drm/i915: make dsm struct resource centric

Now that we are using struct resource to track the stolen region, it is
more convenient if we track dsm in a resource as well.

v2: check range_overflow when writing to 32b registers (Chris)
    pepper in some comments (Chris)
v3: refit i915_stolen_to_dma()
v4: kill ggtt->stolen_size
v5: some more polish

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171211151822.20953-6-matthew.auld@intel.com

8 files changed, 89 insertions, 88 deletions

diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index dde7caac7f9f..0c86b4dfd59c 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -1424,12 +1424,10 @@ int intel_gmch_probe(struct pci_dev *bridge_pdev, struct pci_dev *gpu_pdev,
 EXPORT_SYMBOL(intel_gmch_probe);
 
 void intel_gtt_get(u64 *gtt_total,
-                   u32 *stolen_size,
                    phys_addr_t *mappable_base,
                    u64 *mappable_end)
 {
         *gtt_total = intel_private.gtt_total_entries << PAGE_SHIFT;
-        *stolen_size = intel_private.stolen_size;
         *mappable_base = intel_private.gma_bus_addr;
         *mappable_end = intel_private.gtt_mappable_entries << PAGE_SHIFT;
 }
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d57859cfad8e..1677b7e0d671 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1538,9 +1538,6 @@ struct i915_gem_mm {
          */
         struct pagevec wc_stash;
 
-        /** Usable portion of the GTT for GEM */
-        dma_addr_t stolen_base; /* limited to low memory (32-bit) */
-
         /**
          * tmpfs instance used for shmem backed objects
          */
@@ -2254,6 +2251,15 @@ struct drm_i915_private {
 
         const struct intel_device_info info;
 
+        /**
+         * Data Stolen Memory - aka "i915 stolen memory" gives us the start and
+         * end of stolen which we can optionally use to create GEM objects
+         * backed by stolen memory. Note that ggtt->stolen_usable_size tells us
+         * exactly how much of this we are actually allowed to use, given that
+         * some portion of it is in fact reserved for use by hardware functions.
+         */
+        struct resource dsm;
+
         void __iomem *regs;
 
         struct intel_uncore uncore;
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index c1b8b1c8401e..7a5302318d31 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -3299,8 +3299,6 @@ static int gen8_gmch_probe(struct i915_ggtt *ggtt)
 
         pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
 
-        ggtt->stolen_size = resource_size(&intel_graphics_stolen_res);
-
         if (INTEL_GEN(dev_priv) >= 9) {
                 size = gen8_get_total_gtt_size(snb_gmch_ctl);
         } else if (IS_CHERRYVIEW(dev_priv)) {
@@ -3363,8 +3361,6 @@ static int gen6_gmch_probe(struct i915_ggtt *ggtt)
                 DRM_ERROR("Can't set DMA mask/consistent mask (%d)\n", err);
         pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
 
-        ggtt->stolen_size = resource_size(&intel_graphics_stolen_res);
-
         size = gen6_get_total_gtt_size(snb_gmch_ctl);
         ggtt->base.total = (size / sizeof(gen6_pte_t)) << PAGE_SHIFT;
 
@@ -3410,7 +3406,6 @@ static int i915_gmch_probe(struct i915_ggtt *ggtt)
         }
 
         intel_gtt_get(&ggtt->base.total,
-                      &ggtt->stolen_size,
                       &ggtt->mappable_base,
                       &ggtt->mappable_end);
 
@@ -3482,7 +3477,8 @@ int i915_ggtt_probe_hw(struct drm_i915_private *dev_priv)
         DRM_INFO("Memory usable by graphics device = %lluM\n",
                  ggtt->base.total >> 20);
         DRM_DEBUG_DRIVER("GMADR size = %lldM\n", ggtt->mappable_end >> 20);
-        DRM_DEBUG_DRIVER("GTT stolen size = %uM\n", ggtt->stolen_size >> 20);
+        DRM_DEBUG_DRIVER("GTT stolen size = %lluM\n",
+                         (u64)resource_size(&intel_graphics_stolen_res) >> 20);
         if (intel_vtd_active())
                 DRM_INFO("VT-d active for gfx access\n");
 
