diff options
| -rw-r--r-- | arch/arm/Kconfig | 8 | ||||
| -rw-r--r-- | arch/arm/kernel/Makefile | 4 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 9 | ||||
| -rw-r--r-- | arch/arm/kernel/iwmmxt-notifier.c | 63 | ||||
| -rw-r--r-- | arch/arm/kernel/setup.c | 3 | ||||
| -rw-r--r-- | arch/arm/kernel/xscale-cp0.c | 179 | ||||
| -rw-r--r-- | arch/arm/mach-pxa/Kconfig | 8 | ||||
| -rw-r--r-- | arch/arm/mach-pxa/pm.c | 3 | ||||
| -rw-r--r-- | arch/arm/mm/proc-xscale.S | 9 | ||||
| -rw-r--r-- | include/asm-arm/elf.h | 48 |
10 files changed, 210 insertions, 124 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index ce00c57..7be67ef 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -374,6 +374,14 @@ config PLAT_IOP source arch/arm/mm/Kconfig +config IWMMXT + bool "Enable iWMMXt support" + depends CPU_XSCALE || CPU_XSC3 + default y if PXA27x + help + Enable support for iWMMXt context switching at run time if + running on a CPU that supports it. + # bool 'Use XScale PMU as timer source' CONFIG_XSCALE_PMU_TIMER config XSCALE_PMU bool diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 1320a0e..ab06a86 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -24,7 +24,9 @@ obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312 -obj-$(CONFIG_IWMMXT) += iwmmxt.o iwmmxt-notifier.o +obj-$(CONFIG_CPU_XSCALE) += xscale-cp0.o +obj-$(CONFIG_CPU_XSC3) += xscale-cp0.o +obj-$(CONFIG_IWMMXT) += iwmmxt.o AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt ifneq ($(CONFIG_ARCH_EBSA110),y) diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index bd623b7..2db42b1 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -589,10 +589,6 @@ ENTRY(__switch_to) strex r5, r4, [ip] @ Clear exclusive monitor #endif #endif -#if defined(CONFIG_CPU_XSCALE) && !defined(CONFIG_IWMMXT) - mra r4, r5, acc0 - stmia ip, {r4, r5} -#endif #if defined(CONFIG_HAS_TLS_REG) mcr p15, 0, r3, c13, c0, 3 @ set TLS register #elif !defined(CONFIG_TLS_REG_EMUL) @@ -602,11 +598,6 @@ ENTRY(__switch_to) #ifdef CONFIG_MMU mcr p15, 0, r6, c3, c0, 0 @ Set domain register #endif -#if defined(CONFIG_CPU_XSCALE) && !defined(CONFIG_IWMMXT) - add r4, r2, #TI_CPU_DOMAIN + 40 @ cpu_context_save->extra - ldmib r4, {r4, r5} - mar acc0, r4, r5 -#endif mov r5, r0 add r4, r2, #TI_CPU_SAVE ldr r0, =thread_notify_head diff --git a/arch/arm/kernel/iwmmxt-notifier.c b/arch/arm/kernel/iwmmxt-notifier.c deleted file mode 100644 index 0d1a1db..0000000 --- a/arch/arm/kernel/iwmmxt-notifier.c +++ /dev/null @@ -1,63 +0,0 @@ -/* - * linux/arch/arm/kernel/iwmmxt-notifier.c - * - * XScale iWMMXt (Concan) context switching and handling - * - * Initial code: - * Copyright (c) 2003, Intel Corporation - * - * Full lazy switching support, optimizations and more, by Nicolas Pitre - * Copyright (c) 2003-2004, MontaVista Software, 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 <asm/thread_notify.h> -#include <asm/io.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_RELEASE: - 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 int __init iwmmxt_init(void) -{ - thread_register_notifier(&iwmmxt_notifier_block); - - return 0; -} - -late_initcall(iwmmxt_init); diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 29efc9f..6f12d26 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -357,9 +357,6 @@ static void __init setup_processor(void) #ifndef CONFIG_VFP elf_hwcap &= ~HWCAP_VFP; #endif -#ifndef CONFIG_IWMMXT - elf_hwcap &= ~HWCAP_IWMMXT; -#endif cpu_proc_init(); } diff --git a/arch/arm/kernel/xscale-cp0.c b/arch/arm/kernel/xscale-cp0.c new file mode 100644 index 0000000..180000b --- /dev/null +++ b/arch/arm/kernel/xscale-cp0.c @@ -0,0 +1,179 @@ +/* + * linux/arch/arm/kernel/xscale-cp0.c + * + * XScale DSP and iWMMXt coprocessor context switching and handling + * + * 