From cb4cb2cb9b0b14bdf2fc7125e099ed7e818cea42 Mon Sep 17 00:00:00 2001
From: Prarit Bhargava <prarit@sgi.com>
Date: Wed, 6 Jul 2005 14:59:44 -0700
Subject: [IA64] hotplug/ia64: SN Hotplug Driver: SN IRQ Fixes
This patch fixes the SN IRQ code such that cpu affinity and
Hotplug can modify IRQ values. The sn_irq_info structures are now locked
using a RCU lock mechanism to avoid lock contention in the lost interrupt
WAR code.
Signed-off-by: Prarit Bhargava <prarit@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
arch/ia64/sn/kernel/io_init.c | 39 ++++---
arch/ia64/sn/kernel/irq.c | 250 ++++++++++++++++++++++--------------------
2 files changed, 155 insertions(+), 134 deletions(-)
(limited to 'arch')
diff --git a/arch/ia64/sn/kernel/io_init.c b/arch/ia64/sn/kernel/io_init.c
index 783eb432384..2f03e3f52b6 100644
--- a/arch/ia64/sn/kernel/io_init.c
+++ b/arch/ia64/sn/kernel/io_init.c
@@ -21,7 +21,6 @@
#include <asm/sn/simulator.h>
#include <asm/sn/tioca_provider.h>
-char master_baseio_wid;
nasid_t master_nasid = INVALID_NASID; /* Partition Master */
struct slab_info {
@@ -231,11 +230,13 @@ static void sn_pci_fixup_slot(struct pci_dev *dev)
{
int idx;
int segment = 0;
- uint64_t size;
- struct sn_irq_info *sn_irq_info;
- struct pci_dev *host_pci_dev;
int status = 0;
struct pcibus_bussoft *bs;
+ struct pci_bus *host_pci_bus;
+ struct pci_dev *host_pci_dev;
+ struct sn_irq_info *sn_irq_info;
+ unsigned long size;
+ unsigned int bus_no, devfn;
dev->sysdata = kmalloc(sizeof(struct pcidev_info), GFP_KERNEL);
if (SN_PCIDEV_INFO(dev) <= 0)
@@ -253,7 +254,7 @@ static void sn_pci_fixup_slot(struct pci_dev *dev)
(u64) __pa(SN_PCIDEV_INFO(dev)),
(u64) __pa(sn_irq_info));
if (status)
- BUG(); /* Cannot get platform pci device information information */
+ BUG(); /* Cannot get platform pci device information */
/* Copy over PIO Mapped Addresses */
for (idx = 0; idx <= PCI_ROM_RESOURCE; idx++) {
@@ -275,15 +276,20 @@ static void sn_pci_fixup_slot(struct pci_dev *dev)
dev->resource[idx].parent = &iomem_resource;
}
- /* set up host bus linkages */
- bs = SN_PCIBUS_BUSSOFT(dev->bus);
- host_pci_dev =
- pci_find_slot(SN_PCIDEV_INFO(dev)->pdi_slot_host_handle >> 32,
- SN_PCIDEV_INFO(dev)->
- pdi_slot_host_handle & 0xffffffff);
+ /* Using the PROMs values for the PCI host bus, get the Linux
+ * PCI host_pci_dev struct and set up host bus linkages
