diff options
Diffstat (limited to 'target/linux/ubicom32/files/arch/ubicom32/kernel/thread.c')
| -rw-r--r-- | target/linux/ubicom32/files/arch/ubicom32/kernel/thread.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/target/linux/ubicom32/files/arch/ubicom32/kernel/thread.c b/target/linux/ubicom32/files/arch/ubicom32/kernel/thread.c new file mode 100644 index 000000000..aaa5fbea4 --- /dev/null +++ b/target/linux/ubicom32/files/arch/ubicom32/kernel/thread.c @@ -0,0 +1,228 @@ +/* + * arch/ubicom32/kernel/thread.c + * Ubicom32 architecture hardware thread support. + * + * (C) Copyright 2009, Ubicom, Inc. + * + * This file is part of the Ubicom32 Linux Kernel Port. + * + * The Ubicom32 Linux Kernel Port 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. + * + * The Ubicom32 Linux Kernel Port 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. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with the Ubicom32 Linux Kernel Port. If not, + * see <http://www.gnu.org/licenses/>. + * + * Ubicom32 implementation derived from (with many thanks): + * arch/m68knommu + * arch/blackfin + * arch/parisc + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/profile.h> +#include <linux/clocksource.h> +#include <linux/types.h> +#include <asm/ip5000.h> +#include <asm/machdep.h> +#include <asm/asm-offsets.h> +#include <asm/thread.h> + +/* + * TODO: At some point change the name here to be thread_ksp + */ +unsigned int sw_ksp[THREAD_ARCHITECTURAL_MAX]; + +static unsigned int thread_mask = -1; +static unsigned int thread_mainline_mask; + +/* + * thread_entry() + * Returning from the called function will disable the thread. + * + * This could be a naked call to allow for hwthreads that do not have stacks. + * However, with -O0, the code still writes to thex stack, and this was + * corrupting memory just after the callers stack. + */ +static void thread_entry(void *arg, thread_exec_fn_t exec) +{ + /* + * Call thread function + */ + exec(arg); + + /* + * Complete => Disable self + */ + thread_disable(thread_get_self()); +} + +/* + * thread_start() + * Start the specified function on the specified hardware thread. + */ +thread_t thread_start(thread_t thread, + thread_exec_fn_t exec, + void *arg, + unsigned int *sp_high, + thread_type_t type) +{ + /* + * Sanity check + */ + unsigned int enabled, mask, csr; + asm volatile ( + "move.4 %0, MT_EN\n\t" + : "=m" (enabled) + ); + + mask = 1 << thread; + if (enabled & mask) { + printk(KERN_WARNING "request to enable a previously enabled thread\n"); + return (thread_t)-1; + } + + /* + * Update thread state + */ + csr = (thread << 15) | (1 << 14); + asm volatile ( + "setcsr %0 \n\t" + "setcsr_flush 0 \n\t" + + "move.4 A0, #0 \n\t" + "move.4 A1, #0 \n\t" + "move.4 A2, #0 \n\t" + "move.4 A3, #0 \n\t" + "move.4 A4, #0 \n\t" + "move.4 A5, #0 \n\t" + "move.4 A6, #0 \n\t" + "move.4 SP, %4 \n\t" /* A7 is SP */ + + "move.4 D0, %3 \n\t" + "move.4 D1, %2 \n\t" + "move.4 D2, #0 \n\t" + "move.4 D3, #0 \n\t" + "move.4 D4, #0 \n\t" + "move.4 D5, #0 \n\t" + "move.4 D6, #0 \n\t" + "move.4 D7, #0 \n\t" + "move.4 D8, #0 \n\t" + "move.4 D9, #0 \n\t" + "move.4 D10, #0 \n\t" + "move.4 D11, #0 \n\t" + "move.4 D12, #0 \n\t" + "move.4 D13, #0 \n\t" + "move.4 D14, #0 \n\t" + "move.4 D15, #0 \n\t" + + "move.4 INT_MASK0, #0 \n\t" + "move.4 INT_MASK1, #0 \n\t" + "move.4 PC, %1 \n\t" + "setcsr #0 \n\t" + "setcsr_flush 0 \n\t" + : + : "r" (csr), "r" (thread_entry), "r" (exec), + "r" (arg), "r" (sp_high) + ); + + /* + * Apply HRT state + */ + if (type & THREAD_TYPE_HRT) { + asm volatile ( + "or.4 MT_HRT, MT_HRT, %0\n\t" + : + : "d" (mask) + : "cc" + ); + } else { + asm volatile ( + "and.4 MT_HRT, MT_HRT, %0\n\t" + : + : "d" (~mask) + : "cc" + ); + } + + /* + * Set priority + */ + asm volatile ( + "or.4 MT_HPRI, MT_HPRI, %0\n\t" + : + : "d" (mask) + : "cc" + ); + + /* + * Enable thread + */ + asm volatile ( + "move.4 MT_ACTIVE_SET, %0 \n\t" + : + : "d" (mask) + ); + thread_enable_mask(mask); + return thread; +} + +/* + * thread_get_mainline() + * Return a mask of those threads that are Linux mainline threads. + */ +unsigned int thread_get_mainline(void) +{ + return thread_mainline_mask; +} + +/* + * thread_set_mainline() + * Indicate that the specified thread is a Linux mainline thread. + */ +void thread_set_mainline(thread_t tid) +{ + thread_mainline_mask |= (1 << tid); +} + +/* + * thread_alloc() + * Allocate an unused hardware thread. + */ +thread_t thread_alloc(void) +{ + thread_t tid; + + /* + * If this is the first time we are here get the list of unused + * threads from the processor device tree node. + */ + if (thread_mask == -1) { + thread_mask = processor_threads(); + } + + if (!thread_mask) { + return (thread_t)-1; + } + + tid = ffs(thread_mask); + if (tid != 0) { + tid--; + thread_mask &= ~(1 << tid); + return tid; + } + + return (thread_t)-1; +} |