AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-12-23 11:06:48 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity
d2190a8091
linux_dsm_epyc7002/arch/ia64/sn/kernel/sn2/sn2_smp.c
Christoph Lameter 6065a244a0 ia64: Replace __get_cpu_var uses 
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64@vger.kernel.org
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:52 -04:00

573 lines
15 KiB
C
Raw Blame History

/*
* SN2 Platform specific SMP Support
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2000-2006 Silicon Graphics, Inc. All rights reserved.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/threads.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/mmzone.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/nodemask.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/processor.h>
#include <asm/irq.h>
#include <asm/sal.h>
#include <asm/delay.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/tlb.h>
#include <asm/numa.h>
#include <asm/hw_irq.h>
#include <asm/current.h>
#include <asm/sn/sn_cpuid.h>
#include <asm/sn/sn_sal.h>
#include <asm/sn/addrs.h>
#include <asm/sn/shub_mmr.h>
#include <asm/sn/nodepda.h>
#include <asm/sn/rw_mmr.h>
#include <asm/sn/sn_feature_sets.h>
DEFINE_PER_CPU(struct ptc_stats, ptcstats);
DECLARE_PER_CPU(struct ptc_stats, ptcstats);
static __cacheline_aligned DEFINE_SPINLOCK(sn2_global_ptc_lock);
/* 0 = old algorithm (no IPI flushes), 1 = ipi deadlock flush, 2 = ipi instead of SHUB ptc, >2 = always ipi */
static int sn2_flush_opt = 0;
extern unsigned long
sn2_ptc_deadlock_recovery_core(volatile unsigned long *, unsigned long,
volatile unsigned long *, unsigned long,
volatile unsigned long *, unsigned long);
void
sn2_ptc_deadlock_recovery(short *, short, short, int,
volatile unsigned long *, unsigned long,
volatile unsigned long *, unsigned long);
/*
* Note: some is the following is captured here to make degugging easier
* (the macros make more sense if you see the debug patch - not posted)
*/
#define sn2_ptctest 0
#define local_node_uses_ptc_ga(sh1) ((sh1) ? 1 : 0)
#define max_active_pio(sh1) ((sh1) ? 32 : 7)
#define reset_max_active_on_deadlock() 1
#define PTC_LOCK(sh1) ((sh1) ? &sn2_global_ptc_lock : &sn_nodepda->ptc_lock)
struct ptc_stats {
unsigned long ptc_l;
unsigned long change_rid;
unsigned long shub_ptc_flushes;
unsigned long nodes_flushed;
unsigned long deadlocks;
unsigned long deadlocks2;
unsigned long lock_itc_clocks;
unsigned long shub_itc_clocks;
unsigned long shub_itc_clocks_max;
unsigned long shub_ptc_flushes_not_my_mm;
unsigned long shub_ipi_flushes;
unsigned long shub_ipi_flushes_itc_clocks;
};
#define sn2_ptctest 0
static inline unsigned long wait_piowc(void)
{
volatile unsigned long *piows;
unsigned long zeroval, ws;
piows = pda->pio_write_status_addr;
zeroval = pda->pio_write_status_val;
do {
cpu_relax();
} while (((ws = *piows) & SH_PIO_WRITE_STATUS_PENDING_WRITE_COUNT_MASK) != zeroval);
return (ws & SH_PIO_WRITE_STATUS_WRITE_DEADLOCK_MASK) != 0;
}
/**
* sn_migrate - SN-specific task migration actions
* @task: Task being migrated to new CPU
*
* SN2 PIO writes from separate CPUs are not guaranteed to arrive in order.
* Context switching user threads which have memory-mapped MMIO may cause
* PIOs to issue from separate CPUs, thus the PIO writes must be drained
* from the previous CPU's Shub before execution resumes on the new CPU.
