2005-09-26 06:04:21 +00:00
|
|
|
/*
|
|
|
|
* MMU context allocation for 64-bit kernels.
|
|
|
|
*
|
|
|
|
* Copyright (C) 2004 Anton Blanchard, IBM Corp. <anton@samba.org>
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*
|
|
|
|
* 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
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|
|
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* 2 of the License, or (at your option) any later version.
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*
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*/
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|
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#include <linux/sched.h>
|
|
|
|
#include <linux/kernel.h>
|
|
|
|
#include <linux/errno.h>
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|
|
|
#include <linux/string.h>
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|
|
#include <linux/types.h>
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|
|
|
#include <linux/mm.h>
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|
|
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#include <linux/spinlock.h>
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|
|
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#include <linux/idr.h>
|
2009-11-02 12:02:30 +00:00
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|
|
#include <linux/module.h>
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
|
|
|
#include <linux/gfp.h>
|
2011-05-02 20:43:04 +00:00
|
|
|
#include <linux/slab.h>
|
2005-09-26 06:04:21 +00:00
|
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|
|
#include <asm/mmu_context.h>
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|
|
|
2011-05-02 20:43:04 +00:00
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|
|
#ifdef CONFIG_PPC_ICSWX
|
|
|
|
/*
|
|
|
|
* The processor and its L2 cache cause the icswx instruction to
|
|
|
|
* generate a COP_REQ transaction on PowerBus. The transaction has
|
|
|
|
* no address, and the processor does not perform an MMU access
|
|
|
|
* to authenticate the transaction. The command portion of the
|
|
|
|
* PowerBus COP_REQ transaction includes the LPAR_ID (LPID) and
|
|
|
|
* the coprocessor Process ID (PID), which the coprocessor compares
|
|
|
|
* to the authorized LPID and PID held in the coprocessor, to determine
|
|
|
|
* if the process is authorized to generate the transaction.
|
|
|
|
* The data of the COP_REQ transaction is 128-byte or less and is
|
|
|
|
* placed in cacheable memory on a 128-byte cache line boundary.
|
|
|
|
*
|
|
|
|
* The task to use a coprocessor should use use_cop() to allocate
|
|
|
|
* a coprocessor PID before executing icswx instruction. use_cop()
|
|
|
|
* also enables the coprocessor context switching. Drop_cop() is
|
|
|
|
* used to free the coprocessor PID.
|
|
|
|
*
|
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|
|
* Example:
|
|
|
|
* Host Fabric Interface (HFI) is a PowerPC network coprocessor.
|
|
|
|
* Each HFI have multiple windows. Each HFI window serves as a
|
|
|
|
* network device sending to and receiving from HFI network.
|
|
|
|
* HFI immediate send function uses icswx instruction. The immediate
|
|
|
|
* send function allows small (single cache-line) packets be sent
|
|
|
|
* without using the regular HFI send FIFO and doorbell, which are
|
|
|
|
* much slower than immediate send.
|
|
|
|
*
|
|
|
|
* For each task intending to use HFI immediate send, the HFI driver
|
|
|
|
* calls use_cop() to obtain a coprocessor PID for the task.
|
|
|
|
* The HFI driver then allocate a free HFI window and save the
|
|
|
|
* coprocessor PID to the HFI window to allow the task to use the
|
|
|
|
* HFI window.
|
|
|
|
*
|
|
|
|
* The HFI driver repeatedly creates immediate send packets and
|
|
|
|
* issues icswx instruction to send data through the HFI window.
|
|
|
|
* The HFI compares the coprocessor PID in the CPU PID register
|
|
|
|
* to the PID held in the HFI window to determine if the transaction
|
|
|
|
* is allowed.
|
|
|
|
*
|
|
|
|
* When the task to release the HFI window, the HFI driver calls
|
|
|
|
* drop_cop() to release the coprocessor PID.
|
|
|
|
*/
|
|
|
|
|
|
|
|
#define COP_PID_NONE 0
|
|
|
|
#define COP_PID_MIN (COP_PID_NONE + 1)
|
|
|
|
#define COP_PID_MAX (0xFFFF)
|
|
|
|
|
|
|
|
static DEFINE_SPINLOCK(mmu_context_acop_lock);
|
|
|
|
static DEFINE_IDA(cop_ida);
|
|
|
|
|
|
|
|
void switch_cop(struct mm_struct *next)
|
|
|
|
{
|
|
|
|
mtspr(SPRN_PID, next->context.cop_pid);
|
|
|
|
mtspr(SPRN_ACOP, next->context.acop);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int new_cop_pid(struct ida *ida, int min_id, int max_id,
|
|
|
|
spinlock_t *lock)
|
|
|
|
{
|
|
|
|
int index;
|
|
|
|
int err;
|
|
|
|
|
|
|
|
again:
|
|
|
|
if (!ida_pre_get(ida, GFP_KERNEL))
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
spin_lock(lock);
|
|
|
|
err = ida_get_new_above(ida, min_id, &index);
|
|
|
|
spin_unlock(lock);
|
|
|
|
|
|
|
|
if (err == -EAGAIN)
|
|
|
|
goto again;
|
|
|
|
else if (err)
|
|
|
|
return err;
|
|
|
|
|
|
|
|
if (index > max_id) {
|
|
|
|
spin_lock(lock);
|
|
|
|
ida_remove(ida, index);
|
|
|
|
spin_unlock(lock);
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
|
|
|
|
return index;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void sync_cop(void *arg)
|
|
|
|
{
|
|
|
|
struct mm_struct *mm = arg;
|
|
|
|
|
|
|
|
if (mm == current->active_mm)
|
|
|
|
switch_cop(current->active_mm);
|
|
|
|
}
|
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|
|
/**
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|
|
|
* Start using a coprocessor.
