diff options
author | Jimi Xenidis <jimix@pobox.com> | 2011-09-29 10:55:12 (GMT) |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-11-25 03:11:27 (GMT) |
commit | 9d670280908013004f173b2b86414d9b6918511b (patch) | |
tree | bd7a7483ae7455cb481c72df907a3b4362e121c2 /arch/powerpc/mm/icswx_pid.c | |
parent | 5182a131ddf988fe4f5cef9964dbfb64a188b0c3 (diff) | |
download | linux-9d670280908013004f173b2b86414d9b6918511b.tar.xz |
powerpc: Split ICSWX ACOP and PID processing
Some processors, like embedded, that already have a PID register that
is managed by the system. This patch separates the ACOP and PID
processing into separate files so that the ACOP code can be shared.
Signed-off-by: Jimi Xenidis <jimix@pobox.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/mm/icswx_pid.c')
-rw-r--r-- | arch/powerpc/mm/icswx_pid.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/powerpc/mm/icswx_pid.c b/arch/powerpc/mm/icswx_pid.c new file mode 100644 index 0000000..91e30eb --- /dev/null +++ b/arch/powerpc/mm/icswx_pid.c @@ -0,0 +1,87 @@ +/* + * ICSWX and ACOP/PID Management + * + * Copyright (C) 2011 Anton Blanchard, IBM Corp. <anton@samba.org> + * + * 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. + * + */ + +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/spinlock.h> +#include <linux/idr.h> +#include <linux/module.h> +#include "icswx.h" + +#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); + +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; +} + +int get_cop_pid(struct mm_struct *mm) +{ + int pid; + + if (mm->context.cop_pid == COP_PID_NONE) { + pid = new_cop_pid(&cop_ida, COP_PID_MIN, COP_PID_MAX, + &mmu_context_acop_lock); + if (pid >= 0) + mm->context.cop_pid = pid; + } + return mm->context.cop_pid; +} + +int disable_cop_pid(struct mm_struct *mm) +{ + int free_pid = COP_PID_NONE; + + if ((!mm->context.acop) && (mm->context.cop_pid != COP_PID_NONE)) { + free_pid = mm->context.cop_pid; + mm->context.cop_pid = COP_PID_NONE; + } + return free_pid; +} + +void free_cop_pid(int free_pid) +{ + spin_lock(&mmu_context_acop_lock); + ida_remove(&cop_ida, free_pid); + spin_unlock(&mmu_context_acop_lock); +} |