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 93211a96fdad..30a2920b1291 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -381,7 +381,6 @@ struct i915_ggtt {
          * avoid the first page! The upper end of stolen memory is reserved for
          * hardware functions and similarly removed from the accessible range.
          */
-        u32 stolen_size;                /* Total size of stolen memory */
         u32 stolen_usable_size; /* Total size minus reserved ranges */
         u32 stolen_reserved_base;
         u32 stolen_reserved_size;
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index f8ac1438c35d..5b5558fe70cc 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -76,27 +76,26 @@ void i915_gem_stolen_remove_node(struct drm_i915_private *dev_priv,
         mutex_unlock(&dev_priv->mm.stolen_lock);
 }
 
-static dma_addr_t i915_stolen_to_dma(struct drm_i915_private *dev_priv)
+static int i915_adjust_stolen(struct drm_i915_private *dev_priv,
+                              struct resource *dsm)
 {
         struct i915_ggtt *ggtt = &dev_priv->ggtt;
-        dma_addr_t base = intel_graphics_stolen_res.start;
         struct resource *r;
 
-        GEM_BUG_ON(overflows_type(intel_graphics_stolen_res.start, base));
+        if (dsm->start == 0 || dsm->end <= dsm->start)
+                return -EINVAL;
 
-        if (base == 0 || add_overflows(base, ggtt->stolen_size))
-                return 0;
+        /*
+         * TODO: We have yet too encounter the case where the GTT wasn't at the
+         * end of stolen. With that assumption we could simplify this.
+         */
 
-        /* make sure we don't clobber the GTT if it's within stolen memory */
+        /* Make sure we don't clobber the GTT if it's within stolen memory */
         if (INTEL_GEN(dev_priv) <= 4 &&
             !IS_G33(dev_priv) && !IS_PINEVIEW(dev_priv) && !IS_G4X(dev_priv)) {
-                struct {
-                        dma_addr_t start, end;
-                } stolen[2] = {
-                        { .start = base, .end = base + ggtt->stolen_size, },
-                        { .start = base, .end = base + ggtt->stolen_size, },
-                };
-                u64 ggtt_start, ggtt_end;
+                struct resource stolen[2] = {*dsm, *dsm};
+                struct resource ggtt_res;
+                u64 ggtt_start;
 
                 ggtt_start = I915_READ(PGTBL_CTL);
                 if (IS_GEN4(dev_priv))
@@ -104,70 +103,64 @@ static dma_addr_t i915_stolen_to_dma(struct drm_i915_private *dev_priv)
                                      (ggtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
                 else
                         ggtt_start &= PGTBL_ADDRESS_LO_MASK;
-                ggtt_end = ggtt_start + ggtt_total_entries(ggtt) * 4;
-
-                if (ggtt_start >= stolen[0].start && ggtt_start < stolen[0].end)
-                        stolen[0].end = ggtt_start;
-                if (ggtt_end > stolen[1].start && ggtt_end <= stolen[1].end)
-                        stolen[1].start = ggtt_end;
-
-                /* pick the larger of the two chunks */
-                if (stolen[0].end - stolen[0].start >
-                    stolen[1].end - stolen[1].start) {
-                        base = stolen[0].start;
-                        ggtt->stolen_size = stolen[0].end - stolen[0].start;
-                } else {
-                        base = stolen[1].start;
-                        ggtt->stolen_size = stolen[1].end - stolen[1].start;
-                }
+
+                ggtt_res =
+                        (struct resource) DEFINE_RES_MEM(ggtt_start,
+                                                         ggtt_total_entries(ggtt) * 4);
+
+                if (ggtt_res.start >= stolen[0].start && ggtt_res.start < stolen[0].end)
+                        stolen[0].end = ggtt_res.start;
+                if (ggtt_res.end > stolen[1].start && ggtt_res.end <= stolen[1].end)
+                        stolen[1].start = ggtt_res.end;
+
+                /* Pick the larger of the two chunks */
+                if (resource_size(&stolen[0]) > resource_size(&stolen[1]))
+                        *dsm = stolen[0];
+                else
+                        *dsm = stolen[1];
 
                 if (stolen[0].start != stolen[1].start ||
                     stolen[0].end != stolen[1].end) {
-                        dma_addr_t end = base + ggtt->stolen_size - 1;
-
-                        DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",
-                                      (unsigned long long)ggtt_start,
-                                      (unsigned long long)ggtt_end - 1);
-                        DRM_DEBUG_KMS("Stolen memory adjusted to %pad - %pad\n",
-                                      &base, &end);
+                        DRM_DEBUG_KMS("GTT within stolen memory at %pR\n", &ggtt_res);
+                        DRM_DEBUG_KMS("Stolen memory adjusted to %pR\n", dsm);
                 }
         }
 
