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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-12-28 16:54:33 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-12-28 16:54:33 -0800 |
commit | 3c92ec8ae91ecf59d88c798301833d7cf83f2179 (patch) | |
tree | 08a38cd3523c42bd49882f17cd501fd879e7ca1c /arch/powerpc/mm/mmu_context_hash64.c | |
parent | c4c9f0183b7c4e97836e8fecbb67898b06c47e78 (diff) | |
parent | ca9153a3a2a7556d091dfe080e42b0e67881fff6 (diff) |
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (144 commits)
powerpc/44x: Support 16K/64K base page sizes on 44x
powerpc: Force memory size to be a multiple of PAGE_SIZE
powerpc/32: Wire up the trampoline code for kdump
powerpc/32: Add the ability for a classic ppc kernel to be loaded at 32M
powerpc/32: Allow __ioremap on RAM addresses for kdump kernel
powerpc/32: Setup OF properties for kdump
powerpc/32/kdump: Implement crash_setup_regs() using ppc_save_regs()
powerpc: Prepare xmon_save_regs for use with kdump
powerpc: Remove default kexec/crash_kernel ops assignments
powerpc: Make default kexec/crash_kernel ops implicit
powerpc: Setup OF properties for ppc32 kexec
powerpc/pseries: Fix cpu hotplug
powerpc: Fix KVM build on ppc440
powerpc/cell: add QPACE as a separate Cell platform
powerpc/cell: fix build breakage with CONFIG_SPUFS disabled
powerpc/mpc5200: fix error paths in PSC UART probe function
powerpc/mpc5200: add rts/cts handling in PSC UART driver
powerpc/mpc5200: Make PSC UART driver update serial errors counters
powerpc/mpc5200: Remove obsolete code from mpc5200 MDIO driver
powerpc/mpc5200: Add MDMA/UDMA support to MPC5200 ATA driver
...
Fix trivial conflict in drivers/char/Makefile as per Paul's directions
Diffstat (limited to 'arch/powerpc/mm/mmu_context_hash64.c')
-rw-r--r-- | arch/powerpc/mm/mmu_context_hash64.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/powerpc/mm/mmu_context_hash64.c b/arch/powerpc/mm/mmu_context_hash64.c new file mode 100644 index 00000000000..dbeb86ac90c --- /dev/null +++ b/arch/powerpc/mm/mmu_context_hash64.c @@ -0,0 +1,78 @@ +/* + * MMU context allocation for 64-bit kernels. + * + * Copyright (C) 2004 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/string.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/spinlock.h> +#include <linux/idr.h> + +#include <asm/mmu_context.h> + +static DEFINE_SPINLOCK(mmu_context_lock); +static DEFINE_IDR(mmu_context_idr); + +/* + * 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 NO_CONTEXT 0 +#define MAX_CONTEXT ((1UL << 19) - 1) + +int init_new_context(struct task_struct *tsk, struct mm_struct *mm) +{ + int index; + int err; + +again: + if (!idr_pre_get(&mmu_context_idr, GFP_KERNEL)) + return -ENOMEM; + + spin_lock(&mmu_context_lock); + err = idr_get_new_above(&mmu_context_idr, NULL, 1, &index); + spin_unlock(&mmu_context_lock); + + if (err == -EAGAIN) + goto again; + else if (err) + return err; + + if (index > MAX_CONTEXT) { + spin_lock(&mmu_context_lock); + idr_remove(&mmu_context_idr, index); + spin_unlock(&mmu_context_lock); + return -ENOMEM; + } + + /* 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 + */ + if (slice_mm_new_context(mm)) + slice_set_user_psize(mm, mmu_virtual_psize); + mm->context.id = index; + + return 0; +} + +void destroy_context(struct mm_struct *mm) +{ + spin_lock(&mmu_context_lock); + idr_remove(&mmu_context_idr, mm->context.id); + spin_unlock(&mmu_context_lock); + + mm->context.id = NO_CONTEXT; +} |