powerpc/mm: Update the HID bit when switching from radix to hash

Power9 DD1 requires to update the hid0 register when switching from
hash to radix.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/reg.h

@@ -475,6 +475,9 @@
 #define HID0_POWER8_1TO4LPAR	__MASK(51)
 #define HID0_POWER8_DYNLPARDIS	__MASK(48)
 
+/* POWER9 HID0 bits */
+#define HID0_POWER9_RADIX	__MASK(63 - 8)
+
 #define SPRN_HID1	0x3F1		/* Hardware Implementation Register 1 */
 #ifdef CONFIG_6xx
 #define HID1_EMCP	(1<<31)		/* 7450 Machine Check Pin Enable */

arch/powerpc/mm/hash_utils_64.c

@@ -711,6 +711,29 @@ int remove_section_mapping(unsigned long start, unsigned long end)
 }
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
+static void update_hid_for_hash(void)
+{
+	unsigned long hid0;
+	unsigned long rb = 3UL << PPC_BITLSHIFT(53); /* IS = 3 */
+
+	asm volatile("ptesync": : :"memory");
+	/* prs = 0, ric = 2, rs = 0, r = 1 is = 3 */
+	asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
+		     : : "r"(rb), "i"(0), "i"(0), "i"(2), "r"(0) : "memory");
+	asm volatile("eieio; tlbsync; ptesync; isync; slbia": : :"memory");
+	/*
+	 * now switch the HID
+	 */
+	hid0  = mfspr(SPRN_HID0);
+	hid0 &= ~HID0_POWER9_RADIX;
+	mtspr(SPRN_HID0, hid0);
+	asm volatile("isync": : :"memory");
+
+	/* Wait for it to happen */
+	while ((mfspr(SPRN_HID0) & HID0_POWER9_RADIX))
+		cpu_relax();
+}
+
 static void __init hash_init_partition_table(phys_addr_t hash_table,
 					     unsigned long htab_size)
 {
@@ -737,6 +760,8 @@ static void __init hash_init_partition_table(phys_addr_t hash_table,
 	 */
 	partition_tb->patb1 = 0;
 	pr_info("Partition table %p\n", partition_tb);
+	if (cpu_has_feature(CPU_FTR_POWER9_DD1))
+		update_hid_for_hash();
 	/*
 	 * update partition table control register,
 	 * 64 K size.

arch/powerpc/mm/pgtable-radix.c

@@ -294,6 +294,32 @@ void __init radix__early_init_devtree(void)
 	return;
 }
 
+static void update_hid_for_radix(void)
+{
+	unsigned long hid0;
+	unsigned long rb = 3UL << PPC_BITLSHIFT(53); /* IS = 3 */
+
+	asm volatile("ptesync": : :"memory");
+	/* prs = 0, ric = 2, rs = 0, r = 1 is = 3 */
+	asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
+		     : : "r"(rb), "i"(1), "i"(0), "i"(2), "r"(0) : "memory");
+	/* prs = 1, ric = 2, rs = 0, r = 1 is = 3 */
+	asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
+		     : : "r"(rb), "i"(1), "i"(1), "i"(2), "r"(0) : "memory");
+	asm volatile("eieio; tlbsync; ptesync; isync; slbia": : :"memory");
+	/*
+	 * now switch the HID
+	 */
+	hid0  = mfspr(SPRN_HID0);
+	hid0 |= HID0_POWER9_RADIX;
+	mtspr(SPRN_HID0, hid0);
+	asm volatile("isync": : :"memory");
+
+	/* Wait for it to happen */
+	while (!(mfspr(SPRN_HID0) & HID0_POWER9_RADIX))
+		cpu_relax();
+}
+
 void __init radix__early_init_mmu(void)
 {
 	unsigned long lpcr;
@@ -345,6 +371,8 @@ void __init radix__early_init_mmu(void)
 
 	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
 		radix_init_native();
+		if (cpu_has_feature(CPU_FTR_POWER9_DD1))
+			update_hid_for_radix();
 		lpcr = mfspr(SPRN_LPCR);
 		mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR);
 		radix_init_partition_table();