|
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|
|
* @acop: mask of coprocessor to be used.
|
|
|
|
* @mm: The mm the coprocessor to associate with. Most likely current mm.
|
|
|
|
*
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|
|
|
* Return a positive PID if successful. Negative errno otherwise.
|
|
|
|
* The returned PID will be fed to the coprocessor to determine if an
|
|
|
|
* icswx transaction is authenticated.
|
|
|
|
*/
|
|
|
|
int use_cop(unsigned long acop, struct mm_struct *mm)
|
|
|
|
{
|
|
|
|
int ret;
|
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|
|
|
|
|
|
if (!cpu_has_feature(CPU_FTR_ICSWX))
|
|
|
|
return -ENODEV;
|
|
|
|
|
|
|
|
if (!mm || !acop)
|
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|
|
return -EINVAL;
|
|
|
|
|
|
|
|
/* We need to make sure mm_users doesn't change */
|
|
|
|
down_read(&mm->mmap_sem);
|
|
|
|
spin_lock(mm->context.cop_lockp);
|
|
|
|
|
|
|
|
if (mm->context.cop_pid == COP_PID_NONE) {
|
|
|
|
ret = new_cop_pid(&cop_ida, COP_PID_MIN, COP_PID_MAX,
|
|
|
|
&mmu_context_acop_lock);
|
|
|
|
if (ret < 0)
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
mm->context.cop_pid = ret;
|
|
|
|
}
|
|
|
|
mm->context.acop |= acop;
|
|
|
|
|
|
|
|
sync_cop(mm);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If this is a threaded process then there might be other threads
|
|
|
|
* running. We need to send an IPI to force them to pick up any
|
|
|
|
* change in PID and ACOP.
|
|
|
|
*/
|
|
|
|
if (atomic_read(&mm->mm_users) > 1)
|
|
|
|
smp_call_function(sync_cop, mm, 1);
|
|
|
|
|
|
|
|
ret = mm->context.cop_pid;
|
|
|
|
|
|
|
|
out:
|
|
|
|
spin_unlock(mm->context.cop_lockp);
|
|
|
|
up_read(&mm->mmap_sem);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(use_cop);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* Stop using a coprocessor.
|
|
|
|
* @acop: mask of coprocessor to be stopped.
|
|
|
|
* @mm: The mm the coprocessor associated with.
|
|
|
|
*/
|
|
|
|
void drop_cop(unsigned long acop, struct mm_struct *mm)
|
|
|
|
{
|
|
|
|
int free_pid = COP_PID_NONE;
|
|
|
|
|
|
|
|
if (!cpu_has_feature(CPU_FTR_ICSWX))
|
|
|
|
return;
|
|
|
|
|
|
|
|
if (WARN_ON_ONCE(!mm))
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* We need to make sure mm_users doesn't change */
|
|
|
|
down_read(&mm->mmap_sem);
|
|
|
|
spin_lock(mm->context.cop_lockp);
|
|
|
|
|
|
|
|
mm->context.acop &= ~acop;
|
|
|
|
|
|
|
|
if ((!mm->context.acop) && (mm->context.cop_pid != COP_PID_NONE)) {
|
|
|
|
free_pid = mm->context.cop_pid;
|
|
|
|
mm->context.cop_pid = COP_PID_NONE;
|
|
|
|
}
|
|
|
|
|
|
|
|
sync_cop(mm);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If this is a threaded process then there might be other threads
|
|
|
|
* running. We need to send an IPI to force them to pick up any
|
|
|
|
* change in PID and ACOP.
|
|
|
|
*/
|
|
|
|
if (atomic_read(&mm->mm_users) > 1)
|
|
|
|
smp_call_function(sync_cop, mm, 1);
|
|
|
|
|
|
|
|
if (free_pid != COP_PID_NONE) {
|
|
|
|
spin_lock(&mmu_context_acop_lock);
|
|
|
|
ida_remove(&cop_ida, free_pid);
|
|
|
|
spin_unlock(&mmu_context_acop_lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
spin_unlock(mm->context.cop_lockp);
|
|
|
|
up_read(&mm->mmap_sem);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(drop_cop);
|
|
|
|
|
|
|
|
#endif /* CONFIG_PPC_ICSWX */
|
|
|
|
|
2005-09-26 06:04:21 +00:00
|
|
|
static DEFINE_SPINLOCK(mmu_context_lock);
|
2010-02-07 12:30:12 +00:00
|
|
|
static DEFINE_IDA(mmu_context_ida);
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2008-12-18 19:13:24 +00:00
|
|
|
/*
|
|
|
|
* The proto-VSID space has 2^35 - 1 segments available for user mappings.
