--- /dev/null
+/*
+ * Page table handling routines for radix page table.
+ *
+ * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
+ *
+ * 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 radix__map_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 > RADIX_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) {
+ radix__map_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) | RADIX_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) |
+ RADIX_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 radix__early_init_mmu(void)
+{
+ unsigned long lpcr;
+ /*
+ * setup LPCR UPRT based on mmu_features
+ */
+ lpcr = mfspr(SPRN_LPCR);
+ mtspr(SPRN_LPCR, lpcr | LPCR_UPRT);
+
+#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 = RADIX_PTE_INDEX_SIZE;
+ __pmd_index_size = RADIX_PMD_INDEX_SIZE;
+ __pud_index_size = RADIX_PUD_INDEX_SIZE;
+ __pgd_index_size = RADIX_PGD_INDEX_SIZE;
+ __pmd_cache_index = RADIX_PMD_INDEX_SIZE;
+ __pte_table_size = RADIX_PTE_TABLE_SIZE;
+ __pmd_table_size = RADIX_PMD_TABLE_SIZE;
+ __pud_table_size = RADIX_PUD_TABLE_SIZE;
+ __pgd_table_size = RADIX_PGD_TABLE_SIZE;
+
+ radix_init_page_sizes();
+
+ if (!firmware_has_feature(FW_FEATURE_LPAR))
+ radix_init_partition_table();
+
+ radix_init_pgtable();
+}
+
+void radix__early_init_mmu_secondary(void)
+{
+ unsigned long lpcr;
+ /*
+ * setup LPCR UPRT based on mmu_features
+ */
+ lpcr = mfspr(SPRN_LPCR);
+ mtspr(SPRN_LPCR, lpcr | LPCR_UPRT);
+ /*
+ * 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 radix__setup_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);
+}
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