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Commit 9f9c0382 authored by Chris Metcalf's avatar Chris Metcalf
Browse files

arch/tile: Add driver to enable access to the user dynamic network. 



This network (the "UDN") connects all the cpus on the chip in a
wormhole-routed dynamic network.  Subrectangles of the chip can
be allocated by a "create" ioctl on /dev/hardwall, and then to access the
UDN in that rectangle, tasks must perform an "activate" ioctl on that
same file object after affinitizing themselves to a single cpu in
the region.  Sending a wormhole-routed message that tries to leave
that subrectangle causes all activated tasks to receive a SIGILL
(just as they would if they tried to access the UDN without first
activating themselves to a hardwall rectangle).

The original submission of this code to LKML had the driver
instantiated under /proc/tile/hardwall.  Now we just use a character
device for this, conventionally /dev/hardwall.  Some futures planning
for the TILE-Gx chip suggests that we may want to have other types of
devices that share the general model of "bind a task to a cpu, then
'activate' a file descriptor on a pseudo-device that gives access to
some hardware resource".  As such, we are using a device rather
than, for example, a syscall, to set up and activate this code.

As part of this change, the compat_ptr() declaration was fixed and used
to pass the compat_ioctl argument to the normal ioctl.  So far we limit
compat code to 2GB, so the difference between zero-extend and sign-extend
(the latter being correct, eventually) had been overlooked.

Signed-off-by: default avatarChris Metcalf <cmetcalf@tilera.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
parent fb702b94

arch/tile/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -310,6 +310,10 @@ config VMALLOC_RESERVE 
	hex

	default 0x1000000



config HARDWALL

	bool "Hardwall support to allow access to user dynamic network"

	default y



endmenu  # Tilera-specific configuration



menu "Bus options"

arch/tile/include/asm/compat.h

+1 −1
Original line number Diff line number Diff line
@@ -222,7 +222,7 @@ struct compat_shmid64_ds { 


static inline void __user *compat_ptr(compat_uptr_t uptr)

{

	return (void __user *)(unsigned long)uptr;

	return (void __user *)(long)(s32)uptr;

}



static inline compat_uptr_t ptr_to_compat(void __user *uptr)

arch/tile/include/asm/hardwall.h

0 → 100644
+56 −0
Original line number Diff line number Diff line 
/*

 * 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.

 *

 * Provide methods for the HARDWALL_FILE for accessing the UDN.

 */



#ifndef _ASM_TILE_HARDWALL_H

#define _ASM_TILE_HARDWALL_H



#include <linux/ioctl.h>



#define HARDWALL_IOCTL_BASE 0xa2



/*

 * The HARDWALL_CREATE() ioctl is a macro with a "size" argument.

 * The resulting ioctl value is passed to the kernel in conjunction

 * with a pointer to a little-endian bitmask of cpus, which must be

 * physically in a rectangular configuration on the chip.

 * The "size" is the number of bytes of cpu mask data.

 */

#define _HARDWALL_CREATE 1

#define HARDWALL_CREATE(size) \

  _IOC(_IOC_READ, HARDWALL_IOCTL_BASE, _HARDWALL_CREATE, (size))



#define _HARDWALL_ACTIVATE 2

#define HARDWALL_ACTIVATE \

  _IO(HARDWALL_IOCTL_BASE, _HARDWALL_ACTIVATE)



#define _HARDWALL_DEACTIVATE 3

#define HARDWALL_DEACTIVATE \

 _IO(HARDWALL_IOCTL_BASE, _HARDWALL_DEACTIVATE)



#ifndef __KERNEL__



/* This is the canonical name expected by userspace. */

#define HARDWALL_FILE "/dev/hardwall"



#else



/* Hook for /proc/tile/hardwall. */

struct seq_file;

int proc_tile_hardwall_show(struct seq_file *sf, void *v);



#endif



#endif /* _ASM_TILE_HARDWALL_H */

arch/tile/include/asm/processor.h

+14 −3
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
 * NOTE: we don't include <linux/ptrace.h> or <linux/percpu.h> as one

 * normally would, due to #include dependencies.

 */

#include <linux/types.h>

#include <asm/ptrace.h>

#include <asm/percpu.h>
@@ -29,7 +30,6 @@ 


struct task_struct;

struct thread_struct;

struct list_head;



typedef struct {

	unsigned long seg;
@@ -74,6 +74,9 @@ struct async_tlb { 
	unsigned long address;   /* what address faulted? */

};



#ifdef CONFIG_HARDWALL

struct hardwall_info;

#endif



struct thread_struct {

	/* kernel stack pointer */
@@ -100,6 +103,12 @@ struct thread_struct { 
	/* Any other miscellaneous processor state bits */

	unsigned long proc_status;

#endif

#ifdef CONFIG_HARDWALL

	/* Is this task tied to an activated hardwall? */

	struct hardwall_info *hardwall;

	/* Chains this task into the list at hardwall->list. */

	struct list_head hardwall_list;

#endif

#if CHIP_HAS_TILE_DMA()

	/* Async DMA TLB fault information */

	struct async_tlb dma_async_tlb;
@@ -194,8 +203,6 @@ static inline void release_thread(struct task_struct *dead_task) 


extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);



/* Helper routines for setting home cache modes at exec() time. */





/*

 * Return saved (kernel) PC of a blocked thread.
@@ -240,6 +247,10 @@ struct siginfo; 
extern void arch_coredump_signal(struct siginfo *, struct pt_regs *);

#define arch_coredump_signal arch_coredump_signal



/* Info on this processor (see fs/proc/cpuinfo.c) */

struct seq_operations;

extern const struct seq_operations cpuinfo_op;



/* Provide information about the chip model. */

extern char chip_model[64];

arch/tile/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ obj-y := backtrace.o entry.o init_task.o irq.o messaging.o \ 
	setup.o signal.o single_step.o stack.o sys.o time.o traps.o \

	intvec_$(BITS).o regs_$(BITS).o tile-desc_$(BITS).o



obj-$(CONFIG_HARDWALL)		+= hardwall.o

obj-$(CONFIG_TILEGX)		+= futex_64.o

obj-$(CONFIG_COMPAT)		+= compat.o compat_signal.o

obj-$(CONFIG_SMP)		+= smpboot.o smp.o tlb.o