Changeset 128359eb in mainline for kernel/generic


Ignore:
Timestamp:
2020-06-12T16:46:32Z (5 years ago)
Author:
Martin Decky <martin@…>
Branches:
lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export
Children:
ffccdff0
Parents:
94e75cf
Message:

Replace get_stack_base() with builtin_frame_address(0)

The usage of an intrinsic function to obtain the current stack pointer
should provide the compuler more room for performance optimizations than
the hand-written (and volatile) inline assembly block.

Location:
kernel/generic
Files:
4 edited

Legend:

Unmodified
Added
Removed

  • kernel/generic/include/arch.h

    r94e75cf r128359eb  
    3636#define KERN_ARCH_H_
    3737
    38 #include <arch/asm.h>   /* get_stack_base() */
    3938#include <config.h>
    4039
    41 /*
     40/** Return the current_t structure
     41 *
    4242 * The current_t structure holds pointers to various parts of the current
    4343 * execution state, like running task, thread, address space, etc.
     44 *
     45 * The current_t structure is located at the base address of the current
     46 * stack. The stack is assumed to be STACK_SIZE bytes long. The stack base
     47 * address must be aligned to STACK_SIZE.
     48 *
    4449 */
    45 #define CURRENT  ((current_t * )(get_stack_base()))
     50#define CURRENT \
     51        ((current_t *) (((uintptr_t) __builtin_frame_address(0)) & \
     52            (~((uintptr_t) STACK_SIZE - 1))))
    4653
    47 #define MAGIC                UINT32_C(0xfacefeed)
     54#define MAGIC  UINT32_C(0xfacefeed)
    4855
    4956#define container_check(ctn1, ctn2)  ((ctn1) == (ctn2))
    … …  
    5966struct as;
    6067
    61 /**
     68/** Current structure
     69 *
    6270 * For each possible kernel stack, structure
    6371 * of the following type will be placed at
    6472 * the base address of the stack.
     73 *
    6574 */
    6675typedef struct {
    67         size_t preemption;     /**< Preemption disabled counter and flag. */
    68         struct thread *thread; /**< Current thread. */
    69         struct task *task;     /**< Current task. */
    70         struct cpu *cpu;       /**< Executing cpu. */
    71         struct as *as;         /**< Current address space. */
    72         uint32_t magic;        /**< Magic value */
     76        size_t preemption;      /**< Preemption disabled counter and flag. */
     77        struct thread *thread;  /**< Current thread. */
     78        struct task *task;      /**< Current task. */
     79        struct cpu *cpu;        /**< Executing CPU. */
     80        struct as *as;          /**< Current address space. */
     81        uint32_t magic;         /**< Magic value. */
    7382} current_t;
    7483
    … …  
    8998        } while (0)
    9099
    91 #define ARCH_OP(op)     ARCH_STRUCT_OP(arch_ops, op)
     100#define ARCH_OP(op)  ARCH_STRUCT_OP(arch_ops, op)
    92101
    93102extern void current_initialize(current_t *);

  • kernel/generic/src/cpu/cpu.c

    r94e75cf r128359eb  
    7171                memsetb(cpus, sizeof(cpu_t) * config.cpu_count, 0);
    7272
    73                 // NOTE: All kernel stacks must be aligned to STACK_SIZE,
    74                 //       see get_stack_base().
    75                 size_t i;
    76                 for (i = 0; i < config.cpu_count; i++) {
     73                /*
     74                 * NOTE: All kernel stacks must be aligned to STACK_SIZE,
     75                 *       see CURRENT.
     76                 */
     77                for (size_t i = 0; i < config.cpu_count; i++) {
    7778                        uintptr_t stack_phys = frame_alloc(STACK_FRAMES,
    7879                            FRAME_LOWMEM | FRAME_ATOMIC, STACK_SIZE - 1);

  • kernel/generic/src/main/main.c

    r94e75cf r128359eb  
    170170            ALIGN_UP((uintptr_t) kdata_end - config.base, PAGE_SIZE);
    171171
    172         // NOTE: All kernel stacks must be aligned to STACK_SIZE,
    173         //       see get_stack_base().
     172        /*
     173         * NOTE: All kernel stacks must be aligned to STACK_SIZE,
     174         *       see CURRENT.
     175         */
    174176
    175177        /* Place the stack after the kernel, init and ballocs. */

  • kernel/generic/src/proc/thread.c

    r94e75cf r128359eb  
    191191        kmflags &= ~FRAME_HIGHMEM;
    192192
    193         // NOTE: All kernel stacks must be aligned to STACK_SIZE,
    194         //       see get_stack_base().
     193        /*
     194         * NOTE: All kernel stacks must be aligned to STACK_SIZE,
     195         *       see CURRENT.
     196         */
    195197
    196198        uintptr_t stack_phys =
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