t xdn_pending_count; /* cores in phase 1 of drain */
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#endif
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};
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/* /proc/tile/hardwall */
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static struct proc_dir_entry *hardwall_proc_dir;
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/* Functions to manage files in /proc/tile/hardwall. */
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static void hardwall_add_proc(struct hardwall_info *);
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static void hardwall_remove_proc(struct hardwall_info *);
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/* Allow disabling UDN access. */
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static int __init noudn(char *str)
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{
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pr_info("User-space UDN access is disabled\n");
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hardwall_types[HARDWALL_UDN].disabled = 1;
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return 0;
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}
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early_param("noudn", noudn);
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#ifndef __tilepro__
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/* Allow disabling IDN access. */
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static int __init noidn(char *str)
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{
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pr_info("User-space IDN access is disabled\n");
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hardwall_types[HARDWALL_IDN].disabled = 1;
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return 0;
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}
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early_param("noidn", noidn);
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/* Allow disabling IPI access. */
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static int __init noipi(char *str)
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{
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pr_info("User-space IPI access is disabled\n");
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hardwall_types[HARDWALL_IPI].disabled = 1;
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return 0;
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}
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early_param("noipi", noipi);
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#endif
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/*
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* Low-level primitives for UDN/IDN
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*/
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#ifdef __tilepro__
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#define mtspr_XDN(hwt, name, val) \
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do { (void)(hwt); __insn_mtspr(SPR_UDN_##name, (val)); } while (0)
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#define mtspr_MPL_XDN(hwt, name, val) \
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do { (void)(hwt); __insn_mtspr(SPR_MPL_UDN_##name, (val)); } while (0)
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#define mfspr_XDN(hwt, name) \
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((void)(hwt), __insn_mfspr(SPR_UDN_##name))
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#else
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#define mtspr_XDN(hwt, name, val) \
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do { \
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if ((hwt)->is_idn) \
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__insn_mtspr(SPR_IDN_##name, (val)); \
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else \
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__insn_mtspr(SPR_UDN_##name, (val)); \
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} while (0)
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#define mtspr_MPL_XDN(hwt, name, val) \
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do { \
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if ((hwt)->is_idn) \
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__insn_mtspr(SPR_MPL_IDN_##name, (val)); \
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else \
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__insn_mtspr(SPR_MPL_UDN_##name, (val)); \
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} while (0)
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#define mfspr_XDN(hwt, name) \
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((hwt)->is_idn ? __insn_mfspr(SPR_IDN_##name) : __insn_mfspr(SPR_UDN_##name))
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#endif
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/* Set a CPU bit if the CPU is online. */
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#define cpu_online_set(cpu, dst) do { \
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if (cpu_online(cpu)) \
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cpumask_set_cpu(cpu, dst); \
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} while (0)
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/* Does the given rectangle contain the given x,y coordinate? */
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static int contains(struct hardwall_info *r, int x, int y)
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{
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return (x >= r->ulhc_x && x < r->ulhc_x + r->width) &&
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(y >= r->ulhc_y && y < r->ulhc_y + r->height);
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}
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/* Compute the rectangle parameters and validate the cpumask. */
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static int check_rectangle(struct hardwall_info *r, struct cpumask *mask)
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{
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int x, y, cpu, ulhc, lrhc;
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/* The first cpu is the ULHC, the last the LRHC. */
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ulhc = find_first_bit(cpumask_bits(mask), nr_cpumask_bits);
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lrhc = find_last_bit(cpumask_bits(mask), nr_cpumask_bits);
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/* Compute the rectangle attributes from the cpus. */
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r->ulhc_x = cpu_x(ulhc);
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r->ulhc_y = cpu_y(ulhc);
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r->width = cpu_x(lrhc) - r->ulhc_x + 1;
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r->height = cpu_y(lrhc) - r->ulhc_y + 1;
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/* Width and height must be positive */
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if (r->width <= 0 || r->height <= 0)
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return -EINVAL;
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/* Confirm that the cpumask is exactly the rectangle. */
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for (y = 0, cpu = 0; y < smp_height; ++y)
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for (x = 0; x < smp_width; ++x, ++cpu)
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if (cpumask_test_cpu(cpu, mask) != contains(r, x, y))
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return -EINVAL;
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/*
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* Note that offline cpus can't be drained when this user network
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* rectangle eventually closes. We used to detect this
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* situation and print a warning, but it annoyed users and
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* they ignored it anyway, so now we just return without a
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* warning.
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*/
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return 0;
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}
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/*
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* Hardware management of hardwall setup, teardown, trapping,
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* and enabling/disabling PL0 access to the networks.
