[PATCH V2 32/68] powerpc/mm/radix: Add radix callback for early init routines

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

This add routines for early setup w.r.t radix. We use device tree
property ibm,processor-radix-AP-encodings to find supported page sizes.
If we don't find above we consider 64K and 4K as supported page sizes.

We do map vmemap using 2M page size if we can. Linear mapping is done
such that we use required page size for that range. For ex: memory of
3.5G is mapped such that we use 1G mapping till 3G range and use 2M
mapping for the rest.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/mmu.h   |  17 +-
 arch/powerpc/include/asm/book3s/64/radix.h |   2 +
 arch/powerpc/mm/Makefile                   |   1 +
 arch/powerpc/mm/pgtable-radix.c            | 344 +++++++++++++++++++++++++++++
 arch/powerpc/platforms/powernv/setup.c     |   5 +-
 5 files changed, 367 insertions(+), 2 deletions(-)
 create mode 100644 arch/powerpc/mm/pgtable-radix.c

diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index a66cd3e65a33..a526642f1c02 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -16,7 +16,10 @@ struct mmu_psize_def {
 	int		penc[MMU_PAGE_COUNT];	/* HPTE encoding */
 	unsigned int	tlbiel;	/* tlbiel supported for that page size */
 	unsigned long	avpnm;	/* bits to mask out in AVPN in the HPTE */
-	unsigned long	sllp;	/* SLB L||LP (exact mask to use in slbmte) */
+	union {
+		unsigned long	sllp;	/* SLB L||LP (exact mask to use in slbmte) */
+		unsigned long ap;	/* Ap encoding used by PowerISA 3.0 */
+	};
 };
 extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
 
@@ -98,22 +101,34 @@ extern int mmu_vmemmap_psize;
 extern int mmu_io_psize;
 
 /* MMU initialization */
+extern void radix_init_native(void);
 extern void hlearly_init_mmu(void);
+extern void rearly_init_mmu(void);
 static inline void early_init_mmu(void)
 {
+	if (radix_enabled())
+		return rearly_init_mmu();
 	return hlearly_init_mmu();
 }
 extern void hlearly_init_mmu_secondary(void);
+extern void rearly_init_mmu_secondary(void);
 static inline void early_init_mmu_secondary(void)
 {
+	if (radix_enabled())
+		return rearly_init_mmu_secondary();
 	return hlearly_init_mmu_secondary();
 }
 
 extern void hlsetup_initial_memory_limit(phys_addr_t first_memblock_base,
 					 phys_addr_t first_memblock_size);
+extern void rsetup_initial_memory_limit(phys_addr_t first_memblock_base,
+					 phys_addr_t first_memblock_size);
 static inline void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 					      phys_addr_t first_memblock_size)
 {
+	if (radix_enabled())
+		return rsetup_initial_memory_limit(first_memblock_base,
+						   first_memblock_size);
 	return hlsetup_initial_memory_limit(first_memblock_base,
 					   first_memblock_size);
 }
diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index 46a5381324f5..806dc2195f85 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -133,5 +133,7 @@ static inline int rpmd_trans_huge(pmd_t pmd)
 
