From 9c978c882984e879f6f418733fe95a16310f1373 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Thu, 23 May 2024 19:50:57 -0400
Subject: kernel/amd64: pmap: Add support for TLB shootdowns
Signed-off-by: Ian Moffett <ian@osmora.org>
---
sys/arch/amd64/amd64/pmap.c | 58 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)
(limited to 'sys/arch')
diff --git a/sys/arch/amd64/amd64/pmap.c b/sys/arch/amd64/amd64/pmap.c
index 8af6d39..468cca4 100644
--- a/sys/arch/amd64/amd64/pmap.c
+++ b/sys/arch/amd64/amd64/pmap.c
@@ -31,7 +31,12 @@
#include <vm/vm.h>
#include <vm/physseg.h>
#include <sys/cdefs.h>
+#include <sys/cpu.h>
+#include <sys/intr.h>
#include <machine/tlb.h>
+#include <machine/lapic.h>
+#include <machine/sysvec.h>
+#include <machine/idt.h>
#include <assert.h>
#include <string.h>
@@ -52,6 +57,45 @@
#define PTE_GLOBAL __BIT(8)
#define PTE_NX __BIT(63) /* Execute-disable */
+__attr(interrupt) static void
+tlb_shootdown_isr(void *sf)
+{
+ struct cpu_info *ci = this_cpu();
+ struct intr_info *intr_info = ci->tlb_shootdown;
+
+ /* Setup interrupt information if needed */
+ if (ci->tlb_shootdown == NULL) {
+ intr_info = intr_info_alloc("TLB-Shootdown", "LAPIC-IPI");
+ intr_info->affinity = ci->id;
+
+ ci->tlb_shootdown = intr_info;
+ intr_register(intr_info);
+ }
+
+ ++intr_info->count;
+ tlb_flush(ci->tlb_flush_ptr);
+
+ ci->tlb_flush_ptr = 0;
+ lapic_send_eoi();
+}
+
+static void
+tlb_shootdown(vaddr_t flush_va)
+{
+ struct cpu_info *curcpu, *ci = NULL;
+ size_t idx = 0;
+
+ curcpu = this_cpu();
+ while ((ci = cpu_get(idx++)) != NULL) {
+ if (ci->id == curcpu->id)
+ continue;
+
+ ci->tlb_flush_ptr = flush_va;
+ }
+
+ lapic_send_ipi(0, IPI_SHORTHAND_OTHERS, SYSVEC_TLB);
+}
+
/*
* Convert pmap prot flags to PTE flags.
*/
@@ -160,6 +204,17 @@ pmap_modify_tbl(struct vm_ctx *ctx, struct vas vas, vaddr_t va, size_t val)
/* Map our page */
tbl[pmap_get_level_index(1, va)] = val;
+
+ /*
+ * Do TLB shootdown if CPUs are listed.
+ *
+ * XXX: Some might not be listed during early
+ * startup.
+ */
+ if (cpu_get(0) != NULL) {
+ tlb_shootdown(va);
+ }
+
tlb_flush(va);
done:
return status;
@@ -261,5 +316,8 @@ pmap_read_vas(void)
int
pmap_init(struct vm_ctx *ctx)
{
+ idt_set_desc(SYSVEC_TLB, IDT_INT_GATE_FLAGS,
+ (uintptr_t)tlb_shootdown_isr, 0);
+
return 0;
}
--
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