From 9370bb92b2d16684ee45cf24e879c93c509162da Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Thu, 19 Dec 2024 01:47:39 +0000
Subject: [PATCH] add wifi6 8852be driver
---
kernel/arch/x86/kernel/fpu/core.c | 374 ++++++++++++++++++++++++++++-------------------------
1 files changed, 198 insertions(+), 176 deletions(-)
diff --git a/kernel/arch/x86/kernel/fpu/core.c b/kernel/arch/x86/kernel/fpu/core.c
index 2e5003f..835b948 100644
--- a/kernel/arch/x86/kernel/fpu/core.c
+++ b/kernel/arch/x86/kernel/fpu/core.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 1994 Linus Torvalds
*
@@ -24,17 +25,7 @@
*/
union fpregs_state init_fpstate __read_mostly;
-/*
- * Track whether the kernel is using the FPU state
- * currently.
- *
- * This flag is used:
- *
- * - by IRQ context code to potentially use the FPU
- * if it's unused.
- *
- * - to debug kernel_fpu_begin()/end() correctness
- */
+/* Track in-kernel FPU usage */
static DEFINE_PER_CPU(bool, in_kernel_fpu);
/*
@@ -42,96 +33,113 @@
*/
DEFINE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx);
-static void kernel_fpu_disable(void)
-{
- WARN_ON_FPU(this_cpu_read(in_kernel_fpu));
- this_cpu_write(in_kernel_fpu, true);
-}
-
-static void kernel_fpu_enable(void)
-{
- WARN_ON_FPU(!this_cpu_read(in_kernel_fpu));
- this_cpu_write(in_kernel_fpu, false);
-}
-
-static bool kernel_fpu_disabled(void)
-{
- return this_cpu_read(in_kernel_fpu);
-}
-
-static bool interrupted_kernel_fpu_idle(void)
-{
- return !kernel_fpu_disabled();
-}
-
-/*
- * Were we in user mode (or vm86 mode) when we were
- * interrupted?
- *
- * Doing kernel_fpu_begin/end() is ok if we are running
- * in an interrupt context from user mode - we'll just
- * save the FPU state as required.
- */
-static bool interrupted_user_mode(void)
-{
- struct pt_regs *regs = get_irq_regs();
- return regs && user_mode(regs);
-}
-
/*
* Can we use the FPU in kernel mode with the
* whole "kernel_fpu_begin/end()" sequence?
- *
- * It's always ok in process context (ie "not interrupt")
- * but it is sometimes ok even from an irq.
*/
bool irq_fpu_usable(void)
{
- return !in_interrupt() ||
- interrupted_user_mode() ||
- interrupted_kernel_fpu_idle();
+ if (WARN_ON_ONCE(in_nmi()))
+ return false;
+
+ /* In kernel FPU usage already active? */
+ if (this_cpu_read(in_kernel_fpu))
+ return false;
+
+ /*
+ * When not in NMI or hard interrupt context, FPU can be used in:
+ *
+ * - Task context except from within fpregs_lock()'ed critical
+ * regions.
+ *
+ * - Soft interrupt processing context which cannot happen
+ * while in a fpregs_lock()'ed critical region.
+ */
+ if (!in_irq())
+ return true;
+
+ /*
+ * In hard interrupt context it's safe when soft interrupts
+ * are enabled, which means the interrupt did not hit in
+ * a fpregs_lock()'ed critical region.
+ */
+ return !softirq_count();
}
EXPORT_SYMBOL(irq_fpu_usable);
-static void __kernel_fpu_begin(void)
+/*
+ * These must be called with preempt disabled. Returns
+ * 'true' if the FPU state is still intact and we can
+ * keep registers active.
+ *
+ * The legacy FNSAVE instruction cleared all FPU state
+ * unconditionally, so registers are essentially destroyed.
+ * Modern FPU state can be kept in registers, if there are
+ * no pending FP exceptions.
+ */
+int copy_fpregs_to_fpstate(struct fpu *fpu)
{
- struct fpu *fpu = ¤t->thread.fpu;
+ if (likely(use_xsave())) {
+ copy_xregs_to_kernel(&fpu->state.xsave);
+
+ /*
+ * AVX512 state is tracked here because its use is
+ * known to slow the max clock speed of the core.
