6 files changed, 35 insertions, 17 deletions
diff --git a/arch/loongarch/include/asm/addrspace.h b/arch/loongarch/include/asm/addrspace.h
index 7bd47d65bf7a..fe198b473f84 100644
--- a/arch/loongarch/include/asm/addrspace.h
+++ b/arch/loongarch/include/asm/addrspace.h
@@ -37,6 +37,10 @@ extern unsigned long vm_map_base;
 #define UNCACHE_BASE		CSR_DMW0_BASE
 #endif
 
+#ifndef WRITECOMBINE_BASE
+#define WRITECOMBINE_BASE	CSR_DMW2_BASE
+#endif
+
 #define DMW_PABITS	48
 #define TO_PHYS_MASK	((1ULL << DMW_PABITS) - 1)
 
diff --git a/arch/loongarch/include/asm/io.h b/arch/loongarch/include/asm/io.h
index c2f9979b2979..5e95a60df180 100644
--- a/arch/loongarch/include/asm/io.h
+++ b/arch/loongarch/include/asm/io.h
@@ -25,10 +25,16 @@ extern void __init early_iounmap(void __iomem *addr, unsigned long size);
 static inline void __iomem *ioremap_prot(phys_addr_t offset, unsigned long size,
 					 unsigned long prot_val)
 {
-	if (prot_val & _CACHE_CC)
+	switch (prot_val & _CACHE_MASK) {
+	case _CACHE_CC:
 		return (void __iomem *)(unsigned long)(CACHE_BASE + offset);
-	else
+	case _CACHE_SUC:
 		return (void __iomem *)(unsigned long)(UNCACHE_BASE + offset);
+	case _CACHE_WUC:
+		return (void __iomem *)(unsigned long)(WRITECOMBINE_BASE + offset);
+	default:
+		return NULL;
+	}
 }
 
 #define ioremap(offset, size)		\
diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h
index eb09adda54b7..c430df595376 100644
--- a/arch/loongarch/include/asm/loongarch.h
+++ b/arch/loongarch/include/asm/loongarch.h
@@ -877,7 +877,7 @@
 #define LOONGARCH_CSR_DMWIN2		0x182	/* 64 direct map win2: MEM */
 #define LOONGARCH_CSR_DMWIN3		0x183	/* 64 direct map win3: MEM */
 
-/* Direct Map window 0/1 */
+/* Direct Map window 0/1/2/3 */
 #define CSR_DMW0_PLV0		_CONST64_(1 << 0)
 #define CSR_DMW0_VSEG		_CONST64_(0x8000)
 #define CSR_DMW0_BASE		(CSR_DMW0_VSEG << DMW_PABITS)
@@ -889,6 +889,14 @@
 #define CSR_DMW1_BASE		(CSR_DMW1_VSEG << DMW_PABITS)
 #define CSR_DMW1_INIT		(CSR_DMW1_BASE | CSR_DMW1_MAT | CSR_DMW1_PLV0)
 
+#define CSR_DMW2_PLV0		_CONST64_(1 << 0)
+#define CSR_DMW2_MAT		_CONST64_(2 << 4)
+#define CSR_DMW2_VSEG		_CONST64_(0xa000)
+#define CSR_DMW2_BASE		(CSR_DMW2_VSEG << DMW_PABITS)
+#define CSR_DMW2_INIT		(CSR_DMW2_BASE | CSR_DMW2_MAT | CSR_DMW2_PLV0)
+
+#define CSR_DMW3_INIT		0x0
+
 /* Performance Counter registers */
 #define LOONGARCH_CSR_PERFCTRL0		0x200	/* 32 perf event 0 config */
 #define LOONGARCH_CSR_PERFCNTR0		0x201	/* 64 perf event 0 count value */
diff --git a/arch/loongarch/include/asm/stackframe.h b/arch/loongarch/include/asm/stackframe.h
index d9eafd3ee3d1..66736837085b 100644
--- a/arch/loongarch/include/asm/stackframe.h
+++ b/arch/loongarch/include/asm/stackframe.h
@@ -38,6 +38,17 @@
 	cfi_restore \reg \offset \docfi
 	.endm
 
+	.macro SETUP_DMWINS temp
+	li.d	\temp, CSR_DMW0_INIT	# WUC, PLV0, 0x8000 xxxx xxxx xxxx
+	csrwr	\temp, LOONGARCH_CSR_DMWIN0
+	li.d	\temp, CSR_DMW1_INIT	# CAC, PLV0, 0x9000 xxxx xxxx xxxx
+	csrwr	\temp, LOONGARCH_CSR_DMWIN1
+	li.d	\temp, CSR_DMW2_INIT	# WUC, PLV0, 0xa000 xxxx xxxx xxxx
+	csrwr	\temp, LOONGARCH_CSR_DMWIN2
+	li.d	\temp, CSR_DMW3_INIT	# 0x0, unused
+	csrwr	\temp, LOONGARCH_CSR_DMWIN3
+	.endm
+
 /* Jump to the runtime virtual address. */
 	.macro JUMP_VIRT_ADDR temp1 temp2
 	li.d	\temp1, CACHE_BASE
diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S
index 4677ea8fa8e9..506a99a5bbc7 100644
--- a/arch/loongarch/kernel/head.S
+++ b/arch/loongarch/kernel/head.S
@@ -44,11 +44,7 @@ SYM_DATA(kernel_fsize, .long _kernel_fsize);
 SYM_CODE_START(kernel_entry)			# kernel entry point
 
 	/* Config direct window and set PG */
-	li.d		t0, CSR_DMW0_INIT	# UC, PLV0, 0x8000 xxxx xxxx xxxx
-	csrwr		t0, LOONGARCH_CSR_DMWIN0
-	li.d		t0, CSR_DMW1_INIT	# CA, PLV0, 0x9000 xxxx xxxx xxxx
-	csrwr		t0, LOONGARCH_CSR_DMWIN1
-
+	SETUP_DMWINS	t0
 	JUMP_VIRT_ADDR	t0, t1
 
 	/* Enable PG */
@@ -124,11 +120,8 @@ SYM_CODE_END(kernel_entry)
  * function after setting up the stack and tp registers.
  */
 SYM_CODE_START(smpboot_entry)
-	li.d		t0, CSR_DMW0_INIT	# UC, PLV0
-	csrwr		t0, LOONGARCH_CSR_DMWIN0
-	li.d		t0, CSR_DMW1_INIT	# CA, PLV0
-	csrwr		t0, LOONGARCH_CSR_DMWIN1
 
+	SETUP_DMWINS	t0
 	JUMP_VIRT_ADDR	t0, t1
 
 #ifdef CONFIG_PAGE_SIZE_4KB
diff --git a/arch/loongarch/power/suspend_asm.S b/arch/loongarch/power/suspend_asm.S
index e2fc3b4e31f0..c28ad52b7baf 100644
--- a/arch/loongarch/power/suspend_asm.S
+++ b/arch/loongarch/power/suspend_asm.S
@@ -73,11 +73,7 @@ SYM_FUNC_START(loongarch_suspend_enter)
 	 * Reload all of the registers and return.
 	 */
 SYM_INNER_LABEL(loongarch_wakeup_start, SYM_L_GLOBAL)
-	li.d		t0, CSR_DMW0_INIT	# UC, PLV0
-	csrwr		t0, LOONGARCH_CSR_DMWIN0
-	li.d		t0, CSR_DMW1_INIT	# CA, PLV0
-	csrwr		t0, LOONGARCH_CSR_DMWIN1
-
+	SETUP_DMWINS	t0
 	JUMP_VIRT_ADDR	t0, t1
 
 	/* Enable PG */