drm/i915/gt: Re-do the intel-gtt split

Re-do what was attempted in commit 7a5c922377b4 ("drm/i915/gt: Split
intel-gtt functions by arch"). The goal of that commit was to split the
handlers for older hardware that depend on intel-gtt.ko so i915 can
be built for non-x86 archs, after some more patches. Other archs do not
need intel-gtt.ko.

Main issue with the previous approach: it moved all the hooks, including
the gen8, which is used by all platforms gen8 and newer.  Re-do the
split moving only the handlers for gen < 6, which are the only ones
calling out to the separate module.

While at it do some minor cleanups:
  - Rename the prefix s/gen5_/gmch_/ to be more accurate what platforms
    are covered by intel_ggtt_gmch.c
  - Remove dead code for gen12 out of needs_idle_maps()
  - Remove TODO comment leftover
  - Re-order if/else ladder in ggtt_probe_hw() to keep newest platforms
    first

v2: Add minor cleanups (Matt Roper)

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220617230559.2109427-2-lucas.demarchi@intel.com

1 files changed, 546 insertions, 15 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index 0849a6f66309..ffff96180313 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -3,16 +3,18 @@
  * Copyright © 2020 Intel Corporation
  */
 
-#include <linux/types.h>
 #include <asm/set_memory.h>
 #include <asm/smp.h>
+#include <linux/types.h>
+#include <linux/stop_machine.h>
 
 #include <drm/i915_drm.h>
+#include <drm/intel-gtt.h>
 
 #include "gem/i915_gem_lmem.h"
 
+#include "intel_ggtt_gmch.h"
 #include "intel_gt.h"
-#include "intel_gt_gmch.h"
 #include "intel_gt_regs.h"
 #include "i915_drv.h"
 #include "i915_scatterlist.h"
@@ -208,7 +210,7 @@ void gen6_ggtt_invalidate(struct i915_ggtt *ggtt)
 	spin_unlock_irq(&uncore->lock);
 }
 
-void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
+static void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
 {
 	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
 
@@ -245,11 +247,232 @@ u64 gen8_ggtt_pte_encode(dma_addr_t addr,
 	return pte;
 }
 
