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OpenCloudOS-Kernel/arch/powerpc/mm/tlb_nohash.c

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/*
* This file contains the routines for TLB flushing.
* On machines where the MMU does not use a hash table to store virtual to
* physical translations (ie, SW loaded TLBs or Book3E compilant processors,
* this does -not- include 603 however which shares the implementation with
* hash based processors)
*
* -- BenH
*
* Copyright 2008,2009 Ben Herrenschmidt <benh@kernel.crashing.org>
* IBM Corp.
*
* Derived from arch/ppc/mm/init.c:
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* 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/kernel.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
#include <linux/hugetlb.h>
#include <asm/tlbflush.h>
#include <asm/tlb.h>
#include <asm/code-patching.h>
#include <asm/cputhreads.h>
#include <asm/hugetlb.h>
#include <asm/paca.h>
#include "mmu_decl.h"
/*
* This struct lists the sw-supported page sizes. The hardawre MMU may support
* other sizes not listed here. The .ind field is only used on MMUs that have
* indirect page table entries.
*/
#if defined(CONFIG_PPC_BOOK3E_MMU) || defined(CONFIG_PPC_8xx)
#ifdef CONFIG_PPC_FSL_BOOK3E
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
[MMU_PAGE_4K] = {
.shift = 12,
.enc = BOOK3E_PAGESZ_4K,
},
[MMU_PAGE_2M] = {
.shift = 21,
.enc = BOOK3E_PAGESZ_2M,
},
[MMU_PAGE_4M] = {
.shift = 22,
.enc = BOOK3E_PAGESZ_4M,
},
[MMU_PAGE_16M] = {
.shift = 24,
.enc = BOOK3E_PAGESZ_16M,
},
[MMU_PAGE_64M] = {
.shift = 26,
.enc = BOOK3E_PAGESZ_64M,
},
[MMU_PAGE_256M] = {
.shift = 28,
.enc = BOOK3E_PAGESZ_256M,
},
[MMU_PAGE_1G] = {
.shift = 30,
.enc = BOOK3E_PAGESZ_1GB,
},
};
#elif defined(CONFIG_PPC_8xx)
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
/* we only manage 4k and 16k pages as normal pages */
#ifdef CONFIG_PPC_4K_PAGES
[MMU_PAGE_4K] = {
.shift = 12,
},
#else
[MMU_PAGE_16K] = {
.shift = 14,
},
#endif
[MMU_PAGE_512K] = {
.shift = 19,
},
[MMU_PAGE_8M] = {
.shift = 23,
},
};
#else
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
[MMU_PAGE_4K] = {
.shift = 12,
.ind = 20,
.enc = BOOK3E_PAGESZ_4K,
},
[MMU_PAGE_16K] = {
.shift = 14,
.enc = BOOK3E_PAGESZ_16K,
},
[MMU_PAGE_64K] = {
.shift = 16,
.ind = 28,
.enc = BOOK3E_PAGESZ_64K,
},
[MMU_PAGE_1M] = {
.shift = 20,
.enc = BOOK3E_PAGESZ_1M,
},
[MMU_PAGE_16M] = {
.shift = 24,
.ind = 36,
.enc = BOOK3E_PAGESZ_16M,
},
[MMU_PAGE_256M] = {
.shift = 28,
.enc = BOOK3E_PAGESZ_256M,
},
[MMU_PAGE_1G] = {
.shift = 30,
.enc = BOOK3E_PAGESZ_1GB,
},
};
#endif /* CONFIG_FSL_BOOKE */
static inline int mmu_get_tsize(int psize)
{
return mmu_psize_defs[psize].enc;
}
#else
static inline int mmu_get_tsize(int psize)
{
/* This isn't used on !Book3E for now */
return 0;
}
#endif /* CONFIG_PPC_BOOK3E_MMU */
/* The variables below are currently only used on 64-bit Book3E
* though this will probably be made common with other nohash
* implementations at some point
*/
#ifdef CONFIG_PPC64
int mmu_linear_psize; /* Page size used for the linear mapping */
int mmu_pte_psize; /* Page size used for PTE pages */
int mmu_vmemmap_psize; /* Page size used for the virtual mem map */
int book3e_htw_mode; /* HW tablewalk? Value is PPC_HTW_* */
unsigned long linear_map_top; /* Top of linear mapping */
/*
* Number of bytes to add to SPRN_SPRG_TLB_EXFRAME on crit/mcheck/debug
* exceptions. This is used for bolted and e6500 TLB miss handlers which
* do not modify this SPRG in the TLB miss code; for other TLB miss handlers,
* this is set to zero.
