[PATCH v5 4/7] powerpc/mm: Use UV_WRITE_PATE ucall to register a PATE

[Claudio Carvalho <cclaudio@linux.ibm.com>]

From: Michael Anderson <andmike@linux.ibm.com>

In ultravisor enabled systems, the ultravisor creates and maintains the
partition table in secure memory where the hypervisor cannot access, and
therefore, the hypervisor have to do the UV_WRITE_PATE ucall whenever it
wants to set a partition table entry (PATE).

This patch adds the UV_WRITE_PATE ucall and uses it to set a PATE if
ultravisor is enabled. Additionally, this also also keeps a copy of the
partition table because the nestMMU does not have access to secure
memory. Such copy has entries for nonsecure and hypervisor partition.

Signed-off-by: Michael Anderson <andmike@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[ cclaudio: Write the PATE in HV's table before doing that in UV's ]
Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Reviewed-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/ultravisor-api.h |  5 ++
 arch/powerpc/include/asm/ultravisor.h     |  8 +++
 arch/powerpc/mm/book3s64/pgtable.c        | 60 ++++++++++++++++-------
 3 files changed, 56 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h
index 88ffa78f9d61..8cd49abff4f3 100644
--- a/arch/powerpc/include/asm/ultravisor-api.h
+++ b/arch/powerpc/include/asm/ultravisor-api.h
@@ -11,6 +11,7 @@
 #include <asm/hvcall.h>
 
 /* Return codes */
+#define U_BUSY			H_BUSY
 #define U_FUNCTION		H_FUNCTION
 #define U_NOT_AVAILABLE		H_NOT_AVAILABLE
 #define U_P2			H_P2
@@ -18,6 +19,10 @@
 #define U_P4			H_P4
 #define U_P5			H_P5
 #define U_PARAMETER		H_PARAMETER
+#define U_PERMISSION		H_PERMISSION
 #define U_SUCCESS		H_SUCCESS
 
+/* opcodes */
+#define UV_WRITE_PATE			0xF104
+
 #endif /* _ASM_POWERPC_ULTRAVISOR_API_H */
diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h
index dc6e1ea198f2..6fe1f365dec8 100644
--- a/arch/powerpc/include/asm/ultravisor.h
+++ b/arch/powerpc/include/asm/ultravisor.h
@@ -8,7 +8,15 @@
 #ifndef _ASM_POWERPC_ULTRAVISOR_H
 #define _ASM_POWERPC_ULTRAVISOR_H
 
+#include <asm/asm-prototypes.h>
+#include <asm/ultravisor-api.h>
+
 int early_init_dt_scan_ultravisor(unsigned long node, const char *uname,
 				  int depth, void *data);
 
+static inline int uv_register_pate(u64 lpid, u64 dw0, u64 dw1)
+{
+	return ucall_norets(UV_WRITE_PATE, lpid, dw0, dw1);
+}
+
 #endif	/* _ASM_POWERPC_ULTRAVISOR_H */
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 85bc81abd286..033731f5dbaa 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -16,6 +16,8 @@
 #include <asm/tlb.h>
 #include <asm/trace.h>
 #include <asm/powernv.h>
+#include <asm/firmware.h>
+#include <asm/ultravisor.h>
 
 #include <mm/mmu_decl.h>
 #include <trace/events/thp.h>
@@ -198,7 +200,15 @@ void __init mmu_partition_table_init(void)
 	unsigned long ptcr;
 
 	BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 36), "Partition table size too large.");
-	/* Initialize the Partition Table with no entries */
+	/*
+	 * Initialize the Partition Table with no entries, even in the presence
+	 * of an ultravisor firmware.
+	 *
+	 * In ultravisor enabled systems, the ultravisor creates and maintains
+	 * the partition table in secure memory. However, we keep a copy of the
+	 * partition table because nestMMU cannot access secure memory. Our copy
+	 * contains entries for nonsecure and hypervisor partition.
+	 */
 	partition_tb = memblock_alloc(patb_size, patb_size);
 	if (!partition_tb)
 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
@@ -213,34 +223,50 @@ void __init mmu_partition_table_init(void)
 	powernv_set_nmmu_ptcr(ptcr);
 }
 
-void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
-				   unsigned long dw1)
+/*
+ * Global flush of TLBs and partition table caches for this lpid. The type of
+ * flush (hash or radix) depends on what the previous use of this partition ID
+ * was, not the new use.
+ */
+static void flush_partition(unsigned int lpid, unsigned long old_patb0)
 {
-	unsigned long old = be64_to_cpu(partition_tb[lpid].patb0);
-
-	partition_tb[lpid].patb0 = cpu_to_be64(dw0);
-	partition_tb[lpid].patb1 = cpu_to_be64(dw1);
-
-	/*
-	 * Global flush of TLBs and partition table caches for this lpid.
-	 * The type of flush (hash or radix) depends on what the previous
-	 * use of this partition ID was, not the new use.
-	 */
 	asm volatile("ptesync" : : : "memory");
-	if (old & PATB_HR) {
-		asm volatile(PPC_TLBIE_5(%0,%1,2,0,1) : :
+	if (old_patb0 & PATB_HR) {
+		asm volatile(PPC_TLBIE_5(%0, %1, 2, 0, 1) : :
 			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
-		asm volatile(PPC_TLBIE_5(%0,%1,2,1,1) : :
+		asm volatile(PPC_TLBIE_5(%0, %1, 2, 1, 1) : :
 			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
 		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 1);
 	} else {
-		asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
+		asm volatile(PPC_TLBIE_5(%0, %1, 2, 0, 0) : :
 			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
 		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
 	}
 	/* do we need fixup here ?*/
 	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
 }
+
+void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
+				  unsigned long dw1)
+{
+	unsigned long old = be64_to_cpu(partition_tb[lpid].patb0);
+
+	partition_tb[lpid].patb0 = cpu_to_be64(dw0);
+	partition_tb[lpid].patb1 = cpu_to_be64(dw1);
+
+	/*
+	 * In ultravisor enabled systems, the ultravisor maintains the partition
+	 * table in secure memory where we don't have access, therefore, we have
+	 * to do a ucall to set an entry.
+	 */
+	if (firmware_has_feature(FW_FEATURE_ULTRAVISOR)) {
+		uv_register_pate(lpid, dw0, dw1);
+		pr_info("PATE registered by ultravisor: dw0 = 0x%lx, dw1 = 0x%lx\n",
+			dw0, dw1);
+	} else {
+		flush_partition(lpid, old);
+	}
+}
 EXPORT_SYMBOL_GPL(mmu_partition_table_set_entry);
 
 static pmd_t *get_pmd_from_cache(struct mm_struct *mm)
-- 
2.20.1