+ */
+ if (fpu->state.xsave.header.xfeatures & XFEATURE_MASK_AVX512)
+ fpu->avx512_timestamp = jiffies;
+ return 1;
+ }
+
+ if (likely(use_fxsr())) {
+ copy_fxregs_to_kernel(fpu);
+ return 1;
+ }
+
+ /*
+ * Legacy FPU register saving, FNSAVE always clears FPU registers,
+ * so we have to mark them inactive:
+ */
+ asm volatile("fnsave %[fp]; fwait" : [fp] "=m" (fpu->state.fsave));
+
+ return 0;
+}
+EXPORT_SYMBOL(copy_fpregs_to_fpstate);
+
+void kernel_fpu_begin_mask(unsigned int kfpu_mask)
+{
+ preempt_disable();
WARN_ON_FPU(!irq_fpu_usable());
+ WARN_ON_FPU(this_cpu_read(in_kernel_fpu));
- kernel_fpu_disable();
+ this_cpu_write(in_kernel_fpu, true);
- if (fpu->initialized) {
+ if (!(current->flags & PF_KTHREAD) &&
+ !test_thread_flag(TIF_NEED_FPU_LOAD)) {
+ set_thread_flag(TIF_NEED_FPU_LOAD);
/*
* Ignore return value -- we don't care if reg state
* is clobbered.
*/
- copy_fpregs_to_fpstate(fpu);
- } else {
- __cpu_invalidate_fpregs_state();
+ copy_fpregs_to_fpstate(¤t->thread.fpu);
}
+ __cpu_invalidate_fpregs_state();
+
+ /* Put sane initial values into the control registers. */
+ if (likely(kfpu_mask & KFPU_MXCSR) && boot_cpu_has(X86_FEATURE_XMM))
+ ldmxcsr(MXCSR_DEFAULT);
+
+ if (unlikely(kfpu_mask & KFPU_387) && boot_cpu_has(X86_FEATURE_FPU))
+ asm volatile ("fninit");
}
-
-static void __kernel_fpu_end(void)
-{
- struct fpu *fpu = ¤t->thread.fpu;
-
- if (fpu->initialized)
- copy_kernel_to_fpregs(&fpu->state);
-
- kernel_fpu_enable();
-}
-
-void kernel_fpu_begin(void)
-{
- preempt_disable();
- __kernel_fpu_begin();
-}
-EXPORT_SYMBOL_GPL(kernel_fpu_begin);
+EXPORT_SYMBOL_GPL(kernel_fpu_begin_mask);
void kernel_fpu_end(void)
{
- __kernel_fpu_end();
+ WARN_ON_FPU(!this_cpu_read(in_kernel_fpu));
+
+ this_cpu_write(in_kernel_fpu, false);
preempt_enable();
}
EXPORT_SYMBOL_GPL(kernel_fpu_end);
@@ -145,17 +153,18 @@
{
WARN_ON_FPU(fpu != ¤t->thread.fpu);
- preempt_disable();
+ fpregs_lock();
trace_x86_fpu_before_save(fpu);
- if (fpu->initialized) {
+
+ if (!test_thread_flag(TIF_NEED_FPU_LOAD)) {
if (!copy_fpregs_to_fpstate(fpu)) {
copy_kernel_to_fpregs(&fpu->state);
}
}
+
trace_x86_fpu_after_save(fpu);
- preempt_enable();
+ fpregs_unlock();
}
-EXPORT_SYMBOL_GPL(fpu__save);
/*
* Legacy x87 fpstate state init:
@@ -186,11 +195,14 @@
}
EXPORT_SYMBOL_GPL(fpstate_init);
-int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
+int fpu__copy(struct task_struct *dst, struct task_struct *src)
{
+ struct fpu *dst_fpu = &dst->thread.fpu;
+ struct fpu *src_fpu = &src->thread.fpu;
+
dst_fpu->last_cpu = -1;
- if (!src_fpu->initialized || !static_cpu_has(X86_FEATURE_FPU))
+ if (!static_cpu_has(X86_FEATURE_FPU))
return 0;
WARN_ON_FPU(src_fpu != ¤t->thread.fpu);
@@ -202,16 +214,23 @@
memset(&dst_fpu->state.xsave, 0, fpu_kernel_xstate_size);
/*
- * Save current FPU registers directly into the child
- * FPU context, without any memory-to-memory copying.
+ * If the FPU registers are not current just memcpy() the state.
+ * Otherwise save current FPU registers directly into the child's FPU
+ * context, without any memory-to-memory copying.
