// SPDX-License-Identifier: MIT
/*
 * Copyright © 2020 Intel Corporation
 */

#include <linux/slab.h> /* fault-inject.h is not standalone! */

#include <linux/fault-inject.h>

#include "gem/i915_gem_lmem.h"
#include "i915_trace.h"
#include "intel_gt.h"
#include "intel_gtt.h"

struct drm_i915_gem_object *alloc_pt_lmem(struct i915_address_space *vm, int sz)
{
        struct drm_i915_gem_object *obj;

        /*
         * To avoid severe over-allocation when dealing with min_page_size
         * restrictions, we override that behaviour here by allowing an object
         * size and page layout which can be smaller. In practice this should be
         * totally fine, since GTT paging structures are not typically inserted
         * into the GTT.
         *
         * Note that we also hit this path for the scratch page, and for this
         * case it might need to be 64K, but that should work fine here since we
         * used the passed in size for the page size, which should ensure it
         * also has the same alignment.
         */
        obj = __i915_gem_object_create_lmem_with_ps(vm->i915, sz, sz, 0);
        /*
         * Ensure all paging structures for this vm share the same dma-resv
         * object underneath, with the idea that one object_lock() will lock
         * them all at once.
         */
        if (!IS_ERR(obj)) {
                obj->base.resv = i915_vm_resv_get(vm);
                obj->shares_resv_from = vm;
        }

        return obj;
}

struct drm_i915_gem_object *alloc_pt_dma(struct i915_address_space *vm, int sz)
{
        struct drm_i915_gem_object *obj;

        if (I915_SELFTEST_ONLY(should_fail(&vm->fault_attr, 1)))
                i915_gem_shrink_all(vm->i915);

        obj = i915_gem_object_create_internal(vm->i915, sz);
        /*
         * Ensure all paging structures for this vm share the same dma-resv
         * object underneath, with the idea that one object_lock() will lock
         * them all at once.
         */
        if (!IS_ERR(obj)) {
                obj->base.resv = i915_vm_resv_get(vm);
                obj->shares_resv_from = vm;
        }

        return obj;
}

int map_pt_dma(struct i915_address_space *vm, struct drm_i915_gem_object *obj)
{
        enum i915_map_type type;
        void *vaddr;

        type = i915_coherent_map_type(vm->i915, obj, true);
        vaddr = i915_gem_object_pin_map_unlocked(obj, type);
        if (IS_ERR(vaddr))
                return PTR_ERR(vaddr);

        i915_gem_object_make_unshrinkable(obj);
        return 0;
}

int map_pt_dma_locked(struct i915_address_space *vm, struct drm_i915_gem_object *obj)
{
        enum i915_map_type type;
        void *vaddr;

        type = i915_coherent_map_type(vm->i915, obj, true);
        vaddr = i915_gem_object_pin_map(obj, type);
        if (IS_ERR(vaddr))
                return PTR_ERR(vaddr);

        i915_gem_object_make_unshrinkable(obj);
        return 0;
}

void __i915_vm_close(struct i915_address_space *vm)
{
        struct i915_vma *vma, *vn;

        if (!atomic_dec_and_mutex_lock(&vm->open, &vm->mutex))
                return;

        list_for_each_entry_safe(vma, vn, &vm->bound_list, vm_link) {
                struct drm_i915_gem_object *obj = vma->obj;

                /* Keep the obj (and hence the vma) alive as _we_ destroy it */
                if (!kref_get_unless_zero(&obj->base.refcount))
                        continue;

                atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
                WARN_ON(__i915_vma_unbind(vma));
                __i915_vma_put(vma);

                i915_gem_object_put(obj);
        }
        GEM_BUG_ON(!list_empty(&vm->bound_list));

        mutex_unlock(&vm->mutex);
}

/* lock the vm into the current ww, if we lock one, we lock all */
int i915_vm_lock_objects(struct i915_address_space *vm,
                         struct i915_gem_ww_ctx *ww)
{
        if (vm->scratch[0]->base.resv == &vm->_resv) {
                return i915_gem_object_lock(vm->scratch[0], ww);
        } else {
                struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);

