x86: hpet: print HPET registers during setup (if hpet=verbose is used)

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Mark Hounschell <markh@compro.net>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 48 insertions, 1 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index b182626739ea..01379a822646 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -492,10 +492,12 @@ and is between 256 and 4096 characters. It is defined in the file
                         Default: 64
 
         hpet=           [X86-32,HPET] option to control HPET usage
-                        Format: { enable (default) | disable | force }
+                        Format: { enable (default) | disable | force |
+                                verbose }
                         disable: disable HPET and use PIT instead
                         force: allow force enabled of undocumented chips (ICH4,
                         VIA, nVidia)
+                        verbose: show contents of HPET registers during setup
 
         com20020=       [HW,NET] ARCnet - COM20020 chipset
                         Format:
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index a00545fe5cdd..1d86ca3c1f97 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -80,6 +80,7 @@ static inline void hpet_clear_mapping(void)
  */
 static int boot_hpet_disable;
 int hpet_force_user;
+static int hpet_verbose;
 
 static int __init hpet_setup(char *str)
 {
@@ -88,6 +89,8 @@ static int __init hpet_setup(char *str)
                         boot_hpet_disable = 1;
                 if (!strncmp("force", str, 5))
                         hpet_force_user = 1;
+                if (!strncmp("verbose", str, 7))
+                        hpet_verbose = 1;
         }
         return 1;
 }
@@ -119,6 +122,43 @@ int is_hpet_enabled(void)
 }
 EXPORT_SYMBOL_GPL(is_hpet_enabled);
 
+static void _hpet_print_config(const char *function, int line)
+{
+        u32 i, timers, l, h;
+        printk(KERN_INFO "hpet: %s(%d):\n", function, line);
+        l = hpet_readl(HPET_ID);
+        h = hpet_readl(HPET_PERIOD);
+        timers = ((l & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
+        printk(KERN_INFO "hpet: ID: 0x%x, PERIOD: 0x%x\n", l, h);
+        l = hpet_readl(HPET_CFG);
+        h = hpet_readl(HPET_STATUS);
+        printk(KERN_INFO "hpet: CFG: 0x%x, STATUS: 0x%x\n", l, h);
+        l = hpet_readl(HPET_COUNTER);
+        h = hpet_readl(HPET_COUNTER+4);
+        printk(KERN_INFO "hpet: COUNTER_l: 0x%x, COUNTER_h: 0x%x\n", l, h);
+
+        for (i = 0; i < timers; i++) {
+                l = hpet_readl(HPET_Tn_CFG(i));
+                h = hpet_readl(HPET_Tn_CFG(i)+4);
+                printk(KERN_INFO "hpet: T%d: CFG_l: 0x%x, CFG_h: 0x%x\n",
+                       i, l, h);
+                l = hpet_readl(HPET_Tn_CMP(i));
+                h = hpet_readl(HPET_Tn_CMP(i)+4);
+                printk(KERN_INFO "hpet: T%d: CMP_l: 0x%x, CMP_h: 0x%x\n",
+                       i, l, h);
+                l = hpet_readl(HPET_Tn_ROUTE(i));
+                h = hpet_readl(HPET_Tn_ROUTE(i)+4);
+                printk(KERN_INFO "hpet: T%d ROUTE_l: 0x%x, ROUTE_h: 0x%x\n",
+                       i, l, h);
+        }
+}
+
+#define hpet_print_config()                                     \
+do {                                                            \
+        if (hpet_verbose)                                       \
+                _hpet_print_config(__FUNCTION__, __LINE__);     \
+} while (0)
+
 /*
  * When the hpet driver (/dev/hpet) is enabled, we need to reserve
  * timer 0 and timer 1 in case of RTC emulation.
@@ -282,6 +322,7 @@ static void hpet_set_mode(enum clock_event_mode mode,
                 hpet_writel(cmp, HPET_Tn_CMP(timer));
                 udelay(1);
                 hpet_writel((unsigned long) delta, HPET_Tn_CMP(timer));
+                hpet_print_config();
                 break;
 
         case CLOCK_EVT_MODE_ONESHOT:
@@ -308,6 +349,7 @@ static void hpet_set_mode(enum clock_event_mode mode,
                         irq_set_affinity(hdev->irq, cpumask_of(hdev->cpu));
                         enable_irq(hdev->irq);
                 }
+                hpet_print_config();
                 break;
         }
 }
@@ -526,6 +568,7 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)
 
         num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
         num_timers++; /* Value read out starts from 0 */
+        hpet_print_config();
 
         hpet_devs = kzalloc(sizeof(struct hpet_dev) * num_timers, GFP_KERNEL);
         if (!hpet_devs)
@@ -793,6 +836,7 @@ int __init hpet_enable(void)
          * information and the number of channels
          */
         id = hpet_readl(HPET_ID);
+        hpet_print_config();
 
 #ifdef CONFIG_HPET_EMULATE_RTC
         /*
@@ -845,6 +889,7 @@ static __init int hpet_late_init(void)
                 return -ENODEV;
 
         hpet_reserve_platform_timers(hpet_readl(HPET_ID));
+        hpet_print_config();
 
         for_each_online_cpu(cpu) {
                 hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);