# HG changeset patch
# User Ian Campbell <ian.campbell@xxxxxxxxxx>
# Date 1305548021 -3600
# Node ID 87084ca76c9c24ab0306d39a70d5daa65edf09ba
# Parent 216c2efeb246041cc39e4dcb675368e7e3182b85
x86/ioapic: avoid gcc 4.6 warnings about uninitialised variables
gcc 4.6 complains:
io_apic.c: In function 'restore_IO_APIC_setup':
/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm/io_apic.h:150:26:
error: '*((void *)&entry+4)' may be used uninitialized in this
function [-Werror=uninitialized]
io_apic.c:221:32: note: '*((void *)&entry+4)' was declared
here
/build/user-xen_4.1.0-3-amd64-zSon7K/xen-4.1.0/debian/build/build-hypervisor_amd64_amd64/xen/include/asm/io_apic.h:150:26:
error: 'entry' may be used uninitialized in this function
[-Werror=uninitialized]
io_apic.c:221:32: note: 'entry' was declared here
cc1: all warnings being treated as errors
Add functions to read/write an entire IO APIC entry using an explicit
union to allow gcc to spot the initialisation.
Reported as Debian bug #625438, thanks to Matthias Klose.
Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
diff -r 216c2efeb246 -r 87084ca76c9c xen/arch/x86/io_apic.c
--- a/xen/arch/x86/io_apic.c Mon May 16 13:12:03 2011 +0100
+++ b/xen/arch/x86/io_apic.c Mon May 16 13:13:41 2011 +0100
@@ -156,6 +156,52 @@
return 0;
}
+union entry_union {
+ struct { u32 w1, w2; };
+ struct IO_APIC_route_entry entry;
+};
+
+static struct IO_APIC_route_entry __ioapic_read_entry(int apic, int pin, int
raw)
+{
+ unsigned int (*read)(unsigned int, unsigned int)
+ = raw ? __io_apic_read : io_apic_read;
+ union entry_union eu;
+ eu.w1 = (*read)(apic, 0x10 + 2 * pin);
+ eu.w2 = (*read)(apic, 0x11 + 2 * pin);
+ return eu.entry;
+}
+
+static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin, int raw)
+{
+ struct IO_APIC_route_entry entry;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ioapic_lock, flags);
+ entry = __ioapic_read_entry(apic, pin, raw);
+ spin_unlock_irqrestore(&ioapic_lock, flags);
+ return entry;
+}
+
+static void
+__ioapic_write_entry(int apic, int pin, int raw, struct IO_APIC_route_entry e)
+{
+ void (*write)(unsigned int, unsigned int, unsigned int)
+ = raw ? __io_apic_write : io_apic_write;
+ union entry_union eu = {{0, 0}};
+
+ eu.entry = e;
+ (*write)(apic, 0x11 + 2*pin, eu.w2);
+ (*write)(apic, 0x10 + 2*pin, eu.w1);
+}
+
+static void ioapic_write_entry(int apic, int pin, int raw, struct
IO_APIC_route_entry e)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&ioapic_lock, flags);
+ __ioapic_write_entry(apic, pin, raw, e);
+ spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
/*
* Saves all the IO-APIC RTE's
*/
@@ -170,12 +216,8 @@
if (!ioapic_entries[apic])
return -ENOMEM;
- for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
- *(((int *)&ioapic_entries[apic][pin])+0) =
- __io_apic_read(apic, 0x10+pin*2);
- *(((int *)&ioapic_entries[apic][pin])+1) =
- __io_apic_read(apic, 0x11+pin*2);
- }
+ for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
+ ioapic_entries[apic][pin] = __ioapic_read_entry(apic, pin, 1);
}
return 0;
@@ -197,16 +239,12 @@
for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
struct IO_APIC_route_entry entry;
- unsigned long flags;
entry = ioapic_entries[apic][pin];
if (!entry.mask) {
entry.mask = 1;
- spin_lock_irqsave(&ioapic_lock, flags);
- __io_apic_write(apic, 0x11+2*pin, *(((int *)&entry)+1));
- __io_apic_write(apic, 0x10+2*pin, *(((int *)&entry)+0));
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ ioapic_write_entry(apic, pin, 1, entry);
}
}
}
@@ -218,8 +256,6 @@
int restore_IO_APIC_setup(struct IO_APIC_route_entry **ioapic_entries)
{
int apic, pin;
- unsigned long flags;
- struct IO_APIC_route_entry entry;
if (!ioapic_entries)
