Skip to content

arm64/SMP: Fix FPU and exception handling for ARM64 #13695

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
xiaoxiang781216 merged 4 commits into from
Oct 2, 2024
Merged

arm64/SMP: Fix FPU and exception handling for ARM64 #13695

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
68df8ec
arm64: save FPU regs every time
GUIDINGLI Sep 27, 2024
133ec61
arm64: simply the vectors
GUIDINGLI Oct 1, 2024
30c9212
Kernel build: enter exception save sp_sl0,exit exception restroe sp_el0
lipengfei28 Sep 12, 2024
f387b02
arm64_task/pthread_start: Set sp_el0 upon starting user process
pussuw Oct 1, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions arch/arm64/src/common/arm64_arch.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -292,6 +292,9 @@ struct regs_context
uint64_t spsr;
uint64_t sp_el0;
uint64_t exe_depth;
#ifdef CONFIG_ARCH_FPU
struct fpu_reg fpu_regs;
#endif
};

/****************************************************************************
Expand Down
3 changes: 0 additions & 3 deletions arch/arm64/src/common/arm64_exit.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -67,9 +67,6 @@ void up_exit(int status)
enter_critical_section();

/* Destroy the task at the head of the ready to run list. */
#ifdef CONFIG_ARCH_FPU
arm64_destory_fpu(tcb);
#endif

nxtask_exit();

Expand Down
140 changes: 2 additions & 138 deletions arch/arm64/src/common/arm64_fpu.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -77,11 +77,10 @@ struct arm64_fpu_procfs_file_s
* Private Data
***************************************************************************/

static struct fpu_reg g_idle_thread_fpu[CONFIG_SMP_NCPUS];
static struct arm64_cpu_fpu_context g_cpu_fpu_ctx[CONFIG_SMP_NCPUS];

#ifdef CONFIG_FS_PROCFS_REGISTER

static struct arm64_cpu_fpu_context g_cpu_fpu_ctx[CONFIG_SMP_NCPUS];

/* procfs methods */

static int arm64_fpu_procfs_open(struct file *filep, const char *relpath,
Expand Down Expand Up @@ -262,141 +261,6 @@ static int arm64_fpu_procfs_stat(const char *relpath, struct stat *buf)
}
#endif

/***************************************************************************
* Public Functions
***************************************************************************/

void arm64_init_fpu(struct tcb_s *tcb)
{
if (tcb->pid < CONFIG_SMP_NCPUS)
{
#ifdef CONFIG_SMP
int cpu = tcb->cpu;
#else
int cpu = 0;
#endif
memset(&g_cpu_fpu_ctx[cpu], 0,
sizeof(struct arm64_cpu_fpu_context));
g_cpu_fpu_ctx[cpu].idle_thread = tcb;

tcb->xcp.fpu_regs = (uint64_t *)&g_idle_thread_fpu[cpu];

@pussuw pussuw Oct 1, 2024

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

What about:

  • tcb->xcp.fpu_regs
  • tcb->xcp.fpu_saved_regs

what should we do with those ?

}

memset(tcb->xcp.fpu_regs, 0, sizeof(struct fpu_reg));
}

void arm64_destory_fpu(struct tcb_s *tcb)
{
struct tcb_s *owner;

/* save current fpu owner's context */

owner = g_cpu_fpu_ctx[this_cpu()].fpu_owner;

if (owner == tcb)
{
g_cpu_fpu_ctx[this_cpu()].fpu_owner = NULL;
}
}

/***************************************************************************
* Name: arm64_fpu_enter_exception
*
* Description:
* called at every time get into a exception
*
***************************************************************************/

void arm64_fpu_enter_exception(void)
{
}

void arm64_fpu_exit_exception(void)
{
}

void arm64_fpu_trap(struct regs_context *regs)
{
struct tcb_s *owner;

UNUSED(regs);

/* disable fpu trap access */

arm64_fpu_access_trap_disable();

/* save current fpu owner's context */

owner = g_cpu_fpu_ctx[this_cpu()].fpu_owner;

if (owner != NULL)
{
arm64_fpu_save((struct fpu_reg *)owner->xcp.fpu_regs);
ARM64_DSB();
g_cpu_fpu_ctx[this_cpu()].save_count++;
g_cpu_fpu_ctx[this_cpu()].fpu_owner = NULL;
}

if (arch_get_exception_depth() > 1)
{
/* if get_exception_depth > 1
* it means FPU access exception occurred in exception context
* switch FPU owner to idle thread
*/

owner = g_cpu_fpu_ctx[this_cpu()].idle_thread;
}
else
{
owner = running_task();
}

