linux/arch/powerpc/kernel/paca.c
Costa Shulyupin 17e02586ed docs: move powerpc under arch
and fix all in-tree references.

Architecture-specific documentation is being moved into Documentation/arch/
as a way of cleaning up the top-level documentation directory and making
the docs hierarchy more closely match the source hierarchy.

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230826165737.2101199-1-costa.shul@redhat.com
2023-10-10 13:35:55 -06:00

324 lines
8.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* c 2001 PPC 64 Team, IBM Corp
*/
#include <linux/smp.h>
#include <linux/export.h>
#include <linux/memblock.h>
#include <linux/sched/task.h>
#include <linux/numa.h>
#include <linux/pgtable.h>
#include <asm/lppaca.h>
#include <asm/paca.h>
#include <asm/sections.h>
#include <asm/kexec.h>
#include <asm/svm.h>
#include <asm/ultravisor.h>
#include "setup.h"
#ifndef CONFIG_SMP
#define boot_cpuid 0
#endif
static void *__init alloc_paca_data(unsigned long size, unsigned long align,
unsigned long limit, int cpu)
{
void *ptr;
int nid;
/*
* boot_cpuid paca is allocated very early before cpu_to_node is up.
* Set bottom-up mode, because the boot CPU should be on node-0,
* which will put its paca in the right place.
*/
if (cpu == boot_cpuid) {
nid = NUMA_NO_NODE;
memblock_set_bottom_up(true);
} else {
nid = early_cpu_to_node(cpu);
}
ptr = memblock_alloc_try_nid(size, align, MEMBLOCK_LOW_LIMIT,
limit, nid);
if (!ptr)
panic("cannot allocate paca data");
if (cpu == boot_cpuid)
memblock_set_bottom_up(false);
return ptr;
}
#ifdef CONFIG_PPC_PSERIES
#define LPPACA_SIZE 0x400
static void *__init alloc_shared_lppaca(unsigned long size, unsigned long limit,
int cpu)
{
size_t shared_lppaca_total_size = PAGE_ALIGN(nr_cpu_ids * LPPACA_SIZE);
static unsigned long shared_lppaca_size;
static void *shared_lppaca;
void *ptr;
if (!shared_lppaca) {
memblock_set_bottom_up(true);
/*
* See Documentation/arch/powerpc/ultravisor.rst for more details.
*
* UV/HV data sharing is in PAGE_SIZE granularity. In order to
* minimize the number of pages shared, align the allocation to
* PAGE_SIZE.
*/
shared_lppaca =
memblock_alloc_try_nid(shared_lppaca_total_size,
PAGE_SIZE, MEMBLOCK_LOW_LIMIT,
limit, NUMA_NO_NODE);
if (!shared_lppaca)
panic("cannot allocate shared data");
memblock_set_bottom_up(false);
uv_share_page(PHYS_PFN(__pa(shared_lppaca)),
shared_lppaca_total_size >> PAGE_SHIFT);
}
ptr = shared_lppaca + shared_lppaca_size;
shared_lppaca_size += size;
/*
* This is very early in boot, so no harm done if the kernel crashes at
* this point.
*/
BUG_ON(shared_lppaca_size > shared_lppaca_total_size);
return ptr;
}
/*
* See asm/lppaca.h for more detail.
*
* lppaca structures must must be 1kB in size, L1 cache line aligned,
* and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
* these requirements.
*/
static inline void init_lppaca(struct lppaca *lppaca)
{
BUILD_BUG_ON(sizeof(struct lppaca) != 640);
*lppaca = (struct lppaca) {
.desc = cpu_to_be32(0xd397d781), /* "LpPa" */
.size = cpu_to_be16(LPPACA_SIZE),
.fpregs_in_use = 1,
.slb_count = cpu_to_be16(64),
.vmxregs_in_use = 0,
.page_ins = 0, };
};
static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
{
struct lppaca *lp;
BUILD_BUG_ON(sizeof(struct lppaca) > LPPACA_SIZE);
if (early_cpu_has_feature(CPU_FTR_HVMODE))
return NULL;
if (is_secure_guest())
lp = alloc_shared_lppaca(LPPACA_SIZE, limit, cpu);
else
lp = alloc_paca_data(LPPACA_SIZE, 0x400, limit, cpu);
init_lppaca(lp);
return lp;
}
#endif /* CONFIG_PPC_PSERIES */
#ifdef CONFIG_PPC_64S_HASH_MMU
/*
* 3 persistent SLBs are allocated here. The buffer will be zero
* initially, hence will all be invaild until we actually write them.
*
* If you make the number of persistent SLB entries dynamic, please also
* update PR KVM to flush and restore them accordingly.
*/
static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
{
struct slb_shadow *s;
if (cpu != boot_cpuid) {
/*
* Boot CPU comes here before early_radix_enabled
* is parsed (e.g., for disable_radix). So allocate
* always and this will be fixed up in free_unused_pacas.
*/
if (early_radix_enabled())
return NULL;
}
s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
s->buffer_length = cpu_to_be32(sizeof(*s));
return s;
}
