Commit 2460d587 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

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: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/20190623132435.821728550@linutronix.de
parent e37f0881

arch/x86/kernel/hpet.c

+16 −25
Original line number Diff line number Diff line
@@ -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 num */ 
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_timers(unsigned int id) 
	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_timers(unsigned int id) 


}

#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_timer(void) 
	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 cpu) 


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_lookup(unsigned int start_timer) 


	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_lookup(unsigned int start_timer) 
	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_timers(struct hpet_data *hd) 
	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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