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*/
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/* Bit field values to mask together for writes to SPR_XDN_DIRECTION_PROTECT */
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enum direction_protect {
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N_PROTECT = (1 << 0),
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E_PROTECT = (1 << 1),
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S_PROTECT = (1 << 2),
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W_PROTECT = (1 << 3),
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C_PROTECT = (1 << 4),
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};
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static inline int xdn_which_interrupt(struct hardwall_type *hwt)
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{
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#ifndef __tilepro__
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if (hwt->is_idn)
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return INT_IDN_FIREWALL;
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#endif
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return INT_UDN_FIREWALL;
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}
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static void enable_firewall_interrupts(struct hardwall_type *hwt)
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{
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arch_local_irq_unmask_now(xdn_which_interrupt(hwt));
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}
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static void disable_firewall_interrupts(struct hardwall_type *hwt)
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{
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arch_local_irq_mask_now(xdn_which_interrupt(hwt));
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}
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/* Set up hardwall on this cpu based on the passed hardwall_info. */
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static void hardwall_setup_func(void *info)
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{
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struct hardwall_info *r = info;
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struct hardwall_type *hwt = r->type;
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int cpu = smp_processor_id(); /* on_each_cpu disables preemption */
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int x = cpu_x(cpu);
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int y = cpu_y(cpu);
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int bits = 0;
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if (x == r->ulhc_x)
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bits |= W_PROTECT;
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if (x == r->ulhc_x + r->width - 1)
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bits |= E_PROTECT;
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if (y == r->ulhc_y)
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bits |= N_PROTECT;
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if (y == r->ulhc_y + r->height - 1)
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bits |= S_PROTECT;
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BUG_ON(bits == 0);
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mtspr_XDN(hwt, DIRECTION_PROTECT, bits);
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enable_firewall_interrupts(hwt);
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}
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/* Set up all cpus on edge of rectangle to enable/disable hardwall SPRs. */
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static void hardwall_protect_rectangle(struct hardwall_info *r)
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{
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int x, y, cpu, delta;
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struct cpumask rect_cpus;
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cpumask_clear(&rect_cpus);
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/* First include the top and bottom edges */
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cpu = r->ulhc_y * smp_width + r->ulhc_x;
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delta = (r->height - 1) * smp_width;
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for (x = 0; x < r->width; ++x, ++cpu) {
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cpu_online_set(cpu, &rect_cpus);
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cpu_online_set(cpu + delta, &rect_cpus);
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}
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/* Then the left and right edges */
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cpu -= r->width;
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delta = r->width - 1;
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for (y = 0; y < r->height; ++y, cpu += smp_width) {
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cpu_online_set(cpu, &rect_cpus);
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cpu_online_set(cpu + delta, &rect_cpus);
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}
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/* Then tell all the cpus to set up their protection SPR */
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on_each_cpu_mask(&rect_cpus, hardwall_setup_func, r, 1);
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}
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/* Entered from INT_xDN_FIREWALL interrupt vector with irqs disabled. */
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void __kprobes do_hardwall_trap(struct pt_regs* regs, int fault_num)
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{
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struct hardwall_info *rect;
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struct hardwall_type *hwt;
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struct task_struct *p;
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struct siginfo info;
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int cpu = smp_processor_id();
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int found_processes;
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struct pt_regs *old_regs = set_irq_regs(regs);
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irq_enter();
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/* Figure out which network trapped. */
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switch (fault_num) {
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#ifndef __tilepro__
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case INT_IDN_FIREWALL:
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hwt = &hardwall_types[HARDWALL_IDN];
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break;
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#endif
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case INT_UDN_FIREWALL:
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hwt = &hardwall_types[HARDWALL_UDN];
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break;
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default:
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BUG();
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}
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BUG_ON(hwt->disabled);
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/* This tile trapped a network access; find the rectangle. */
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spin_lock(&hwt->lock);
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list_for_each_entry(rect, &hwt->list, list) {
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if (cpumask_test_cpu(cpu, &rect->cpumask))
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break;
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}
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/*
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* It shouldn't be possible not to find this cpu on the
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* rectangle list, since only cpus in rectangles get hardwalled.
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* The hardwall is only removed after the user network is drained.
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*/
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BUG_ON(&rect->list == &hwt->list);
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/*
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* If we already started teardown on this hardwall, don't worry;
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* the abort signal has been sent and we are just waiting for things
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* to quiesce.
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*/
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if (rect->teardown_in_progress) {
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pr_notice("cpu %d: detected %s hardwall violation %#lx"
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" while teardown already in progress\n",
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cpu, hwt->name,
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(long)mfspr_XDN(hwt, DIRECTION_PROTECT));
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goto done;
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}
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/*
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* Kill off any process that is activated in this rectangle.
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* We bypass security to deliver the signal, since it must be
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* one of the activated processes that generated the user network
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* message that caused this trap, and all the activated
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* processes shared a single open file so are pretty tightly
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* bound together from a security point of view to begin with.