+static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
+{
+	writeq(pte, addr);
+}
+
+static void gen8_ggtt_insert_page(struct i915_address_space *vm,
+				  dma_addr_t addr,
+				  u64 offset,
+				  enum i915_cache_level level,
+				  u32 flags)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	gen8_pte_t __iomem *pte =
+		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
+
+	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
+
+	ggtt->invalidate(ggtt);
+}
+
+static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
+				     struct i915_vma_resource *vma_res,
+				     enum i915_cache_level level,
+				     u32 flags)
+{
+	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, flags);
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	gen8_pte_t __iomem *gte;
+	gen8_pte_t __iomem *end;
+	struct sgt_iter iter;
+	dma_addr_t addr;
+
+	/*
+	 * Note that we ignore PTE_READ_ONLY here. The caller must be careful
+	 * not to allow the user to override access to a read only page.
+	 */
+
+	gte = (gen8_pte_t __iomem *)ggtt->gsm;
+	gte += vma_res->start / I915_GTT_PAGE_SIZE;
+	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
+
+	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
+		gen8_set_pte(gte++, pte_encode | addr);
+	GEM_BUG_ON(gte > end);
+
+	/* Fill the allocated but "unused" space beyond the end of the buffer */
+	while (gte < end)
+		gen8_set_pte(gte++, vm->scratch[0]->encode);
+
+	/*
+	 * We want to flush the TLBs only after we're certain all the PTE
+	 * updates have finished.
+	 */
+	ggtt->invalidate(ggtt);
+}
+
+static void gen6_ggtt_insert_page(struct i915_address_space *vm,
+				  dma_addr_t addr,
+				  u64 offset,
+				  enum i915_cache_level level,
+				  u32 flags)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	gen6_pte_t __iomem *pte =
+		(gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
+
+	iowrite32(vm->pte_encode(addr, level, flags), pte);
+
+	ggtt->invalidate(ggtt);
+}
+
+/*
+ * Binds an object into the global gtt with the specified cache level.
+ * The object will be accessible to the GPU via commands whose operands
+ * reference offsets within the global GTT as well as accessible by the GPU
+ * through the GMADR mapped BAR (i915->mm.gtt->gtt).
+ */
+static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
+				     struct i915_vma_resource *vma_res,
+				     enum i915_cache_level level,
+				     u32 flags)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	gen6_pte_t __iomem *gte;
+	gen6_pte_t __iomem *end;
+	struct sgt_iter iter;
+	dma_addr_t addr;
+
+	gte = (gen6_pte_t __iomem *)ggtt->gsm;
+	gte += vma_res->start / I915_GTT_PAGE_SIZE;
+	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
+
+	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
+		iowrite32(vm->pte_encode(addr, level, flags), gte++);
+	GEM_BUG_ON(gte > end);
+
+	/* Fill the allocated but "unused" space beyond the end of the buffer */
+	while (gte < end)
+		iowrite32(vm->scratch[0]->encode, gte++);
+
+	/*
+	 * We want to flush the TLBs only after we're certain all the PTE
+	 * updates have finished.
+	 */
+	ggtt->invalidate(ggtt);
+}
+
+static void nop_clear_range(struct i915_address_space *vm,
+			    u64 start, u64 length)
+{
+}
+
+static void gen8_ggtt_clear_range(struct i915_address_space *vm,
+				  u64 start, u64 length)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
+	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
+	const gen8_pte_t scratch_pte = vm->scratch[0]->encode;
+	gen8_pte_t __iomem *gtt_base =
+		(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
+	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
+	int i;
+
+	if (WARN(num_entries > max_entries,
+		 "First entry = %d; Num entries = %d (max=%d)\n",
+		 first_entry, num_entries, max_entries))
+		num_entries = max_entries;
+
+	for (i = 0; i < num_entries; i++)
+		gen8_set_pte(&gtt_base[i], scratch_pte);
+}
+
+static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
+{
+	/*
+	 * Make sure the internal GAM fifo has been cleared of all GTT
+	 * writes before exiting stop_machine(). This guarantees that
+	 * any aperture accesses waiting to start in another process
+	 * cannot back up behind the GTT writes causing a hang.
+	 * The register can be any arbitrary GAM register.
+	 */
+	intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
+}
+
+struct insert_page {
+	struct i915_address_space *vm;
+	dma_addr_t addr;
+	u64 offset;
+	enum i915_cache_level level;
+};
+
+static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
+{
+	struct insert_page *arg = _arg;
+
+	gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, arg->level, 0);
+	bxt_vtd_ggtt_wa(arg->vm);
+
+	return 0;
+}
+
+static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space *vm,
+					  dma_addr_t addr,
+					  u64 offset,
+					  enum i915_cache_level level,
+					  u32 unused)
+{
+	struct insert_page arg = { vm, addr, offset, level };
+
+	stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
+}
+
+struct insert_entries {
+	struct i915_address_space *vm;
+	struct i915_vma_resource *vma_res;
+	enum i915_cache_level level;
+	u32 flags;
+};
+
+static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
+{
+	struct insert_entries *arg = _arg;
+
+	gen8_ggtt_insert_entries(arg->vm, arg->vma_res, arg->level, arg->flags);
+	bxt_vtd_ggtt_wa(arg->vm);
+
+	return 0;
+}
+
+static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
+					     struct i915_vma_resource *vma_res,
+					     enum i915_cache_level level,
+					     u32 flags)
+{
+	struct insert_entries arg = { vm, vma_res, level, flags };
+
+	stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
+}
+
+static void gen6_ggtt_clear_range(struct i915_address_space *vm,
+				  u64 start, u64 length)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
+	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
+	gen6_pte_t scratch_pte, __iomem *gtt_base =
+		(gen6_pte_t __iomem *)ggtt->gsm + first_entry;
+	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
+	int i;
+
+	if (WARN(num_entries > max_entries,
+		 "First entry = %d; Num entries = %d (max=%d)\n",
+		 first_entry, num_entries, max_entries))
+		num_entries = max_entries;
+
+	scratch_pte = vm->scratch[0]->encode;
+	for (i = 0; i < num_entries; i++)
+		iowrite32(scratch_pte, &gtt_base[i]);
+}
+
 void intel_ggtt_bind_vma(struct i915_address_space *vm,
-			  struct i915_vm_pt_stash *stash,
-			  struct i915_vma_resource *vma_res,
-			  enum i915_cache_level cache_level,
-			  u32 flags)
+			 struct i915_vm_pt_stash *stash,
+			 struct i915_vma_resource *vma_res,
+			 enum i915_cache_level cache_level,
+			 u32 flags)
 {
 	u32 pte_flags;
 