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 <asm/thread_notify.h> +#include <asm/io.h> + +static inline void dsp_save_state(u32 *state) +{ + __asm__ __volatile__ ( + "mrrc p0, 0, %0, %1, c0\n" + : "=r" (state[0]), "=r" (state[1])); +} + +static inline void dsp_load_state(u32 *state) +{ + __asm__ __volatile__ ( + "mcrr p0, 0, %0, %1, c0\n" + : : "r" (state[0]), "r" (state[1])); +} + +static int dsp_do(struct notifier_block *self, unsigned long cmd, void *t) +{ + struct thread_info *thread = t; + + switch (cmd) { + case THREAD_NOTIFY_FLUSH: + thread->cpu_context.extra[0] = 0; + thread->cpu_context.extra[1] = 0; + break; + + case THREAD_NOTIFY_SWITCH: + dsp_save_state(current_thread_info()->cpu_context.extra); + dsp_load_state(thread->cpu_context.extra); + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block dsp_notifier_block = { + .notifier_call = dsp_do, +}; + + +#ifdef CONFIG_IWMMXT +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_RELEASE: + 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, +}; +#endif + + +static u32 __init xscale_cp_access_read(void) +{ + u32 value; + + __asm__ __volatile__ ( + "mrc p15, 0, %0, c15, c1, 0\n\t" + : "=r" (value)); + + return value; +} + +static void __init xscale_cp_access_write(u32 value) +{ + u32 temp; + + __asm__ __volatile__ ( + "mcr p15, 0, %1, c15, c1, 0\n\t" + "mrc p15, 0, %0, c15, c1, 0\n\t" + "mov %0, %0\n\t" + "sub pc, pc, #4\n\t" + : "=r" (temp) : "r" (value)); +} + +/* + * Detect whether we have a MAC coprocessor (40 bit register) or an + * iWMMXt coprocessor (64 bit registers) by loading 00000100:00000000 + * into a coprocessor register and reading it back, and checking + * whether the upper word survived intact. + */ +static int __init cpu_has_iwmmxt(void) +{ + u32 lo; + u32 hi; + + /* + * This sequence is interpreted by the DSP coprocessor as: + * mar acc0, %2, %3 + * mra %0, %1, acc0 + * + * And by the iWMMXt coprocessor as: + * tmcrr wR0, %2, %3 + * tmrrc %0, %1, wR0 + */ + __asm__ __volatile__ ( + "mcrr p0, 0, %2, %3, c0\n" + "mrrc p0, 0, %0, %1, c0\n" + : "=r" (lo), "=r" (hi) + : "r" (0), "r" (0x100)); + + return !!hi; +} + + +/* + * If we detect that the CPU has iWMMXt (and CONFIG_IWMMXT=y), we + * disable CP0/CP1 on boot, and let call_fpe() and the iWMMXt lazy + * switch code handle iWMMXt context switching. If on the other + * hand the CPU has a DSP coprocessor, we keep access to CP0 enabled + * all the time, and save/restore acc0 on context switch in non-lazy + * fashion. + */ +static int __init xscale_cp0_init(void) +{ + u32 cp_access; + + cp_access = xscale_cp_access_read() & ~3; + xscale_cp_access_write(cp_access | 1); + + if (cpu_has_iwmmxt()) { +#ifndef CONFIG_IWMMXT + printk(KERN_WARNING "CAUTION: XScale iWMMXt coprocessor " + "detected, but kernel support is missing.\n"); +#else + printk(KERN_INFO "XScale iWMMXt coprocessor detected.\n"); + elf_hwcap |= HWCAP_IWMMXT; + thread_register_notifier(&iwmmxt_notifier_block); +#endif + } else { + printk(KERN_INFO "XScale DSP coprocessor detected.\n"); + thread_register_notifier(&dsp_notifier_block); + cp_access |= 1; + } + + xscale_cp_access_write(cp_access); + + return 0; +} + +late_initcall(xscale_cp0_init); diff --git a/arch/arm/mach-pxa/Kconfig b/arch/arm/mach-pxa/Kconfig index 03d07ca..9e3d0bd 100644 --- a/arch/arm/mach-pxa/Kconfig +++ b/arch/arm/mach-pxa/Kconfig @@ -13,12 +13,10 @@ config ARCH_LUBBOCK config MACH_LOGICPD_PXA270 bool "LogicPD PXA270 Card Engine Development Platform" select PXA27x - select IWMMXT config MACH_MAINSTONE bool "Intel HCDDBBVA0 Development Platform" select PXA27x - select IWMMXT config ARCH_PXA_IDP bool "Accelent Xscale IDP" @@ -53,7 +51,6 @@ config PXA_SHARPSL_25x config PXA_SHARPSL_27x bool "Sharp PXA270 models (SL-Cxx00)" select PXA27x - select IWMMXT