                /* We borrowed the scratch page from ggtt, take the top level object */
                return i915_gem_object_lock(ppgtt->pd->pt.base, ww);
        }
}

void i915_address_space_fini(struct i915_address_space *vm)
{
        drm_mm_takedown(&vm->mm);
        mutex_destroy(&vm->mutex);
}

/**
 * i915_vm_resv_release - Final struct i915_address_space destructor
 * @kref: Pointer to the &i915_address_space.resv_ref member.
 *
 * This function is called when the last lock sharer no longer shares the
 * &i915_address_space._resv lock.
 */
void i915_vm_resv_release(struct kref *kref)
{
        struct i915_address_space *vm =
                container_of(kref, typeof(*vm), resv_ref);

        dma_resv_fini(&vm->_resv);
        kfree(vm);
}

static void __i915_vm_release(struct work_struct *work)
{
        struct i915_address_space *vm =
                container_of(work, struct i915_address_space, rcu.work);

        vm->cleanup(vm);
        i915_address_space_fini(vm);

        i915_vm_resv_put(vm);
}

void i915_vm_release(struct kref *kref)
{
        struct i915_address_space *vm =
                container_of(kref, struct i915_address_space, ref);

        GEM_BUG_ON(i915_is_ggtt(vm));
        trace_i915_ppgtt_release(vm);

        queue_rcu_work(vm->i915->wq, &vm->rcu);
}

void i915_address_space_init(struct i915_address_space *vm, int subclass)
{
        kref_init(&vm->ref);

        /*
         * Special case for GGTT that has already done an early
         * kref_init here.
         */
        if (!kref_read(&vm->resv_ref))
                kref_init(&vm->resv_ref);

        INIT_RCU_WORK(&vm->rcu, __i915_vm_release);
        atomic_set(&vm->open, 1);

        /*
         * The vm->mutex must be reclaim safe (for use in the shrinker).
         * Do a dummy acquire now under fs_reclaim so that any allocation
         * attempt holding the lock is immediately reported by lockdep.
         */
        mutex_init(&vm->mutex);
        lockdep_set_subclass(&vm->mutex, subclass);

        if (!intel_vm_no_concurrent_access_wa(vm->i915)) {
                i915_gem_shrinker_taints_mutex(vm->i915, &vm->mutex);
        } else {
                /*
                 * CHV + BXT VTD workaround use stop_machine(),
                 * which is allowed to allocate memory. This means &vm->mutex
                 * is the outer lock, and in theory we can allocate memory inside
                 * it through stop_machine().
                 *
                 * Add the annotation for this, we use trylock in shrinker.
                 */
                mutex_acquire(&vm->mutex.dep_map, 0, 0, _THIS_IP_);
                might_alloc(GFP_KERNEL);
                mutex_release(&vm->mutex.dep_map, _THIS_IP_);
        }
        dma_resv_init(&vm->_resv);

        GEM_BUG_ON(!vm->total);
        drm_mm_init(&vm->mm, 0, vm->total);
        vm->mm.head_node.color = I915_COLOR_UNEVICTABLE;

        INIT_LIST_HEAD(&vm->bound_list);
}

void clear_pages(struct i915_vma *vma)
{
        GEM_BUG_ON(!vma->pages);

        if (vma->pages != vma->obj->mm.pages) {
                sg_free_table(vma->pages);
                kfree(vma->pages);
        }
        vma->pages = NULL;

        memset(&vma->page_sizes, 0, sizeof(vma->page_sizes));
}

void *__px_vaddr(struct drm_i915_gem_object *p)
{
        enum i915_map_type type;

