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-rw-r--r--arch/arm/vfp/entry.S3
-rw-r--r--arch/arm/vfp/vfphw.S20
-rw-r--r--arch/arm/vfp/vfpmodule.c42
3 files changed, 38 insertions, 27 deletions
diff --git a/arch/arm/vfp/entry.S b/arch/arm/vfp/entry.S
index 4fa9903..c1a9784 100644
--- a/arch/arm/vfp/entry.S
+++ b/arch/arm/vfp/entry.S
@@ -10,7 +10,7 @@
*
* Basic entry code, called from the kernel's undefined instruction trap.
* r0 = faulted instruction
- * r5 = faulted PC+4
+ * r2 = faulted PC+4
* r9 = successful return
* r10 = thread_info structure
* lr = failure return
@@ -26,6 +26,7 @@ ENTRY(do_vfp)
str r11, [r10, #TI_PREEMPT]
#endif
enable_irq
+ str r2, [sp, #S_PC] @ update regs->ARM_pc for Thumb 2 case
ldr r4, .LCvfp
ldr r11, [r10, #TI_CPU] @ CPU number
add r10, r10, #TI_VFPSTATE @ r10 = workspace
diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
index 9897dcf..404538a 100644
--- a/arch/arm/vfp/vfphw.S
+++ b/arch/arm/vfp/vfphw.S
@@ -77,15 +77,12 @@ ENTRY(vfp_support_entry)
bne look_for_VFP_exceptions @ VFP is already enabled
DBGSTR1 "enable %x", r10
- ldr r3, last_VFP_context_address
+ ldr r3, vfp_current_hw_state_address
orr r1, r1, #FPEXC_EN @ user FPEXC has the enable bit set
- ldr r4, [r3, r11, lsl #2] @ last_VFP_context pointer
+ ldr r4, [r3, r11, lsl #2] @ vfp_current_hw_state pointer
bic r5, r1, #FPEXC_EX @ make sure exceptions are disabled
- cmp r4, r10
- beq check_for_exception @ we are returning to the same
- @ process, so the registers are
- @ still there. In this case, we do
- @ not want to drop a pending exception.
+ cmp r4, r10 @ this thread owns the hw context?
+ beq vfp_hw_state_valid
VFPFMXR FPEXC, r5 @ enable VFP, disable any pending
@ exceptions, so we can get at the
@@ -116,7 +113,7 @@ ENTRY(vfp_support_entry)
no_old_VFP_process:
DBGSTR1 "load state %p", r10
- str r10, [r3, r11, lsl #2] @ update the last_VFP_context pointer
+ str r10, [r3, r11, lsl #2] @ update the vfp_current_hw_state pointer
@ Load the saved state back into the VFP
VFPFLDMIA r10, r5 @ reload the working registers while
@ FPEXC is in a safe state
@@ -132,7 +129,8 @@ no_old_VFP_process:
#endif
VFPFMXR FPSCR, r5 @ restore status
-check_for_exception:
+@ The context stored in the VFP hardware is up to date with this thread
+vfp_hw_state_valid:
tst r1, #FPEXC_EX
bne process_exception @ might as well handle the pending
@ exception before retrying branch
@@ -207,8 +205,8 @@ ENTRY(vfp_save_state)
ENDPROC(vfp_save_state)
.align
-last_VFP_context_address:
- .word last_VFP_context
+vfp_current_hw_state_address:
+ .word vfp_current_hw_state
.macro tbl_branch, base, tmp, shift
#ifdef CONFIG_THUMB2_KERNEL
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index f25e7ec..78829fa 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -33,7 +33,13 @@ void vfp_support_entry(void);
void vfp_null_entry(void);
void (*vfp_vector)(void) = vfp_null_entry;
-union vfp_state *last_VFP_context[NR_CPUS];
+
+/*
+ * The pointer to the vfpstate structure of the thread which currently
+ * owns the context held in the VFP hardware, or NULL if the hardware
+ * context is invalid.
+ */
+union vfp_state *vfp_current_hw_state[NR_CPUS];
/*
* Dual-use variable.