#endif /* CONFIG_PPC_64S_HASH_MMU */
/* The Paca is an array with one entry per processor. Each contains an
* lppaca, which contains the information shared between the
* hypervisor and Linux.
* On systems with hardware multi-threading, there are two threads
* per processor. The Paca array must contain an entry for each thread.
* The VPD Areas will give a max logical processors = 2 * max physical
* processors. The processor VPD array needs one entry per physical
* processor (not thread).
*/
struct paca_struct **paca_ptrs __read_mostly;
EXPORT_SYMBOL(paca_ptrs);
void __init initialise_paca(struct paca_struct *new_paca, int cpu)
{
#ifdef CONFIG_PPC_PSERIES
new_paca->lppaca_ptr = NULL;
#endif
#ifdef CONFIG_PPC_BOOK3E_64
new_paca->kernel_pgd = swapper_pg_dir;
#endif
new_paca->lock_token = 0x8000;
new_paca->paca_index = cpu;
#ifndef CONFIG_PPC_KERNEL_PCREL
new_paca->kernel_toc = kernel_toc_addr();
#endif
new_paca->kernelbase = (unsigned long) _stext;
/* Only set MSR:IR/DR when MMU is initialized */
new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
new_paca->hw_cpu_id = 0xffff;
new_paca->kexec_state = KEXEC_STATE_NONE;
new_paca->__current = &init_task;
new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
#ifdef CONFIG_PPC_64S_HASH_MMU
new_paca->slb_shadow_ptr = NULL;
#endif
#ifdef CONFIG_PPC_BOOK3E_64
/* For now -- if we have threads this will be adjusted later */
new_paca->tcd_ptr = &new_paca->tcd;
#endif
}
/* Put the paca pointer into r13 and SPRG_PACA */
void setup_paca(struct paca_struct *new_paca)
{
/* Setup r13 */
local_paca = new_paca;
#ifdef CONFIG_PPC_BOOK3E_64
/* On Book3E, initialize the TLB miss exception frames */
mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
#else
/*
* In HV mode, we setup both HPACA and PACA to avoid problems
* if we do a GET_PACA() before the feature fixups have been
* applied.
*
* Normally you should test against CPU_FTR_HVMODE, but CPU features
* are not yet set up when we first reach here.
*/
if (mfmsr() & MSR_HV)
mtspr(SPRN_SPRG_HPACA, local_paca);
#endif
mtspr(SPRN_SPRG_PACA, local_paca);
}
static int __initdata paca_nr_cpu_ids;
static int __initdata paca_ptrs_size;
static int __initdata paca_struct_size;
void __init allocate_paca_ptrs(void)
{
paca_nr_cpu_ids = nr_cpu_ids;
paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
paca_ptrs = memblock_alloc_raw(paca_ptrs_size, SMP_CACHE_BYTES);
if (!paca_ptrs)
panic("Failed to allocate %d bytes for paca pointers\n",
paca_ptrs_size);
memset(paca_ptrs, 0x88, paca_ptrs_size);
}
void __init allocate_paca(int cpu)
{
u64 limit;
struct paca_struct *paca;
BUG_ON(cpu >= paca_nr_cpu_ids);
#ifdef CONFIG_PPC_BOOK3S_64
/*
* We access pacas in real mode, and cannot take SLB faults
* on them when in virtual mode, so allocate them accordingly.
*/
limit = min(ppc64_bolted_size(), ppc64_rma_size);
#else
limit = ppc64_rma_size;
#endif
paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
limit, cpu);
paca_ptrs[cpu] = paca;
initialise_paca(paca, cpu);
#ifdef CONFIG_PPC_PSERIES
paca->lppaca_ptr = new_lppaca(cpu, limit);
#endif
#ifdef CONFIG_PPC_64S_HASH_MMU
paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
#endif
paca_struct_size += sizeof(struct paca_struct);
}
void __init free_unused_pacas(void)
{
int new_ptrs_size;
new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
if (new_ptrs_size < paca_ptrs_size)
memblock_phys_free(__pa(paca_ptrs) + new_ptrs_size,
paca_ptrs_size - new_ptrs_size);
paca_nr_cpu_ids = nr_cpu_ids;
paca_ptrs_size = new_ptrs_size;
#ifdef CONFIG_PPC_64S_HASH_MMU
if (early_radix_enabled()) {
/* Ugly fixup, see new_slb_shadow() */
memblock_phys_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
sizeof(struct slb_shadow));
paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
}
#endif
printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
paca_ptrs_size + paca_struct_size, nr_cpu_ids);
}
#ifdef CONFIG_PPC_64S_HASH_MMU
void copy_mm_to_paca(struct mm_struct *mm)
{
mm_context_t *context = &mm->context;
VM_BUG_ON(!mm_ctx_slb_addr_limit(context));
memcpy(&get_paca()->mm_ctx_low_slices_psize, mm_ctx_low_slices(context),
LOW_SLICE_ARRAY_SZ);
memcpy(&get_paca()->mm_ctx_high_slices_psize, mm_ctx_high_slices(context),
TASK_SLICE_ARRAY_SZ(context));
}
#endif /* CONFIG_PPC_64S_HASH_MMU */