lkml.org 
[lkml]   [2019]   [Jun]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch 18/29] x86/hpet: Introduce struct hpet_base and struct hpet_channel
Introduce new data structures to replace the ad hoc collection of separate
variables and pointers.

Replace the boot configuration store and restore as a first step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/hpet.c | 84 ++++++++++++++++++++++++++++---------------------
1 file changed, 49 insertions(+), 35 deletions(-)

--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -22,6 +22,17 @@ struct hpet_dev {
char name[10];
};

+struct hpet_channel {
+ unsigned int num;
+ unsigned int boot_cfg;
+};
+
+struct hpet_base {
+ unsigned int nr_channels;
+ unsigned int boot_cfg;
+ struct hpet_channel *channels;
+};
+
#define HPET_MASK CLOCKSOURCE_MASK(32)

#define HPET_DEV_USED_BIT 2
@@ -48,7 +59,7 @@ static struct irq_domain *hpet_domain;
#endif

static void __iomem *hpet_virt_address;
-static u32 *hpet_boot_cfg;
+static struct hpet_base hpet_base;

static bool hpet_legacy_int_enabled;
static unsigned long hpet_freq;
@@ -860,6 +871,7 @@ int __init hpet_enable(void)
{
u32 hpet_period, cfg, id;
unsigned int i, channels;
+ struct hpet_channel *hc;
u64 freq;

if (!is_hpet_capable())
@@ -899,34 +911,39 @@ int __init hpet_enable(void)
/* This is the HPET channel number which is zero based */
channels = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;

-#ifdef CONFIG_HPET_EMULATE_RTC
/*
* The legacy routing mode needs at least two channels, tick timer
* and the rtc emulation channel.
*/
- if (channels < 2)
+ if (IS_ENABLED(CONFIG_HPET_EMULATE_RTC) && channels < 2)
goto out_nohpet;
-#endif

+ hc = kcalloc(channels, sizeof(*hc), GFP_KERNEL);
+ if (!hc) {
+ pr_warn("Disabling HPET.\n");
+ goto out_nohpet;
+ }
+ hpet_base.channels = hc;
+ hpet_base.nr_channels = channels;
+
+ /* Read, store and sanitize the global configuration */
cfg = hpet_readl(HPET_CFG);
- /* Allocate entries for the global and the channel configurations */
- hpet_boot_cfg = kmalloc_array(channels + 1, sizeof(*hpet_boot_cfg),
- GFP_KERNEL);
- if (hpet_boot_cfg)
- *hpet_boot_cfg = cfg;
- else
- pr_warn("HPET initial state will not be saved\n");
+ hpet_base.boot_cfg = cfg;
cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY);
hpet_writel(cfg, HPET_CFG);
if (cfg)
pr_warn("Global config: Unknown bits %#x\n", cfg);

- for (i = 0; i < channels; ++i) {
+ /* Read, store and sanitize the per channel configuration */
+ for (i = 0; i < channels; i++, hc++) {
+ hc->num = i;
+
cfg = hpet_readl(HPET_Tn_CFG(i));
- if (hpet_boot_cfg)
- hpet_boot_cfg[i + 1] = cfg;
+ hc->boot_cfg = cfg;
+
cfg &= ~(HPET_TN_ENABLE | HPET_TN_LEVEL | HPET_TN_FSB);
hpet_writel(cfg, HPET_Tn_CFG(i));
+
cfg &= ~(HPET_TN_PERIODIC | HPET_TN_PERIODIC_CAP
| HPET_TN_64BIT_CAP | HPET_TN_32BIT | HPET_TN_ROUTE
| HPET_TN_FSB | HPET_TN_FSB_CAP);
@@ -944,6 +961,9 @@ int __init hpet_enable(void)
return 0;

out_nohpet:
+ kfree(hpet_base.channels);
+ hpet_base.channels = NULL;
+ hpet_base.nr_channels = 0;
hpet_clear_mapping();
hpet_address = 0;
return 0;
@@ -1000,30 +1020,24 @@ fs_initcall(hpet_late_init);

void hpet_disable(void)
{
- if (is_hpet_capable() && hpet_virt_address) {
- unsigned int cfg = hpet_readl(HPET_CFG), id, last;
-
- if (hpet_boot_cfg)
- cfg = *hpet_boot_cfg;
- else if (hpet_legacy_int_enabled) {
- cfg &= ~HPET_CFG_LEGACY;
- hpet_legacy_int_enabled = false;
- }
- cfg &= ~HPET_CFG_ENABLE;
- hpet_writel(cfg, HPET_CFG);
-
- if (!hpet_boot_cfg)
- return;
+ unsigned int i;
+ u32 cfg;

- id = hpet_readl(HPET_ID);
- last = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
+ if (!is_hpet_capable() || !hpet_virt_address)
+ return;

- for (id = 0; id <= last; ++id)
- hpet_writel(hpet_boot_cfg[id + 1], HPET_Tn_CFG(id));
+ /* Restore boot configuration with the enable bit cleared */
+ cfg = hpet_base.boot_cfg;
+ cfg &= ~HPET_CFG_ENABLE;
+ hpet_writel(cfg, HPET_CFG);

- if (*hpet_boot_cfg & HPET_CFG_ENABLE)
- hpet_writel(*hpet_boot_cfg, HPET_CFG);
- }
+ /* Restore the channel boot configuration */
+ for (i = 0; i < hpet_base.nr_channels; i++)
+ hpet_writel(hpet_base.channels[i].boot_cfg, HPET_Tn_CFG(i));
+
+ /* If the HPET was enabled at boot time, reenable it */
+ if (hpet_base.boot_cfg & HPET_CFG_ENABLE)
+ hpet_writel(hpet_base.boot_cfg, HPET_CFG);
}

#ifdef CONFIG_HPET_EMULATE_RTC

\
 
 \ /
  Last update: 2019-06-23 15:29    [W:0.194 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site