*/
int extlb_level_exc;
#endif /* CONFIG_PPC64 */
#ifdef CONFIG_PPC_FSL_BOOK3E
/* next_tlbcam_idx is used to round-robin tlbcam entry assignment */
DEFINE_PER_CPU(int, next_tlbcam_idx);
EXPORT_PER_CPU_SYMBOL(next_tlbcam_idx);
#endif
/*
* Base TLB flushing operations:
*
* - flush_tlb_mm(mm) flushes the specified mm context TLB's
* - flush_tlb_page(vma, vmaddr) flushes one page
* - flush_tlb_range(vma, start, end) flushes a range of pages
* - flush_tlb_kernel_range(start, end) flushes kernel pages
*
* - local_* variants of page and mm only apply to the current
* processor
*/
/*
* These are the base non-SMP variants of page and mm flushing
*/
void local_flush_tlb_mm(struct mm_struct *mm)
{
unsigned int pid;
preempt_disable();
pid = mm->context.id;
if (pid != MMU_NO_CONTEXT)
_tlbil_pid(pid);
preempt_enable();
}
EXPORT_SYMBOL(local_flush_tlb_mm);
void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
int tsize, int ind)
{
unsigned int pid;
preempt_disable();
pid = mm ? mm->context.id : 0;
if (pid != MMU_NO_CONTEXT)
_tlbil_va(vmaddr, pid, tsize, ind);
preempt_enable();
}
void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
__local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
mmu_get_tsize(mmu_virtual_psize), 0);
}
EXPORT_SYMBOL(local_flush_tlb_page);
/*
* And here are the SMP non-local implementations
*/
#ifdef CONFIG_SMP
static DEFINE_RAW_SPINLOCK(tlbivax_lock);
struct tlb_flush_param {
unsigned long addr;
unsigned int pid;
unsigned int tsize;
unsigned int ind;
};
static void do_flush_tlb_mm_ipi(void *param)
{
struct tlb_flush_param *p = param;
_tlbil_pid(p ? p->pid : 0);
}
static void do_flush_tlb_page_ipi(void *param)
{
struct tlb_flush_param *p = param;
_tlbil_va(p->addr, p->pid, p->tsize, p->ind);
}
/* Note on invalidations and PID:
*
* We snapshot the PID with preempt disabled. At this point, it can still
* change either because:
* - our context is being stolen (PID -> NO_CONTEXT) on another CPU
* - we are invaliating some target that isn't currently running here
* and is concurrently acquiring a new PID on another CPU
* - some other CPU is re-acquiring a lost PID for this mm
* etc...
*
* However, this shouldn't be a problem as we only guarantee
* invalidation of TLB entries present prior to this call, so we
* don't care about the PID changing, and invalidating a stale PID
* is generally harmless.
*/
void flush_tlb_mm(struct mm_struct *mm)
{
unsigned int pid;
preempt_disable();
pid = mm->context.id;
if (unlikely(pid == MMU_NO_CONTEXT))
goto no_context;
if (!mm_is_core_local(mm)) {
struct tlb_flush_param p = { .pid = pid };
/* Ignores smp_processor_id() even if set. */
smp_call_function_many(mm_cpumask(mm),
do_flush_tlb_mm_ipi, &p, 1);
}
_tlbil_pid(pid);
no_context:
preempt_enable();
}
EXPORT_SYMBOL(flush_tlb_mm);
void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
int tsize, int ind)
{
struct cpumask *cpu_mask;
unsigned int pid;
/*
* This function as well as __local_flush_tlb_page() must only be called
* for user contexts.