return -ENOMEM;
@@ -229,11 +265,7 @@
return -ENOMEM;
for (pin = 0; pin < nr_ioapic_registers[apic]; pin++)
- entry = ioapic_entries[apic][pin];
- spin_lock_irqsave(&ioapic_lock, flags);
- __io_apic_write(apic, 0x11+2*pin, *(((int *)&entry)+1));
- __io_apic_write(apic, 0x10+2*pin, *(((int *)&entry)+0));
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ ioapic_write_entry(apic, pin, 1, ioapic_entries[apic][pin]);
}
return 0;
@@ -338,18 +370,10 @@
#define clear_IO_APIC_pin_raw(a,p) __clear_IO_APIC_pin(a,p,1)
static void __clear_IO_APIC_pin(unsigned int apic, unsigned int pin, int raw)
{
- unsigned int (*read)(unsigned int, unsigned int)
- = raw ? __io_apic_read : io_apic_read;
- void (*write)(unsigned int, unsigned int, unsigned int)
- = raw ? __io_apic_write : io_apic_write;
struct IO_APIC_route_entry entry;
- unsigned long flags;
-
+
/* Check delivery_mode to be sure we're not clearing an SMI pin */
- spin_lock_irqsave(&ioapic_lock, flags);
- *(((int*)&entry) + 0) = (*read)(apic, 0x10 + 2 * pin);
- *(((int*)&entry) + 1) = (*read)(apic, 0x11 + 2 * pin);
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ entry = ioapic_read_entry(apic, pin, raw);
if (entry.delivery_mode == dest_SMI)
return;
@@ -358,10 +382,7 @@
*/
memset(&entry, 0, sizeof(entry));
entry.mask = 1;
- spin_lock_irqsave(&ioapic_lock, flags);
- (*write)(apic, 0x10 + 2 * pin, *(((int *)&entry) + 0));
- (*write)(apic, 0x11 + 2 * pin, *(((int *)&entry) + 1));
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ ioapic_write_entry(apic, pin, raw, entry);
}
static void clear_IO_APIC (void)
@@ -990,11 +1011,10 @@
SET_DEST(entry.dest.dest32, entry.dest.logical.logical_dest,
cpu_mask_to_apicid(&cfg->cpu_mask));
spin_lock_irqsave(&ioapic_lock, flags);
- io_apic_write(apic, 0x11+2*pin, *(((int *)&entry)+1));
- io_apic_write(apic, 0x10+2*pin, *(((int *)&entry)+0));
+ __ioapic_write_entry(apic, pin, 0, entry);
set_native_irq_info(irq, TARGET_CPUS);
spin_unlock_irqrestore(&ioapic_lock, flags);
- }
+ }
}
if (!first_notcon)
@@ -1007,7 +1027,6 @@
static void __init setup_ExtINT_IRQ0_pin(unsigned int apic, unsigned int pin,
int vector)
{
struct IO_APIC_route_entry entry;
- unsigned long flags;
memset(&entry,0,sizeof(entry));
@@ -1038,10 +1057,7 @@
/*
* Add it to the IO-APIC irq-routing table:
*/
- spin_lock_irqsave(&ioapic_lock, flags);
- io_apic_write(apic, 0x11+2*pin, *(((int *)&entry)+1));
- io_apic_write(apic, 0x10+2*pin, *(((int *)&entry)+0));
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ ioapic_write_entry(apic, pin, 0, entry);
enable_8259A_irq(0);
}
@@ -1148,10 +1164,7 @@
for (i = 0; i <= reg_01.bits.entries; i++) {
struct IO_APIC_route_entry entry;
- spin_lock_irqsave(&ioapic_lock, flags);
- *(((int *)&entry)+0) = io_apic_read(apic, 0x10+i*2);
- *(((int *)&entry)+1) = io_apic_read(apic, 0x11+i*2);
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ entry = ioapic_read_entry(apic, i, 0);
printk(KERN_DEBUG " %02x %03X %02X ",
i,
@@ -1212,7 +1225,6 @@
{
int i8259_apic, i8259_pin;
int i, apic;
- unsigned long flags;
/* Initialise dynamic irq_2_pin free list. */
irq_2_pin = xmalloc_array(struct irq_pin_list, PIN_MAP_SIZE);
@@ -1227,12 +1239,7 @@
int pin;
/* See if any of the pins is in ExtINT mode */
for (pin = 0; pin < nr_ioapic_registers[apic]; pin++) {
- struct IO_APIC_route_entry entry;
- spin_lock_irqsave(&ioapic_lock, flags);
- *(((int *)&entry) + 0) = io_apic_read(apic, 0x10 + 2 * pin);
- *(((int *)&entry) + 1) = io_apic_read(apic, 0x11 + 2 * pin);
- spin_unlock_irqrestore(&ioapic_lock, flags);
-
+ struct IO_APIC_route_entry entry = ioapic_read_entry(apic, pin, 0);
/* If the interrupt line is enabled and in ExtInt mode
* I have found the pin where the i8259 is connected.
