[RFC Patch V1 1/4] x86, irq: refine mp_register_ioapic() to prepare for IOAPIC hotplug
From: Jiang Liu
Date: Tue May 27 2014 - 04:24:01 EST
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/io_apic.h | 4 +-
arch/x86/kernel/apic/io_apic.c | 143 ++++++++++++++++++++++++++--------------
2 files changed, 94 insertions(+), 53 deletions(-)
diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 6b40122bec0c..64379c285435 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -181,8 +181,8 @@ extern int mp_find_ioapic_pin(int ioapic, u32 gsi);
extern u32 mp_pin_to_gsi(int ioapic, int pin);
extern int mp_map_gsi_to_irq(u32 gsi, unsigned int flags);
extern void mp_unmap_irq(int irq);
-extern void __init mp_register_ioapic(int id, u32 address, u32 gsi_base,
- ioapic_create_domain_fn cb, void *arg);
+extern int mp_register_ioapic(int id, u32 address, u32 gsi_base,
+ ioapic_create_domain_fn cb, void *arg);
extern struct irq_domain *mp_irqdomain_create(int ioapic,
struct device_node *np, const struct irq_domain_ops *ops);
extern int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index c7c84d5c0e57..f70fa239f34b 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -85,6 +85,7 @@ int sis_apic_bug = -1;
static DEFINE_RAW_SPINLOCK(ioapic_lock);
static DEFINE_RAW_SPINLOCK(vector_lock);
static DEFINE_MUTEX(ioapic_mutex);
+static int ioapic_initialized;
struct mp_pin_info {
int trigger;
@@ -2920,19 +2921,40 @@ out:
*/
#define PIC_IRQS (1UL << PIC_CASCADE_IR)
-static void ioapic_create_irqdomains(void)
+static int ioapic_create_irqdomain(int idx)
{
- int i, size;
- struct ioapic *ip;
+ int size;
+ struct ioapic *ip = &ioapics[idx];
- for_each_ioapic(i) {
- ip = &ioapics[i];
- size = sizeof(struct mp_pin_info) * mp_ioapic_pin_count(i);
- ip->pin_info = kzalloc(size, GFP_KERNEL);
- BUG_ON(!ip->pin_info);
- if (ip->irqdomain_cb)
- ip->irqdomain = ip->irqdomain_cb(i, ip->irqdomain_arg);
+ size = sizeof(struct mp_pin_info) * mp_ioapic_pin_count(idx);
+ ip->pin_info = kzalloc(size, GFP_KERNEL);
+ if (ip->pin_info == NULL && ioapic_initialized) {
+ pr_warn("failed to allocate memory IOAPIC pin_info.\n");
+ return -ENOMEM;
}
+ BUG_ON(!ip->pin_info);
+
+ if (ip->irqdomain_cb) {
+ ip->irqdomain = ip->irqdomain_cb(idx, ip->irqdomain_arg);
+ if (ip->irqdomain == NULL && ioapic_initialized) {
+ pr_warn("failed to create irqdomain for IOAPIC%d\n",
+ idx);
+ kfree(ip->pin_info);
+ ip->pin_info = NULL;
+ return -ENOMEM;
+ }
+ BUG_ON(!ip->irqdomain);
+ }
+
+ return 0;
+}
+
+static void ioapic_create_irqdomains(void)
+{
+ int idx;
+
+ for_each_ioapic(idx)
+ ioapic_create_irqdomain(idx);
}
void __init setup_IO_APIC(void)
@@ -2955,6 +2977,8 @@ void __init setup_IO_APIC(void)
init_IO_APIC_traps();
if (legacy_pic->nr_legacy_irqs)
check_timer();
+
+ ioapic_initialized = 1;
}
/*
@@ -3408,7 +3432,7 @@ io_apic_setup_irq_pin(unsigned int irq, int node, struct io_apic_irq_attr *attr)
return ret;
}
-static int __init io_apic_get_redir_entries(int ioapic)
+static int io_apic_get_redir_entries(int ioapic)
{
union IO_APIC_reg_01 reg_01;
unsigned long flags;
@@ -3455,7 +3479,7 @@ int __init arch_probe_nr_irqs(void)
}
#ifdef CONFIG_X86_32
-static int __init io_apic_get_unique_id(int ioapic, int apic_id)
+static int io_apic_get_unique_id(int ioapic, int apic_id)
{
union IO_APIC_reg_00 reg_00;
static physid_mask_t apic_id_map = PHYSID_MASK_NONE;
@@ -3530,7 +3554,7 @@ static int __init io_apic_get_unique_id(int ioapic, int apic_id)
return apic_id;
}
-static u8 __init io_apic_unique_id(u8 id)
+static u8 io_apic_unique_id(u8 id)
{
if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
!APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))
@@ -3539,7 +3563,7 @@ static u8 __init io_apic_unique_id(u8 id)
return id;
}
#else
-static u8 __init io_apic_unique_id(u8 id)
+static u8 io_apic_unique_id(u8 id)
{
int i;
DECLARE_BITMAP(used, 256);
@@ -3553,7 +3577,7 @@ static u8 __init io_apic_unique_id(u8 id)
}
#endif
-static int __init io_apic_get_version(int ioapic)
+static int io_apic_get_version(int ioapic)