*/
if (WARN_ON(!mm))
return;
preempt_disable();
pid = mm->context.id;
if (unlikely(pid == MMU_NO_CONTEXT))
goto bail;
cpu_mask = mm_cpumask(mm);
if (!mm_is_core_local(mm)) {
/* If broadcast tlbivax is supported, use it */
if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);
if (lock)
raw_spin_lock(&tlbivax_lock);
_tlbivax_bcast(vmaddr, pid, tsize, ind);
if (lock)
raw_spin_unlock(&tlbivax_lock);
goto bail;
} else {
struct tlb_flush_param p = {
.pid = pid,
.addr = vmaddr,
.tsize = tsize,
.ind = ind,
};
/* Ignores smp_processor_id() even if set in cpu_mask */
smp_call_function_many(cpu_mask,
do_flush_tlb_page_ipi, &p, 1);
}
}
_tlbil_va(vmaddr, pid, tsize, ind);
bail:
preempt_enable();
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
#ifdef CONFIG_HUGETLB_PAGE
if (vma && is_vm_hugetlb_page(vma))
flush_hugetlb_page(vma, vmaddr);
#endif
__flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
mmu_get_tsize(mmu_virtual_psize), 0);
}
EXPORT_SYMBOL(flush_tlb_page);
#endif /* CONFIG_SMP */
#ifdef CONFIG_PPC_47x
void __init early_init_mmu_47x(void)
{
#ifdef CONFIG_SMP
unsigned long root = of_get_flat_dt_root();
if (of_get_flat_dt_prop(root, "cooperative-partition", NULL))
mmu_clear_feature(MMU_FTR_USE_TLBIVAX_BCAST);
#endif /* CONFIG_SMP */
}
#endif /* CONFIG_PPC_47x */
/*
* Flush kernel TLB entries in the given range
*/
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
#ifdef CONFIG_SMP
preempt_disable();
smp_call_function(do_flush_tlb_mm_ipi, NULL, 1);
_tlbil_pid(0);
preempt_enable();
#else
_tlbil_pid(0);
#endif
}
EXPORT_SYMBOL(flush_tlb_kernel_range);
/*
* Currently, for range flushing, we just do a full mm flush. This should
* be optimized based on a threshold on the size of the range, since
* some implementation can stack multiple tlbivax before a tlbsync but
* for now, we keep it that way
*/
void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
if (end - start == PAGE_SIZE && !(start & ~PAGE_MASK))
flush_tlb_page(vma, start);
else
flush_tlb_mm(vma->vm_mm);
}
EXPORT_SYMBOL(flush_tlb_range);
void tlb_flush(struct mmu_gather *tlb)
{
flush_tlb_mm(tlb->mm);
}
/*
* Below are functions specific to the 64-bit variant of Book3E though that
* may change in the future
*/
#ifdef CONFIG_PPC64
/*
* Handling of virtual linear page tables or indirect TLB entries
* flushing when PTE pages are freed
*/
void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address)
{
int tsize = mmu_psize_defs[mmu_pte_psize].enc;
if (book3e_htw_mode != PPC_HTW_NONE) {
unsigned long start = address & PMD_MASK;
unsigned long end = address + PMD_SIZE;
unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift;
/* This isn't the most optimal, ideally we would factor out the
* while preempt & CPU mask mucking around, or even the IPI but
* it will do for now
*/
while (start < end) {
__flush_tlb_page(tlb->mm, start, tsize, 1);
start += size;
}
} else {
unsigned long rmask = 0xf000000000000000ul;
unsigned long rid = (address & rmask) | 0x1000000000000000ul;
unsigned long vpte = address & ~rmask;
#ifdef CONFIG_PPC_64K_PAGES
vpte = (vpte >> (PAGE_SHIFT - 4)) & ~0xfffful;
#else
vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful;
#endif
vpte |= rid;
__flush_tlb_page(tlb->mm, vpte, tsize, 0);
}
}
static void setup_page_sizes(void)
{
unsigned int tlb0cfg;
unsigned int tlb0ps;
unsigned int eptcfg;
int i, psize;
#ifdef CONFIG_PPC_FSL_BOOK3E
unsigned int mmucfg = mfspr(SPRN_MMUCFG);
int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E);
if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG);
unsigned int min_pg, max_pg;
min_pg = (tlb1cfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT;
max_pg = (tlb1cfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT;
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
struct mmu_psize_def *def;
unsigned int shift;
def = &mmu_psize_defs[psize];
shift = def->shift;
if (shift == 0 || shift & 1)
continue;
/* adjust to be in terms of 4^shift Kb */
shift = (shift - 10) >> 1;
if ((shift >= min_pg) && (shift <= max_pg))
def->flags |= MMU_PAGE_SIZE_DIRECT;
}
goto out;
}
if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) {
u32 tlb1cfg, tlb1ps;
tlb0cfg = mfspr(SPRN_TLB0CFG);
tlb1cfg = mfspr(SPRN_TLB1CFG);
tlb1ps = mfspr(SPRN_TLB1PS);
eptcfg = mfspr(SPRN_EPTCFG);
if ((tlb1cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT))
book3e_htw_mode = PPC_HTW_E6500;
/*
* We expect 4K subpage size and unrestricted indirect size.