*/
void sn_migrate(struct task_struct *task)
{
pda_t *last_pda = pdacpu(task_thread_info(task)->last_cpu);
volatile unsigned long *adr = last_pda->pio_write_status_addr;
unsigned long val = last_pda->pio_write_status_val;
/* Drain PIO writes from old CPU's Shub */
while (unlikely((*adr & SH_PIO_WRITE_STATUS_PENDING_WRITE_COUNT_MASK)
!= val))
cpu_relax();
}
void sn_tlb_migrate_finish(struct mm_struct *mm)
{
/* flush_tlb_mm is inefficient if more than 1 users of mm */
if (mm == current->mm && mm && atomic_read(&mm->mm_users) == 1)
flush_tlb_mm(mm);
}
static void
sn2_ipi_flush_all_tlb(struct mm_struct *mm)
{
unsigned long itc;
itc = ia64_get_itc();
smp_flush_tlb_cpumask(*mm_cpumask(mm));
itc = ia64_get_itc() - itc;
__this_cpu_add(ptcstats.shub_ipi_flushes_itc_clocks, itc);
__this_cpu_inc(ptcstats.shub_ipi_flushes);
}
/**
* sn2_global_tlb_purge - globally purge translation cache of virtual address range
* @mm: mm_struct containing virtual address range
* @start: start of virtual address range
* @end: end of virtual address range
* @nbits: specifies number of bytes to purge per instruction (num = 1<<(nbits & 0xfc))
*
* Purges the translation caches of all processors of the given virtual address
* range.
*
* Note:
* - cpu_vm_mask is a bit mask that indicates which cpus have loaded the context.
* - cpu_vm_mask is converted into a nodemask of the nodes containing the
* cpus in cpu_vm_mask.
* - if only one bit is set in cpu_vm_mask & it is the current cpu & the
* process is purging its own virtual address range, then only the
* local TLB needs to be flushed. This flushing can be done using
* ptc.l. This is the common case & avoids the global spinlock.
* - if multiple cpus have loaded the context, then flushing has to be
* done with ptc.g/MMRs under protection of the global ptc_lock.
*/
void
sn2_global_tlb_purge(struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned long nbits)
{
int i, ibegin, shub1, cnode, mynasid, cpu, lcpu = 0, nasid;
int mymm = (mm == current->active_mm && mm == current->mm);
int use_cpu_ptcga;
volatile unsigned long *ptc0, *ptc1;
unsigned long itc, itc2, flags, data0 = 0, data1 = 0, rr_value, old_rr = 0;
short nasids[MAX_NUMNODES], nix;
nodemask_t nodes_flushed;
int active, max_active, deadlock, flush_opt = sn2_flush_opt;
if (flush_opt > 2) {
sn2_ipi_flush_all_tlb(mm);
return;
}
nodes_clear(nodes_flushed);
i = 0;
for_each_cpu(cpu, mm_cpumask(mm)) {
cnode = cpu_to_node(cpu);
node_set(cnode, nodes_flushed);
lcpu = cpu;
i++;
}
if (i == 0)
return;
preempt_disable();
if (likely(i == 1 && lcpu == smp_processor_id() && mymm)) {
do {
ia64_ptcl(start, nbits << 2);
start += (1UL << nbits);
} while (start < end);
ia64_srlz_i();
__this_cpu_inc(ptcstats.ptc_l);
preempt_enable();
return;
}
if (atomic_read(&mm->mm_users) == 1 && mymm) {