 #endif
 
+extern int map_radix_kernel_page(unsigned long ea, unsigned long pa,
+				 pgprot_t flags, unsigned int psz);
 #endif /* __ASSEMBLY__ */
 #endif
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index ef778997daa9..d734934cbb1e 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_PPC_BOOK3E)	+= tlb_low_$(CONFIG_WORD_SIZE)e.o
 hash64-$(CONFIG_PPC_NATIVE)	:= hash_native_64.o
 obj-$(CONFIG_PPC_BOOK3E_64)   += pgtable-book3e.o
 obj-$(CONFIG_PPC_STD_MMU_64)	+= pgtable-hash64.o hash_utils_64.o slb_low.o slb.o $(hash64-y)
+obj-$(CONFIG_PPC_RADIX_MMU)	+= pgtable-radix.o
 obj-$(CONFIG_PPC_STD_MMU_32)	+= ppc_mmu_32.o hash_low_32.o
 obj-$(CONFIG_PPC_STD_MMU)	+= tlb_hash$(CONFIG_WORD_SIZE).o \
 				   mmu_context_hash$(CONFIG_WORD_SIZE).o
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
new file mode 100644
index 000000000000..5737769469b3
--- /dev/null
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -0,0 +1,344 @@
+/*
+ * page table handling routines for radix page table
+ *
+ *  Copyright (C) 2015 Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ */
+#include <linux/sched.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/dma.h>
+#include <asm/machdep.h>
+#include <asm/mmu.h>
+#include <asm/firmware.h>
+
+static int native_update_partition_table(u64 patb1)
+{
+	partition_tb->patb1 = cpu_to_be64(patb1);
+	return 0;
+}
+
+static __ref void *early_alloc_pgtable(unsigned long size)
+{
+	void *pt;
+
+	pt = __va(memblock_alloc_base(size, size, MEMBLOCK_ALLOC_ANYWHERE));
+	memset(pt, 0, size);
+
+	return pt;
+}
+
+int map_radix_kernel_page(unsigned long ea, unsigned long pa,
+			  pgprot_t flags,
+			  unsigned int map_page_size)
+{
+	pgd_t *pgdp;
+	pud_t *pudp;
+	pmd_t *pmdp;
+	pte_t *ptep;
+	/*
+	 * Make sure task size is correct as per the max adddr
+	 */
+	BUILD_BUG_ON(TASK_SIZE_USER64 > R_PGTABLE_RANGE);
+	if (slab_is_available()) {
+		pgdp = pgd_offset_k(ea);
+		pudp = pud_alloc(&init_mm, pgdp, ea);
+		if (!pudp)
+			return -ENOMEM;
+		if (map_page_size == PUD_SIZE) {
+			ptep = (pte_t *)pudp;
+			goto set_the_pte;
+		}
+		pmdp = pmd_alloc(&init_mm, pudp, ea);
+		if (!pmdp)
+			return -ENOMEM;
+		if (map_page_size == PMD_SIZE) {
+			ptep = (pte_t *)pudp;
+			goto set_the_pte;
+		}
+		ptep = pte_alloc_kernel(pmdp, ea);
+		if (!ptep)
+			return -ENOMEM;
+	} else {
+		pgdp = pgd_offset_k(ea);
+		if (pgd_none(*pgdp)) {
+			pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
+			BUG_ON(pudp == NULL);
+			pgd_populate(&init_mm, pgdp, pudp);
+		}
+		pudp = pud_offset(pgdp, ea);
+		if (map_page_size == PUD_SIZE) {
+			ptep = (pte_t *)pudp;
+			goto set_the_pte;
+		}
+		if (pud_none(*pudp)) {
+			pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
+			BUG_ON(pmdp == NULL);
+			pud_populate(&init_mm, pudp, pmdp);
+		}
+		pmdp = pmd_offset(pudp, ea);
+		if (map_page_size == PMD_SIZE) {
+			ptep = (pte_t *)pudp;
+			goto set_the_pte;
+		}
+		if (!pmd_present(*pmdp)) {
+			ptep = early_alloc_pgtable(PAGE_SIZE);
+			BUG_ON(ptep == NULL);
+			pmd_populate_kernel(&init_mm, pmdp, ptep);
+		}
+		ptep = pte_offset_kernel(pmdp, ea);
+	}
+
+set_the_pte:
+	set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, flags));
+	smp_wmb();
+	return 0;
+}
+
+static void __init radix_init_pgtable(void)
+{
+	int loop_count;
+	u64 base, end, start_addr;