* The lack of a restriction on indirect size is a Freescale
* extension, indicated by PSn = 0 but SPSn != 0.
*/
if (eptcfg != 2)
book3e_htw_mode = PPC_HTW_NONE;
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
struct mmu_psize_def *def = &mmu_psize_defs[psize];
if (!def->shift)
continue;
if (tlb1ps & (1U << (def->shift - 10))) {
def->flags |= MMU_PAGE_SIZE_DIRECT;
if (book3e_htw_mode && psize == MMU_PAGE_2M)
def->flags |= MMU_PAGE_SIZE_INDIRECT;
}
}
goto out;
}
#endif
tlb0cfg = mfspr(SPRN_TLB0CFG);
tlb0ps = mfspr(SPRN_TLB0PS);
eptcfg = mfspr(SPRN_EPTCFG);
/* Look for supported direct sizes */
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
struct mmu_psize_def *def = &mmu_psize_defs[psize];
if (tlb0ps & (1U << (def->shift - 10)))
def->flags |= MMU_PAGE_SIZE_DIRECT;
}
/* Indirect page sizes supported ? */
if ((tlb0cfg & TLBnCFG_IND) == 0 ||
(tlb0cfg & TLBnCFG_PT) == 0)
goto out;
book3e_htw_mode = PPC_HTW_IBM;
/* Now, we only deal with one IND page size for each
* direct size. Hopefully all implementations today are
* unambiguous, but we might want to be careful in the
* future.
*/
for (i = 0; i < 3; i++) {
unsigned int ps, sps;
sps = eptcfg & 0x1f;
eptcfg >>= 5;
ps = eptcfg & 0x1f;
eptcfg >>= 5;
if (!ps || !sps)
continue;
for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
struct mmu_psize_def *def = &mmu_psize_defs[psize];
if (ps == (def->shift - 10))
def->flags |= MMU_PAGE_SIZE_INDIRECT;
if (sps == (def->shift - 10))
def->ind = ps + 10;
}
}
out:
/* Cleanup array and print summary */
pr_info("MMU: Supported page sizes\n");
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
struct mmu_psize_def *def = &mmu_psize_defs[psize];
const char *__page_type_names[] = {
"unsupported",
"direct",
"indirect",
"direct & indirect"
};
if (def->flags == 0) {
def->shift = 0;
continue;
}
pr_info(" %8ld KB as %s\n", 1ul << (def->shift - 10),
__page_type_names[def->flags & 0x3]);
}
}
static void setup_mmu_htw(void)
{
/*
* If we want to use HW tablewalk, enable it by patching the TLB miss
* handlers to branch to the one dedicated to it.
*/
switch (book3e_htw_mode) {
case PPC_HTW_IBM:
patch_exception(0x1c0, exc_data_tlb_miss_htw_book3e);
patch_exception(0x1e0, exc_instruction_tlb_miss_htw_book3e);
break;
#ifdef CONFIG_PPC_FSL_BOOK3E
case PPC_HTW_E6500:
extlb_level_exc = EX_TLB_SIZE;
patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
break;
#endif
}
pr_info("MMU: Book3E HW tablewalk %s\n",
book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
}
/*
* Early initialization of the MMU TLB code
*/
static void early_init_this_mmu(void)
{
unsigned int mas4;
/* Set MAS4 based on page table setting */
mas4 = 0x4 << MAS4_WIMGED_SHIFT;
switch (book3e_htw_mode) {
case PPC_HTW_E6500:
mas4 |= MAS4_INDD;
mas4 |= BOOK3E_PAGESZ_2M << MAS4_TSIZED_SHIFT;
mas4 |= MAS4_TLBSELD(1);
mmu_pte_psize = MMU_PAGE_2M;
break;
case PPC_HTW_IBM:
mas4 |= MAS4_INDD;
#ifdef CONFIG_PPC_64K_PAGES
mas4 |= BOOK3E_PAGESZ_256M << MAS4_TSIZED_SHIFT;
mmu_pte_psize = MMU_PAGE_256M;
#else
mas4 |= BOOK3E_PAGESZ_1M << MAS4_TSIZED_SHIFT;
mmu_pte_psize = MMU_PAGE_1M;
#endif
break;
case PPC_HTW_NONE:
#ifdef CONFIG_PPC_64K_PAGES
mas4 |= BOOK3E_PAGESZ_64K << MAS4_TSIZED_SHIFT;
#else
mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT;
#endif
mmu_pte_psize = mmu_virtual_psize;
break;
}
mtspr(SPRN_MAS4, mas4);
#ifdef CONFIG_PPC_FSL_BOOK3E
if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
unsigned int num_cams;
int __maybe_unused cpu = smp_processor_id();
bool map = true;
/* use a quarter of the TLBCAM for bolted linear map */
num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
/*
* Only do the mapping once per core, or else the
* transient mapping would cause problems.