        GEM_BUG_ON(!i915_gem_object_has_pages(p));
        return page_unpack_bits(p->mm.mapping, &type);
}

dma_addr_t __px_dma(struct drm_i915_gem_object *p)
{
        GEM_BUG_ON(!i915_gem_object_has_pages(p));
        return sg_dma_address(p->mm.pages->sgl);
}

struct page *__px_page(struct drm_i915_gem_object *p)
{
        GEM_BUG_ON(!i915_gem_object_has_pages(p));
        return sg_page(p->mm.pages->sgl);
}

void
fill_page_dma(struct drm_i915_gem_object *p, const u64 val, unsigned int count)
{
        void *vaddr = __px_vaddr(p);

        memset64(vaddr, val, count);
        clflush_cache_range(vaddr, PAGE_SIZE);
}

static void poison_scratch_page(struct drm_i915_gem_object *scratch)
{
        void *vaddr = __px_vaddr(scratch);
        u8 val;

        val = 0;
        if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
                val = POISON_FREE;

        memset(vaddr, val, scratch->base.size);
}

int setup_scratch_page(struct i915_address_space *vm)
{
        unsigned long size;

        /*
         * In order to utilize 64K pages for an object with a size < 2M, we will
         * need to support a 64K scratch page, given that every 16th entry for a
         * page-table operating in 64K mode must point to a properly aligned 64K
         * region, including any PTEs which happen to point to scratch.
         *
         * This is only relevant for the 48b PPGTT where we support
         * huge-gtt-pages, see also i915_vma_insert(). However, as we share the
         * scratch (read-only) between all vm, we create one 64k scratch page
         * for all.
         */
        size = I915_GTT_PAGE_SIZE_4K;
        if (i915_vm_is_4lvl(vm) &&
            HAS_PAGE_SIZES(vm->i915, I915_GTT_PAGE_SIZE_64K))
                size = I915_GTT_PAGE_SIZE_64K;

        do {
                struct drm_i915_gem_object *obj;

                obj = vm->alloc_pt_dma(vm, size);
                if (IS_ERR(obj))
                        goto skip;

                if (map_pt_dma(vm, obj))
                        goto skip_obj;

                /* We need a single contiguous page for our scratch */
                if (obj->mm.page_sizes.sg < size)
                        goto skip_obj;

                /* And it needs to be correspondingly aligned */
                if (__px_dma(obj) & (size - 1))
                        goto skip_obj;

                /*
                 * Use a non-zero scratch page for debugging.
                 *
                 * We want a value that should be reasonably obvious
                 * to spot in the error state, while also causing a GPU hang
                 * if executed. We prefer using a clear page in production, so
                 * should it ever be accidentally used, the effect should be
                 * fairly benign.
                 */
                poison_scratch_page(obj);

                vm->scratch[0] = obj;
                vm->scratch_order = get_order(size);
                return 0;

skip_obj:
                i915_gem_object_put(obj);
skip:
                if (size == I915_GTT_PAGE_SIZE_4K)
                        return -ENOMEM;

                size = I915_GTT_PAGE_SIZE_4K;
        } while (1);
}

void free_scratch(struct i915_address_space *vm)
{
        int i;

        for (i = 0; i <= vm->top; i++)
                i915_gem_object_put(vm->scratch[i]);
}

void gtt_write_workarounds(struct intel_gt *gt)
{
        struct drm_i915_private *i915 = gt->i915;
        struct intel_uncore *uncore = gt->uncore;

        /*
         * This function is for gtt related workarounds. This function is
         * called on driver load and after a GPU reset, so you can place
         * workarounds here even if they get overwritten by GPU reset.
         */
        /* WaIncreaseDefaultTLBEntries:chv,bdw,skl,bxt,kbl,glk,cfl,cnl,icl */
        if (IS_BROADWELL(i915))
                intel_uncore_write(uncore,
                                   GEN8_L3_LRA_1_GPGPU,
                                   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_BDW);
        else if (IS_CHERRYVIEW(i915))
                intel_uncore_write(uncore,
                                   GEN8_L3_LRA_1_GPGPU,
                                   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_CHV);
        else if (IS_GEN9_LP(i915))
                intel_uncore_write(uncore,
                                   GEN8_L3_LRA_1_GPGPU,
                                   GEN9_L3_LRA_1_GPGPU_DEFAULT_VALUE_BXT);
        else if (GRAPHICS_VER(i915) >= 9 && GRAPHICS_VER(i915) <= 11)
                intel_uncore_write(uncore,
                                   GEN8_L3_LRA_1_GPGPU,
                                   GEN9_L3_LRA_1_GPGPU_DEFAULT_VALUE_SKL);

