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-rw-r--r--Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-ioapic.txt26
-rw-r--r--Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-ioapic.yaml60
-rw-r--r--Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-lapic.yaml71
-rw-r--r--arch/x86/Kconfig4
-rw-r--r--arch/x86/include/asm/apic.h3
-rw-r--r--arch/x86/kernel/apic/apic.c13
-rw-r--r--arch/x86/kernel/devicetree.c18
7 files changed, 152 insertions, 43 deletions
diff --git a/Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-ioapic.txt b/Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-ioapic.txt
deleted file mode 100644
index 7d19f494f19a..000000000000
--- a/Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-ioapic.txt
+++ /dev/null
@@ -1,26 +0,0 @@
-Interrupt chips
----------------
-
-* Intel I/O Advanced Programmable Interrupt Controller (IO APIC)
-
- Required properties:
- --------------------
- compatible = "intel,ce4100-ioapic";
- #interrupt-cells = <2>;
-
- Device's interrupt property:
-
- interrupts = <P S>;
-
- The first number (P) represents the interrupt pin which is wired to the
- IO APIC. The second number (S) represents the sense of interrupt which
- should be configured and can be one of:
- 0 - Edge Rising
- 1 - Level Low
- 2 - Level High
- 3 - Edge Falling
-
-* Local APIC
- Required property:
-
- compatible = "intel,ce4100-lapic";
diff --git a/Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-ioapic.yaml b/Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-ioapic.yaml
new file mode 100644
index 000000000000..39ab8cdd19b4
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-ioapic.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/interrupt-controller/intel,ce4100-ioapic.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Intel I/O Advanced Programmable Interrupt Controller (IO APIC)
+
+maintainers:
+ - Rahul Tanwar <rtanwar@maxlinear.com>
+
+description: |
+ Intel's Advanced Programmable Interrupt Controller (APIC) is a
+ family of interrupt controllers. The APIC is a split
+ architecture design, with a local component (LAPIC) integrated
+ into the processor itself and an external I/O APIC. Local APIC
+ (lapic) receives interrupts from the processor's interrupt pins,
+ from internal sources and from an external I/O APIC (ioapic).
+ And it sends these to the processor core for handling.
+ See [1] Chapter 8 for more details.
+
+ Many of the Intel's generic devices like hpet, ioapic, lapic have
+ the ce4100 name in their compatible property names because they
+ first appeared in CE4100 SoC.
+
+ This schema defines bindings for I/O APIC interrupt controller.
+
+ [1] https://pdos.csail.mit.edu/6.828/2008/readings/ia32/IA32-3A.pdf
+
+properties:
+ compatible:
+ const: intel,ce4100-ioapic
+
+ reg:
+ maxItems: 1
+
+ interrupt-controller: true
+
+ '#interrupt-cells':
+ const: 2
+
+ interrupts:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - interrupt-controller
+ - '#interrupt-cells'
+
+additionalProperties: false
+
+examples:
+ - |
+ ioapic1: interrupt-controller@fec00000 {
+ compatible = "intel,ce4100-ioapic";
+ reg = <0xfec00000 0x1000>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ };
diff --git a/Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-lapic.yaml b/Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-lapic.yaml
new file mode 100644
index 000000000000..d2d0145cb889
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/intel,ce4100-lapic.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/interrupt-controller/intel,ce4100-lapic.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Intel Local Advanced Programmable Interrupt Controller (LAPIC)
+
+maintainers:
+ - Rahul Tanwar <rtanwar@maxlinear.com>
+
+description: |
+ Intel's Advanced Programmable Interrupt Controller (APIC) is a
+ family of interrupt controllers. The APIC is a split
+ architecture design, with a local component (LAPIC) integrated
+ into the processor itself and an external I/O APIC. Local APIC
+ (lapic) receives interrupts from the processor's interrupt pins,
+ from internal sources and from an external I/O APIC (ioapic).
+ And it sends these to the processor core for handling.
+ See [1] Chapter 8 for more details.
+
+ Many of the Intel's generic devices like hpet, ioapic, lapic have
+ the ce4100 name in their compatible property names because they
+ first appeared in CE4100 SoC.
+
+ This schema defines bindings for local APIC interrupt controller.
+
+ [1] https://pdos.csail.mit.edu/6.828/2008/readings/ia32/IA32-3A.pdf
+
+properties:
+ compatible:
+ const: intel,ce4100-lapic
+
+ reg:
+ maxItems: 1
+
+ interrupt-controller: true
+
+ '#interrupt-cells':
+ const: 2
+
+ intel,virtual-wire-mode:
+ description: Intel defines a few possible interrupt delivery
+ modes. With respect to boot/init time, mainly two interrupt
+ delivery modes are possible.
+ PIC Mode - Legacy external 8259 compliant PIC interrupt controller.