|
|
|
|
* Each segment contains 2^28 bytes. Each context maps 2^44 bytes,
|
|
|
|
* so we can support 2^19-1 contexts (19 == 35 + 28 - 44).
|
|
|
|
*/
|
|
|
|
#define MAX_CONTEXT ((1UL << 19) - 1)
|
|
|
|
|
2009-11-02 12:02:30 +00:00
|
|
|
int __init_new_context(void)
|
2005-09-26 06:04:21 +00:00
|
|
|
{
|
|
|
|
int index;
|
|
|
|
int err;
|
|
|
|
|
|
|
|
again:
|
2010-02-07 12:30:12 +00:00
|
|
|
if (!ida_pre_get(&mmu_context_ida, GFP_KERNEL))
|
2005-09-26 06:04:21 +00:00
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
spin_lock(&mmu_context_lock);
|
2010-02-07 12:30:12 +00:00
|
|
|
err = ida_get_new_above(&mmu_context_ida, 1, &index);
|
2005-09-26 06:04:21 +00:00
|
|
|
spin_unlock(&mmu_context_lock);
|
|
|
|
|
|
|
|
if (err == -EAGAIN)
|
|
|
|
goto again;
|
|
|
|
else if (err)
|
|
|
|
return err;
|
|
|
|
|
|
|
|
if (index > MAX_CONTEXT) {
|
2006-06-27 12:46:09 +00:00
|
|
|
spin_lock(&mmu_context_lock);
|
2010-02-07 12:30:12 +00:00
|
|
|
ida_remove(&mmu_context_ida, index);
|
2006-06-27 12:46:09 +00:00
|
|
|
spin_unlock(&mmu_context_lock);
|
2005-09-26 06:04:21 +00:00
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
|
2009-11-02 12:02:30 +00:00
|
|
|
return index;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(__init_new_context);
|
|
|
|
|
|
|
|
int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
|
|
|
|
{
|
|
|
|
int index;
|
|
|
|
|
|
|
|
index = __init_new_context();
|
|
|
|
if (index < 0)
|
|
|
|
return index;
|
|
|
|
|
2007-05-08 06:27:27 +00:00
|
|
|
/* The old code would re-promote on fork, we don't do that
|
|
|
|
* when using slices as it could cause problem promoting slices
|
|
|
|
* that have been forced down to 4K
|
|
|
|
*/
|
2007-08-15 06:51:18 +00:00
|
|
|
if (slice_mm_new_context(mm))
|
2007-05-08 06:27:27 +00:00
|
|
|
slice_set_user_psize(mm, mmu_virtual_psize);
|
2009-11-26 18:56:04 +00:00
|
|
|
subpage_prot_init_new_context(mm);
|
2007-08-15 06:33:55 +00:00
|
|
|
mm->context.id = index;
|
2011-05-02 20:43:04 +00:00
|
|
|
#ifdef CONFIG_PPC_ICSWX
|
|
|
|
mm->context.cop_lockp = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
|
|
|
|
if (!mm->context.cop_lockp) {
|
|
|
|
__destroy_context(index);
|
|
|
|
subpage_prot_free(mm);
|
|
|
|
mm->context.id = NO_CONTEXT;
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
spin_lock_init(mm->context.cop_lockp);
|
|
|
|
#endif /* CONFIG_PPC_ICSWX */
|
2005-09-26 06:04:21 +00:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-11-02 12:02:30 +00:00
|
|
|
void __destroy_context(int context_id)
|
2005-09-26 06:04:21 +00:00
|
|
|
{
|
|
|
|
spin_lock(&mmu_context_lock);
|
2010-02-07 12:30:12 +00:00
|
|
|
ida_remove(&mmu_context_ida, context_id);
|
2005-09-26 06:04:21 +00:00
|
|
|
spin_unlock(&mmu_context_lock);
|
2009-11-02 12:02:30 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(__destroy_context);
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2009-11-02 12:02:30 +00:00
|
|
|
void destroy_context(struct mm_struct *mm)
|
|
|
|
{
|
2011-05-02 20:43:04 +00:00
|
|
|
#ifdef CONFIG_PPC_ICSWX
|
|
|
|
drop_cop(mm->context.acop, mm);
|
|
|
|
kfree(mm->context.cop_lockp);
|
|
|
|
mm->context.cop_lockp = NULL;
|
|
|
|
#endif /* CONFIG_PPC_ICSWX */
|
2009-11-02 12:02:30 +00:00
|
|
|
__destroy_context(mm->context.id);
|
2009-11-26 18:56:04 +00:00
|
|
|
subpage_prot_free(mm);
|
2011-04-12 19:00:04 +00:00
|
|
|
mm->context.id = MMU_NO_CONTEXT;
|
2005-09-26 06:04:21 +00:00
|
|
|
}
|