        /*
         * To support 64K PTEs we need to first enable the use of the
         * Intermediate-Page-Size(IPS) bit of the PDE field via some magical
         * mmio, otherwise the page-walker will simply ignore the IPS bit. This
         * shouldn't be needed after GEN10.
         *
         * 64K pages were first introduced from BDW+, although technically they
         * only *work* from gen9+. For pre-BDW we instead have the option for
         * 32K pages, but we don't currently have any support for it in our
         * driver.
         */
        if (HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_64K) &&
            GRAPHICS_VER(i915) <= 10)
                intel_uncore_rmw(uncore,
                                 GEN8_GAMW_ECO_DEV_RW_IA,
                                 0,
                                 GAMW_ECO_ENABLE_64K_IPS_FIELD);

        if (IS_GRAPHICS_VER(i915, 8, 11)) {
                bool can_use_gtt_cache = true;

                /*
                 * According to the BSpec if we use 2M/1G pages then we also
                 * need to disable the GTT cache. At least on BDW we can see
                 * visual corruption when using 2M pages, and not disabling the
                 * GTT cache.
                 */
                if (HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_2M))
                        can_use_gtt_cache = false;

                /* WaGttCachingOffByDefault */
                intel_uncore_write(uncore,
                                   HSW_GTT_CACHE_EN,
                                   can_use_gtt_cache ? GTT_CACHE_EN_ALL : 0);
                drm_WARN_ON_ONCE(&i915->drm, can_use_gtt_cache &&
                                 intel_uncore_read(uncore,
                                                   HSW_GTT_CACHE_EN) == 0);
        }
}

static void tgl_setup_private_ppat(struct intel_uncore *uncore)
{
        /* TGL doesn't support LLC or AGE settings */
        intel_uncore_write(uncore, GEN12_PAT_INDEX(0), GEN8_PPAT_WB);
        intel_uncore_write(uncore, GEN12_PAT_INDEX(1), GEN8_PPAT_WC);
        intel_uncore_write(uncore, GEN12_PAT_INDEX(2), GEN8_PPAT_WT);
        intel_uncore_write(uncore, GEN12_PAT_INDEX(3), GEN8_PPAT_UC);
        intel_uncore_write(uncore, GEN12_PAT_INDEX(4), GEN8_PPAT_WB);
        intel_uncore_write(uncore, GEN12_PAT_INDEX(5), GEN8_PPAT_WB);
        intel_uncore_write(uncore, GEN12_PAT_INDEX(6), GEN8_PPAT_WB);
        intel_uncore_write(uncore, GEN12_PAT_INDEX(7), GEN8_PPAT_WB);
}

static void icl_setup_private_ppat(struct intel_uncore *uncore)
{
        intel_uncore_write(uncore,
                           GEN10_PAT_INDEX(0),
                           GEN8_PPAT_WB | GEN8_PPAT_LLC);
        intel_uncore_write(uncore,
                           GEN10_PAT_INDEX(1),
                           GEN8_PPAT_WC | GEN8_PPAT_LLCELLC);
        intel_uncore_write(uncore,
                           GEN10_PAT_INDEX(2),
                           GEN8_PPAT_WB | GEN8_PPAT_ELLC_OVERRIDE);
        intel_uncore_write(uncore,
                           GEN10_PAT_INDEX(3),
                           GEN8_PPAT_UC);
        intel_uncore_write(uncore,
                           GEN10_PAT_INDEX(4),
                           GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0));
        intel_uncore_write(uncore,
                           GEN10_PAT_INDEX(5),
                           GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1));
        intel_uncore_write(uncore,
                           GEN10_PAT_INDEX(6),
                           GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2));
        intel_uncore_write(uncore,
                           GEN10_PAT_INDEX(7),
                           GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
}

