[3/4] ACPI: replace casts by container_of()

Commit Message

Jan Beulich Jan. 8, 2021, 1:44 p.m. UTC

The latter is slightly more type-safe. Also add const where possible,
including without need to touch further code. Additionally replace an
adjacent unnecessary use of u16.

Signed-off-by: Jan Beulich <[e-mail]>
---
Intentionally not paying attention to line length in acpi/tables.c, as
adjacent code violates the limit already quite heavily.

Patch

--- a/xen/arch/x86/acpi/boot.c
+++ b/xen/arch/x86/acpi/boot.c
@@ -63,9 +63,8 @@  static u64 acpi_lapic_addr __initdata =
 
 static int __init acpi_parse_madt(struct acpi_table_header *table)
 {
-	struct acpi_table_madt *madt;
-
-	madt = (struct acpi_table_madt *)table;
+	struct acpi_table_madt *madt =
+		container_of(table, struct acpi_table_madt, header);
 
 	if (madt->address) {
 		acpi_lapic_addr = (u64) madt->address;
@@ -277,7 +276,8 @@  acpi_parse_nmi_src(struct acpi_subtable_
 
 static int __init acpi_parse_hpet(struct acpi_table_header *table)
 {
-	struct acpi_table_hpet *hpet_tbl = (struct acpi_table_hpet *)table;
+	const struct acpi_table_hpet *hpet_tbl =
+		container_of(table, const struct acpi_table_hpet, header);
 
 	if (hpet_tbl->address.space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
 		printk(KERN_WARNING PREFIX "HPET timers must be located in "
@@ -471,7 +471,8 @@  acpi_fadt_parse_sleep_info(const struct
 
 static int __init acpi_parse_fadt(struct acpi_table_header *table)
 {
-	struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;
+	const struct acpi_table_fadt *fadt =
+		container_of(table, const struct acpi_table_fadt, header);
 
 #ifdef	CONFIG_ACPI_INTERPRETER
 	/* initialize sci_int early for INT_SRC_OVR MADT parsing */
--- a/xen/drivers/acpi/tables.c
+++ b/xen/drivers/acpi/tables.c
@@ -55,8 +55,9 @@  void __init acpi_table_print_madt_entry(
 	case ACPI_MADT_TYPE_LOCAL_APIC:
 		if (acpi_verbose)
 		{
-			struct acpi_madt_local_apic *p =
-			    (struct acpi_madt_local_apic *)header;
+			const struct acpi_madt_local_apic *p =
+			    container_of(header, const struct acpi_madt_local_apic, header);
+
 			printk(KERN_INFO PREFIX
 			       "LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
 			       p->processor_id, p->id,
@@ -67,8 +68,9 @@  void __init acpi_table_print_madt_entry(
 	case ACPI_MADT_TYPE_LOCAL_X2APIC:
 		if (acpi_verbose)
 		{
-			struct acpi_madt_local_x2apic *p =
-			    (struct acpi_madt_local_x2apic *)header;
+			const struct acpi_madt_local_x2apic *p =
+			    container_of(header, const struct acpi_madt_local_x2apic, header);
+
 			printk(KERN_INFO PREFIX
 			       "X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
 			       p->local_apic_id, p->uid,
@@ -79,8 +81,9 @@  void __init acpi_table_print_madt_entry(
 
 	case ACPI_MADT_TYPE_IO_APIC:
 		{
-			struct acpi_madt_io_apic *p =
-			    (struct acpi_madt_io_apic *)header;
+			const struct acpi_madt_io_apic *p =
+			    container_of(header, const struct acpi_madt_io_apic, header);
+
 			printk(KERN_INFO PREFIX
 			       "IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
 			       p->id, p->address, p->global_irq_base);
@@ -89,8 +92,9 @@  void __init acpi_table_print_madt_entry(
 
 	case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
 		{
-			struct acpi_madt_interrupt_override *p =
-			    (struct acpi_madt_interrupt_override *)header;
+			const struct acpi_madt_interrupt_override *p =
+			    container_of(header, const struct acpi_madt_interrupt_override, header);
+
 			printk(KERN_INFO PREFIX
 			       "INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
 			       p->bus, p->source_irq, p->global_irq,
@@ -108,8 +112,9 @@  void __init acpi_table_print_madt_entry(
 
