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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-06 16:50:35 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-06 16:50:35 -0800 |
commit | 3c0cb7c31c206aaedb967e44b98442bbeb17a6c4 (patch) | |
tree | 3ecba45d7ffae4fba4a5aafaef4af5b0b1105bde /arch/arm/kernel/pj4-cp0.c | |
parent | f70f5b9dc74ca7d0a64c4ead3fb28da09dc1b234 (diff) | |
parent | 404a02cbd2ae8bf256a2fa1169bdfe86bb5ebb34 (diff) |
Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits)
ARM: DMA: add support for DMA debugging
ARM: PL011: add DMA burst threshold support for ST variants
ARM: PL011: Add support for transmit DMA
ARM: PL011: Ensure IRQs are disabled in UART interrupt handler
ARM: PL011: Separate hardware FIFO size from TTY FIFO size
ARM: PL011: Allow better handling of vendor data
ARM: PL011: Ensure error flags are clear at startup
ARM: PL011: include revision number in boot-time port printk
ARM: vexpress: add sched_clock() for Versatile Express
ARM i.MX53: Make MX53 EVK bootable
ARM i.MX53: Some bug fix about MX53 MSL code
ARM: 6607/1: sa1100: Update platform device registration
ARM: 6606/1: sa1100: Fix platform device registration
ARM i.MX51: rename IPU irqs
ARM i.MX51: Add ipu clock support
ARM: imx/mx27_3ds: Add PMIC support
ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn()
mx51: fix usb clock support
MX51: Add support for usb host 2
arch/arm/plat-mxc/ehci.c: fix errors/typos
...
Diffstat (limited to 'arch/arm/kernel/pj4-cp0.c')
-rw-r--r-- | arch/arm/kernel/pj4-cp0.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/arm/kernel/pj4-cp0.c b/arch/arm/kernel/pj4-cp0.c new file mode 100644 index 00000000000..a4b1b0748fd --- /dev/null +++ b/arch/arm/kernel/pj4-cp0.c @@ -0,0 +1,94 @@ +/* + * linux/arch/arm/kernel/pj4-cp0.c + * + * PJ4 iWMMXt coprocessor context switching and handling + * + * Copyright (c) 2010 Marvell International Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/io.h> +#include <asm/thread_notify.h> + +static int iwmmxt_do(struct notifier_block *self, unsigned long cmd, void *t) +{ + struct thread_info *thread = t; + + switch (cmd) { + case THREAD_NOTIFY_FLUSH: + /* + * flush_thread() zeroes thread->fpstate, so no need + * to do anything here. + * + * FALLTHROUGH: Ensure we don't try to overwrite our newly + * initialised state information on the first fault. + */ + + case THREAD_NOTIFY_EXIT: + iwmmxt_task_release(thread); + break; + + case THREAD_NOTIFY_SWITCH: + iwmmxt_task_switch(thread); + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block iwmmxt_notifier_block = { + .notifier_call = iwmmxt_do, +}; + + +static u32 __init pj4_cp_access_read(void) +{ + u32 value; + + __asm__ __volatile__ ( + "mrc p15, 0, %0, c1, c0, 2\n\t" + : "=r" (value)); + return value; +} + +static void __init pj4_cp_access_write(u32 value) +{ + u32 temp; + + __asm__ __volatile__ ( + "mcr p15, 0, %1, c1, c0, 2\n\t" + "mrc p15, 0, %0, c1, c0, 2\n\t" + "mov %0, %0\n\t" + "sub pc, pc, #4\n\t" + : "=r" (temp) : "r" (value)); +} + + +/* + * Disable CP0/CP1 on boot, and let call_fpe() and the iWMMXt lazy + * switch code handle iWMMXt context switching. + */ +static int __init pj4_cp0_init(void) +{ + u32 cp_access; + + cp_access = pj4_cp_access_read() & ~0xf; + pj4_cp_access_write(cp_access); + + printk(KERN_INFO "PJ4 iWMMXt coprocessor enabled.\n"); + elf_hwcap |= HWCAP_IWMMXT; + thread_register_notifier(&iwmmxt_notifier_block); + + return 0; +} + +late_initcall(pj4_cp0_init); |