/*
 * The GGTT and PPGTT need a private PPAT setup in order to handle cacheability
 * bits. When using advanced contexts each context stores its own PAT, but
 * writing this data shouldn't be harmful even in those cases.
 */
static void bdw_setup_private_ppat(struct intel_uncore *uncore)
{
        struct drm_i915_private *i915 = uncore->i915;
        u64 pat;

        pat = GEN8_PPAT(0, GEN8_PPAT_WB | GEN8_PPAT_LLC) |      /* for normal objects, no eLLC */
              GEN8_PPAT(1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC) |  /* for something pointing to ptes? */
              GEN8_PPAT(3, GEN8_PPAT_UC) |                      /* Uncached objects, mostly for scanout */
              GEN8_PPAT(4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0)) |
              GEN8_PPAT(5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1)) |
              GEN8_PPAT(6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2)) |
              GEN8_PPAT(7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));

        /* for scanout with eLLC */
        if (GRAPHICS_VER(i915) >= 9)
                pat |= GEN8_PPAT(2, GEN8_PPAT_WB | GEN8_PPAT_ELLC_OVERRIDE);
        else
                pat |= GEN8_PPAT(2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC);

        intel_uncore_write(uncore, GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
        intel_uncore_write(uncore, GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
}

static void chv_setup_private_ppat(struct intel_uncore *uncore)
{
        u64 pat;

        /*
         * Map WB on BDW to snooped on CHV.
         *
         * Only the snoop bit has meaning for CHV, the rest is
         * ignored.
         *
         * The hardware will never snoop for certain types of accesses:
         * - CPU GTT (GMADR->GGTT->no snoop->memory)
         * - PPGTT page tables
         * - some other special cycles
         *
         * As with BDW, we also need to consider the following for GT accesses:
         * "For GGTT, there is NO pat_sel[2:0] from the entry,
         * so RTL will always use the value corresponding to
         * pat_sel = 000".
         * Which means we must set the snoop bit in PAT entry 0
         * in order to keep the global status page working.
         */

        pat = GEN8_PPAT(0, CHV_PPAT_SNOOP) |
              GEN8_PPAT(1, 0) |
              GEN8_PPAT(2, 0) |
              GEN8_PPAT(3, 0) |
              GEN8_PPAT(4, CHV_PPAT_SNOOP) |
              GEN8_PPAT(5, CHV_PPAT_SNOOP) |
              GEN8_PPAT(6, CHV_PPAT_SNOOP) |
              GEN8_PPAT(7, CHV_PPAT_SNOOP);

        intel_uncore_write(uncore, GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
        intel_uncore_write(uncore, GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
}

void setup_private_pat(struct intel_uncore *uncore)
{
        struct drm_i915_private *i915 = uncore->i915;

        GEM_BUG_ON(GRAPHICS_VER(i915) < 8);

        if (GRAPHICS_VER(i915) >= 12)
                tgl_setup_private_ppat(uncore);
        else if (GRAPHICS_VER(i915) >= 11)
                icl_setup_private_ppat(uncore);
        else if (IS_CHERRYVIEW(i915) || IS_GEN9_LP(i915))
                chv_setup_private_ppat(uncore);
        else
                bdw_setup_private_ppat(uncore);
}

struct i915_vma *
__vm_create_scratch_for_read(struct i915_address_space *vm, unsigned long size)
{
        struct drm_i915_gem_object *obj;
        struct i915_vma *vma;

        obj = i915_gem_object_create_internal(vm->i915, PAGE_ALIGN(size));
        if (IS_ERR(obj))
                return ERR_CAST(obj);

        i915_gem_object_set_cache_coherency(obj, I915_CACHING_CACHED);

        vma = i915_vma_instance(obj, vm, NULL);
        if (IS_ERR(vma)) {
                i915_gem_object_put(obj);
                return vma;
        }

        return vma;
}

struct i915_vma *
__vm_create_scratch_for_read_pinned(struct i915_address_space *vm, unsigned long size)
{
        struct i915_vma *vma;
        int err;

        vma = __vm_create_scratch_for_read(vm, size);
        if (IS_ERR(vma))
                return vma;

        err = i915_vma_pin(vma, 0, 0,
                           i915_vma_is_ggtt(vma) ? PIN_GLOBAL : PIN_USER);
        if (err) {
                i915_vma_put(vma);
                return ERR_PTR(err);
        }

        return vma;
}

#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftests/mock_gtt.c"
#endif