flush_tlb_mm(mm);
__this_cpu_inc(ptcstats.change_rid);
preempt_enable();
return;
}
if (flush_opt == 2) {
sn2_ipi_flush_all_tlb(mm);
preempt_enable();
return;
}
itc = ia64_get_itc();
nix = 0;
for_each_node_mask(cnode, nodes_flushed)
nasids[nix++] = cnodeid_to_nasid(cnode);
rr_value = (mm->context << 3) | REGION_NUMBER(start);
shub1 = is_shub1();
if (shub1) {
data0 = (1UL << SH1_PTC_0_A_SHFT) |
(nbits << SH1_PTC_0_PS_SHFT) |
(rr_value << SH1_PTC_0_RID_SHFT) |
(1UL << SH1_PTC_0_START_SHFT);
ptc0 = (long *)GLOBAL_MMR_PHYS_ADDR(0, SH1_PTC_0);
ptc1 = (long *)GLOBAL_MMR_PHYS_ADDR(0, SH1_PTC_1);
} else {
data0 = (1UL << SH2_PTC_A_SHFT) |
(nbits << SH2_PTC_PS_SHFT) |
(1UL << SH2_PTC_START_SHFT);
ptc0 = (long *)GLOBAL_MMR_PHYS_ADDR(0, SH2_PTC +
(rr_value << SH2_PTC_RID_SHFT));
ptc1 = NULL;
}
mynasid = get_nasid();
use_cpu_ptcga = local_node_uses_ptc_ga(shub1);
max_active = max_active_pio(shub1);
itc = ia64_get_itc();
spin_lock_irqsave(PTC_LOCK(shub1), flags);
itc2 = ia64_get_itc();
__this_cpu_add(ptcstats.lock_itc_clocks, itc2 - itc);
__this_cpu_inc(ptcstats.shub_ptc_flushes);
__this_cpu_add(ptcstats.nodes_flushed, nix);
if (!mymm)
__this_cpu_inc(ptcstats.shub_ptc_flushes_not_my_mm);
if (use_cpu_ptcga && !mymm) {
old_rr = ia64_get_rr(start);
ia64_set_rr(start, (old_rr & 0xff) | (rr_value << 8));
ia64_srlz_d();
}
wait_piowc();
do {
if (shub1)
data1 = start | (1UL << SH1_PTC_1_START_SHFT);
else
data0 = (data0 & ~SH2_PTC_ADDR_MASK) | (start & SH2_PTC_ADDR_MASK);
deadlock = 0;
active = 0;
for (ibegin = 0, i = 0; i < nix; i++) {
nasid = nasids[i];
if (use_cpu_ptcga && unlikely(nasid == mynasid)) {
ia64_ptcga(start, nbits << 2);
ia64_srlz_i();
} else {
ptc0 = CHANGE_NASID(nasid, ptc0);
if (ptc1)
ptc1 = CHANGE_NASID(nasid, ptc1);
pio_atomic_phys_write_mmrs(ptc0, data0, ptc1, data1);
active++;
}
if (active >= max_active || i == (nix - 1)) {
if ((deadlock = wait_piowc())) {
if (flush_opt == 1)
goto done;
sn2_ptc_deadlock_recovery(nasids, ibegin, i, mynasid, ptc0, data0, ptc1, data1);
if (reset_max_active_on_deadlock())
max_active = 1;
}
active = 0;
ibegin = i + 1;
}
}
start += (1UL << nbits);
} while (start < end);
done:
itc2 = ia64_get_itc() - itc2;
__this_cpu_add(ptcstats.shub_itc_clocks, itc2);
if (itc2 > __this_cpu_read(ptcstats.shub_itc_clocks_max))
__this_cpu_write(ptcstats.shub_itc_clocks_max, itc2);
if (old_rr) {
ia64_set_rr(start, old_rr);
ia64_srlz_d();
}
spin_unlock_irqrestore(PTC_LOCK(shub1), flags);
if (flush_opt == 1 && deadlock) {
__this_cpu_inc(ptcstats.deadlocks);
sn2_ipi_flush_all_tlb(mm);
}
preempt_enable();
}
/*
* sn2_ptc_deadlock_recovery
*
* Recover from PTC deadlocks conditions. Recovery requires stepping thru each
* TLB flush transaction. The recovery sequence is somewhat tricky & is
* coded in assembly language.