+ */
+
+ bus_no = SN_PCIDEV_INFO(dev)->pdi_slot_host_handle >> 32;
+ devfn = SN_PCIDEV_INFO(dev)->pdi_slot_host_handle & 0xffffffff;
+ host_pci_bus = pci_find_bus(pci_domain_nr(dev->bus), bus_no);
+ host_pci_dev = pci_get_slot(host_pci_bus, devfn);
+
+ SN_PCIDEV_INFO(dev)->host_pci_dev = host_pci_dev;
SN_PCIDEV_INFO(dev)->pdi_host_pcidev_info =
- SN_PCIDEV_INFO(host_pci_dev);
+ SN_PCIDEV_INFO(host_pci_dev);
SN_PCIDEV_INFO(dev)->pdi_linux_pcidev = dev;
+ bs = SN_PCIBUS_BUSSOFT(dev->bus);
SN_PCIDEV_INFO(dev)->pdi_pcibus_info = bs;
if (bs && bs->bs_asic_type < PCIIO_ASIC_MAX_TYPES) {
@@ -297,6 +303,9 @@ static void sn_pci_fixup_slot(struct pci_dev *dev)
SN_PCIDEV_INFO(dev)->pdi_sn_irq_info = sn_irq_info;
dev->irq = SN_PCIDEV_INFO(dev)->pdi_sn_irq_info->irq_irq;
sn_irq_fixup(dev, sn_irq_info);
+ } else {
+ SN_PCIDEV_INFO(dev)->pdi_sn_irq_info = NULL;
+ kfree(sn_irq_info);
}
}
@@ -403,11 +412,7 @@ static int __init sn_pci_init(void)
*/
ia64_max_iommu_merge_mask = ~PAGE_MASK;
sn_fixup_ionodes();
- sn_irq = kmalloc(sizeof(struct sn_irq_info *) * NR_IRQS, GFP_KERNEL);
- if (sn_irq <= 0)
- BUG(); /* Canno afford to run out of memory. */
- memset(sn_irq, 0, sizeof(struct sn_irq_info *) * NR_IRQS);
-
+ sn_irq_lh_init();
sn_init_cpei_timer();
#ifdef CONFIG_PROC_FS
diff --git a/arch/ia64/sn/kernel/irq.c b/arch/ia64/sn/kernel/irq.c
index 0f4e8138658..e6f7551edfd 100644
--- a/arch/ia64/sn/kernel/irq.c
+++ b/arch/ia64/sn/kernel/irq.c
@@ -9,6 +9,7 @@
*/
#include <linux/irq.h>
+#include <linux/spinlock.h>
#include <asm/sn/intr.h>
#include <asm/sn/addrs.h>
#include <asm/sn/arch.h>
@@ -25,7 +26,8 @@ static void unregister_intr_pda(struct sn_irq_info *sn_irq_info);
extern int sn_force_interrupt_flag;
extern int sn_ioif_inited;
-struct sn_irq_info **sn_irq;
+static struct list_head **sn_irq_lh;
+static spinlock_t sn_irq_info_lock = SPIN_LOCK_UNLOCKED; /* non-IRQ lock */
static inline uint64_t sn_intr_alloc(nasid_t local_nasid, int local_widget,
u64 sn_irq_info,
@@ -101,7 +103,7 @@ static void sn_end_irq(unsigned int irq)
nasid = get_nasid();
event_occurred = HUB_L((uint64_t *) GLOBAL_MMR_ADDR
(nasid, SH_EVENT_OCCURRED));
- /* If the UART bit is set here, we may have received an
+ /* If the UART bit is set here, we may have received an
* interrupt from the UART that the driver missed. To
* make sure, we IPI ourselves to force us to look again.