+ Virtual Wire Mode - use lapic as virtual wire interrupt delivery mode.
+ For ACPI or MPS spec compliant systems, it is figured out by some read
+ only bit field/s available in their respective defined data structures.
+ For OF based systems, it is by default set to PIC mode.
+ But if this optional boolean property is set, then the interrupt delivery
+ mode is configured to virtual wire compatibility mode.
+ type: boolean
+
+required:
+ - compatible
+ - reg
+ - interrupt-controller
+ - '#interrupt-cells'
+
+additionalProperties: false
+
+examples:
+ - |
+ lapic0: interrupt-controller@fee00000 {
+ compatible = "intel,ce4100-lapic";
+ reg = <0xfee00000 0x1000>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ intel,virtual-wire-mode;
+ };
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e2eebb193ee0..68a2a04c02e5 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -463,8 +463,8 @@ config X86_X2APIC
Some Intel systems circa 2022 and later are locked into x2APIC mode
and can not fall back to the legacy APIC modes if SGX or TDX are
- enabled in the BIOS. They will be unable to boot without enabling
- this option.
+ enabled in the BIOS. They will boot with very reduced functionality
+ without enabling this option.
If you don't know what to do here, say N.
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 3415321c8240..3216da7074ba 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -249,7 +249,6 @@ static inline u64 native_x2apic_icr_read(void)
extern int x2apic_mode;
extern int x2apic_phys;
extern void __init x2apic_set_max_apicid(u32 apicid);
-extern void __init check_x2apic(void);
extern void x2apic_setup(void);
static inline int x2apic_enabled(void)
{
@@ -258,13 +257,13 @@ static inline int x2apic_enabled(void)
#define x2apic_supported() (boot_cpu_has(X86_FEATURE_X2APIC))
#else /* !CONFIG_X86_X2APIC */
-static inline void check_x2apic(void) { }
static inline void x2apic_setup(void) { }
static inline int x2apic_enabled(void) { return 0; }
#define x2apic_mode (0)
#define x2apic_supported() (0)
#endif /* !CONFIG_X86_X2APIC */
+extern void __init check_x2apic(void);
struct irq_data;
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index c6876d3ea4b1..20d9a604da7c 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1931,16 +1931,19 @@ void __init check_x2apic(void)
}
}
#else /* CONFIG_X86_X2APIC */
-static int __init validate_x2apic(void)
+void __init check_x2apic(void)
{
if (!apic_is_x2apic_enabled())
- return 0;
+ return;
/*
- * Checkme: Can we simply turn off x2apic here instead of panic?
+ * Checkme: Can we simply turn off x2APIC here instead of disabling the APIC?
*/
- panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
+ pr_err("Kernel does not support x2APIC, please recompile with CONFIG_X86_X2APIC.\n");
+ pr_err("Disabling APIC, expect reduced performance and functionality.\n");
+
+ disable_apic = 1;
+ setup_clear_cpu_cap(X86_FEATURE_APIC);
}
-early_initcall(validate_x2apic);
static inline void try_to_enable_x2apic(int remap_mode) { }
static inline void __x2apic_enable(void) { }
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 5cd51f25f446..28da5dd83fc0 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -31,11 +31,6 @@ char __initdata cmd_line[COMMAND_LINE_SIZE];
int __initdata of_ioapic;
-void __init early_init_dt_add_memory_arch(u64 base, u64 size)
-{
- BUG();
-}
-
void __init add_dtb(u64 data)
{
initial_dtb = data + offsetof(struct setup_data, data);
@@ -167,7 +162,14 @@ static void __init dtb_lapic_setup(void)
return;
}
smp_found_config = 1;
- pic_mode = 1;
+ if (of_property_read_bool(dn, "intel,virtual-wire-mode")) {
+ pr_info("Virtual Wire compatibility mode.\n");
+ pic_mode = 0;
+ } else {
+ pr_info("IMCR and PIC compatibility mode.\n");
+ pic_mode = 1;
+ }
+
register_lapic_address(lapic_addr);
}
@@ -248,7 +250,7 @@ static void __init dtb_add_ioapic(struct device_node *dn)
ret = of_address_to_resource(dn, 0, &r);
if (ret) {
- printk(KERN_ERR "Can't obtain address from device node %pOF.\n", dn);
+ pr_err("Can't obtain address from device node %pOF.\n", dn);
return;
}
mp_register_ioapic(++ioapic_id, r.start, gsi_top, &cfg);
@@ -265,7 +267,7 @@ static void __init dtb_ioapic_setup(void)
of_ioapic = 1;
return;
}
- printk(KERN_ERR "Error: No information about IO-APIC in OF.\n");
+ pr_err("Error: No information about IO-APIC in OF.\n");
}
#else
static void __init dtb_ioapic_setup(void) {}