From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
linux-kernel@vger.kernel.org
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: [PATCH v2 5/7] x86/boot: Add MMIO byte accessors
Date: Tue, 19 Mar 2019 21:43:23 +0300 [thread overview]
Message-ID: <20190319184325.72807-6-andriy.shevchenko@linux.intel.com> (raw)
In-Reply-To: <20190319184325.72807-1-andriy.shevchenko@linux.intel.com>
readb() and writeb() would help to access serial device
via MMIO address space.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
arch/x86/boot/boot.h | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index 86641b2e83f8..b2a272d3f36b 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -79,6 +79,18 @@ static inline void io_delay(void)
asm volatile("outb %%al,%0" : : "dN" (DELAY_PORT));
}
+static inline u8 readb(const volatile void __iomem *addr)
+{
+ u8 v;
+ asm volatile("movb %1,%0" : "=q" (v) : "m" (*(volatile u8 __force *)addr));
+ return v;
+}
+
+static inline void writeb(u8 v, volatile void __iomem *addr)
+{
+ asm volatile("movb %0,%1" : : "q" (v), "m" (*(volatile u8 __force *)addr));
+}
+
/* These functions are used to reference data in other segments. */
static inline u16 ds(void)
--
2.20.1
next prev parent reply other threads:[~2019-03-19 18:43 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-19 18:43 [PATCH v2 0/7] x86/boot: Enable earlyprintk for HS UARTs Andy Shevchenko
2019-03-19 18:43 ` [PATCH v2 1/7] x86/boot: Convert early_serial_base to unsigned long Andy Shevchenko
2019-03-28 8:28 ` Borislav Petkov
2019-03-28 9:09 ` Andy Shevchenko
2019-03-28 10:54 ` Borislav Petkov
2019-03-19 18:43 ` [PATCH v2 2/7] x86/boot: Introduce helpers for serial I/O Andy Shevchenko
2019-03-28 12:32 ` Borislav Petkov
2019-03-28 13:11 ` Andy Shevchenko
2019-03-28 13:28 ` Borislav Petkov
2019-03-28 13:52 ` Andy Shevchenko
2019-03-28 14:05 ` Borislav Petkov
2019-03-28 14:20 ` Andy Shevchenko
2019-03-28 14:34 ` Borislav Petkov
2019-03-28 14:51 ` Andy Shevchenko
2019-03-19 18:43 ` [PATCH v2 3/7] x86/boot: Split out parse_serial_port() helper for earlyprintk Andy Shevchenko
2019-03-28 12:35 ` Borislav Petkov
2019-03-28 13:15 ` Andy Shevchenko
2019-03-28 13:39 ` Borislav Petkov
2019-03-28 13:50 ` Andy Shevchenko
2019-03-28 14:03 ` Borislav Petkov
2019-03-28 14:23 ` Andy Shevchenko
2019-03-28 14:35 ` Borislav Petkov
2019-03-28 14:49 ` Andy Shevchenko
2019-03-19 18:43 ` [PATCH v2 4/7] x86/boot: Allow longer parameter list " Andy Shevchenko
2019-03-19 18:43 ` Andy Shevchenko [this message]
2019-03-19 18:43 ` [PATCH v2 6/7] x86/boot: Introduce MMIO accessors and their support in earlyprintk Andy Shevchenko
2019-03-19 18:43 ` [PATCH v2 7/7] x86/boot: Support nocfg parameter for earlyprintk Andy Shevchenko
2019-03-20 15:05 ` Randy Dunlap
2019-03-20 15:17 ` Andy Shevchenko
2019-03-20 15:19 ` Randy Dunlap
2019-03-20 16:15 ` Andy Shevchenko
2019-03-20 16:30 ` Borislav Petkov
2019-03-20 17:29 ` Andy Shevchenko
2019-03-28 13:03 ` Borislav Petkov
2019-03-28 13:21 ` Andy Shevchenko
2019-03-28 13:42 ` Borislav Petkov
2019-03-28 14:00 ` Andy Shevchenko
2019-03-28 14:13 ` Borislav Petkov
2019-03-28 14:27 ` Andy Shevchenko
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