/*
* 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);
}
#ifdef CONFIG_SPARSEMEM_VMEMMAP
int __meminit radix__vmemmap_create_mapping(unsigned long start,
unsigned long page_size,
unsigned long phys)
{
/* Create a PTE encoding */
unsigned long flags = _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_KERNEL_RW;
BUG_ON(radix__map_kernel_page(start, phys, __pgprot(flags), page_size));
return 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG
void radix__vmemmap_remove_mapping(unsigned long start, unsigned long page_size)
{
/* FIXME!! intel does more. We should free page tables mapping vmemmap ? */
}
#endif
#endif