@@ -1288,7 +1295,6 @@
*/
if (ioapic_i8259.pin != -1) {
struct IO_APIC_route_entry entry;
- unsigned long flags;
memset(&entry, 0, sizeof(entry));
entry.mask = 0; /* Enabled */
@@ -1305,12 +1311,7 @@
/*
* Add it to the IO-APIC irq-routing table:
*/
- spin_lock_irqsave(&ioapic_lock, flags);
- io_apic_write(ioapic_i8259.apic, 0x11+2*ioapic_i8259.pin,
- *(((int *)&entry)+1));
- io_apic_write(ioapic_i8259.apic, 0x10+2*ioapic_i8259.pin,
- *(((int *)&entry)+0));
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ ioapic_write_entry(ioapic_i8259.apic, ioapic_i8259.pin, 0, entry);
}
disconnect_bsp_APIC(ioapic_i8259.pin != -1);
}
@@ -1838,17 +1839,13 @@
int apic, pin, i;
struct IO_APIC_route_entry entry0, entry1;
unsigned char save_control, save_freq_select;
- unsigned long flags;
pin = find_isa_irq_pin(8, mp_INT);
apic = find_isa_irq_apic(8, mp_INT);
if (pin == -1)
return;
- spin_lock_irqsave(&ioapic_lock, flags);
- *(((int *)&entry0) + 1) = io_apic_read(apic, 0x11 + 2 * pin);
- *(((int *)&entry0) + 0) = io_apic_read(apic, 0x10 + 2 * pin);
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ entry0 = ioapic_read_entry(apic, pin, 0);
clear_IO_APIC_pin(apic, pin);
memset(&entry1, 0, sizeof(entry1));
@@ -1862,10 +1859,7 @@
entry1.trigger = 0;
entry1.vector = 0;
- spin_lock_irqsave(&ioapic_lock, flags);
- io_apic_write(apic, 0x11 + 2 * pin, *(((int *)&entry1) + 1));
- io_apic_write(apic, 0x10 + 2 * pin, *(((int *)&entry1) + 0));
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ ioapic_write_entry(apic, pin, 0, entry1);
save_control = CMOS_READ(RTC_CONTROL);
save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
@@ -1884,10 +1878,7 @@
CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
clear_IO_APIC_pin(apic, pin);
- spin_lock_irqsave(&ioapic_lock, flags);
- io_apic_write(apic, 0x11 + 2 * pin, *(((int *)&entry0) + 1));
- io_apic_write(apic, 0x10 + 2 * pin, *(((int *)&entry0) + 0));
- spin_unlock_irqrestore(&ioapic_lock, flags);
+ ioapic_write_entry(apic, pin, 0, entry0);
}
/*
@@ -2262,8 +2253,7 @@
disable_8259A_irq(irq);
spin_lock_irqsave(&ioapic_lock, flags);
- io_apic_write(ioapic, 0x11+2*pin, *(((int *)&entry)+1));
- io_apic_write(ioapic, 0x10+2*pin, *(((int *)&entry)+0));
+ __ioapic_write_entry(ioapic, pin, 0, entry);
set_native_irq_info(irq, TARGET_CPUS);
spin_unlock(&ioapic_lock);
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