/* restore our context */

arm64_fpu_restore((struct fpu_reg *)owner->xcp.fpu_regs);
g_cpu_fpu_ctx[this_cpu()].restore_count++;

/* become new owner */

g_cpu_fpu_ctx[this_cpu()].fpu_owner = owner;
}

void arm64_fpu_context_restore(void)
{
struct tcb_s *new_tcb = running_task();

arm64_fpu_access_trap_disable();

/* FPU trap has happened at this task */

if (new_tcb == g_cpu_fpu_ctx[this_cpu()].fpu_owner)
{
arm64_fpu_access_trap_disable();
}
else
{
arm64_fpu_access_trap_enable();
}

g_cpu_fpu_ctx[this_cpu()].switch_count++;
}

#ifdef CONFIG_SMP
void arm64_fpu_context_save(void)
{
struct tcb_s *tcb = running_task();

if (tcb == g_cpu_fpu_ctx[this_cpu()].fpu_owner)
{
arm64_fpu_access_trap_disable();
arm64_fpu_save((struct fpu_reg *)tcb->xcp.fpu_regs);
ARM64_DSB();
g_cpu_fpu_ctx[this_cpu()].save_count++;
g_cpu_fpu_ctx[this_cpu()].fpu_owner = NULL;
}
}
#endif

void arm64_fpu_enable(void)
{
irqstate_t flags = up_irq_save();
Expand Down
16 changes: 8 additions & 8 deletions arch/arm64/src/common/arm64_fpu_func.S
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -66,10 +66,10 @@ SECTION_FUNC(text, arm64_fpu_save)
stp q28, q29, [x0, #(16 * FPU_REG_Q28)]
stp q30, q31, [x0, #(16 * FPU_REG_Q30)]

mrs x1, fpsr
mrs x2, fpcr
str w1, [x0, #(16 * 32 + 0)]
str w2, [x0, #(16 * 32 + 4)]
mrs x10, fpsr
mrs x11, fpcr
str w10, [x0, #(16 * 32 + 0)]
str w11, [x0, #(16 * 32 + 4)]

ret

Expand All @@ -93,9 +93,9 @@ SECTION_FUNC(text, arm64_fpu_restore)
ldp q28, q29, [x0, #(16 * FPU_REG_Q28)]
ldp q30, q31, [x0, #(16 * FPU_REG_Q30)]

ldr w1, [x0, #(16 * 32 + 0)]
ldr w2, [x0, #(16 * 32 + 4)]
msr fpsr, x1
msr fpcr, x2
ldr w10, [x0, #(16 * 32 + 0)]
ldr w11, [x0, #(16 * 32 + 4)]
msr fpsr, x10
msr fpcr, x11

ret
20 changes: 0 additions & 20 deletions arch/arm64/src/common/arm64_initialstate.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -47,10 +47,6 @@
#include "chip.h"
#include "arm64_fatal.h"

#ifdef CONFIG_ARCH_FPU
#include "arm64_fpu.h"
#endif

/****************************************************************************
* Public Functions
****************************************************************************/
Expand All @@ -70,17 +66,6 @@ void arm64_new_task(struct tcb_s * tcb)
}
#endif

#ifdef CONFIG_ARCH_FPU
struct fpu_reg *pfpuctx;
pfpuctx = STACK_PTR_TO_FRAME(struct fpu_reg, stack_ptr);
tcb->xcp.fpu_regs = (uint64_t *)pfpuctx;

/* set fpu context */

arm64_init_fpu(tcb);
stack_ptr = (uintptr_t)pfpuctx;
#endif

pinitctx = STACK_PTR_TO_FRAME(struct regs_context, stack_ptr);
memset(pinitctx, 0, sizeof(struct regs_context));
pinitctx->elr = (uint64_t)tcb->start;
Expand Down Expand Up @@ -150,11 +135,6 @@ void up_initial_state(struct tcb_s *tcb)
tcb->stack_base_ptr = tcb->stack_alloc_ptr;
tcb->adj_stack_size = CONFIG_IDLETHREAD_STACKSIZE;