{
union IO_APIC_reg_01 reg_01;
unsigned long flags;
@@ -3757,21 +3781,7 @@ int mp_find_ioapic_pin(int ioapic, u32 gsi)
return gsi - gsi_cfg->gsi_base;
}
-static __init int bad_ioapic(unsigned long address)
-{
- if (nr_ioapics >= MAX_IO_APICS) {
- pr_warn("WARNING: Max # of I/O APICs (%d) exceeded (found %d), skipping\n",
- MAX_IO_APICS, nr_ioapics);
- return 1;
- }
- if (!address) {
- pr_warn("WARNING: Bogus (zero) I/O APIC address found in table, skipping!\n");
- return 1;
- }
- return 0;
-}
-
-static __init int bad_ioapic_register(int idx)
+static int bad_ioapic_register(int idx)
{
union IO_APIC_reg_00 reg_00;
union IO_APIC_reg_01 reg_01;
@@ -3790,30 +3800,43 @@ static __init int bad_ioapic_register(int idx)
return 0;
}
-void __init mp_register_ioapic(int id, u32 address, u32 gsi_base,
- ioapic_create_domain_fn cb, void *arg)
+static int find_free_ioapic_entry(void)
+{
+ return nr_ioapics;
+}
+
+int mp_register_ioapic(int id, u32 address, u32 gsi_base,
+ ioapic_create_domain_fn cb, void *arg)
{
- int idx = 0;
- int entries;
+ u32 gsi_end;
+ int idx, ioapic, entries;
struct mp_ioapic_gsi *gsi_cfg;
- if (bad_ioapic(address))
- return;
+ if (!address) {
+ pr_warn("WARNING: Bogus (zero) I/O APIC address found in table, skipping!\n");
+ return -EINVAL;
+ }
+ for_each_ioapic(ioapic)
+ if (ioapics[ioapic].mp_config.apicaddr == address) {
+ pr_warn("address 0x%x conflicts with IOAPIC%d\n",
+ address, ioapic);
+ return -EEXIST;
+ }
- idx = nr_ioapics;
+ idx = find_free_ioapic_entry();
+ if (idx >= MAX_IO_APICS) {
+ pr_warn("WARNING: Max # of I/O APICs (%d) exceeded (found %d), skipping\n",
+ MAX_IO_APICS, idx);
+ return -ENOSPC;
+ }
ioapics[idx].mp_config.type = MP_IOAPIC;
ioapics[idx].mp_config.flags = MPC_APIC_USABLE;
ioapics[idx].mp_config.apicaddr = address;
- ioapics[idx].irqdomain_cb = cb;
- ioapics[idx].irqdomain_arg = arg;
- ioapics[idx].irqdomain = NULL;
-
set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
-
if (bad_ioapic_register(idx)) {
clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
- return;
+ return -ENODEV;
}
ioapics[idx].mp_config.apicid = io_apic_unique_id(id);
@@ -3824,24 +3847,43 @@ void __init mp_register_ioapic(int id, u32 address, u32 gsi_base,
* and to prevent reprogramming of IOAPIC pins (PCI GSIs).
*/
entries = io_apic_get_redir_entries(idx);
+ gsi_end = gsi_base + entries - 1;
+ for_each_ioapic(ioapic) {
+ gsi_cfg = mp_ioapic_gsi_routing(idx);
+ if ((gsi_base >= gsi_cfg->gsi_base &&
+ gsi_base <= gsi_cfg->gsi_end) ||
+ (gsi_end >= gsi_cfg->gsi_base &&
+ gsi_end <= gsi_cfg->gsi_end)) {
+ pr_warn("GSI range [%u-%u] for new IOAPIC conflicts with GSI[%u-%u]\n",
+ gsi_base, gsi_end,
+ gsi_cfg->gsi_base, gsi_cfg->gsi_end);
+ clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
+ return -EEXIST;
+ }
+ }
gsi_cfg = mp_ioapic_gsi_routing(idx);
gsi_cfg->gsi_base = gsi_base;
- gsi_cfg->gsi_end = gsi_base + entries - 1;
+ gsi_cfg->gsi_end = gsi_end;
- /*
- * The number of IO-APIC IRQ registers (== #pins):
- */
- ioapics[idx].nr_registers = entries;
+ ioapics[idx].irqdomain_cb = cb;
+ ioapics[idx].irqdomain_arg = arg;
+ ioapics[idx].irqdomain = NULL;
if (gsi_cfg->gsi_end >= gsi_top)
gsi_top = gsi_cfg->gsi_end + 1;
+ if (nr_ioapics <= idx)
+ nr_ioapics = idx + 1;
+
+ /* Set nr_registers to mark entry present */
+ ioapics[idx].nr_registers = entries;
+
pr_info("IOAPIC[%d]: apic_id %d, version %d, address 0x%x, GSI %d-%d\n",
idx, mpc_ioapic_id(idx),
mpc_ioapic_ver(idx), mpc_ioapic_addr(idx),
gsi_cfg->gsi_base, gsi_cfg->gsi_end);
- nr_ioapics++;
+ return 0;
}
struct irq_domain *mp_irqdomain_create(int ioapic, struct device_node *np,
@@ -3852,8 +3894,7 @@ struct irq_domain *mp_irqdomain_create(int ioapic, struct device_node *np,
int hwirqs = mp_ioapic_pin_count(ioapic);
domain = irq_domain_add_linear(np, hwirqs, ops, (void *)(long)ioapic);
- BUG_ON(!domain);
- if (gsi_cfg->gsi_base == 0)
+ if (domain && gsi_cfg->gsi_base == 0)
irq_set_default_host(domain);
return domain;
--
1.7.10.4
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