*/
@@ -115,82 +117,84 @@ static void sn_end_irq(unsigned int irq)
force_interrupt(irq);
}
+static void sn_irq_info_free(struct rcu_head *head);
+
static void sn_set_affinity_irq(unsigned int irq, cpumask_t mask)
{
- struct sn_irq_info *sn_irq_info = sn_irq[irq];
- struct sn_irq_info *tmp_sn_irq_info;
+ struct sn_irq_info *sn_irq_info, *sn_irq_info_safe;
int cpuid, cpuphys;
- nasid_t t_nasid; /* nasid to target */
- int t_slice; /* slice to target */
-
- /* allocate a temp sn_irq_info struct to get new target info */
- tmp_sn_irq_info = kmalloc(sizeof(*tmp_sn_irq_info), GFP_KERNEL);
- if (!tmp_sn_irq_info)
- return;
cpuid = first_cpu(mask);
cpuphys = cpu_physical_id(cpuid);
- t_nasid = cpuid_to_nasid(cpuid);
- t_slice = cpuid_to_slice(cpuid);
- while (sn_irq_info) {
- int status;
- int local_widget;
- uint64_t bridge = (uint64_t) sn_irq_info->irq_bridge;
- nasid_t local_nasid = NASID_GET(bridge);
+ list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
+ sn_irq_lh[irq], list) {
+ uint64_t bridge;
+ int local_widget, status;
+ nasid_t local_nasid;
+ struct sn_irq_info *new_irq_info;
+
+ new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);
+ if (new_irq_info == NULL)
+ break;
+ memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));
+
+ bridge = (uint64_t) new_irq_info->irq_bridge;
+ if (!bridge) {
+ kfree(new_irq_info);
+ break; /* irq is not a device interrupt */
+ }
- if (!bridge)
- break; /* irq is not a device interrupt */
+ local_nasid = NASID_GET(bridge);
if (local_nasid & 1)
local_widget = TIO_SWIN_WIDGETNUM(bridge);
else
local_widget = SWIN_WIDGETNUM(bridge);
- /* Free the old PROM sn_irq_info structure */
- sn_intr_free(local_nasid, local_widget, sn_irq_info);
+ /* Free the old PROM new_irq_info structure */
+ sn_intr_free(local_nasid, local_widget, new_irq_info);
+ /* Update kernels new_irq_info with new target info */
+ unregister_intr_pda(new_irq_info);
- /* allocate a new PROM sn_irq_info struct */
+ /* allocate a new PROM new_irq_info struct */
status = sn_intr_alloc(local_nasid, local_widget,
- __pa(tmp_sn_irq_info), irq, t_nasid,
- t_slice);
-
- if (status == 0) {
- /* Update kernels sn_irq_info with new target info */
- unregister_intr_pda(sn_irq_info);
- sn_irq_info->irq_cpuid = cpuid;
- sn_irq_info->irq_nasid = t_nasid;
- sn_irq_info->irq_slice = t_slice;
- sn_irq_info->irq_xtalkaddr =
- tmp_sn_irq_info->irq_xtalkaddr;
- sn_irq_info->irq_cookie = tmp_sn_irq_info->irq_cookie;
- register_intr_pda(sn_irq_info);
-
- if (IS_PCI_BRIDGE_ASIC(sn_irq_info->irq_bridge_type)) {
- pcibr_change_devices_irq(sn_irq_info);
- }
+ __pa(new_irq_info), irq,
+ cpuid_to_nasid(cpuid),
+ cpuid_to_slice(cpuid));
+
+ /* SAL call failed */
+ if (status) {
+ kfree(new_irq_info);
+ break;
+ }
- sn_irq_info = sn_irq_info->irq_next;
+ new_irq_info->irq_cpuid = cpuid;
+ register_intr_pda(new_irq_info);
+
+ if (IS_PCI_BRIDGE_ASIC(new_irq_info->irq_bridge_type))
+ pcibr_change_devices_irq(new_irq_info);
+
+ spin_lock(&sn_irq_info_lock);