@@ -57,12 +63,12 @@ static void vfp_thread_flush(struct thread_info *thread)
/*
* Disable VFP to ensure we initialize it first. We must ensure
- * that the modification of last_VFP_context[] and hardware disable
+ * that the modification of vfp_current_hw_state[] and hardware disable
* are done for the same CPU and without preemption.
*/
cpu = get_cpu();
- if (last_VFP_context[cpu] == vfp)
- last_VFP_context[cpu] = NULL;
+ if (vfp_current_hw_state[cpu] == vfp)
+ vfp_current_hw_state[cpu] = NULL;
fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
put_cpu();
}
@@ -73,8 +79,8 @@ static void vfp_thread_exit(struct thread_info *thread)
union vfp_state *vfp = &thread->vfpstate;
unsigned int cpu = get_cpu();
- if (last_VFP_context[cpu] == vfp)
- last_VFP_context[cpu] = NULL;
+ if (vfp_current_hw_state[cpu] == vfp)
+ vfp_current_hw_state[cpu] = NULL;
put_cpu();
}
@@ -129,9 +135,9 @@ static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v)
* case the thread migrates to a different CPU. The
* restoring is done lazily.
*/
- if ((fpexc & FPEXC_EN) && last_VFP_context[cpu]) {
- vfp_save_state(last_VFP_context[cpu], fpexc);
- last_VFP_context[cpu]->hard.cpu = cpu;
+ if ((fpexc & FPEXC_EN) && vfp_current_hw_state[cpu]) {
+ vfp_save_state(vfp_current_hw_state[cpu], fpexc);
+ vfp_current_hw_state[cpu]->hard.cpu = cpu;
}
/*
* Thread migration, just force the reloading of the
@@ -139,7 +145,7 @@ static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v)
* contain stale data.
*/
if (thread->vfpstate.hard.cpu != cpu)
- last_VFP_context[cpu] = NULL;
+ vfp_current_hw_state[cpu] = NULL;
#endif
/*
@@ -412,10 +418,16 @@ static int vfp_pm_suspend(void)
/* disable, just in case */
fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
+ } else if (vfp_current_hw_state[ti->cpu]) {
+#ifndef CONFIG_SMP
+ fmxr(FPEXC, fpexc | FPEXC_EN);
+ vfp_save_state(vfp_current_hw_state[ti->cpu], fpexc);
+ fmxr(FPEXC, fpexc);
+#endif
}
/* clear any information we had about last context state */
- memset(last_VFP_context, 0, sizeof(last_VFP_context));
+ vfp_current_hw_state[ti->cpu] = NULL;
return 0;
}
@@ -451,7 +463,7 @@ void vfp_sync_hwstate(struct thread_info *thread)
* If the thread we're interested in is the current owner of the
* hardware VFP state, then we need to save its state.
*/
- if (last_VFP_context[cpu] == &thread->vfpstate) {
+ if (vfp_current_hw_state[cpu] == &thread->vfpstate) {
u32 fpexc = fmrx(FPEXC);
/*
@@ -473,7 +485,7 @@ void vfp_flush_hwstate(struct thread_info *thread)
* If the thread we're interested in is the current owner of the
* hardware VFP state, then we need to save its state.
*/
- if (last_VFP_context[cpu] == &thread->vfpstate) {
+ if (vfp_current_hw_state[cpu] == &thread->vfpstate) {
u32 fpexc = fmrx(FPEXC);
fmxr(FPEXC, fpexc & ~FPEXC_EN);
@@ -482,7 +494,7 @@ void vfp_flush_hwstate(struct thread_info *thread)
* Set the context to NULL to force a reload the next time
* the thread uses the VFP.
*/
- last_VFP_context[cpu] = NULL;
+ vfp_current_hw_state[cpu] = NULL;
}
#ifdef CONFIG_SMP
@@ -514,7 +526,7 @@ static int vfp_hotplug(struct notifier_block *b, unsigned long action,
{
if (action == CPU_DYING || action == CPU_DYING_FROZEN) {
unsigned int cpu = (long)hcpu;
- last_VFP_context[cpu] = NULL;
+ vfp_current_hw_state[cpu] = NULL;
} else if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
vfp_enable(NULL);
return NOTIFY_OK;
generated by cgit v1.1 at 2025-08-17 18:59:28 +0000