[PATCH] RISC-V: KVM: AIA: Initialize per-CPU HGEI free_bitmap only once

[PATCH] RISC-V: KVM: AIA: Initialize per-CPU HGEI free_bitmap only once

[GUO Ren (XuanTie)]

kvm_riscv_aia_enable() may run more than once on the same CPU.  The
per-CPU free_bitmap only needs to be initialized once, from the HGEIE
width discovered on that CPU.  Perform the HGEIE probe and bitmap
setup only on the first call, and set free_bitmap_initialized after
the bitmap has been populated.

Signed-off-by: GUO Ren (XuanTie) <guoren@kernel.org>
---
 arch/riscv/kvm/aia.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kvm/aia.c b/arch/riscv/kvm/aia.c
index b3b466e4db33..a65748321f7d 100644
--- a/arch/riscv/kvm/aia.c
+++ b/arch/riscv/kvm/aia.c
@@ -610,6 +610,9 @@ void kvm_riscv_aia_enable(void)
 	lc = (gc) ? this_cpu_ptr(gc->local) : NULL;
 	hgctrl = this_cpu_ptr(&aia_hgei);
 
+	if (hgctrl->free_bitmap_initialized)
+		goto skip_hgctrl_init;
+
 	/* Figure-out number of bits in HGEIE */
 	csr_write(CSR_HGEIE, -1UL);
 	hgctrl->nr_hgei = fls_long(csr_read(CSR_HGEIE));
@@ -634,12 +637,11 @@ void kvm_riscv_aia_enable(void)
 	} while (!atomic_try_cmpxchg(&kvm_riscv_aia_nr_hgei, &aia_nr_hgei, hgctrl->nr_hgei));
 
 	raw_spin_lock_irqsave(&hgctrl->lock, flags);
-	if (!hgctrl->free_bitmap_initialized) {
-		hgctrl->free_bitmap = (hgctrl->nr_hgei) ? GENMASK_ULL(hgctrl->nr_hgei, 1) : 0;
-		hgctrl->free_bitmap_initialized = true;
-	}
+	hgctrl->free_bitmap = (hgctrl->nr_hgei) ? GENMASK_ULL(hgctrl->nr_hgei, 1) : 0;
+	hgctrl->free_bitmap_initialized = true;
 	raw_spin_unlock_irqrestore(&hgctrl->lock, flags);
 
+skip_hgctrl_init:
 	csr_write(CSR_HVICTL, aia_hvictl_value(false));
 	csr_write(CSR_HVIPRIO1, 0x0);
 	csr_write(CSR_HVIPRIO2, 0x0);

---
base-commit: 93f51579e7df248780214094418f205253383cc5
change-id: 20260924-free_bitmap_initialized-abdc94a528fb

Best regards,
--  
GUO Ren (XuanTie) <guoren@kernel.org>