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*/
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rect->teardown_in_progress = 1;
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wmb(); /* Ensure visibility of rectangle before notifying processes. */
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pr_notice("cpu %d: detected %s hardwall violation %#lx...\n",
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cpu, hwt->name, (long)mfspr_XDN(hwt, DIRECTION_PROTECT));
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info.si_signo = SIGILL;
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info.si_errno = 0;
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info.si_code = ILL_HARDWALL;
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found_processes = 0;
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list_for_each_entry(p, &rect->task_head,
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thread.hardwall[hwt->index].list) {
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BUG_ON(p->thread.hardwall[hwt->index].info != rect);
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if (!(p->flags & PF_EXITING)) {
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found_processes = 1;
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pr_notice("hardwall: killing %d\n", p->pid);
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do_send_sig_info(info.si_signo, &info, p, false);
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}
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}
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if (!found_processes)
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pr_notice("hardwall: no associated processes!\n");
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done:
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spin_unlock(&hwt->lock);
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/*
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* We have to disable firewall interrupts now, or else when we
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* return from this handler, we will simply re-interrupt back to
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* it. However, we can't clear the protection bits, since we
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* haven't yet drained the network, and that would allow packets
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* to cross out of the hardwall region.
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*/
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disable_firewall_interrupts(hwt);
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irq_exit();
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set_irq_regs(old_regs);
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}
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/* Allow access from user space to the user network. */
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void grant_hardwall_mpls(struct hardwall_type *hwt)
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{
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#ifndef __tilepro__
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if (!hwt->is_xdn) {
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__insn_mtspr(SPR_MPL_IPI_0_SET_0, 1);
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return;
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}
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#endif
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mtspr_MPL_XDN(hwt, ACCESS_SET_0, 1);
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mtspr_MPL_XDN(hwt, AVAIL_SET_0, 1);
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mtspr_MPL_XDN(hwt, COMPLETE_SET_0, 1);
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mtspr_MPL_XDN(hwt, TIMER_SET_0, 1);
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#if !CHIP_HAS_REV1_XDN()
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mtspr_MPL_XDN(hwt, REFILL_SET_0, 1);
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mtspr_MPL_XDN(hwt, CA_SET_0, 1);
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#endif
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}
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/* Deny access from user space to the user network. */
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void restrict_hardwall_mpls(struct hardwall_type *hwt)
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{
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#ifndef __tilepro__
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if (!hwt->is_xdn) {
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__insn_mtspr(SPR_MPL_IPI_0_SET_1, 1);
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return;
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}
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#endif
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mtspr_MPL_XDN(hwt, ACCESS_SET_1, 1);
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mtspr_MPL_XDN(hwt, AVAIL_SET_1, 1);
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mtspr_MPL_XDN(hwt, COMPLETE_SET_1, 1);
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mtspr_MPL_XDN(hwt, TIMER_SET_1, 1);
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#if !CHIP_HAS_REV1_XDN()
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mtspr_MPL_XDN(hwt, REFILL_SET_1, 1);
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mtspr_MPL_XDN(hwt, CA_SET_1, 1);
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#endif
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}
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|
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/* Restrict or deny as necessary for the task we're switching to. */
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void hardwall_switch_tasks(struct task_struct *prev,
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struct task_struct *next)
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{
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int i;
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for (i = 0; i < HARDWALL_TYPES; ++i) {
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if (prev->thread.hardwall[i].info != NULL) {
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if (next->thread.hardwall[i].info == NULL)
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restrict_hardwall_mpls(&hardwall_types[i]);
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} else if (next->thread.hardwall[i].info != NULL) {
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grant_hardwall_mpls(&hardwall_types[i]);
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}
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}
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}
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|
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/* Does this task have the right to IPI the given cpu? */
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int hardwall_ipi_valid(int cpu)
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{
|
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#ifdef __tilegx__
|
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struct hardwall_info *info =
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current->thread.hardwall[HARDWALL_IPI].info;
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return info && cpumask_test_cpu(cpu, &info->cpumask);
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Code to create, activate, deactivate, and destroy hardwall resources.
|
|
*/
|
|
|
|
/* Create a hardwall for the given resource */
|
|
static struct hardwall_info *hardwall_create(struct hardwall_type *hwt,
|
|
size_t size,
|
|
const unsigned char __user *bits)
|
|
{
|
|
struct hardwall_info *iter, *info;
|
|
struct cpumask mask;
|
|
unsigned long flags;
|
|
int rc;
|
|
|
|
/* Reject crazy sizes out of hand, a la sys_mbind(). */
|
|
if (size > PAGE_SIZE)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
/* Copy whatever fits into a cpumask. */
|
|
if (copy_from_user(&mask, bits, min(sizeof(struct cpumask), size)))
|
|
return ERR_PTR(-EFAULT);
|
|
|
|
/*
|
|
* If the size was short, clear the rest of the mask;
|
|
* otherwise validate that the rest of the user mask was zero
|
|
* (we don't try hard to be efficient when validating huge masks).