#ifdef CONFIG_ARCH_FPU
/* set fpu context */

arm64_init_fpu(tcb);
#endif
/* set initialize idle thread tcb and exception depth
* core 0, idle0
*/
Expand Down
5 changes: 2 additions & 3 deletions arch/arm64/src/common/arm64_internal.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -261,7 +261,7 @@ EXTERN uint8_t g_idle_topstack[]; /* End+1 of heap */

void arm64_new_task(struct tcb_s *tak_new);
void arm64_jump_to_user(uint64_t entry, uint64_t x0, uint64_t x1,
uint64_t *regs) noreturn_function;
uint64_t sp_el0, uint64_t *regs) noreturn_function;

/* Low level initialization provided by chip logic */

Expand Down Expand Up @@ -302,8 +302,7 @@ void arm64_pginitialize(void);
# define arm64_pginitialize()
#endif /* CONFIG_LEGACY_PAGING */

uint64_t * arm64_syscall_switch(uint64_t *regs);
int arm64_syscall(uint64_t *regs);
uint64_t *arm64_syscall(uint64_t *regs);

/* Low level serial output **************************************************/

Expand Down
4 changes: 3 additions & 1 deletion arch/arm64/src/common/arm64_pthread_start.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -68,6 +68,8 @@
void up_pthread_start(pthread_trampoline_t startup,
pthread_startroutine_t entrypt, pthread_addr_t arg)
{
struct tcb_s *rtcb = this_task();

/* Set up to enter the user-space pthread start-up function in
* unprivileged mode. We need:
*
Expand All @@ -78,7 +80,7 @@ void up_pthread_start(pthread_trampoline_t startup,
*/

arm64_jump_to_user((uint64_t)startup, (uint64_t)entrypt, (uint64_t)arg,
this_task()->xcp.initregs);
(uint64_t)rtcb->xcp.ustkptr, rtcb->xcp.initregs);
}

#endif /* !CONFIG_BUILD_FLAT && __KERNEL__ && !CONFIG_DISABLE_PTHREAD */
17 changes: 0 additions & 17 deletions arch/arm64/src/common/arm64_schedulesigaction.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -38,10 +38,6 @@
#include "irq/irq.h"
#include "arm64_fatal.h"

#ifdef CONFIG_ARCH_FPU
#include "arm64_fpu.h"
#endif

/****************************************************************************
* Public Functions
****************************************************************************/
Expand All @@ -58,16 +54,6 @@ void arm64_init_signal_process(struct tcb_s *tcb, struct regs_context *regs)
struct regs_context *psigctx;
char *stack_ptr = (char *)pctx->sp_elx - sizeof(struct regs_context);

#ifdef CONFIG_ARCH_FPU
struct fpu_reg *pfpuctx;
pfpuctx = STACK_PTR_TO_FRAME(struct fpu_reg, stack_ptr);
tcb->xcp.fpu_regs = (uint64_t *)pfpuctx;

/* set fpu context */

arm64_init_fpu(tcb);
stack_ptr = (char *)pfpuctx;
#endif
psigctx = STACK_PTR_TO_FRAME(struct regs_context, stack_ptr);
memset(psigctx, 0, sizeof(struct regs_context));
psigctx->elr = (uint64_t)arm64_sigdeliver;
Expand Down Expand Up @@ -168,9 +154,6 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
* have been delivered.
*/

#ifdef CONFIG_ARCH_FPU
tcb->xcp.saved_fpu_regs = tcb->xcp.fpu_regs;
#endif
tcb->xcp.saved_reg = tcb->xcp.regs;

/* create signal process context */
Expand Down
9 changes: 0 additions & 9 deletions arch/arm64/src/common/arm64_sigdeliver.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -38,10 +38,6 @@
#include "irq/irq.h"
#include "arm64_fatal.h"

#ifdef CONFIG_ARCH_FPU
#include "arm64_fpu.h"
#endif

/****************************************************************************
* Public Functions
****************************************************************************/
Expand Down Expand Up @@ -157,11 +153,6 @@ void arm64_sigdeliver(void)
rtcb->xcp.sigdeliver = NULL; /* Allows next handler to be scheduled */
rtcb->xcp.regs = rtcb->xcp.saved_reg;

#ifdef CONFIG_ARCH_FPU
arm64_destory_fpu(rtcb);
rtcb->xcp.fpu_regs = rtcb->xcp.saved_fpu_regs;
#endif

/* Then restore the correct state for this thread of execution. */

#ifdef CONFIG_SMP
Expand Down
Loading