[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Minios-devel] [PATCH v3 22/43] arm64: implement the __arch_switch_threads
Hi Shijie, On 16/04/18 07:32, Huang Shijie wrote: The __arch_switch_threads is used for switching the threads. This patch implements it. Signed-off-by: Huang Shijie <shijie.huang@xxxxxxx> --- arch/arm/arm64/arm64.S | 38 ++++++++++++++++++++++++++++++++++++++ include/arm/arm64/os.h | 4 ++++ 2 files changed, 42 insertions(+) diff --git a/arch/arm/arm64/arm64.S b/arch/arm/arm64/arm64.S index fa3406f..5f55f99 100644 --- a/arch/arm/arm64/arm64.S +++ b/arch/arm/arm64/arm64.S @@ -1,5 +1,6 @@ #include "asm.h" #include <arch_limits.h> +#include <arm64/os.h> #include <arm64/pagetable.h> #include <arm64/traps.h> #include <xen/xen.h> @@ -434,3 +435,40 @@ ENTRY(vector_table) vector_entry el0_fiq_invalid /* FIQ 32-bit EL0 */ vector_entry el0_error_invalid /* Error 32-bit EL0 */ END(vector_table) + +/* + * => x0 = &prev->sp + * x1 = &next->sp + * <= switch to the next thread Some documentation about the layout of the structure in memory would be useful. + */ +ENTRY(__arch_switch_threads) + /* Store the callee-saved registers to prev's struct thread */ AFAICT, you don't store the callee-saved registers in struct thread but on the stack. Am I right? + mov x2, sp + + sub x2, x2, #(CALLEE_SAVED_REGISTERS * 8) > + stp x19, x20, [x2, #16 * 0] + stp x21, x22, [x2, #16 * 1] + stp x23, x24, [x2, #16 * 2] + stp x25, x26, [x2, #16 * 3] + stp x27, x28, [x2, #16 * 4] + str x29, [x2, #16 * 5] + + /* Store current sp/ip to prev's struct thread */ + stp x2, x30, [x0] + + /* Load the sp/ip from next's struct thread */ + ldp x2, x30, [x1] + + /* Restore the callee-saved registers */ + ldp x19, x20, [x2, #16 * 0] + ldp x21, x22, [x2, #16 * 1] + ldp x23, x24, [x2, #16 * 2] + ldp x25, x26, [x2, #16 * 3] + ldp x27, x28, [x2, #16 * 4] + ldr x29, [x2, #16 * 5] + + add x2, x2, #(CALLEE_SAVED_REGISTERS * 8) + mov sp, x2 + + br x30 +ENDPROC(__arch_switch_threads) diff --git a/include/arm/arm64/os.h b/include/arm/arm64/os.h index 89b4002..2d55023 100644 --- a/include/arm/arm64/os.h +++ b/include/arm/arm64/os.h @@ -1,6 +1,8 @@ #ifndef _ARM64_OS_H_ #define _ARM64_OS_H_+#ifndef __ASSEMBLY__+ #define BUG() __asm__ __volatile("wfi" ::: "memory")static inline void local_irq_disable(void)@@ -25,6 +27,8 @@ static inline void local_irq_enable(void) __asm__ __volatile__("mrs %0, daif":"=r"(x)::"memory"); \ }+#endif+ /* The Callee-saved registers : x19 ~ x29 */ #define CALLEE_SAVED_REGISTERS 11 Cheers, -- Julien Grall _______________________________________________ Minios-devel mailing list Minios-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/minios-devel
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