|
|
*/
|
|
if (size < sizeof(struct cpumask)) {
|
|
memset((char *)&mask + size, 0, sizeof(struct cpumask) - size);
|
|
} else if (size > sizeof(struct cpumask)) {
|
|
size_t i;
|
|
for (i = sizeof(struct cpumask); i < size; ++i) {
|
|
char c;
|
|
if (get_user(c, &bits[i]))
|
|
return ERR_PTR(-EFAULT);
|
|
if (c)
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
}
|
|
|
|
/* Allocate a new hardwall_info optimistically. */
|
|
info = kmalloc(sizeof(struct hardwall_info),
|
|
GFP_KERNEL | __GFP_ZERO);
|
|
if (info == NULL)
|
|
return ERR_PTR(-ENOMEM);
|
|
INIT_LIST_HEAD(&info->task_head);
|
|
info->type = hwt;
|
|
|
|
/* Compute the rectangle size and validate that it's plausible. */
|
|
cpumask_copy(&info->cpumask, &mask);
|
|
info->id = find_first_bit(cpumask_bits(&mask), nr_cpumask_bits);
|
|
if (hwt->is_xdn) {
|
|
rc = check_rectangle(info, &mask);
|
|
if (rc != 0) {
|
|
kfree(info);
|
|
return ERR_PTR(rc);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Eliminate cpus that are not part of this Linux client.
|
|
* Note that this allows for configurations that we might not want to
|
|
* support, such as one client on every even cpu, another client on
|
|
* every odd cpu.
|
|
*/
|
|
cpumask_and(&info->cpumask, &info->cpumask, cpu_online_mask);
|
|
|
|
/* Confirm it doesn't overlap and add it to the list. */
|
|
spin_lock_irqsave(&hwt->lock, flags);
|
|
list_for_each_entry(iter, &hwt->list, list) {
|
|
if (cpumask_intersects(&iter->cpumask, &info->cpumask)) {
|
|
spin_unlock_irqrestore(&hwt->lock, flags);
|
|
kfree(info);
|
|
return ERR_PTR(-EBUSY);
|
|
}
|
|
}
|
|
list_add_tail(&info->list, &hwt->list);
|
|
spin_unlock_irqrestore(&hwt->lock, flags);
|
|
|
|
/* Set up appropriate hardwalling on all affected cpus. */
|
|
if (hwt->is_xdn)
|
|
hardwall_protect_rectangle(info);
|
|
|
|
/* Create a /proc/tile/hardwall entry. */
|
|
hardwall_add_proc(info);
|
|
|
|
return info;
|
|
}
|
|
|
|
/* Activate a given hardwall on this cpu for this process. */
|
|
static int hardwall_activate(struct hardwall_info *info)
|
|
{
|
|
int cpu;
|
|
unsigned long flags;
|
|
struct task_struct *p = current;
|
|
struct thread_struct *ts = &p->thread;
|
|
struct hardwall_type *hwt;
|
|
|
|
/* Require a hardwall. */
|
|
if (info == NULL)
|
|
return -ENODATA;
|
|
|
|
/* Not allowed to activate a hardwall that is being torn down. */
|
|
if (info->teardown_in_progress)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Get our affinity; if we're not bound to this tile uniquely,
|
|
* we can't access the network registers.
|
|
*/
|
|
if (cpumask_weight(&p->cpus_allowed) != 1)
|
|
return -EPERM;
|
|
|
|
/* Make sure we are bound to a cpu assigned to this resource. */
|
|
cpu = smp_processor_id();
|
|
BUG_ON(cpumask_first(&p->cpus_allowed) != cpu);
|
|
if (!cpumask_test_cpu(cpu, &info->cpumask))
|
|
return -EINVAL;
|
|
|
|
/* If we are already bound to this hardwall, it's a no-op. */
|
|
hwt = info->type;
|
|
if (ts->hardwall[hwt->index].info) {
|
|
BUG_ON(ts->hardwall[hwt->index].info != info);
|
|
return 0;
|
|
}
|
|
|
|
/* Success! This process gets to use the resource on this cpu. */
|
|
ts->hardwall[hwt->index].info = info;
|
|
spin_lock_irqsave(&hwt->lock, flags);
|
|
list_add(&ts->hardwall[hwt->index].list, &info->task_head);
|
|
spin_unlock_irqrestore(&hwt->lock, flags);
|
|
grant_hardwall_mpls(hwt);
|
|
printk(KERN_DEBUG "Pid %d (%s) activated for %s hardwall: cpu %d\n",
|
|
p->pid, p->comm, hwt->name, cpu);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Deactivate a task's hardwall. Must hold lock for hardwall_type.
|
|
* This method may be called from exit_thread(), so we don't want to
|
|
* rely on too many fields of struct task_struct still being valid.
|
|
* We assume the cpus_allowed, pid, and comm fields are still valid.