*/
void
sn2_ptc_deadlock_recovery(short *nasids, short ib, short ie, int mynasid,
volatile unsigned long *ptc0, unsigned long data0,
volatile unsigned long *ptc1, unsigned long data1)
{
short nasid, i;
unsigned long *piows, zeroval, n;
__this_cpu_inc(ptcstats.deadlocks);
piows = (unsigned long *) pda->pio_write_status_addr;
zeroval = pda->pio_write_status_val;
for (i=ib; i <= ie; i++) {
nasid = nasids[i];
if (local_node_uses_ptc_ga(is_shub1()) && nasid == mynasid)
continue;
ptc0 = CHANGE_NASID(nasid, ptc0);
if (ptc1)
ptc1 = CHANGE_NASID(nasid, ptc1);
n = sn2_ptc_deadlock_recovery_core(ptc0, data0, ptc1, data1, piows, zeroval);
__this_cpu_add(ptcstats.deadlocks2, n);
}
}
/**
* sn_send_IPI_phys - send an IPI to a Nasid and slice
* @nasid: nasid to receive the interrupt (may be outside partition)
* @physid: physical cpuid to receive the interrupt.
* @vector: command to send
* @delivery_mode: delivery mechanism
*
* Sends an IPI (interprocessor interrupt) to the processor specified by
* @physid
*
* @delivery_mode can be one of the following
*
* %IA64_IPI_DM_INT - pend an interrupt
* %IA64_IPI_DM_PMI - pend a PMI
* %IA64_IPI_DM_NMI - pend an NMI
* %IA64_IPI_DM_INIT - pend an INIT interrupt
*/
void sn_send_IPI_phys(int nasid, long physid, int vector, int delivery_mode)
{
long val;
unsigned long flags = 0;
volatile long *p;
p = (long *)GLOBAL_MMR_PHYS_ADDR(nasid, SH_IPI_INT);
val = (1UL << SH_IPI_INT_SEND_SHFT) |
(physid << SH_IPI_INT_PID_SHFT) |
((long)delivery_mode << SH_IPI_INT_TYPE_SHFT) |
((long)vector << SH_IPI_INT_IDX_SHFT) |
(0x000feeUL << SH_IPI_INT_BASE_SHFT);
mb();
if (enable_shub_wars_1_1()) {
spin_lock_irqsave(&sn2_global_ptc_lock, flags);
}
pio_phys_write_mmr(p, val);
if (enable_shub_wars_1_1()) {
wait_piowc();
spin_unlock_irqrestore(&sn2_global_ptc_lock, flags);
}
}
EXPORT_SYMBOL(sn_send_IPI_phys);
/**
* sn2_send_IPI - send an IPI to a processor
* @cpuid: target of the IPI
* @vector: command to send
* @delivery_mode: delivery mechanism
* @redirect: redirect the IPI?
*
* Sends an IPI (InterProcessor Interrupt) to the processor specified by
* @cpuid. @vector specifies the command to send, while @delivery_mode can
* be one of the following
*
* %IA64_IPI_DM_INT - pend an interrupt
* %IA64_IPI_DM_PMI - pend a PMI
* %IA64_IPI_DM_NMI - pend an NMI
* %IA64_IPI_DM_INIT - pend an INIT interrupt
*/
void sn2_send_IPI(int cpuid, int vector, int delivery_mode, int redirect)
{
long physid;
int nasid;
physid = cpu_physical_id(cpuid);
nasid = cpuid_to_nasid(cpuid);
/* the following is used only when starting cpus at boot time */
if (unlikely(nasid == -1))
ia64_sn_get_sapic_info(physid, &nasid, NULL, NULL);
sn_send_IPI_phys(nasid, physid, vector, delivery_mode);
}
#ifdef CONFIG_HOTPLUG_CPU
/**
* sn_cpu_disable_allowed - Determine if a CPU can be disabled.
* @cpu - CPU that is requested to be disabled.
*
* CPU disable is only allowed on SHub2 systems running with a PROM
* that supports CPU disable. It is not permitted to disable the boot processor.
