:: commit ab5936bd5833b9ba7c3d89a1f7077e55bcd79289
sys/lapic: Preserve LVT entries with SMI/INIT/reserved delivery modes
diff --git a/common/sys/lapic.c b/common/sys/lapic.c
index ddaa7f10..0efc1213 100644
--- a/common/sys/lapic.c
+++ b/common/sys/lapic.c
@@ -20,8 +20,8 @@
#define LAPIC_REG_TPR 0x080
#define LAPIC_REG_VERSION 0x030
-static uint32_t pending_lint0 = 0x00010000; // masked
-static uint32_t pending_lint1 = 0x00010000; // masked
+static uint32_t pending_lint0 = UINT32_MAX; // no override
+static uint32_t pending_lint1 = UINT32_MAX; // no override
static uint32_t lapic_madt_nmi_flags_to_lvt(uint16_t flags) {
uint32_t lvt = 0x10400; // masked + NMI delivery mode
@@ -43,14 +43,9 @@ static uint32_t lapic_madt_nmi_flags_to_lvt(uint16_t flags) {
return lvt;
}
-void lapic_prep_lint(struct madt *madt, uint32_t acpi_uid, bool is_bsp, bool x2apic) {
- // Set defaults
- if (is_bsp) {
- pending_lint0 = 0x00010700; // ExtINT delivery mode, masked
- } else {
- pending_lint0 = 0x00010000; // masked
- }
- pending_lint1 = 0x00010000; // masked
+void lapic_prep_lint(struct madt *madt, uint32_t acpi_uid, bool x2apic) {
+ pending_lint0 = UINT32_MAX; // no override
+ pending_lint1 = UINT32_MAX; // no override
// Walk MADT entries looking for NMI entries
for (uint8_t *madt_ptr = (uint8_t *)madt->madt_entries_begin;
@@ -109,6 +104,18 @@ void lapic_prep_lint(struct madt *madt, uint32_t acpi_uid, bool is_bsp, bool x2a
}
}
+static bool lvt_should_mask(uint32_t lvt) {
+ switch ((lvt >> 8) & 7) {
+ case 0b000: // Fixed
+ case 0b001: // Lowest Priority
+ case 0b100: // NMI
+ case 0b111: // ExtINT
+ return true;
+ default: // SMI, INIT, Reserved
+ return false;
+ }
+}
+
void lapic_configure_handoff_state(void) {
bool is_x2 = !!(rdmsr(0x1b) & (1 << 10));
@@ -119,38 +126,82 @@ void lapic_configure_handoff_state(void) {
max_lvt = (lapic_read(LAPIC_REG_VERSION) >> 16) & 0xff;
}
+ uint32_t lvt;
+
if (is_x2) {
x2apic_write(LAPIC_REG_SVR, 0x1ff);
x2apic_write(LAPIC_REG_TPR, 0);
if (max_lvt >= 6) {
- x2apic_write(LAPIC_REG_LVT_CMCI, 0x00010000);
+ lvt = x2apic_read(LAPIC_REG_LVT_CMCI);
+ if (lvt_should_mask(lvt)) {
+ x2apic_write(LAPIC_REG_LVT_CMCI, lvt | (1 << 16));
+ }
+ }
+ lvt = x2apic_read(LAPIC_REG_LVT_TIMER);
+ if (lvt_should_mask(lvt)) {
+ x2apic_write(LAPIC_REG_LVT_TIMER, lvt | (1 << 16));
}
- x2apic_write(LAPIC_REG_LVT_TIMER, 0x00010000);
if (max_lvt >= 5) {
- x2apic_write(LAPIC_REG_LVT_THERMAL, 0x00010000);
+ lvt = x2apic_read(LAPIC_REG_LVT_THERMAL);
+ if (lvt_should_mask(lvt)) {
+ x2apic_write(LAPIC_REG_LVT_THERMAL, lvt | (1 << 16));
+ }
}
if (max_lvt >= 4) {
- x2apic_write(LAPIC_REG_LVT_PMC, 0x00010000);
+ lvt = x2apic_read(LAPIC_REG_LVT_PMC);
+ if (lvt_should_mask(lvt)) {
+ x2apic_write(LAPIC_REG_LVT_PMC, lvt | (1 << 16));
+ }
+ }
+ lvt = x2apic_read(LAPIC_REG_LVT_ERROR);
+ if (lvt_should_mask(lvt)) {
+ x2apic_write(LAPIC_REG_LVT_ERROR, lvt | (1 << 16));
+ }
+ lvt = x2apic_read(LAPIC_REG_LVT_LINT0);
+ if (lvt_should_mask(lvt)) {
+ x2apic_write(LAPIC_REG_LVT_LINT0, pending_lint0 != UINT32_MAX ? pending_lint0 : lvt | (1 << 16));
+ }
+ lvt = x2apic_read(LAPIC_REG_LVT_LINT1);
+ if (lvt_should_mask(lvt)) {