|
|
*/
|
|
static void _hardwall_deactivate(struct hardwall_type *hwt,
|
|
struct task_struct *task)
|
|
{
|
|
struct thread_struct *ts = &task->thread;
|
|
|
|
if (cpumask_weight(&task->cpus_allowed) != 1) {
|
|
pr_err("pid %d (%s) releasing %s hardwall with"
|
|
" an affinity mask containing %d cpus!\n",
|
|
task->pid, task->comm, hwt->name,
|
|
cpumask_weight(&task->cpus_allowed));
|
|
BUG();
|
|
}
|
|
|
|
BUG_ON(ts->hardwall[hwt->index].info == NULL);
|
|
ts->hardwall[hwt->index].info = NULL;
|
|
list_del(&ts->hardwall[hwt->index].list);
|
|
if (task == current)
|
|
restrict_hardwall_mpls(hwt);
|
|
}
|
|
|
|
/* Deactivate a task's hardwall. */
|
|
static int hardwall_deactivate(struct hardwall_type *hwt,
|
|
struct task_struct *task)
|
|
{
|
|
unsigned long flags;
|
|
int activated;
|
|
|
|
spin_lock_irqsave(&hwt->lock, flags);
|
|
activated = (task->thread.hardwall[hwt->index].info != NULL);
|
|
if (activated)
|
|
_hardwall_deactivate(hwt, task);
|
|
spin_unlock_irqrestore(&hwt->lock, flags);
|
|
|
|
if (!activated)
|
|
return -EINVAL;
|
|
|
|
printk(KERN_DEBUG "Pid %d (%s) deactivated for %s hardwall: cpu %d\n",
|
|
task->pid, task->comm, hwt->name, raw_smp_processor_id());
|
|
return 0;
|
|
}
|
|
|
|
void hardwall_deactivate_all(struct task_struct *task)
|
|
{
|
|
int i;
|
|
for (i = 0; i < HARDWALL_TYPES; ++i)
|
|
if (task->thread.hardwall[i].info)
|
|
hardwall_deactivate(&hardwall_types[i], task);
|
|
}
|
|
|
|
/* Stop the switch before draining the network. */
|
|
static void stop_xdn_switch(void *arg)
|
|
{
|
|
#if !CHIP_HAS_REV1_XDN()
|
|
/* Freeze the switch and the demux. */
|
|
__insn_mtspr(SPR_UDN_SP_FREEZE,
|
|
SPR_UDN_SP_FREEZE__SP_FRZ_MASK |
|
|
SPR_UDN_SP_FREEZE__DEMUX_FRZ_MASK |
|
|
SPR_UDN_SP_FREEZE__NON_DEST_EXT_MASK);
|
|
#else
|
|
/*
|
|
* Drop all packets bound for the core or off the edge.
|
|
* We rely on the normal hardwall protection setup code
|
|
* to have set the low four bits to trigger firewall interrupts,
|
|
* and shift those bits up to trigger "drop on send" semantics,
|
|
* plus adding "drop on send to core" for all switches.
|
|
* In practice it seems the switches latch the DIRECTION_PROTECT
|
|
* SPR so they won't start dropping if they're already
|
|
* delivering the last message to the core, but it doesn't
|
|
* hurt to enable it here.
|
|
*/
|
|
struct hardwall_type *hwt = arg;
|
|
unsigned long protect = mfspr_XDN(hwt, DIRECTION_PROTECT);
|
|
mtspr_XDN(hwt, DIRECTION_PROTECT, (protect | C_PROTECT) << 5);
|
|
#endif
|
|
}
|
|
|
|
static void empty_xdn_demuxes(struct hardwall_type *hwt)
|
|
{
|
|
#ifndef __tilepro__
|
|
if (hwt->is_idn) {
|
|
while (__insn_mfspr(SPR_IDN_DATA_AVAIL) & (1 << 0))
|
|
(void) __tile_idn0_receive();
|
|
while (__insn_mfspr(SPR_IDN_DATA_AVAIL) & (1 << 1))
|
|
(void) __tile_idn1_receive();
|
|
return;
|
|
}
|
|
#endif
|
|
while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 0))
|
|
(void) __tile_udn0_receive();
|
|
while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 1))
|
|
(void) __tile_udn1_receive();
|
|
while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 2))
|
|
(void) __tile_udn2_receive();
|
|
while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 3))
|
|
(void) __tile_udn3_receive();
|
|
}
|
|
|
|
/* Drain all the state from a stopped switch. */
|
|
static void drain_xdn_switch(void *arg)
|
|
{
|
|
struct hardwall_info *info = arg;
|
|
struct hardwall_type *hwt = info->type;
|
|
|
|
#if CHIP_HAS_REV1_XDN()
|
|
/*
|
|
* The switches have been configured to drop any messages
|
|
* destined for cores (or off the edge of the rectangle).
|
|
* But the current message may continue to be delivered,
|
|
* so we wait until all the cores have finished any pending
|
|
* messages before we stop draining.