*/
#ifdef CONFIG_SMP
if (hweight32(get_tensr()) > 1)
map = false;
#endif
if (map)
linear_map_top = map_mem_in_cams(linear_map_top,
num_cams, false);
}
#endif
/* A sync won't hurt us after mucking around with
* the MMU configuration
*/
mb();
}
static void __init early_init_mmu_global(void)
{
/* XXX This will have to be decided at runtime, but right
* now our boot and TLB miss code hard wires it. Ideally
* we should find out a suitable page size and patch the
* TLB miss code (either that or use the PACA to store
* the value we want)
*/
mmu_linear_psize = MMU_PAGE_1G;
/* XXX This should be decided at runtime based on supported
* page sizes in the TLB, but for now let's assume 16M is
* always there and a good fit (which it probably is)
*
* Freescale booke only supports 4K pages in TLB0, so use that.
*/
if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
mmu_vmemmap_psize = MMU_PAGE_4K;
else
mmu_vmemmap_psize = MMU_PAGE_16M;
/* XXX This code only checks for TLB 0 capabilities and doesn't
* check what page size combos are supported by the HW. It
* also doesn't handle the case where a separate array holds
* the IND entries from the array loaded by the PT.
*/
/* Look for supported page sizes */
setup_page_sizes();
/* Look for HW tablewalk support */
setup_mmu_htw();
#ifdef CONFIG_PPC_FSL_BOOK3E
if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
if (book3e_htw_mode == PPC_HTW_NONE) {
extlb_level_exc = EX_TLB_SIZE;
patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
patch_exception(0x1e0,
exc_instruction_tlb_miss_bolted_book3e);
}
}
#endif
/* Set the global containing the top of the linear mapping
* for use by the TLB miss code
*/
linear_map_top = memblock_end_of_DRAM();
}
static void __init early_mmu_set_memory_limit(void)
{
#ifdef CONFIG_PPC_FSL_BOOK3E
if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
/*
* Limit memory so we dont have linear faults.
* Unlike memblock_set_current_limit, which limits
* memory available during early boot, this permanently
* reduces the memory available to Linux. We need to
* do this because highmem is not supported on 64-bit.
*/
memblock_enforce_memory_limit(linear_map_top);
}
#endif
memblock_set_current_limit(linear_map_top);
}
/* boot cpu only */
void __init early_init_mmu(void)
{
early_init_mmu_global();
early_init_this_mmu();
early_mmu_set_memory_limit();
}
void early_init_mmu_secondary(void)
{
early_init_this_mmu();
}
void setup_initial_memory_limit(phys_addr_t first_memblock_base,
phys_addr_t first_memblock_size)
{
/* On non-FSL Embedded 64-bit, we adjust the RMA size to match
* the bolted TLB entry. We know for now that only 1G
* entries are supported though that may eventually
* change.
*
* on FSL Embedded 64-bit, usually all RAM is bolted, but with
* unusual memory sizes it's possible for some RAM to not be mapped
* (such RAM is not used at all by Linux, since we don't support
* highmem on 64-bit). We limit ppc64_rma_size to what would be
* mappable if this memblock is the only one. Additional memblocks
* can only increase, not decrease, the amount that ends up getting
* mapped. We still limit max to 1G even if we'll eventually map
* more. This is due to what the early init code is set up to do.
*
* We crop it to the size of the first MEMBLOCK to
* avoid going over total available memory just in case...
*/
#ifdef CONFIG_PPC_FSL_BOOK3E
if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
unsigned long linear_sz;
unsigned int num_cams;
/* use a quarter of the TLBCAM for bolted linear map */
num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
linear_sz = map_mem_in_cams(first_memblock_size, num_cams,
true);
ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
} else
#endif
ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
/* Finally limit subsequent allocations */
memblock_set_current_limit(first_memblock_base + ppc64_rma_size);
}
#else /* ! CONFIG_PPC64 */
void __init early_init_mmu(void)
{
#ifdef CONFIG_PPC_47x
early_init_mmu_47x();
#endif
}
#endif /* CONFIG_PPC64 */
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