+ list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);
+ spin_unlock(&sn_irq_info_lock);
+ call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
#ifdef CONFIG_SMP
- set_irq_affinity_info((irq & 0xff), cpuphys, 0);
+ set_irq_affinity_info((irq & 0xff), cpuphys, 0);
#endif
- } else {
- break; /* snp_affinity failed the intr_alloc */
- }
}
- kfree(tmp_sn_irq_info);
}
struct hw_interrupt_type irq_type_sn = {
- "SN hub",
- sn_startup_irq,
- sn_shutdown_irq,
- sn_enable_irq,
- sn_disable_irq,
- sn_ack_irq,
- sn_end_irq,
- sn_set_affinity_irq
+ .typename = "SN hub",
+ .startup = sn_startup_irq,
+ .shutdown = sn_shutdown_irq,
+ .enable = sn_enable_irq,
+ .disable = sn_disable_irq,
+ .ack = sn_ack_irq,
+ .end = sn_end_irq,
+ .set_affinity = sn_set_affinity_irq
};
unsigned int sn_local_vector_to_irq(u8 vector)
@@ -231,19 +235,18 @@ static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
struct sn_irq_info *tmp_irq_info;
int i, foundmatch;
+ rcu_read_lock();
if (pdacpu(cpu)->sn_last_irq == irq) {
foundmatch = 0;
- for (i = pdacpu(cpu)->sn_last_irq - 1; i; i--) {
- tmp_irq_info = sn_irq[i];
- while (tmp_irq_info) {
+ for (i = pdacpu(cpu)->sn_last_irq - 1;
+ i && !foundmatch; i--) {
+ list_for_each_entry_rcu(tmp_irq_info,
+ sn_irq_lh[i],
+ list) {
if (tmp_irq_info->irq_cpuid == cpu) {
- foundmatch++;
+ foundmatch = 1;
break;
}
- tmp_irq_info = tmp_irq_info->irq_next;
- }
- if (foundmatch) {
- break;
}
}
pdacpu(cpu)->sn_last_irq = i;
@@ -251,60 +254,27 @@ static void unregister_intr_pda(struct sn_irq_info *sn_irq_info)
if (pdacpu(cpu)->sn_first_irq == irq) {
foundmatch = 0;
- for (i = pdacpu(cpu)->sn_first_irq + 1; i < NR_IRQS; i++) {
- tmp_irq_info = sn_irq[i];
- while (tmp_irq_info) {
+ for (i = pdacpu(cpu)->sn_first_irq + 1;
+ i < NR_IRQS && !foundmatch; i++) {
+ list_for_each_entry_rcu(tmp_irq_info,
+ sn_irq_lh[i],
+ list) {
if (tmp_irq_info->irq_cpuid == cpu) {
- foundmatch++;
+ foundmatch = 1;
break;
}
- tmp_irq_info = tmp_irq_info->irq_next;
- }
- if (foundmatch) {
- break;
}
}
pdacpu(cpu)->sn_first_irq = ((i == NR_IRQS) ? 0 : i);
}
+ rcu_read_unlock();
}
-struct sn_irq_info *sn_irq_alloc(nasid_t local_nasid, int local_widget, int irq,
- nasid_t nasid, int slice)
+static void sn_irq_info_free(struct rcu_head *head)
{
struct sn_irq_info *sn_irq_info;
- int status;
-
- sn_irq_info = kmalloc(sizeof(*sn_irq_info), GFP_KERNEL);
- if (sn_irq_info == NULL)
- return NULL;
-
- memset(sn_irq_info, 0x0, sizeof(*sn_irq_info));
-
- status =
- sn_intr_alloc(local_nasid, local_widget, __pa(sn_irq_info), irq,
- nasid, slice);
-
- if (status) {
- kfree(sn_irq_info);
- return NULL;
- } else {
- return sn_irq_info;
- }
-}
-
-void sn_irq_free(struct sn_irq_info *sn_irq_info)
-{
- uint64_t bridge = (uint64_t) sn_irq_info->irq_bridge;
- nasid_t local_nasid = NASID_GET(bridge);
- int local_widget;
-
- if (local_nasid & 1) /* tio check */
- local_widget = TIO_SWIN_WIDGETNUM(bridge);
- else
- local_widget = SWIN_WIDGETNUM(bridge);
-