+ x2apic_write(LAPIC_REG_LVT_LINT1, pending_lint1 != UINT32_MAX ? pending_lint1 : lvt | (1 << 16));
}
- x2apic_write(LAPIC_REG_LVT_ERROR, 0x00010000);
- x2apic_write(LAPIC_REG_LVT_LINT0, pending_lint0);
- x2apic_write(LAPIC_REG_LVT_LINT1, pending_lint1);
} else {
lapic_write(LAPIC_REG_SVR, 0x1ff);
lapic_write(LAPIC_REG_TPR, 0);
if (max_lvt >= 6) {
- lapic_write(LAPIC_REG_LVT_CMCI, 0x00010000);
+ lvt = lapic_read(LAPIC_REG_LVT_CMCI);
+ if (lvt_should_mask(lvt)) {
+ lapic_write(LAPIC_REG_LVT_CMCI, lvt | (1 << 16));
+ }
+ }
+ lvt = lapic_read(LAPIC_REG_LVT_TIMER);
+ if (lvt_should_mask(lvt)) {
+ lapic_write(LAPIC_REG_LVT_TIMER, lvt | (1 << 16));
}
- lapic_write(LAPIC_REG_LVT_TIMER, 0x00010000);
if (max_lvt >= 5) {
- lapic_write(LAPIC_REG_LVT_THERMAL, 0x00010000);
+ lvt = lapic_read(LAPIC_REG_LVT_THERMAL);
+ if (lvt_should_mask(lvt)) {
+ lapic_write(LAPIC_REG_LVT_THERMAL, lvt | (1 << 16));
+ }
}
if (max_lvt >= 4) {
- lapic_write(LAPIC_REG_LVT_PMC, 0x00010000);
+ lvt = lapic_read(LAPIC_REG_LVT_PMC);
+ if (lvt_should_mask(lvt)) {
+ lapic_write(LAPIC_REG_LVT_PMC, lvt | (1 << 16));
+ }
+ }
+ lvt = lapic_read(LAPIC_REG_LVT_ERROR);
+ if (lvt_should_mask(lvt)) {
+ lapic_write(LAPIC_REG_LVT_ERROR, lvt | (1 << 16));
+ }
+ lvt = lapic_read(LAPIC_REG_LVT_LINT0);
+ if (lvt_should_mask(lvt)) {
+ lapic_write(LAPIC_REG_LVT_LINT0, pending_lint0 != UINT32_MAX ? pending_lint0 : lvt | (1 << 16));
+ }
+ lvt = lapic_read(LAPIC_REG_LVT_LINT1);
+ if (lvt_should_mask(lvt)) {
+ lapic_write(LAPIC_REG_LVT_LINT1, pending_lint1 != UINT32_MAX ? pending_lint1 : lvt | (1 << 16));
}
- lapic_write(LAPIC_REG_LVT_ERROR, 0x00010000);
- lapic_write(LAPIC_REG_LVT_LINT0, pending_lint0);
- lapic_write(LAPIC_REG_LVT_LINT1, pending_lint1);
}
}
@@ -209,7 +260,7 @@ void lapic_configure_bsp(void) {
}
found:
- lapic_prep_lint(madt, bsp_acpi_uid, true, is_x2);
+ lapic_prep_lint(madt, bsp_acpi_uid, is_x2);
lapic_configure_handoff_state();
}
diff --git a/common/sys/lapic.h b/common/sys/lapic.h
index 9edcfd69..876cc05c 100644
--- a/common/sys/lapic.h
+++ b/common/sys/lapic.h
@@ -26,7 +26,7 @@ uint64_t x2apic_read(uint32_t reg);
void x2apic_write(uint32_t reg, uint64_t data);
void lapic_configure_bsp(void);
-void lapic_prep_lint(struct madt *madt, uint32_t acpi_uid, bool is_bsp, bool x2apic);
+void lapic_prep_lint(struct madt *madt, uint32_t acpi_uid, bool x2apic);
void lapic_configure_handoff_state(void);
void init_io_apics(void);
diff --git a/common/sys/smp.c b/common/sys/smp.c
index 4ecc3049..403957c8 100644
--- a/common/sys/smp.c
+++ b/common/sys/smp.c
@@ -252,7 +252,7 @@ struct limine_mp_info *init_smp(size_t *cpu_count,
// Set up per-AP LINT values before starting
if (smp_configure_apic) {
- lapic_prep_lint(madt, lapic->acpi_processor_uid, false, x2apic);
+ lapic_prep_lint(madt, lapic->acpi_processor_uid, x2apic);
}
// Try to start the AP
@@ -297,7 +297,7 @@ struct limine_mp_info *init_smp(size_t *cpu_count,
// Set up per-AP LINT values before starting
if (smp_configure_apic) {
- lapic_prep_lint(madt, x2lapic->acpi_processor_uid, false, true);
+ lapic_prep_lint(madt, x2lapic->acpi_processor_uid, true);
}
// Try to start the AP