|
|
*/
|
|
int pending = mfspr_XDN(hwt, PENDING);
|
|
while (pending--) {
|
|
empty_xdn_demuxes(hwt);
|
|
if (hwt->is_idn)
|
|
__tile_idn_send(0);
|
|
else
|
|
__tile_udn_send(0);
|
|
}
|
|
atomic_dec(&info->xdn_pending_count);
|
|
while (atomic_read(&info->xdn_pending_count))
|
|
empty_xdn_demuxes(hwt);
|
|
#else
|
|
int i;
|
|
int from_tile_words, ca_count;
|
|
|
|
/* Empty out the 5 switch point fifos. */
|
|
for (i = 0; i < 5; i++) {
|
|
int words, j;
|
|
__insn_mtspr(SPR_UDN_SP_FIFO_SEL, i);
|
|
words = __insn_mfspr(SPR_UDN_SP_STATE) & 0xF;
|
|
for (j = 0; j < words; j++)
|
|
(void) __insn_mfspr(SPR_UDN_SP_FIFO_DATA);
|
|
BUG_ON((__insn_mfspr(SPR_UDN_SP_STATE) & 0xF) != 0);
|
|
}
|
|
|
|
/* Dump out the 3 word fifo at top. */
|
|
from_tile_words = (__insn_mfspr(SPR_UDN_DEMUX_STATUS) >> 10) & 0x3;
|
|
for (i = 0; i < from_tile_words; i++)
|
|
(void) __insn_mfspr(SPR_UDN_DEMUX_WRITE_FIFO);
|
|
|
|
/* Empty out demuxes. */
|
|
empty_xdn_demuxes(hwt);
|
|
|
|
/* Empty out catch all. */
|
|
ca_count = __insn_mfspr(SPR_UDN_DEMUX_CA_COUNT);
|
|
for (i = 0; i < ca_count; i++)
|
|
(void) __insn_mfspr(SPR_UDN_CA_DATA);
|
|
BUG_ON(__insn_mfspr(SPR_UDN_DEMUX_CA_COUNT) != 0);
|
|
|
|
/* Clear demux logic. */
|
|
__insn_mtspr(SPR_UDN_DEMUX_CTL, 1);
|
|
|
|
/*
|
|
* Write switch state; experimentation indicates that 0xc3000
|
|
* is an idle switch point.
|
|
*/
|
|
for (i = 0; i < 5; i++) {
|
|
__insn_mtspr(SPR_UDN_SP_FIFO_SEL, i);
|
|
__insn_mtspr(SPR_UDN_SP_STATE, 0xc3000);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/* Reset random XDN state registers at boot up and during hardwall teardown. */
|
|
static void reset_xdn_network_state(struct hardwall_type *hwt)
|
|
{
|
|
if (hwt->disabled)
|
|
return;
|
|
|
|
/* Clear out other random registers so we have a clean slate. */
|
|
mtspr_XDN(hwt, DIRECTION_PROTECT, 0);
|
|
mtspr_XDN(hwt, AVAIL_EN, 0);
|
|
mtspr_XDN(hwt, DEADLOCK_TIMEOUT, 0);
|
|
|
|
#if !CHIP_HAS_REV1_XDN()
|
|
/* Reset UDN coordinates to their standard value */
|
|
{
|
|
unsigned int cpu = smp_processor_id();
|
|
unsigned int x = cpu_x(cpu);
|
|
unsigned int y = cpu_y(cpu);
|
|
__insn_mtspr(SPR_UDN_TILE_COORD, (x << 18) | (y << 7));
|
|
}
|
|
|
|
/* Set demux tags to predefined values and enable them. */
|
|
__insn_mtspr(SPR_UDN_TAG_VALID, 0xf);
|
|
__insn_mtspr(SPR_UDN_TAG_0, (1 << 0));
|
|
__insn_mtspr(SPR_UDN_TAG_1, (1 << 1));
|
|
__insn_mtspr(SPR_UDN_TAG_2, (1 << 2));
|
|
__insn_mtspr(SPR_UDN_TAG_3, (1 << 3));
|
|
|
|
/* Set other rev0 random registers to a clean state. */
|
|
__insn_mtspr(SPR_UDN_REFILL_EN, 0);
|
|
__insn_mtspr(SPR_UDN_DEMUX_QUEUE_SEL, 0);
|
|
__insn_mtspr(SPR_UDN_SP_FIFO_SEL, 0);
|
|
|
|
/* Start the switch and demux. */
|
|
__insn_mtspr(SPR_UDN_SP_FREEZE, 0);
|
|
#endif
|
|
}
|
|
|
|
void reset_network_state(void)
|
|
{
|
|
reset_xdn_network_state(&hardwall_types[HARDWALL_UDN]);
|
|
#ifndef __tilepro__
|
|
reset_xdn_network_state(&hardwall_types[HARDWALL_IDN]);
|
|
#endif
|
|
}
|
|
|
|
/* Restart an XDN switch after draining. */
|
|
static void restart_xdn_switch(void *arg)
|
|
{
|
|
struct hardwall_type *hwt = arg;
|
|
|
|
#if CHIP_HAS_REV1_XDN()
|
|
/* One last drain step to avoid races with injection and draining. */
|
|
empty_xdn_demuxes(hwt);
|
|
#endif
|
|
|
|
reset_xdn_network_state(hwt);
|
|
|
|
/* Disable firewall interrupts. */
|
|
disable_firewall_interrupts(hwt);
|
|
}
|
|
|
|
/* Last reference to a hardwall is gone, so clear the network. */
|
|
static void hardwall_destroy(struct hardwall_info *info)
|
|
{
|
|
struct task_struct *task;
|
|
struct hardwall_type *hwt;
|
|
unsigned long flags;
|
|
|
|
/* Make sure this file actually represents a hardwall. */
|
|
if (info == NULL)
|
|
return;
|
|
|
|
/*
|
|
* Deactivate any remaining tasks. It's possible to race with
|
|
* some other thread that is exiting and hasn't yet called
|
|
* deactivate (when freeing its thread_info), so we carefully
|
|
* deactivate any remaining tasks before freeing the
|
|
* hardwall_info object itself.