+	unsigned long rts_field;
+	struct memblock_region *reg;
+	unsigned long linear_page_size;
+
+	/* We don't support slb for radix */
+	mmu_slb_size = 0;
+	/*
+	 * Create the linear mapping, using standard page size for now
+	 */
+	loop_count = 0;
+	for_each_memblock(memory, reg) {
+
+		start_addr = reg->base;
+
+redo:
+		if (loop_count < 1 && mmu_psize_defs[MMU_PAGE_1G].shift)
+			linear_page_size = PUD_SIZE;
+		else if (loop_count < 2 && mmu_psize_defs[MMU_PAGE_2M].shift)
+			linear_page_size = PMD_SIZE;
+		else
+			linear_page_size = PAGE_SIZE;
+
+		base = _ALIGN_UP(start_addr, linear_page_size);
+		end = _ALIGN_DOWN(reg->base + reg->size, linear_page_size);
+
+		pr_info("Mapping range 0x%lx - 0x%lx with 0x%lx\n",
+			(unsigned long)base, (unsigned long)end,
+			linear_page_size);
+
+		while (base < end) {
+			map_radix_kernel_page((unsigned long)__va(base),
+					      base, PAGE_KERNEL_X,
+					      linear_page_size);
+			base += linear_page_size;
+		}
+		/*
+		 * map the rest using lower page size
+		 */
+		if (end < reg->base + reg->size) {
+			start_addr = end;
+			loop_count++;
+			goto redo;
+		}
+	}
+	/*
+	 * Allocate Partition table and process table for the
+	 * host.
+	 */
+	BUILD_BUG_ON_MSG((PRTB_SIZE_SHIFT > 23), "Process table size too large.");
+	process_tb = early_alloc_pgtable(1UL << PRTB_SIZE_SHIFT);
+	/*
+	 * Fill in the process table.
+	 * we support 52 bits, hence 52-28 = 24, 11000
+	 */
+	rts_field = 3ull << PPC_BITLSHIFT(2);
+	process_tb->prtb0 = cpu_to_be64(rts_field | __pa(init_mm.pgd) | R_PGD_INDEX_SIZE);
+	/*
+	 * Fill in the partition table. We are suppose to use effective address
+	 * of process table here. But our linear mapping also enable us to use
+	 * physical address here.
+	 */
+	ppc_md.update_partition_table(__pa(process_tb) | (PRTB_SIZE_SHIFT - 12) | PATB_GR);
+	pr_info("Process table %p and radix root for kernel: %p\n", process_tb, init_mm.pgd);
+}
+
+static void __init radix_init_partition_table(void)
+{
+	unsigned long rts_field;
+	/*
+	 * we support 52 bits, hence 52-28 = 24, 11000
+	 */
+	rts_field = 3ull << PPC_BITLSHIFT(2);
+
+	BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 24), "Partition table size too large.");
+	partition_tb = early_alloc_pgtable(1UL << PATB_SIZE_SHIFT);
+	partition_tb->patb0 = cpu_to_be64(rts_field | __pa(init_mm.pgd) |
+					  R_PGD_INDEX_SIZE | PATB_HR);
+	printk("Partition table %p\n", partition_tb);
+
+	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
+	/*
+	 * update partition table control register,
+	 * 64 K size.
+	 */
+	mtspr(SPRN_PTCR, __pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
+}
+
+void __init radix_init_native(void)
+{
+	ppc_md.update_partition_table = native_update_partition_table;
+}
+
+static int __init get_idx_from_shift(unsigned int shift)
+{
+	int idx = -1;
+
+	switch (shift) {
+	case 0xc:
+		idx = MMU_PAGE_4K;
+		break;
+	case 0x10:
+		idx = MMU_PAGE_64K;
+		break;
+	case 0x15:
+		idx = MMU_PAGE_2M;
+		break;
+	case 0x1e:
+		idx = MMU_PAGE_1G;
+		break;
+	}
+	return idx;
+}
+
+static int __init radix_dt_scan_page_sizes(unsigned long node,
+					   const char *uname, int depth,
+					   void *data)
+{
+	int size = 0;
+	int shift, idx;
+	unsigned int ap;
+	const __be32 *prop;
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+
