[PATCH v2 14/20] mips: Use offset-sized IO-mem accessors in CPS debug printout

Sergey.Semin
2020-05-06T17:45:07Z

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

Similar to commit 8e5c62e38a88 ("mips: early_printk_8250: Use offset-sized
IO-mem accessors") the IO-memory might require to use a proper load/store
instructions (like Bailal-T1 IO-memory). To fix the cps-vec UART debug
printout lets use the memory access instructions in accordance with the
UART registers offset config specified at boot time.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-pm@vger.kernel.org
Cc: devicetree@vger.kernel.org

---
There might be another problem in cps-vec-ns16550.S connected with the
difference in CPU/devices endinanness on some platforms. But there is
no such for Baikal-T1 SoC.
---
arch/mips/kernel/cps-vec-ns16550.S | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/mips/kernel/cps-vec-ns16550.S b/arch/mips/kernel/cps-vec-ns16550.S
index d5a67b4ce9f6..2adb1c56c7c5 100644
--- a/arch/mips/kernel/cps-vec-ns16550.S
+++ b/arch/mips/kernel/cps-vec-ns16550.S
@@ -14,16 +14,30 @@
#define UART_TX_OFS (UART_TX << CONFIG_MIPS_CPS_NS16550_SHIFT)
#define UART_LSR_OFS (UART_LSR << CONFIG_MIPS_CPS_NS16550_SHIFT)

+#if CONFIG_MIPS_CPS_NS16550_SHIFT == 0
+# define UART_L lb
+# define UART_S sb
+#elif CONFIG_MIPS_CPS_NS16550_SHIFT == 1
+# define UART_L lh
+# define UART_S sh
+#elif CONFIG_MIPS_CPS_NS16550_SHIFT == 2
+# define UART_L lw
+# define UART_S sw
+#else
+# define UART_L lw
+# define UART_S sb
+#endif
+
/**
* _mips_cps_putc() - write a character to the UART
* @a0: ASCII character to write
* @t9: UART base address
*/
LEAF(_mips_cps_putc)
-1: lw t0, UART_LSR_OFS(t9)
+1: UART_L t0, UART_LSR_OFS(t9)
andi t0, t0, UART_LSR_TEMT
beqz t0, 1b
- sb a0, UART_TX_OFS(t9)
+ UART_S a0, UART_TX_OFS(t9)
jr ra
END(_mips_cps_putc)

--
2.25.1