 	case ACPI_MADT_TYPE_NMI_SOURCE:
 		{
-			struct acpi_madt_nmi_source *p =
-			    (struct acpi_madt_nmi_source *)header;
+			const struct acpi_madt_nmi_source *p =
+			    container_of(header, const struct acpi_madt_nmi_source, header);
+
 			printk(KERN_INFO PREFIX
 			       "NMI_SRC (%s %s global_irq %d)\n",
 			       mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
@@ -121,8 +126,9 @@  void __init acpi_table_print_madt_entry(
 	case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
 		if (acpi_verbose)
 		{
-			struct acpi_madt_local_apic_nmi *p =
-			    (struct acpi_madt_local_apic_nmi *)header;
+			const struct acpi_madt_local_apic_nmi *p =
+			    container_of(header, const struct acpi_madt_local_apic_nmi, header);
+
 			printk(KERN_INFO PREFIX
 			       "LAPIC_NMI (acpi_id[0x%02x] %s %s lint[%#x])\n",
 			       p->processor_id,
@@ -135,12 +141,10 @@  void __init acpi_table_print_madt_entry(
 	case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
 		if (acpi_verbose)
 		{
-			u16 polarity, trigger;
-			struct acpi_madt_local_x2apic_nmi *p =
-			    (struct acpi_madt_local_x2apic_nmi *)header;
-
-			polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
-			trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
+			const struct acpi_madt_local_x2apic_nmi *p =
+			    container_of(header, const struct acpi_madt_local_x2apic_nmi, header);
+			unsigned int polarity = MASK_EXTR(p->inti_flags, ACPI_MADT_POLARITY_MASK);
+			unsigned int trigger = MASK_EXTR(p->inti_flags, ACPI_MADT_TRIGGER_MASK);
 
 			printk(KERN_INFO PREFIX
 			       "X2APIC_NMI (uid[0x%02x] %s %s lint[%#x])\n",
@@ -153,8 +157,9 @@  void __init acpi_table_print_madt_entry(
 
 	case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
 		{
-			struct acpi_madt_local_apic_override *p =
-			    (struct acpi_madt_local_apic_override *)header;
+			const struct acpi_madt_local_apic_override *p =
+			    container_of(header, const struct acpi_madt_local_apic_override, header);
+
 			printk(KERN_INFO PREFIX
 			       "LAPIC_ADDR_OVR (address[%p])\n",
 			       (void *)(unsigned long)p->address);
@@ -163,8 +168,9 @@  void __init acpi_table_print_madt_entry(
 
 	case ACPI_MADT_TYPE_IO_SAPIC:
 		{
-			struct acpi_madt_io_sapic *p =
-			    (struct acpi_madt_io_sapic *)header;
+			const struct acpi_madt_io_sapic *p =
+			    container_of(header, const struct acpi_madt_io_sapic, header);
+
 			printk(KERN_INFO PREFIX
 			       "IOSAPIC (id[%#x] address[%p] gsi_base[%d])\n",
 			       p->id, (void *)(unsigned long)p->address,
@@ -175,8 +181,9 @@  void __init acpi_table_print_madt_entry(
 	case ACPI_MADT_TYPE_LOCAL_SAPIC:
 		if (acpi_verbose)
 		{
-			struct acpi_madt_local_sapic *p =
-			    (struct acpi_madt_local_sapic *)header;
+			const struct acpi_madt_local_sapic *p =
+			    container_of(header, const struct acpi_madt_local_sapic, header);
+
 			printk(KERN_INFO PREFIX
 			       "LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
 			       p->processor_id, p->id, p->eid,
@@ -186,8 +193,9 @@  void __init acpi_table_print_madt_entry(
 
 	case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
 		{
-			struct acpi_madt_interrupt_source *p =
-			    (struct acpi_madt_interrupt_source *)header;
+			const struct acpi_madt_interrupt_source *p =
+			    container_of(header, const struct acpi_madt_interrupt_source, header);
+
 			printk(KERN_INFO PREFIX
 			       "PLAT_INT_SRC (%s %s type[%#x] id[0x%04x] eid[%#x] iosapic_vector[%#x] global_irq[%#x]\n",
 			       mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],