-
-        /* Verify that nothing else uses this physical address. Stolen
+        /*
+         * Verify that nothing else uses this physical address. Stolen
          * memory should be reserved by the BIOS and hidden from the
          * kernel. So if the region is already marked as busy, something
          * is seriously wrong.
          */
-        r = devm_request_mem_region(dev_priv->drm.dev, base, ggtt->stolen_size,
+        r = devm_request_mem_region(dev_priv->drm.dev, dsm->start,
+                                    resource_size(dsm),
                                     "Graphics Stolen Memory");
         if (r == NULL) {
                 /*
                  * One more attempt but this time requesting region from
-                 * base + 1, as we have seen that this resolves the region
+                 * start + 1, as we have seen that this resolves the region
                  * conflict with the PCI Bus.
                  * This is a BIOS w/a: Some BIOS wrap stolen in the root
                  * PCI bus, but have an off-by-one error. Hence retry the
                  * reservation starting from 1 instead of 0.
                  * There's also BIOS with off-by-one on the other end.
                  */
-                r = devm_request_mem_region(dev_priv->drm.dev, base + 1,
-                                            ggtt->stolen_size - 2,
+                r = devm_request_mem_region(dev_priv->drm.dev, dsm->start + 1,
+                                            resource_size(dsm) - 2,
                                             "Graphics Stolen Memory");
                 /*
                  * GEN3 firmware likes to smash pci bridges into the stolen
                  * range. Apparently this works.
                  */
                 if (r == NULL && !IS_GEN3(dev_priv)) {
-                        dma_addr_t end = base + ggtt->stolen_size;
+                        DRM_ERROR("conflict detected with stolen region: %pR\n",
+                                  dsm);
 
-                        DRM_ERROR("conflict detected with stolen region: [%pad - %pad]\n",
-                                  &base, &end);
-                        base = 0;
+                        return -EBUSY;
                 }
         }
 
-        return base;
+        return 0;
 }
 
 void i915_gem_cleanup_stolen(struct drm_device *dev)
@@ -183,11 +176,10 @@ void i915_gem_cleanup_stolen(struct drm_device *dev)
 static void g4x_get_stolen_reserved(struct drm_i915_private *dev_priv,
                                     dma_addr_t *base, u32 *size)
 {
-        struct i915_ggtt *ggtt = &dev_priv->ggtt;
         uint32_t reg_val = I915_READ(IS_GM45(dev_priv) ?
                                      CTG_STOLEN_RESERVED :
                                      ELK_STOLEN_RESERVED);
-        dma_addr_t stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size;
+        dma_addr_t stolen_top = dev_priv->dsm.end + 1;
 
         if ((reg_val & G4X_STOLEN_RESERVED_ENABLE) == 0) {
                 *base = 0;
@@ -308,7 +300,6 @@ static void chv_get_stolen_reserved(struct drm_i915_private *dev_priv,
 static void bdw_get_stolen_reserved(struct drm_i915_private *dev_priv,
                                     dma_addr_t *base, u32 *size)
 {
-        struct i915_ggtt *ggtt = &dev_priv->ggtt;
         uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
         dma_addr_t stolen_top;
 
@@ -318,7 +309,7 @@ static void bdw_get_stolen_reserved(struct drm_i915_private *dev_priv,
                 return;
         }
 
-        stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size;
+        stolen_top = dev_priv->dsm.end + 1;
 
         *base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
 
@@ -351,14 +342,18 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv)
                 return 0;
         }
 
-        if (ggtt->stolen_size == 0)
+        if (resource_size(&intel_graphics_stolen_res) == 0)
                 return 0;
 