*
* ( The function 'fails' in the FNSAVE case, which destroys
- * register contents so we have to copy them back. )
+ * register contents so we have to load them back. )
*/
- if (!copy_fpregs_to_fpstate(dst_fpu)) {
- memcpy(&src_fpu->state, &dst_fpu->state, fpu_kernel_xstate_size);
- copy_kernel_to_fpregs(&src_fpu->state);
- }
+ fpregs_lock();
+ if (test_thread_flag(TIF_NEED_FPU_LOAD))
+ memcpy(&dst_fpu->state, &src_fpu->state, fpu_kernel_xstate_size);
+
+ else if (!copy_fpregs_to_fpstate(dst_fpu))
+ copy_kernel_to_fpregs(&dst_fpu->state);
+
+ fpregs_unlock();
+
+ set_tsk_thread_flag(dst, TIF_NEED_FPU_LOAD);
trace_x86_fpu_copy_src(src_fpu);
trace_x86_fpu_copy_dst(dst_fpu);
@@ -223,20 +242,14 @@
* Activate the current task's in-memory FPU context,
* if it has not been used before:
*/
-void fpu__initialize(struct fpu *fpu)
+static void fpu__initialize(struct fpu *fpu)
{
WARN_ON_FPU(fpu != ¤t->thread.fpu);
- if (!fpu->initialized) {
- fpstate_init(&fpu->state);
- trace_x86_fpu_init_state(fpu);
-
- trace_x86_fpu_activate_state(fpu);
- /* Safe to do for the current task: */
- fpu->initialized = 1;
- }
+ set_thread_flag(TIF_NEED_FPU_LOAD);
+ fpstate_init(&fpu->state);
+ trace_x86_fpu_init_state(fpu);
}
-EXPORT_SYMBOL_GPL(fpu__initialize);
/*
* This function must be called before we read a task's fpstate.
@@ -248,32 +261,20 @@
*
* - or it's called for stopped tasks (ptrace), in which case the
* registers were already saved by the context-switch code when
- * the task scheduled out - we only have to initialize the registers
- * if they've never been initialized.
+ * the task scheduled out.
*
* If the task has used the FPU before then save it.
*/
void fpu__prepare_read(struct fpu *fpu)
{
- if (fpu == ¤t->thread.fpu) {
+ if (fpu == ¤t->thread.fpu)
fpu__save(fpu);
- } else {
- if (!fpu->initialized) {
- fpstate_init(&fpu->state);
- trace_x86_fpu_init_state(fpu);
-
- trace_x86_fpu_activate_state(fpu);
- /* Safe to do for current and for stopped child tasks: */
- fpu->initialized = 1;
- }
- }
}
/*
* This function must be called before we write a task's fpstate.
*
- * If the task has used the FPU before then invalidate any cached FPU registers.
- * If the task has not used the FPU before then initialize its fpstate.
+ * Invalidate any cached FPU registers.
*
* After this function call, after registers in the fpstate are
* modified and the child task has woken up, the child task will
@@ -290,42 +291,9 @@
*/
WARN_ON_FPU(fpu == ¤t->thread.fpu);
- if (fpu->initialized) {
- /* Invalidate any cached state: */
- __fpu_invalidate_fpregs_state(fpu);
- } else {
- fpstate_init(&fpu->state);
- trace_x86_fpu_init_state(fpu);
-
- trace_x86_fpu_activate_state(fpu);
- /* Safe to do for stopped child tasks: */
- fpu->initialized = 1;
- }
+ /* Invalidate any cached state: */
+ __fpu_invalidate_fpregs_state(fpu);
}
-
-/*
- * 'fpu__restore()' is called to copy FPU registers from
- * the FPU fpstate to the live hw registers and to activate
- * access to the hardware registers, so that FPU instructions
- * can be used afterwards.
- *
- * Must be called with kernel preemption disabled (for example
- * with local interrupts disabled, as it is in the case of
- * do_device_not_available()).
