From 833b441ec0f6f3c57cc2106ef628bb19d8fb0ee2 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.ibm.com>
Date: Tue, 23 Apr 2019 13:14:28 +0200
Subject: [PATCH] s390: enable processes for mio instructions
Allow for userspace to use PCI MIO instructions.
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
arch/s390/include/asm/pci_insn.h | 10 ++++++++++
arch/s390/kernel/early.c | 2 ++
2 files changed, 12 insertions(+)
diff --git a/arch/s390/include/asm/pci_insn.h b/arch/s390/include/asm/pci_insn.h
index 61cf9531f68f2..ff81ed19c5065 100644
--- a/arch/s390/include/asm/pci_insn.h
+++ b/arch/s390/include/asm/pci_insn.h
@@ -143,4 +143,14 @@ static inline int zpci_set_irq_ctrl(u16 ctl, u8 isc)
return __zpci_set_irq_ctrl(ctl, isc, &iib);
}
+#ifdef CONFIG_PCI
+static inline void enable_mio_ctl(void)
+{
+ if (static_branch_likely(&have_mio))
+ __ctl_set_bit(2, 5);
+}
+#else /* CONFIG_PCI */
+static inline void enable_mio_ctl(void) {}
+#endif /* CONFIG_PCI */
+
#endif
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index c196abda36c77..ab09ada0e930d 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -30,6 +30,7 @@
#include <asm/sclp.h>
#include <asm/facility.h>
#include <asm/boot_data.h>
+#include <asm/pci_insn.h>
#include "entry.h"
/*
@@ -235,6 +236,7 @@ static __init void detect_machine_facilities(void)
clock_comparator_max = -1ULL >> 1;
__ctl_set_bit(0, 53);
}
+ enable_mio_ctl();
}
static inline void save_vector_registers(void)
--
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