- sn_intr_free(local_nasid, local_widget, sn_irq_info);
+ sn_irq_info = container_of(head, struct sn_irq_info, rcu);
kfree(sn_irq_info);
}
@@ -314,30 +284,54 @@ void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
int slice = sn_irq_info->irq_slice;
int cpu = nasid_slice_to_cpuid(nasid, slice);
+ pci_dev_get(pci_dev);
+
sn_irq_info->irq_cpuid = cpu;
sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
/* link it into the sn_irq[irq] list */
- sn_irq_info->irq_next = sn_irq[sn_irq_info->irq_irq];
- sn_irq[sn_irq_info->irq_irq] = sn_irq_info;
+ spin_lock(&sn_irq_info_lock);
+ list_add_rcu(&sn_irq_info->list, sn_irq_lh[sn_irq_info->irq_irq]);
+ spin_unlock(&sn_irq_info_lock);
(void)register_intr_pda(sn_irq_info);
}
+void sn_irq_unfixup(struct pci_dev *pci_dev)
+{
+ struct sn_irq_info *sn_irq_info;
+
+ /* Only cleanup IRQ stuff if this device has a host bus context */
+ if (!SN_PCIDEV_BUSSOFT(pci_dev))
+ return;
+
+ sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
+ if (!sn_irq_info || !sn_irq_info->irq_irq)
+ return;
+
+ unregister_intr_pda(sn_irq_info);
+ spin_lock(&sn_irq_info_lock);
+ list_del_rcu(&sn_irq_info->list);
+ spin_unlock(&sn_irq_info_lock);
+ call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
+
+ pci_dev_put(pci_dev);
+}
+
static void force_interrupt(int irq)
{
struct sn_irq_info *sn_irq_info;
if (!sn_ioif_inited)
return;
- sn_irq_info = sn_irq[irq];
- while (sn_irq_info) {
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[irq], list) {
if (IS_PCI_BRIDGE_ASIC(sn_irq_info->irq_bridge_type) &&
- (sn_irq_info->irq_bridge != NULL)) {
+ (sn_irq_info->irq_bridge != NULL))
pcibr_force_interrupt(sn_irq_info);
- }
- sn_irq_info = sn_irq_info->irq_next;
}
+ rcu_read_unlock();
}
/*
@@ -402,19 +396,41 @@ static void sn_check_intr(int irq, struct sn_irq_info *sn_irq_info)
void sn_lb_int_war_check(void)
{
+ struct sn_irq_info *sn_irq_info;
int i;
if (!sn_ioif_inited || pda->sn_first_irq == 0)
return;
+
+ rcu_read_lock();
for (i = pda->sn_first_irq; i <= pda->sn_last_irq; i++) {
- struct sn_irq_info *sn_irq_info = sn_irq[i];
- while (sn_irq_info) {
- /* Only call for PCI bridges that are fully initialized. */
+ list_for_each_entry_rcu(sn_irq_info, sn_irq_lh[i], list) {
+ /*
+ * Only call for PCI bridges that are fully
+ * initialized.
+ */
if (IS_PCI_BRIDGE_ASIC(sn_irq_info->irq_bridge_type) &&
- (sn_irq_info->irq_bridge != NULL)) {
+ (sn_irq_info->irq_bridge != NULL))
sn_check_intr(i, sn_irq_info);
- }
- sn_irq_info = sn_irq_info->irq_next;
}
}
+ rcu_read_unlock();
+}
+
+void sn_irq_lh_init(void)
+{
+ int i;
+
+ sn_irq_lh = kmalloc(sizeof(struct list_head *) * NR_IRQS, GFP_KERNEL);
+ if (!sn_irq_lh)
+ panic("SN PCI INIT: Failed to allocate memory for PCI init\n");
+
+ for (i = 0; i < NR_IRQS; i++) {
+ sn_irq_lh[i] = kmalloc(sizeof(struct list_head), GFP_KERNEL);
+ if (!sn_irq_lh[i])
+ panic("SN PCI INIT: Failed IRQ memory allocation\n");
+
+ INIT_LIST_HEAD(sn_irq_lh[i]);
+ }
+
}
--
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