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Date: Sun, 23 Jun 2019 15:23:59 +0200
From: Thomas Gleixner <tglx@...utronix.de>
To: LKML <linux-kernel@...r.kernel.org>
Cc: x86@...nel.org, Peter Zijlstra <peterz@...radead.org>,
Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>,
Ashok Raj <ashok.raj@...el.com>,
Andi Kleen <andi.kleen@...el.com>,
Suravee Suthikulpanit <Suravee.Suthikulpanit@....com>,
Stephane Eranian <eranian@...gle.com>,
Ravi Shankar <ravi.v.shankar@...el.com>
Subject: [patch 19/29] x86/hpet: Use cached channel data
Instead of rereading the HPET registers over and over use the information
which was cached in hpet_enable().
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
arch/x86/kernel/hpet.c | 41 ++++++++++++++++-------------------------
1 file changed, 16 insertions(+), 25 deletions(-)
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -24,6 +24,7 @@ struct hpet_dev {
struct hpet_channel {
unsigned int num;
+ unsigned int irq;
unsigned int boot_cfg;
};
@@ -52,7 +53,6 @@ u8 hpet_blockid; /* OS timer block n
bool hpet_msi_disable;
#ifdef CONFIG_PCI_MSI
-static unsigned int hpet_num_timers;
static struct hpet_dev *hpet_devs;
static DEFINE_PER_CPU(struct hpet_dev *, cpu_hpet_dev);
static struct irq_domain *hpet_domain;
@@ -189,19 +189,15 @@ do { \
static void hpet_reserve_msi_timers(struct hpet_data *hd);
-static void __init hpet_reserve_platform_timers(unsigned int id)
+static void __init hpet_reserve_platform_timers(void)
{
- struct hpet __iomem *hpet = hpet_virt_address;
- struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
- unsigned int nrtimers, i;
struct hpet_data hd;
-
- nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
+ unsigned int i;
memset(&hd, 0, sizeof(hd));
hd.hd_phys_address = hpet_address;
- hd.hd_address = hpet;
- hd.hd_nirqs = nrtimers;
+ hd.hd_address = hpet_virt_address;
+ hd.hd_nirqs = hpet_base.nr_channels;
hpet_reserve_timer(&hd, 0);
#ifdef CONFIG_HPET_EMULATE_RTC
@@ -216,10 +212,8 @@ static void __init hpet_reserve_platform
hd.hd_irq[0] = HPET_LEGACY_8254;
hd.hd_irq[1] = HPET_LEGACY_RTC;
- for (i = 2; i < nrtimers; timer++, i++) {
- hd.hd_irq[i] = (readl(&timer->hpet_config) &
- Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
- }
+ for (i = 2; i < hpet_base.nr_channels; i++)
+ hd.hd_irq[i] = hpet_base.channels[i].irq;
hpet_reserve_msi_timers(&hd);
@@ -227,7 +221,7 @@ static void __init hpet_reserve_platform
}
#else
-static void hpet_reserve_platform_timers(unsigned int id) { }
+static inline void hpet_reserve_platform_timers(void) { }
#endif
/* Common HPET functions */
@@ -569,7 +563,7 @@ static struct hpet_dev *hpet_get_unused_
if (!hpet_devs)
return NULL;
- for (i = 0; i < hpet_num_timers; i++) {
+ for (i = 0; i < hpet_base.nr_channels; i++) {
struct hpet_dev *hdev = &hpet_devs[i];
if (!(hdev->flags & HPET_DEV_VALID))
@@ -612,7 +606,6 @@ static int hpet_cpuhp_dead(unsigned int
static void __init hpet_msi_capability_lookup(unsigned int start_timer)
{
- unsigned int id;
unsigned int num_timers;
unsigned int num_timers_used = 0;
int i, irq;
@@ -622,10 +615,8 @@ static void __init hpet_msi_capability_l
if (boot_cpu_has(X86_FEATURE_ARAT))
return;
- id = hpet_readl(HPET_ID);
- num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
- num_timers++; /* Value read out starts from 0 */
+ num_timers = hpet_base.nr_channels;
hpet_print_config();
hpet_domain = hpet_create_irq_domain(hpet_blockid);
@@ -636,11 +627,9 @@ static void __init hpet_msi_capability_l
if (!hpet_devs)
return;
- hpet_num_timers = num_timers;
-
for (i = start_timer; i < num_timers - RESERVE_TIMERS; i++) {
struct hpet_dev *hdev = &hpet_devs[num_timers_used];
- unsigned int cfg = hpet_readl(HPET_Tn_CFG(i));
+ unsigned int cfg = hpet_base.channels[i].boot_cfg;
/* Only consider HPET timer with MSI support */
if (!(cfg & HPET_TN_FSB_CAP))
@@ -676,7 +665,7 @@ static void __init hpet_reserve_msi_time
if (!hpet_devs)
return;
- for (i = 0; i < hpet_num_timers; i++) {
+ for (i = 0; i < hpet_base.nr_channels; i++) {
struct hpet_dev *hdev = &hpet_devs[i];
if (!(hdev->flags & HPET_DEV_VALID))
@@ -869,7 +858,7 @@ static bool __init hpet_counting(void)
*/
int __init hpet_enable(void)
{
- u32 hpet_period, cfg, id;
+ u32 hpet_period, cfg, id, irq;
unsigned int i, channels;
struct hpet_channel *hc;
u64 freq;
@@ -940,6 +929,8 @@ int __init hpet_enable(void)
cfg = hpet_readl(HPET_Tn_CFG(i));
hc->boot_cfg = cfg;
+ irq = (cfg & Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
+ hc->irq = irq;
cfg &= ~(HPET_TN_ENABLE | HPET_TN_LEVEL | HPET_TN_FSB);
hpet_writel(cfg, HPET_Tn_CFG(i));
@@ -993,7 +984,7 @@ static __init int hpet_late_init(void)
else
hpet_msi_capability_lookup(0);
- hpet_reserve_platform_timers(hpet_readl(HPET_ID));
+ hpet_reserve_platform_timers();
hpet_print_config();
if (hpet_msi_disable)
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