powerpc/mm/hash: Add support for Power9 Hash

PowerISA 3.0 adds a parition table indexed by LPID. Parition table
allows us to specify the MMU model that will be used for guest and host
translation.

This patch adds support with SLB based hash model (UPRT = 0). What is
required with this model is to support the new hash page table entry
format and also setup partition table such that we use hash table for
address translation.

We don't have segment table support yet.

In order to make sure we don't load KVM module on Power9 (since we don't
have kvm support yet) this patch also disables KVM on Power9.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 40 insertions, 2 deletions

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index eb928d86ce01..f76a033d1e16 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -676,6 +676,41 @@ int remove_section_mapping(unsigned long start, unsigned long end)
 }
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
+static void __init hash_init_partition_table(phys_addr_t hash_table,
+					     unsigned long pteg_count)
+{
+	unsigned long ps_field;
+	unsigned long htab_size;
+	unsigned long patb_size = 1UL << PATB_SIZE_SHIFT;
+
+	/*
+	 * slb llp encoding for the page size used in VPM real mode.
+	 * We can ignore that for lpid 0
+	 */
+	ps_field = 0;
+	htab_size =  __ilog2(pteg_count) - 11;
+
+	BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 24), "Partition table size too large.");
+	partition_tb = __va(memblock_alloc_base(patb_size, patb_size,
+						MEMBLOCK_ALLOC_ANYWHERE));
+
+	/* Initialize the Partition Table with no entries */
+	memset((void *)partition_tb, 0, patb_size);
+	partition_tb->patb0 = cpu_to_be64(ps_field | hash_table | htab_size);
+	/*
+	 * FIXME!! This should be done via update_partition table
+	 * For now UPRT is 0 for us.
+	 */
+	partition_tb->patb1 = 0;
+	DBG("Partition table %p\n", partition_tb);
+	/*
+	 * update partition table control register,
+	 * 64 K size.
+	 */
+	mtspr(SPRN_PTCR, __pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
+
+}
+
 static void __init htab_initialize(void)
 {
 	unsigned long table;
@@ -744,8 +779,11 @@ static void __init htab_initialize(void)
 		/* Initialize the HPT with no entries */
 		memset((void *)table, 0, htab_size_bytes);
 
-		/* Set SDR1 */
-		mtspr(SPRN_SDR1, _SDR1);
+		if (!cpu_has_feature(CPU_FTR_ARCH_300))
+			/* Set SDR1 */
+			mtspr(SPRN_SDR1, _SDR1);
+		else
+			hash_init_partition_table(table, pteg_count);
 	}
 
 	prot = pgprot_val(PAGE_KERNEL);