|
|
*/
|
|
hwt = info->type;
|
|
info->teardown_in_progress = 1;
|
|
spin_lock_irqsave(&hwt->lock, flags);
|
|
list_for_each_entry(task, &info->task_head,
|
|
thread.hardwall[hwt->index].list)
|
|
_hardwall_deactivate(hwt, task);
|
|
spin_unlock_irqrestore(&hwt->lock, flags);
|
|
|
|
if (hwt->is_xdn) {
|
|
/* Configure the switches for draining the user network. */
|
|
printk(KERN_DEBUG
|
|
"Clearing %s hardwall rectangle %dx%d %d,%d\n",
|
|
hwt->name, info->width, info->height,
|
|
info->ulhc_x, info->ulhc_y);
|
|
on_each_cpu_mask(&info->cpumask, stop_xdn_switch, hwt, 1);
|
|
|
|
/* Drain the network. */
|
|
#if CHIP_HAS_REV1_XDN()
|
|
atomic_set(&info->xdn_pending_count,
|
|
cpumask_weight(&info->cpumask));
|
|
on_each_cpu_mask(&info->cpumask, drain_xdn_switch, info, 0);
|
|
#else
|
|
on_each_cpu_mask(&info->cpumask, drain_xdn_switch, info, 1);
|
|
#endif
|
|
|
|
/* Restart switch and disable firewall. */
|
|
on_each_cpu_mask(&info->cpumask, restart_xdn_switch, hwt, 1);
|
|
}
|
|
|
|
/* Remove the /proc/tile/hardwall entry. */
|
|
hardwall_remove_proc(info);
|
|
|
|
/* Now free the hardwall from the list. */
|
|
spin_lock_irqsave(&hwt->lock, flags);
|
|
BUG_ON(!list_empty(&info->task_head));
|
|
list_del(&info->list);
|
|
spin_unlock_irqrestore(&hwt->lock, flags);
|
|
kfree(info);
|
|
}
|
|
|
|
|
|
static int hardwall_proc_show(struct seq_file *sf, void *v)
|
|
{
|
|
struct hardwall_info *info = sf->private;
|
|
char buf[256];
|
|
|
|
int rc = cpulist_scnprintf(buf, sizeof(buf), &info->cpumask);
|
|
buf[rc++] = '\n';
|
|
seq_write(sf, buf, rc);
|
|
return 0;
|
|
}
|
|
|
|
static int hardwall_proc_open(struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
return single_open(file, hardwall_proc_show, PDE_DATA(inode));
|
|
}
|
|
|
|
static const struct file_operations hardwall_proc_fops = {
|
|
.open = hardwall_proc_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
};
|
|
|
|
static void hardwall_add_proc(struct hardwall_info *info)
|
|
{
|
|
char buf[64];
|
|
snprintf(buf, sizeof(buf), "%d", info->id);
|
|
proc_create_data(buf, 0444, info->type->proc_dir,
|
|
&hardwall_proc_fops, info);
|
|
}
|
|
|
|
static void hardwall_remove_proc(struct hardwall_info *info)
|
|
{
|
|
char buf[64];
|
|
snprintf(buf, sizeof(buf), "%d", info->id);
|
|
remove_proc_entry(buf, info->type->proc_dir);
|
|
}
|
|
|
|
int proc_pid_hardwall(struct seq_file *m, struct pid_namespace *ns,
|
|
struct pid *pid, struct task_struct *task)
|
|
{
|
|
int i;
|
|
int n = 0;
|
|
for (i = 0; i < HARDWALL_TYPES; ++i) {
|
|
struct hardwall_info *info = task->thread.hardwall[i].info;
|
|
if (info)
|
|
seq_printf(m, "%s: %d\n", info->type->name, info->id);
|
|
}
|
|
return n;
|
|
}
|
|
|
|
void proc_tile_hardwall_init(struct proc_dir_entry *root)
|
|
{
|
|
int i;
|
|
for (i = 0; i < HARDWALL_TYPES; ++i) {
|
|
struct hardwall_type *hwt = &hardwall_types[i];
|
|
if (hwt->disabled)
|
|
continue;
|
|
if (hardwall_proc_dir == NULL)
|
|
hardwall_proc_dir = proc_mkdir("hardwall", root);
|
|
hwt->proc_dir = proc_mkdir(hwt->name, hardwall_proc_dir);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Character device support via ioctl/close.