@@ -270,7 +493,7 @@ void intel_ggtt_bind_vma(struct i915_address_space *vm,
 }
 
 void intel_ggtt_unbind_vma(struct i915_address_space *vm,
-			    struct i915_vma_resource *vma_res)
+			   struct i915_vma_resource *vma_res)
 {
 	vm->clear_range(vm, vma_res->start, vma_res->vma_size);
 }
@@ -589,12 +812,316 @@ void i915_ggtt_driver_late_release(struct drm_i915_private *i915)
 	dma_resv_fini(&ggtt->vm._resv);
 }
 
-struct resource intel_pci_resource(struct pci_dev *pdev, int bar)
+static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
+{
+	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
+	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
+	return snb_gmch_ctl << 20;
+}
+
+static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
+{
+	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
+	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
+	if (bdw_gmch_ctl)
+		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
+
+#ifdef CONFIG_X86_32
+	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * I915_GTT_PAGE_SIZE */
+	if (bdw_gmch_ctl > 4)
+		bdw_gmch_ctl = 4;
+#endif
+
+	return bdw_gmch_ctl << 20;
+}
+
+static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
+{
+	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
+	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
+
+	if (gmch_ctrl)
+		return 1 << (20 + gmch_ctrl);
+
+	return 0;
+}
+
+static unsigned int gen6_gttmmadr_size(struct drm_i915_private *i915)
+{
+	/*
+	 * GEN6: GTTMMADR size is 4MB and GTTADR starts at 2MB offset
+	 * GEN8: GTTMMADR size is 16MB and GTTADR starts at 8MB offset
+	 */
+	GEM_BUG_ON(GRAPHICS_VER(i915) < 6);
+	return (GRAPHICS_VER(i915) < 8) ? SZ_4M : SZ_16M;
+}
+
+static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915)
+{
+	return gen6_gttmmadr_size(i915) / 2;
+}
+
+static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
+{
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
+	phys_addr_t phys_addr;
+	u32 pte_flags;
+	int ret;
+
+	GEM_WARN_ON(pci_resource_len(pdev, 0) != gen6_gttmmadr_size(i915));
+	phys_addr = pci_resource_start(pdev, 0) + gen6_gttadr_offset(i915);
+
+	/*
+	 * On BXT+/ICL+ writes larger than 64 bit to the GTT pagetable range
+	 * will be dropped. For WC mappings in general we have 64 byte burst
+	 * writes when the WC buffer is flushed, so we can't use it, but have to
+	 * resort to an uncached mapping. The WC issue is easily caught by the
+	 * readback check when writing GTT PTE entries.
+	 */
+	if (IS_GEN9_LP(i915) || GRAPHICS_VER(i915) >= 11)
+		ggtt->gsm = ioremap(phys_addr, size);
+	else
+		ggtt->gsm = ioremap_wc(phys_addr, size);
+	if (!ggtt->gsm) {
+		drm_err(&i915->drm, "Failed to map the ggtt page table\n");
+		return -ENOMEM;
+	}
+
+	kref_init(&ggtt->vm.resv_ref);
+	ret = setup_scratch_page(&ggtt->vm);
+	if (ret) {
+		drm_err(&i915->drm, "Scratch setup failed\n");
+		/* iounmap will also get called at remove, but meh */
+		iounmap(ggtt->gsm);
+		return ret;
+	}
+
+	pte_flags = 0;
+	if (i915_gem_object_is_lmem(ggtt->vm.scratch[0]))
+		pte_flags |= PTE_LM;
+
+	ggtt->vm.scratch[0]->encode =
+		ggtt->vm.pte_encode(px_dma(ggtt->vm.scratch[0]),
+				    I915_CACHE_NONE, pte_flags);
+
+	return 0;
+}
+
+static void gen6_gmch_remove(struct i915_address_space *vm)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+
+	iounmap(ggtt->gsm);
+	free_scratch(vm);
+}
+
+static struct resource pci_resource(struct pci_dev *pdev, int bar)
 {
 	return (struct resource)DEFINE_RES_MEM(pci_resource_start(pdev, bar),
 					       pci_resource_len(pdev, bar));
 }
 