-        dev_priv->mm.stolen_base = i915_stolen_to_dma(dev_priv);
-        if (dev_priv->mm.stolen_base == 0)
+        dev_priv->dsm = intel_graphics_stolen_res;
+
+        if (i915_adjust_stolen(dev_priv, &dev_priv->dsm))
                 return 0;
 
-        stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size;
+        GEM_BUG_ON(dev_priv->dsm.start == 0);
+        GEM_BUG_ON(dev_priv->dsm.end <= dev_priv->dsm.start);
+
+        stolen_top = dev_priv->dsm.end + 1;
         reserved_base = 0;
         reserved_size = 0;
 
@@ -399,12 +394,11 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv)
                 reserved_base = stolen_top;
         }
 
-        if (reserved_base < dev_priv->mm.stolen_base ||
+        if (reserved_base < dev_priv->dsm.start ||
             reserved_base + reserved_size > stolen_top) {
                 dma_addr_t reserved_top = reserved_base + reserved_size;
-                DRM_ERROR("Stolen reserved area [%pad - %pad] outside stolen memory [%pad - %pad]\n",
-                          &reserved_base, &reserved_top,
-                          &dev_priv->mm.stolen_base, &stolen_top);
+                DRM_ERROR("Stolen reserved area [%pad - %pad] outside stolen memory %pR\n",
+                          &reserved_base, &reserved_top, &dev_priv->dsm);
                 return 0;
         }
 
@@ -415,9 +409,9 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv)
          * memory, so just consider the start. */
         reserved_total = stolen_top - reserved_base;
 
-        DRM_DEBUG_KMS("Memory reserved for graphics device: %uK, usable: %uK\n",
-                      ggtt->stolen_size >> 10,
-                      (ggtt->stolen_size - reserved_total) >> 10);
+        DRM_DEBUG_KMS("Memory reserved for graphics device: %lluK, usable: %lluK\n",
+                      (u64)resource_size(&dev_priv->dsm) >> 10,
+                      ((u64)resource_size(&dev_priv->dsm) - reserved_total) >> 10);
 
         stolen_usable_start = 0;
         /* WaSkipStolenMemoryFirstPage:bdw+ */
@@ -425,7 +419,7 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv)
                 stolen_usable_start = 4096;
 
         ggtt->stolen_usable_size =
-                ggtt->stolen_size - reserved_total - stolen_usable_start;
+                resource_size(&dev_priv->dsm) - reserved_total - stolen_usable_start;
 
         /* Basic memrange allocator for stolen space. */
         drm_mm_init(&dev_priv->mm.stolen, stolen_usable_start,
@@ -442,7 +436,8 @@ i915_pages_create_for_stolen(struct drm_device *dev,
         struct sg_table *st;
         struct scatterlist *sg;
 
-        GEM_BUG_ON(range_overflows(offset, size, dev_priv->ggtt.stolen_size));
+        GEM_BUG_ON(range_overflows_t(resource_size_t, offset, size,
+                                     resource_size(&dev_priv->dsm)));
 
         /* We hide that we have no struct page backing our stolen object
          * by wrapping the contiguous physical allocation with a fake
@@ -462,7 +457,7 @@ i915_pages_create_for_stolen(struct drm_device *dev,
         sg->offset = 0;
         sg->length = size;
 
-        sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
+        sg_dma_address(sg) = (dma_addr_t)dev_priv->dsm.start + offset;
         sg_dma_len(sg) = size;
 
         return st;
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 4aefc658a5cf..f88c1b5dae4c 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -531,7 +531,6 @@ static int find_compression_threshold(struct drm_i915_private *dev_priv,
                                       int size,
                                       int fb_cpp)
 {
-        struct i915_ggtt *ggtt = &dev_priv->ggtt;
         int compression_threshold = 1;
         int ret;
         u64 end;
@@ -541,7 +540,7 @@ static int find_compression_threshold(struct drm_i915_private *dev_priv,
          * If we enable FBC using a CFB on that memory range we'll get FIFO
          * underruns, even if that range is not reserved by the BIOS. */
         if (IS_BROADWELL(dev_priv) || IS_GEN9_BC(dev_priv))
-                end = ggtt->stolen_size - 8 * 1024 * 1024;
+                end = resource_size(&dev_priv->dsm) - 8 * 1024 * 1024;
         else
                 end = U64_MAX;
 
