x86 BIOS interface for RTC on SGI UV
Real-time code needs to know the number of cycles per second
on SGI UV. The information is provided via a run time BIOS
call. This patch provides the linux side of that interface.
This is the first of several run time BIOS calls to be defined
in uv/bios.h and bios_uv.c.
Note that BIOS_CALL() is just a stub for now. The bios
side is being worked on.
Signed-off-by: Russ Anderson <rja@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index da14061..b78a17b1 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -102,6 +102,7 @@
# 64 bit specific files
ifeq ($(CONFIG_X86_64),y)
obj-y += genapic_64.o genapic_flat_64.o genx2apic_uv_x.o tlb_uv.o
+ obj-y += bios_uv.o
obj-$(CONFIG_X86_PM_TIMER) += pmtimer_64.o
obj-$(CONFIG_AUDIT) += audit_64.o
diff --git a/arch/x86/kernel/bios_uv.c b/arch/x86/kernel/bios_uv.c
new file mode 100644
index 0000000..c639bd5
--- /dev/null
+++ b/arch/x86/kernel/bios_uv.c
@@ -0,0 +1,48 @@
+/*
+ * BIOS run time interface routines.
+ *
+ * Copyright (c) 2008 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <asm/uv/bios.h>
+
+const char *
+x86_bios_strerror(long status)
+{
+ const char *str;
+ switch (status) {
+ case 0: str = "Call completed without error"; break;
+ case -1: str = "Not implemented"; break;
+ case -2: str = "Invalid argument"; break;
+ case -3: str = "Call completed with error"; break;
+ default: str = "Unknown BIOS status code"; break;
+ }
+ return str;
+}
+
+long
+x86_bios_freq_base(unsigned long which, unsigned long *ticks_per_second,
+ unsigned long *drift_info)
+{
+ struct uv_bios_retval isrv;
+
+ BIOS_CALL(isrv, BIOS_FREQ_BASE, which, 0, 0, 0, 0, 0, 0);
+ *ticks_per_second = isrv.v0;
+ *drift_info = isrv.v1;
+ return isrv.status;
+}
+EXPORT_SYMBOL_GPL(x86_bios_freq_base);
diff --git a/arch/x86/kernel/genx2apic_uv_x.c b/arch/x86/kernel/genx2apic_uv_x.c
index 711f11c..3c39293 100644
--- a/arch/x86/kernel/genx2apic_uv_x.c
+++ b/arch/x86/kernel/genx2apic_uv_x.c
@@ -24,6 +24,7 @@
#include <asm/pgtable.h>
#include <asm/uv/uv_mmrs.h>
#include <asm/uv/uv_hub.h>
+#include <asm/uv/bios.h>
DEFINE_PER_CPU(struct uv_hub_info_s, __uv_hub_info);
EXPORT_PER_CPU_SYMBOL_GPL(__uv_hub_info);
@@ -40,6 +41,9 @@
short uv_possible_blades;
EXPORT_SYMBOL_GPL(uv_possible_blades);
+unsigned long sn_rtc_cycles_per_second;
+EXPORT_SYMBOL(sn_rtc_cycles_per_second);
+
/* Start with all IRQs pointing to boot CPU. IRQ balancing will shift them. */
static cpumask_t uv_target_cpus(void)
@@ -272,6 +276,23 @@
map_high("MMIOH", mmioh.s.base, shift, map_uc);
}
+static __init void uv_rtc_init(void)
+{
+ long status, ticks_per_sec, drift;
+
+ status =
+ x86_bios_freq_base(BIOS_FREQ_BASE_REALTIME_CLOCK, &ticks_per_sec,
+ &drift);
+ if (status != 0 || ticks_per_sec < 100000) {
+ printk(KERN_WARNING
+ "unable to determine platform RTC clock frequency, "
+ "guessing.\n");
+ /* BIOS gives wrong value for clock freq. so guess */
+ sn_rtc_cycles_per_second = 1000000000000UL / 30000UL;
+ } else
+ sn_rtc_cycles_per_second = ticks_per_sec;
+}
+
static __init void uv_system_init(void)
{
union uvh_si_addr_map_config_u m_n_config;
@@ -326,6 +347,8 @@
gnode_upper = (((unsigned long)node_id.s.node_id) &
~((1 << n_val) - 1)) << m_val;
+ uv_rtc_init();
+
for_each_present_cpu(cpu) {
nid = cpu_to_node(cpu);
pnode = uv_apicid_to_pnode(per_cpu(x86_cpu_to_apicid, cpu));
diff --git a/include/asm-x86/uv/bios.h b/include/asm-x86/uv/bios.h
new file mode 100644
index 0000000..aa73362
--- /dev/null
+++ b/include/asm-x86/uv/bios.h
@@ -0,0 +1,68 @@
+#ifndef _ASM_X86_BIOS_H
+#define _ASM_X86_BIOS_H
+
+/*
+ * BIOS layer definitions.
+ *
+ * Copyright (c) 2008 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/rtc.h>
+
+#define BIOS_FREQ_BASE 0x01000001
+
+enum {
+ BIOS_FREQ_BASE_PLATFORM = 0,
+ BIOS_FREQ_BASE_INTERVAL_TIMER = 1,
+ BIOS_FREQ_BASE_REALTIME_CLOCK = 2
+};
+
+# define BIOS_CALL(result, a0, a1, a2, a3, a4, a5, a6, a7) \
+ do { \
+ /* XXX - the real call goes here */ \
+ result.status = BIOS_STATUS_UNIMPLEMENTED; \
+ isrv.v0 = 0; \
+ isrv.v1 = 0; \
+ } while (0)
+
+enum {
+ BIOS_STATUS_SUCCESS = 0,
+ BIOS_STATUS_UNIMPLEMENTED = -1,
+ BIOS_STATUS_EINVAL = -2,
+ BIOS_STATUS_ERROR = -3
+};
+
+struct uv_bios_retval {
+ /*
+ * A zero status value indicates call completed without error.
+ * A negative status value indicates reason of call failure.
+ * A positive status value indicates success but an
+ * informational value should be printed (e.g., "reboot for
+ * change to take effect").
+ */
+ s64 status;
+ u64 v0;
+ u64 v1;
+ u64 v2;
+};
+
+extern long
+x86_bios_freq_base(unsigned long which, unsigned long *ticks_per_second,
+ unsigned long *drift_info);
+extern const char *x86_bios_strerror(long status);
+
+#endif /* _ASM_X86_BIOS_H */