*/
bool sn_cpu_disable_allowed(int cpu)
{
if (is_shub2() && sn_prom_feature_available(PRF_CPU_DISABLE_SUPPORT)) {
if (cpu != 0)
return true;
else
printk(KERN_WARNING
"Disabling the boot processor is not allowed.\n");
} else
printk(KERN_WARNING
"CPU disable is not supported on this system.\n");
return false;
}
#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_PROC_FS
#define PTC_BASENAME "sgi_sn/ptc_statistics"
static void *sn2_ptc_seq_start(struct seq_file *file, loff_t * offset)
{
if (*offset < nr_cpu_ids)
return offset;
return NULL;
}
static void *sn2_ptc_seq_next(struct seq_file *file, void *data, loff_t * offset)
{
(*offset)++;
if (*offset < nr_cpu_ids)
return offset;
return NULL;
}
static void sn2_ptc_seq_stop(struct seq_file *file, void *data)
{
}
static int sn2_ptc_seq_show(struct seq_file *file, void *data)
{
struct ptc_stats *stat;
int cpu;
cpu = *(loff_t *) data;
if (!cpu) {
seq_printf(file,
"# cpu ptc_l newrid ptc_flushes nodes_flushed deadlocks lock_nsec shub_nsec shub_nsec_max not_my_mm deadlock2 ipi_fluches ipi_nsec\n");
seq_printf(file, "# ptctest %d, flushopt %d\n", sn2_ptctest, sn2_flush_opt);
}
if (cpu < nr_cpu_ids && cpu_online(cpu)) {
stat = &per_cpu(ptcstats, cpu);
seq_printf(file, "cpu %d %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld\n", cpu, stat->ptc_l,
stat->change_rid, stat->shub_ptc_flushes, stat->nodes_flushed,
stat->deadlocks,
1000 * stat->lock_itc_clocks / per_cpu(ia64_cpu_info, cpu).cyc_per_usec,
1000 * stat->shub_itc_clocks / per_cpu(ia64_cpu_info, cpu).cyc_per_usec,
1000 * stat->shub_itc_clocks_max / per_cpu(ia64_cpu_info, cpu).cyc_per_usec,
stat->shub_ptc_flushes_not_my_mm,
stat->deadlocks2,
stat->shub_ipi_flushes,
1000 * stat->shub_ipi_flushes_itc_clocks / per_cpu(ia64_cpu_info, cpu).cyc_per_usec);
}
return 0;
}
static ssize_t sn2_ptc_proc_write(struct file *file, const char __user *user, size_t count, loff_t *data)
{
int cpu;
char optstr[64];
if (count == 0 || count > sizeof(optstr))
return -EINVAL;
if (copy_from_user(optstr, user, count))
return -EFAULT;
optstr[count - 1] = '\0';
sn2_flush_opt = simple_strtoul(optstr, NULL, 0);
for_each_online_cpu(cpu)
memset(&per_cpu(ptcstats, cpu), 0, sizeof(struct ptc_stats));
return count;
}
static const struct seq_operations sn2_ptc_seq_ops = {
.start = sn2_ptc_seq_start,
.next = sn2_ptc_seq_next,
.stop = sn2_ptc_seq_stop,
.show = sn2_ptc_seq_show
};
static int sn2_ptc_proc_open(struct inode *inode, struct file *file)
{
return seq_open(file, &sn2_ptc_seq_ops);
}
static const struct file_operations proc_sn2_ptc_operations = {
.open = sn2_ptc_proc_open,
.read = seq_read,
.write = sn2_ptc_proc_write,
.llseek = seq_lseek,
.release = seq_release,
};
static struct proc_dir_entry *proc_sn2_ptc;
static int __init sn2_ptc_init(void)
{
if (!ia64_platform_is("sn2"))
return 0;
proc_sn2_ptc = proc_create(PTC_BASENAME, 0444,
NULL, &proc_sn2_ptc_operations);
if (!proc_sn2_ptc) {
printk(KERN_ERR "unable to create %s proc entry", PTC_BASENAME);
return -EINVAL;
}
spin_lock_init(&sn2_global_ptc_lock);
return 0;
}
static void __exit sn2_ptc_exit(void)
{
remove_proc_entry(PTC_BASENAME, NULL);
}
module_init(sn2_ptc_init);
module_exit(sn2_ptc_exit);
#endif /* CONFIG_PROC_FS */
Reference in New Issue View Git Blame Copy Permalink