MIPS: Netlogic: Add 32-bit support for XLP
Update asm/netlogic/haldefs.h to extend register access functions
nlm_{read,write}_reg64() for 32-bit compilation. When compiled for 32-bit
the functions will read 64 IO registers with interrupts disabled.
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/5026/
Acked-by: John Crispin <blogic@openwrt.org>
diff --git a/arch/mips/include/asm/netlogic/haldefs.h b/arch/mips/include/asm/netlogic/haldefs.h
index 419d8ae..61fecb8 100644
--- a/arch/mips/include/asm/netlogic/haldefs.h
+++ b/arch/mips/include/asm/netlogic/haldefs.h
@@ -35,14 +35,13 @@
#ifndef __NLM_HAL_HALDEFS_H__
#define __NLM_HAL_HALDEFS_H__
+#include <linux/irqflags.h> /* for local_irq_disable */
+
/*
* This file contains platform specific memory mapped IO implementation
* and will provide a way to read 32/64 bit memory mapped registers in
* all ABIs
*/
-#if !defined(CONFIG_64BIT) && defined(CONFIG_CPU_XLP)
-#error "o32 compile not supported on XLP yet"
-#endif
/*
* For o32 compilation, we have to disable interrupts and enable KX bit to
* access 64 bit addresses or data.
@@ -87,13 +86,40 @@
*addr = val;
}
+/*
+ * For o32 compilation, we have to disable interrupts to access 64 bit
+ * registers
+ *
+ * We need to disable interrupts because we save just the lower 32 bits of
+ * registers in interrupt handling. So if we get hit by an interrupt while
+ * using the upper 32 bits of a register, we lose.
+ */
+
static inline uint64_t
nlm_read_reg64(uint64_t base, uint32_t reg)
{
uint64_t addr = base + (reg >> 1) * sizeof(uint64_t);
volatile uint64_t *ptr = (volatile uint64_t *)(long)addr;
+ uint64_t val;
- return *ptr;
+ if (sizeof(unsigned long) == 4) {
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __asm__ __volatile__(
+ ".set push" "\n\t"
+ ".set mips64" "\n\t"
+ "ld %L0, %1" "\n\t"
+ "dsra32 %M0, %L0, 0" "\n\t"
+ "sll %L0, %L0, 0" "\n\t"
+ ".set pop" "\n"
+ : "=r" (val)
+ : "m" (*ptr));
+ local_irq_restore(flags);
+ } else
+ val = *ptr;
+
+ return val;
}
static inline void
@@ -102,7 +128,25 @@
uint64_t addr = base + (reg >> 1) * sizeof(uint64_t);
volatile uint64_t *ptr = (volatile uint64_t *)(long)addr;
- *ptr = val;
+ if (sizeof(unsigned long) == 4) {
+ unsigned long flags;
+ uint64_t tmp;
+
+ local_irq_save(flags);
+ __asm__ __volatile__(
+ ".set push" "\n\t"
+ ".set mips64" "\n\t"
+ "dsll32 %L0, %L0, 0" "\n\t"
+ "dsrl32 %L0, %L0, 0" "\n\t"
+ "dsll32 %M0, %M0, 0" "\n\t"
+ "or %L0, %L0, %M0" "\n\t"
+ "sd %L0, %2" "\n\t"
+ ".set pop" "\n"
+ : "=r" (tmp)
+ : "0" (val), "m" (*ptr));
+ local_irq_restore(flags);
+ } else
+ *ptr = val;
}
/*