- */
-void fpu__restore(struct fpu *fpu)
-{
- fpu__initialize(fpu);
-
- /* Avoid __kernel_fpu_begin() right after fpregs_activate() */
- kernel_fpu_disable();
- trace_x86_fpu_before_restore(fpu);
- fpregs_activate(fpu);
- copy_kernel_to_fpregs(&fpu->state);
- trace_x86_fpu_after_restore(fpu);
- kernel_fpu_enable();
-}
-EXPORT_SYMBOL_GPL(fpu__restore);
/*
* Drops current FPU state: deactivates the fpregs and
@@ -341,16 +309,12 @@
preempt_disable();
if (fpu == ¤t->thread.fpu) {
- if (fpu->initialized) {
- /* Ignore delayed exceptions from user space */
- asm volatile("1: fwait\n"
- "2:\n"
- _ASM_EXTABLE(1b, 2b));
- fpregs_deactivate(fpu);
- }
+ /* Ignore delayed exceptions from user space */
+ asm volatile("1: fwait\n"
+ "2:\n"
+ _ASM_EXTABLE(1b, 2b));
+ fpregs_deactivate(fpu);
}
-
- fpu->initialized = 0;
trace_x86_fpu_dropped(fpu);
@@ -358,13 +322,13 @@
}
/*
- * Clear FPU registers by setting them up from
- * the init fpstate:
+ * Clear FPU registers by setting them up from the init fpstate.
+ * Caller must do fpregs_[un]lock() around it.
*/
-static inline void copy_init_fpstate_to_fpregs(void)
+static inline void copy_init_fpstate_to_fpregs(u64 features_mask)
{
if (use_xsave())
- copy_kernel_to_xregs(&init_fpstate.xsave, -1);
+ copy_kernel_to_xregs(&init_fpstate.xsave, features_mask);
else if (static_cpu_has(X86_FEATURE_FXSR))
copy_kernel_to_fxregs(&init_fpstate.fxsave);
else
@@ -380,24 +344,82 @@
* Called by sys_execve(), by the signal handler code and by various
* error paths.
*/
-void fpu__clear(struct fpu *fpu)
+static void fpu__clear(struct fpu *fpu, bool user_only)
{
- WARN_ON_FPU(fpu != ¤t->thread.fpu); /* Almost certainly an anomaly */
+ WARN_ON_FPU(fpu != ¤t->thread.fpu);
- fpu__drop(fpu);
-
- /*
- * Make sure fpstate is cleared and initialized.
- */
- if (static_cpu_has(X86_FEATURE_FPU)) {
- preempt_disable();
+ if (!static_cpu_has(X86_FEATURE_FPU)) {
+ fpu__drop(fpu);
fpu__initialize(fpu);
- user_fpu_begin();
- copy_init_fpstate_to_fpregs();
- preempt_enable();
+ return;
}
+
+ fpregs_lock();
+
+ if (user_only) {
+ if (!fpregs_state_valid(fpu, smp_processor_id()) &&
+ xfeatures_mask_supervisor())
+ copy_kernel_to_xregs(&fpu->state.xsave,
+ xfeatures_mask_supervisor());
+ copy_init_fpstate_to_fpregs(xfeatures_mask_user());
+ } else {
+ copy_init_fpstate_to_fpregs(xfeatures_mask_all);
+ }
+
+ fpregs_mark_activate();
+ fpregs_unlock();
}
+void fpu__clear_user_states(struct fpu *fpu)
+{
+ fpu__clear(fpu, true);
+}
+
+void fpu__clear_all(struct fpu *fpu)
+{
+ fpu__clear(fpu, false);
+}
+
+/*
+ * Load FPU context before returning to userspace.
+ */
+void switch_fpu_return(void)
+{
+ if (!static_cpu_has(X86_FEATURE_FPU))
+ return;
+
+ __fpregs_load_activate();
+}
+EXPORT_SYMBOL_GPL(switch_fpu_return);
+
+#ifdef CONFIG_X86_DEBUG_FPU
+/*
+ * If current FPU state according to its tracking (loaded FPU context on this
+ * CPU) is not valid then we must have TIF_NEED_FPU_LOAD set so the context is
+ * loaded on return to userland.
+ */
+void fpregs_assert_state_consistent(void)
+{
+ struct fpu *fpu = ¤t->thread.fpu;
+
+ if (test_thread_flag(TIF_NEED_FPU_LOAD))
+ return;
+
+ WARN_ON_FPU(!fpregs_state_valid(fpu, smp_processor_id()));
+}
+EXPORT_SYMBOL_GPL(fpregs_assert_state_consistent);
+#endif
+
+void fpregs_mark_activate(void)
+{
+ struct fpu *fpu = ¤t->thread.fpu;
+
+ fpregs_activate(fpu);
+ fpu->last_cpu = smp_processor_id();
+ clear_thread_flag(TIF_NEED_FPU_LOAD);
+}
+EXPORT_SYMBOL_GPL(fpregs_mark_activate);
+
/*
* x87 math exception handling:
*/
--
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