+	/* We are scanning "cpu" nodes only */
+	if (type == NULL || strcmp(type, "cpu") != 0)
+		return 0;
+
+	prop = of_get_flat_dt_prop(node, "ibm,processor-radix-AP-encodings", &size);
+	if (!prop)
+		return 0;
+
+	pr_info("Page sizes from device-tree:\n");
+	for (; size >= 4; size -= 4, ++prop) {
+
+		struct mmu_psize_def *def;
+
+		/* top 3 bit is AP encoding */
+		shift = be32_to_cpu(prop[0]) & ~(0xe << 28);
+		ap = be32_to_cpu(prop[0]) >> 29;
+		pr_info("Page size sift = %d AP=0x%x\n", shift, ap);
+
+		idx = get_idx_from_shift(shift);
+		if (idx < 0)
+			continue;
+
+		def = &mmu_psize_defs[idx];
+		def->shift = shift;
+		def->ap  = ap;
+	}
+
+	/* needed ? */
+	cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
+	return 1;
+}
+
+static void __init radix_init_page_sizes(void)
+{
+	int rc;
+
+	/*
+	 * Try to find the available page sizes in the device-tree
+	 */
+	rc = of_scan_flat_dt(radix_dt_scan_page_sizes, NULL);
+	if (rc != 0)  /* Found */
+		goto found;
+	/*
+	 * let's assume we have page 4k and 64k support
+	 */
+	mmu_psize_defs[MMU_PAGE_4K].shift = 12;
+	mmu_psize_defs[MMU_PAGE_4K].ap = 0x0;
+
+	mmu_psize_defs[MMU_PAGE_64K].shift = 16;
+	mmu_psize_defs[MMU_PAGE_64K].ap = 0x5;
+found:
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	if (mmu_psize_defs[MMU_PAGE_2M].shift) {
+		/*
+		 * map vmemmap using 2M if available
+		 */
+		mmu_vmemmap_psize = MMU_PAGE_2M;
+	}
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+	return;
+}
+
+void __init rearly_init_mmu(void)
+{
+#ifdef CONFIG_PPC_64K_PAGES
+	/* PAGE_SIZE mappings */
+	mmu_virtual_psize = MMU_PAGE_64K;
+#else
+	mmu_virtual_psize = MMU_PAGE_4K;
+#endif
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	/* vmemmap mapping */
+	mmu_vmemmap_psize = mmu_virtual_psize;
+#endif
+	/*
+	 * initialize page table size
+	 */
+	__pte_index_size = R_PTE_INDEX_SIZE;
+	__pmd_index_size = R_PMD_INDEX_SIZE;
+	__pud_index_size = R_PUD_INDEX_SIZE;
+	__pgd_index_size = R_PGD_INDEX_SIZE;
+	__pmd_cache_index = R_PMD_INDEX_SIZE;
+	__pte_table_size = R_PTE_TABLE_SIZE;
+	__pmd_table_size = R_PMD_TABLE_SIZE;
+	__pud_table_size = R_PUD_TABLE_SIZE;
+	__pgd_table_size = R_PGD_TABLE_SIZE;
+
+	radix_init_page_sizes();
+
+	if (!firmware_has_feature(FW_FEATURE_LPAR))
+		radix_init_partition_table();
+
+	radix_init_pgtable();
+}
+
+void rearly_init_mmu_secondary(void)
+{
+	/*
+	 * update partition table control register, 64 K size.
+	 */
+	if (!firmware_has_feature(FW_FEATURE_LPAR))
+		mtspr(SPRN_PTCR,
+		      __pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
+}
+
+void rsetup_initial_memory_limit(phys_addr_t first_memblock_base,
+				phys_addr_t first_memblock_size)
+{
+	/* Finally limit subsequent allocations */
+	memblock_set_current_limit(first_memblock_base + first_memblock_size);
+}
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 1acb0c72d923..ee6430bedcc3 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -273,7 +273,10 @@ static int __init pnv_probe(void)
 	if (!of_flat_dt_is_compatible(root, "ibm,powernv"))
 		return 0;
 
-	hpte_init_native();
+	if (IS_ENABLED(CONFIG_PPC_RADIX_MMU) && radix_enabled())
+		radix_init_native();
+	else if (IS_ENABLED(CONFIG_PPC_STD_MMU_64))
+		hpte_init_native();
 
 	if (firmware_has_feature(FW_FEATURE_OPAL))
 		pnv_setup_machdep_opal();
-- 
2.5.0