+static int gen8_gmch_probe(struct i915_ggtt *ggtt)
+{
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
+	unsigned int size;
+	u16 snb_gmch_ctl;
+
+	if (!HAS_LMEM(i915)) {
+		ggtt->gmadr = pci_resource(pdev, 2);
+		ggtt->mappable_end = resource_size(&ggtt->gmadr);
+	}
+
+	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
+	if (IS_CHERRYVIEW(i915))
+		size = chv_get_total_gtt_size(snb_gmch_ctl);
+	else
+		size = gen8_get_total_gtt_size(snb_gmch_ctl);
+
+	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
+	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
+	ggtt->vm.lmem_pt_obj_flags = I915_BO_ALLOC_PM_EARLY;
+
+	ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
+	ggtt->vm.cleanup = gen6_gmch_remove;
+	ggtt->vm.insert_page = gen8_ggtt_insert_page;
+	ggtt->vm.clear_range = nop_clear_range;
+	if (intel_scanout_needs_vtd_wa(i915))
+		ggtt->vm.clear_range = gen8_ggtt_clear_range;
+
+	ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
+
+	/*
+	 * Serialize GTT updates with aperture access on BXT if VT-d is on,
+	 * and always on CHV.
+	 */
+	if (intel_vm_no_concurrent_access_wa(i915)) {
+		ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
+		ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
+		ggtt->vm.bind_async_flags =
+			I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
+	}
+
+	ggtt->invalidate = gen8_ggtt_invalidate;
+
+	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
+	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
+
+	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
+
+	setup_private_pat(ggtt->vm.gt->uncore);
+
+	return ggtt_probe_common(ggtt, size);
+}
+
+static u64 snb_pte_encode(dma_addr_t addr,
+			  enum i915_cache_level level,
+			  u32 flags)
+{
+	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	switch (level) {
+	case I915_CACHE_L3_LLC:
+	case I915_CACHE_LLC:
+		pte |= GEN6_PTE_CACHE_LLC;
+		break;
+	case I915_CACHE_NONE:
+		pte |= GEN6_PTE_UNCACHED;
+		break;
+	default:
+		MISSING_CASE(level);
+	}
+
+	return pte;
+}
+
+static u64 ivb_pte_encode(dma_addr_t addr,
+			  enum i915_cache_level level,
+			  u32 flags)
+{
+	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	switch (level) {
+	case I915_CACHE_L3_LLC:
+		pte |= GEN7_PTE_CACHE_L3_LLC;
+		break;
+	case I915_CACHE_LLC:
+		pte |= GEN6_PTE_CACHE_LLC;
+		break;
+	case I915_CACHE_NONE:
+		pte |= GEN6_PTE_UNCACHED;
+		break;
+	default:
+		MISSING_CASE(level);
+	}
+
+	return pte;
+}
+
+static u64 byt_pte_encode(dma_addr_t addr,
+			  enum i915_cache_level level,
+			  u32 flags)
+{
+	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	if (!(flags & PTE_READ_ONLY))
+		pte |= BYT_PTE_WRITEABLE;
+
+	if (level != I915_CACHE_NONE)
+		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
+
+	return pte;
+}
+
+static u64 hsw_pte_encode(dma_addr_t addr,
+			  enum i915_cache_level level,
+			  u32 flags)
+{
+	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	if (level != I915_CACHE_NONE)
+		pte |= HSW_WB_LLC_AGE3;
+
+	return pte;
+}
+