endchoice @@ -129,11 +126,6 @@ config PXA27x help Select code specific to PXA27x variants -config IWMMXT - bool - help - Enable support for iWMMXt - config PXA_SHARP_C7xx bool select PXA_SSP diff --git a/arch/arm/mach-pxa/pm.c b/arch/arm/mach-pxa/pm.c index 2112c41..b4d8276 100644 --- a/arch/arm/mach-pxa/pm.c +++ b/arch/arm/mach-pxa/pm.c @@ -83,7 +83,8 @@ int pxa_pm_enter(suspend_state_t state) #ifdef CONFIG_IWMMXT /* force any iWMMXt context to ram **/ - iwmmxt_task_disable(NULL); + if (elf_hwcap & HWCAP_IWMMXT) + iwmmxt_task_disable(NULL); #endif /* preserve current time */ diff --git a/arch/arm/mm/proc-xscale.S b/arch/arm/mm/proc-xscale.S index 906e9de..cc1004b 100644 --- a/arch/arm/mm/proc-xscale.S +++ b/arch/arm/mm/proc-xscale.S @@ -491,12 +491,7 @@ __xscale_setup: mcr p15, 0, ip, c7, c7, 0 @ invalidate I, D caches & BTB mcr p15, 0, ip, c7, c10, 4 @ Drain Write (& Fill) Buffer mcr p15, 0, ip, c8, c7, 0 @ invalidate I, D TLBs -#ifdef CONFIG_IWMMXT - mov r0, #0 @ initially disallow access to CP0/CP1 -#else - mov r0, #1 @ Allow access to CP0 -#endif - orr r0, r0, #1 << 6 @ cp6 for IOP3xx and Bulverde + mov r0, #1 << 6 @ cp6 for IOP3xx and Bulverde orr r0, r0, #1 << 13 @ Its undefined whether this mcr p15, 0, r0, c15, c1, 0 @ affects USR or SVC modes @@ -909,7 +904,7 @@ __pxa270_proc_info: b __xscale_setup .long cpu_arch_name .long cpu_elf_name - .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_IWMMXT + .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP .long cpu_pxa270_name .long xscale_processor_functions .long v4wbi_tlb_fns diff --git a/include/asm-arm/elf.h b/include/asm-arm/elf.h index f392930..642382d 100644 --- a/include/asm-arm/elf.h +++ b/include/asm-arm/elf.h @@ -114,40 +114,24 @@ extern char elf_platform[]; have no such handler. */ #define ELF_PLAT_INIT(_r, load_addr) (_r)->ARM_r0 = 0 -#ifndef CONFIG_IWMMXT - -/* Old NetWinder binaries were compiled in such a way that the iBCS - heuristic always trips on them. Until these binaries become uncommon - enough not to care, don't trust the `ibcs' flag here. In any case - there is no other ELF system currently supported by iBCS. - @@ Could print a warning message to encourage users to upgrade. */ -#define SET_PERSONALITY(ex,ibcs2) \ - set_personality(((ex).e_flags & EF_ARM_APCS26 ? PER_LINUX : PER_LINUX_32BIT)) - -#else - /* - * All iWMMXt capable CPUs don't support 26-bit mode. Yet they can run - * legacy binaries which used to contain FPA11 floating point instructions - * that have always been emulated by the kernel. PFA11 and iWMMXt overlap - * on coprocessor 1 space though. We therefore must decide if given task - * is allowed to use CP 0 and 1 for iWMMXt, or if they should be blocked - * at all times for the prefetch exception handler to catch FPA11 opcodes - * and emulate them. The best indication to discriminate those two cases - * is the SOFT_FLOAT flag in the ELF header. + * Since the FPA coprocessor uses CP1 and CP2, and iWMMXt uses CP0 + * and CP1, we only enable access to the iWMMXt coprocessor if the + * binary is EABI or softfloat (and thus, guaranteed not to use + * FPA instructions.) */ - -#define SET_PERSONALITY(ex,ibcs2) \ -do { \ - set_personality(PER_LINUX_32BIT); \ - if (((ex).e_flags & EF_ARM_EABI_MASK) || \ - ((ex).e_flags & EF_ARM_SOFT_FLOAT)) \ - set_thread_flag(TIF_USING_IWMMXT); \ - else \ - clear_thread_flag(TIF_USING_IWMMXT); \ -} while (0) - -#endif +#define SET_PERSONALITY(ex, ibcs2) \ + do { \ + if ((ex).e_flags & EF_ARM_APCS26) { \ + set_personality(PER_LINUX); \ + } else { \ + set_personality(PER_LINUX_32BIT); \ + if (elf_hwcap & HWCAP_IWMMXT && (ex).e_flags & (EF_ARM_EABI_MASK | EF_ARM_SOFT_FLOAT)) \ + set_thread_flag(TIF_USING_IWMMXT); \ + else \ + clear_thread_flag(TIF_USING_IWMMXT); \ + } \ + } while (0) #endif |