|
|
*/
|
|
|
|
static long hardwall_ioctl(struct file *file, unsigned int a, unsigned long b)
|
|
{
|
|
struct hardwall_info *info = file->private_data;
|
|
int minor = iminor(file->f_mapping->host);
|
|
struct hardwall_type* hwt;
|
|
|
|
if (_IOC_TYPE(a) != HARDWALL_IOCTL_BASE)
|
|
return -EINVAL;
|
|
|
|
BUILD_BUG_ON(HARDWALL_TYPES != _HARDWALL_TYPES);
|
|
BUILD_BUG_ON(HARDWALL_TYPES !=
|
|
sizeof(hardwall_types)/sizeof(hardwall_types[0]));
|
|
|
|
if (minor < 0 || minor >= HARDWALL_TYPES)
|
|
return -EINVAL;
|
|
hwt = &hardwall_types[minor];
|
|
WARN_ON(info && hwt != info->type);
|
|
|
|
switch (_IOC_NR(a)) {
|
|
case _HARDWALL_CREATE:
|
|
if (hwt->disabled)
|
|
return -ENOSYS;
|
|
if (info != NULL)
|
|
return -EALREADY;
|
|
info = hardwall_create(hwt, _IOC_SIZE(a),
|
|
(const unsigned char __user *)b);
|
|
if (IS_ERR(info))
|
|
return PTR_ERR(info);
|
|
file->private_data = info;
|
|
return 0;
|
|
|
|
case _HARDWALL_ACTIVATE:
|
|
return hardwall_activate(info);
|
|
|
|
case _HARDWALL_DEACTIVATE:
|
|
if (current->thread.hardwall[hwt->index].info != info)
|
|
return -EINVAL;
|
|
return hardwall_deactivate(hwt, current);
|
|
|
|
case _HARDWALL_GET_ID:
|
|
return info ? info->id : -EINVAL;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long hardwall_compat_ioctl(struct file *file,
|
|
unsigned int a, unsigned long b)
|
|
{
|
|
/* Sign-extend the argument so it can be used as a pointer. */
|
|
return hardwall_ioctl(file, a, (unsigned long)compat_ptr(b));
|
|
}
|
|
#endif
|
|
|
|
/* The user process closed the file; revoke access to user networks. */
|
|
static int hardwall_flush(struct file *file, fl_owner_t owner)
|
|
{
|
|
struct hardwall_info *info = file->private_data;
|
|
struct task_struct *task, *tmp;
|
|
unsigned long flags;
|
|
|
|
if (info) {
|
|
/*
|
|
* NOTE: if multiple threads are activated on this hardwall
|
|
* file, the other threads will continue having access to the
|
|
* user network until they are context-switched out and back
|
|
* in again.
|
|
*
|
|
* NOTE: A NULL files pointer means the task is being torn
|
|
* down, so in that case we also deactivate it.
|
|
*/
|
|
struct hardwall_type *hwt = info->type;
|
|
spin_lock_irqsave(&hwt->lock, flags);
|
|
list_for_each_entry_safe(task, tmp, &info->task_head,
|
|
thread.hardwall[hwt->index].list) {
|
|
if (task->files == owner || task->files == NULL)
|
|
_hardwall_deactivate(hwt, task);
|
|
}
|
|
spin_unlock_irqrestore(&hwt->lock, flags);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* This hardwall is gone, so destroy it. */
|
|
static int hardwall_release(struct inode *inode, struct file *file)
|
|
{
|
|
hardwall_destroy(file->private_data);
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations dev_hardwall_fops = {
|
|
.open = nonseekable_open,
|
|
.unlocked_ioctl = hardwall_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = hardwall_compat_ioctl,
|
|
#endif
|
|
.flush = hardwall_flush,
|
|
.release = hardwall_release,
|
|
};
|
|
|
|
static struct cdev hardwall_dev;
|
|
|
|
static int __init dev_hardwall_init(void)
|
|
{
|
|
int rc;
|
|
dev_t dev;
|
|
|
|
rc = alloc_chrdev_region(&dev, 0, HARDWALL_TYPES, "hardwall");
|
|
if (rc < 0)
|
|
return rc;
|
|
cdev_init(&hardwall_dev, &dev_hardwall_fops);
|
|
rc = cdev_add(&hardwall_dev, dev, HARDWALL_TYPES);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
return 0;
|
|
}
|
|
late_initcall(dev_hardwall_init);
|