+static u64 iris_pte_encode(dma_addr_t addr,
+			   enum i915_cache_level level,
+			   u32 flags)
+{
+	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	switch (level) {
+	case I915_CACHE_NONE:
+		break;
+	case I915_CACHE_WT:
+		pte |= HSW_WT_ELLC_LLC_AGE3;
+		break;
+	default:
+		pte |= HSW_WB_ELLC_LLC_AGE3;
+		break;
+	}
+
+	return pte;
+}
+
+static int gen6_gmch_probe(struct i915_ggtt *ggtt)
+{
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
+	unsigned int size;
+	u16 snb_gmch_ctl;
+
+	ggtt->gmadr = pci_resource(pdev, 2);
+	ggtt->mappable_end = resource_size(&ggtt->gmadr);
+
+	/*
+	 * 64/512MB is the current min/max we actually know of, but this is
+	 * just a coarse sanity check.
+	 */
+	if (ggtt->mappable_end < (64 << 20) ||
+	    ggtt->mappable_end > (512 << 20)) {
+		drm_err(&i915->drm, "Unknown GMADR size (%pa)\n",
+			&ggtt->mappable_end);
+		return -ENXIO;
+	}
+
+	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
+
+	size = gen6_get_total_gtt_size(snb_gmch_ctl);
+	ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
+
+	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
+	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
+
+	ggtt->vm.clear_range = nop_clear_range;
+	if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
+		ggtt->vm.clear_range = gen6_ggtt_clear_range;
+	ggtt->vm.insert_page = gen6_ggtt_insert_page;
+	ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
+	ggtt->vm.cleanup = gen6_gmch_remove;
+
+	ggtt->invalidate = gen6_ggtt_invalidate;
+
+	if (HAS_EDRAM(i915))
+		ggtt->vm.pte_encode = iris_pte_encode;
+	else if (IS_HASWELL(i915))
+		ggtt->vm.pte_encode = hsw_pte_encode;
+	else if (IS_VALLEYVIEW(i915))
+		ggtt->vm.pte_encode = byt_pte_encode;
+	else if (GRAPHICS_VER(i915) >= 7)
+		ggtt->vm.pte_encode = ivb_pte_encode;
+	else
+		ggtt->vm.pte_encode = snb_pte_encode;
+
+	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
+	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
+
+	return ggtt_probe_common(ggtt, size);
+}
+
 static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
 {
 	struct drm_i915_private *i915 = gt->i915;
@@ -605,12 +1132,13 @@ static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
 	ggtt->vm.dma = i915->drm.dev;
 	dma_resv_init(&ggtt->vm._resv);
 
-	if (GRAPHICS_VER(i915) <= 5)
-		ret = intel_gt_gmch_gen5_probe(ggtt);
-	else if (GRAPHICS_VER(i915) < 8)
-		ret = intel_gt_gmch_gen6_probe(ggtt);
+	if (GRAPHICS_VER(i915) >= 8)
+		ret = gen8_gmch_probe(ggtt);
+	else if (GRAPHICS_VER(i915) >= 6)
+		ret = gen6_gmch_probe(ggtt);
 	else
-		ret = intel_gt_gmch_gen8_probe(ggtt);
+		ret = intel_ggtt_gmch_probe(ggtt);
+
 	if (ret) {
 		dma_resv_fini(&ggtt->vm._resv);
 		return ret;
@@ -664,7 +1192,10 @@ int i915_ggtt_probe_hw(struct drm_i915_private *i915)
 
 int i915_ggtt_enable_hw(struct drm_i915_private *i915)
 {
-	return intel_gt_gmch_gen5_enable_hw(i915);
+	if (GRAPHICS_VER(i915) < 6)
+		return intel_ggtt_gmch_enable_hw(i915);
+
+	return 0;
 }
 
 void i915_ggtt_enable_guc(struct i915_ggtt *ggtt)