@@ -615,10 +614,16 @@ static int intel_fbc_alloc_cfb(struct intel_crtc *crtc)
 
                 fbc->compressed_llb = compressed_llb;
 
+                GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
+                                             fbc->compressed_fb.start,
+                                             U32_MAX));
+                GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
+                                             fbc->compressed_llb->start,
+                                             U32_MAX));
                 I915_WRITE(FBC_CFB_BASE,
-                           dev_priv->mm.stolen_base + fbc->compressed_fb.start);
+                           dev_priv->dsm.start + fbc->compressed_fb.start);
                 I915_WRITE(FBC_LL_BASE,
-                           dev_priv->mm.stolen_base + compressed_llb->start);
+                           dev_priv->dsm.start + compressed_llb->start);
         }
 
         DRM_DEBUG_KMS("reserved %llu bytes of contiguous stolen space for FBC, threshold: %d\n",
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 5836181d6f8a..79b3fd617de0 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -7020,7 +7020,7 @@ static void valleyview_check_pctx(struct drm_i915_private *dev_priv)
 {
         unsigned long pctx_addr = I915_READ(VLV_PCBR) & ~4095;
 
-        WARN_ON(pctx_addr != dev_priv->mm.stolen_base +
+        WARN_ON(pctx_addr != dev_priv->dsm.start +
                              dev_priv->vlv_pctx->stolen->start);
 }
 
@@ -7035,7 +7035,6 @@ static void cherryview_check_pctx(struct drm_i915_private *dev_priv)
 
 static void cherryview_setup_pctx(struct drm_i915_private *dev_priv)
 {
-        struct i915_ggtt *ggtt = &dev_priv->ggtt;
         unsigned long pctx_paddr, paddr;
         u32 pcbr;
         int pctx_size = 32*1024;
@@ -7043,8 +7042,8 @@ static void cherryview_setup_pctx(struct drm_i915_private *dev_priv)
         pcbr = I915_READ(VLV_PCBR);
         if ((pcbr >> VLV_PCBR_ADDR_SHIFT) == 0) {
                 DRM_DEBUG_DRIVER("BIOS didn't set up PCBR, fixing up\n");
-                paddr = (dev_priv->mm.stolen_base +
-                         (ggtt->stolen_size - pctx_size));
+                paddr = dev_priv->dsm.end + 1 - pctx_size;
+                GEM_BUG_ON(paddr > U32_MAX);
 
                 pctx_paddr = (paddr & (~4095));
                 I915_WRITE(VLV_PCBR, pctx_paddr);
@@ -7065,7 +7064,7 @@ static void valleyview_setup_pctx(struct drm_i915_private *dev_priv)
                 /* BIOS set it up already, grab the pre-alloc'd space */
                 int pcbr_offset;
 
-                pcbr_offset = (pcbr & (~4095)) - dev_priv->mm.stolen_base;
+                pcbr_offset = (pcbr & (~4095)) - dev_priv->dsm.start;
                 pctx = i915_gem_object_create_stolen_for_preallocated(dev_priv,
                                                                       pcbr_offset,
                                                                       I915_GTT_OFFSET_NONE,
@@ -7089,7 +7088,11 @@ static void valleyview_setup_pctx(struct drm_i915_private *dev_priv)
                 goto out;
         }
 
-        pctx_paddr = dev_priv->mm.stolen_base + pctx->stolen->start;
+        GEM_BUG_ON(range_overflows_t(u64,
+                                     dev_priv->dsm.start,
+                                     pctx->stolen->start,
+                                     U32_MAX));
+        pctx_paddr = dev_priv->dsm.start + pctx->stolen->start;
         I915_WRITE(VLV_PCBR, pctx_paddr);
 
 out:
diff --git a/include/drm/intel-gtt.h b/include/drm/intel-gtt.h
index c5db7975c640..8c577ca38e2e 100644
--- a/include/drm/intel-gtt.h
+++ b/include/drm/intel-gtt.h
@@ -5,7 +5,6 @@
 #define _DRM_INTEL_GTT_H
 
 void intel_gtt_get(u64 *gtt_total,
-                   u32 *stolen_size,
                    phys_addr_t *mappable_base,
                    u64 *mappable_end);