// 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 <asm/rtas.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/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_BOOK3S_64

/*
 * 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_BOOK3S_64 */

#ifdef CONFIG_PPC_PSERIES
/**
 * new_rtas_args() - Allocates rtas args
 * @cpu:        CPU number
 * @limit:      Memory limit for this allocation
 *
 * Allocates a struct rtas_args and return it's pointer,
 * if not in Hypervisor mode
 *
 * Return:      Pointer to allocated rtas_args
 *              NULL if CPU in Hypervisor Mode
 */
static struct rtas_args * __init new_rtas_args(int cpu, unsigned long limit)
{
        limit = min_t(unsigned long, limit, RTAS_INSTANTIATE_MAX);

        if (early_cpu_has_feature(CPU_FTR_HVMODE))
                return NULL;

        return alloc_paca_data(sizeof(struct rtas_args), L1_CACHE_BYTES,
                               limit, cpu);
}
#endif /* CONFIG_PPC_PSERIES */

/* 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
        new_paca->kernel_pgd = swapper_pg_dir;
#endif
        new_paca->lock_token = 0x8000;
        new_paca->paca_index = cpu;
        new_paca->kernel_toc = kernel_toc_addr();
        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_BOOK3S_64
        new_paca->slb_shadow_ptr = NULL;
#endif

#ifdef CONFIG_PPC_BOOK3E
        /* For now -- if we have threads this will be adjusted later */
        new_paca->tcd_ptr = &new_paca->tcd;
#endif

#ifdef CONFIG_PPC_PSERIES
        new_paca->rtas_args_reentrant = NULL;
#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
        /* 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_BOOK3S_64
        paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
#endif
#ifdef CONFIG_PPC_PSERIES
        paca->rtas_args_reentrant = new_rtas_args(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_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_BOOK3S_64
        if (early_radix_enabled()) {
                /* Ugly fixup, see new_slb_shadow() */
                memblock_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);
}

void copy_mm_to_paca(struct mm_struct *mm)
{
#ifdef CONFIG_PPC_BOOK3S
        mm_context_t *context = &mm->context;

#ifdef CONFIG_PPC_MM_SLICES
        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));
#else /* CONFIG_PPC_MM_SLICES */
        get_paca()->mm_ctx_user_psize = context->user_psize;
        get_paca()->mm_ctx_sllp = context->sllp;
#endif
#else /* !CONFIG_PPC_BOOK3S */
        return;
#endif
}