drm/i915/gvt: Optimize MMIO register handling for some large MMIO blocks

Some of traced MMIO registers are a large continuous section. These
stuffed the MMIO lookup hash table and so waste lots of memory and
get much lower lookup performance.

Here we picked out these sections by special handling. These sections
include:
  o Display pipe registers, total 768.
  o The PVINFO page, total 1024.
  o MCHBAR_MIRROR, total 65536.
  o CSR_MMIO, total 3072.

So we removed 70,400 items from the hash table, and speed up guest
boot time by ~500ms.

v2:
  o add a local function find_mmio_block().
  o fix comments.

Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

1 files changed, 133 insertions, 29 deletions

diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
index bb7037c6c347..60c0db10ae15 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -92,11 +92,22 @@ static void write_vreg(struct intel_vgpu *vgpu, unsigned int offset,
 	memcpy(&vgpu_vreg(vgpu, offset), p_data, bytes);
 }
 
+static struct intel_gvt_mmio_info *find_mmio_info(struct intel_gvt *gvt,
+						  unsigned int offset)
+{
+	struct intel_gvt_mmio_info *e;
+
+	hash_for_each_possible(gvt->mmio.mmio_info_table, e, node, offset) {
+		if (e->offset == offset)
+			return e;
+	}
+	return NULL;
+}
+
 static int new_mmio_info(struct intel_gvt *gvt,
 		u32 offset, u32 flags, u32 size,
 		u32 addr_mask, u32 ro_mask, u32 device,
-		int (*read)(struct intel_vgpu *, unsigned int, void *, unsigned int),
-		int (*write)(struct intel_vgpu *, unsigned int, void *, unsigned int))
+		gvt_mmio_func read, gvt_mmio_func write)
 {
 	struct intel_gvt_mmio_info *info, *p;
 	u32 start, end, i;
@@ -116,7 +127,7 @@ static int new_mmio_info(struct intel_gvt *gvt,
 			return -ENOMEM;
 
 		info->offset = i;
-		p = intel_gvt_find_mmio_info(gvt, info->offset);
+		p = find_mmio_info(gvt, info->offset);
 		if (p)
 			gvt_err("dup mmio definition offset %x\n",
 				info->offset);
@@ -1794,10 +1805,6 @@ static int init_generic_mmio_info(struct intel_gvt *gvt)
 	MMIO_D(SPRSCALE(PIPE_C), D_ALL);
 	MMIO_D(SPRSURFLIVE(PIPE_C), D_ALL);
 
-	MMIO_F(LGC_PALETTE(PIPE_A, 0), 4 * 256, 0, 0, 0, D_ALL, NULL, NULL);
-	MMIO_F(LGC_PALETTE(PIPE_B, 0), 4 * 256, 0, 0, 0, D_ALL, NULL, NULL);
-	MMIO_F(LGC_PALETTE(PIPE_C, 0), 4 * 256, 0, 0, 0, D_ALL, NULL, NULL);
-
 	MMIO_D(HTOTAL(TRANSCODER_A), D_ALL);
 	MMIO_D(HBLANK(TRANSCODER_A), D_ALL);
 	MMIO_D(HSYNC(TRANSCODER_A), D_ALL);
@@ -2245,11 +2252,8 @@ static int init_generic_mmio_info(struct intel_gvt *gvt)
 
 	MMIO_DH(GEN6_GDRST, D_ALL, NULL, gdrst_mmio_write);
 	MMIO_F(FENCE_REG_GEN6_LO(0), 0x80, 0, 0, 0, D_ALL, fence_mmio_read, fence_mmio_write);
-	MMIO_F(VGT_PVINFO_PAGE, VGT_PVINFO_SIZE, F_UNALIGN, 0, 0, D_ALL, pvinfo_mmio_read, pvinfo_mmio_write);
 	MMIO_DH(CPU_VGACNTRL, D_ALL, NULL, vga_control_mmio_write);
 
-	MMIO_F(MCHBAR_MIRROR_BASE_SNB, 0x40000, 0, 0, 0, D_ALL, NULL, NULL);
-
 	MMIO_D(TILECTL, D_ALL);
 
 	MMIO_D(GEN6_UCGCTL1, D_ALL);
@@ -2778,7 +2782,6 @@ static int init_skl_mmio_info(struct intel_gvt *gvt)
 	MMIO_D(0x72380, D_SKL_PLUS);
 	MMIO_D(0x7039c, D_SKL_PLUS);
 
-	MMIO_F(0x80000, 0x3000, 0, 0, 0, D_SKL_PLUS, NULL, NULL);
 	MMIO_D(0x8f074, D_SKL | D_KBL);
 	MMIO_D(0x8f004, D_SKL | D_KBL);
 	MMIO_D(0x8f034, D_SKL | D_KBL);
@@ -2852,26 +2855,36 @@ static int init_skl_mmio_info(struct intel_gvt *gvt)
 	return 0;
 }
 
-/**
- * intel_gvt_find_mmio_info - find MMIO information entry by aligned offset
- * @gvt: GVT device
- * @offset: register offset
- *
- * This function is used to find the MMIO information entry from hash table
- *
- * Returns:
- * pointer to MMIO information entry, NULL if not exists
- */
-struct intel_gvt_mmio_info *intel_gvt_find_mmio_info(struct intel_gvt *gvt,
-	unsigned int offset)
-{
-	struct intel_gvt_mmio_info *e;
+/* Special MMIO blocks. */
+static struct gvt_mmio_block {
+	unsigned int device;
+	i915_reg_t   offset;
+	unsigned int size;
+	gvt_mmio_func read;
+	gvt_mmio_func write;
+} gvt_mmio_blocks[] = {
+	{D_SKL_PLUS, _MMIO(CSR_MMIO_START_RANGE), 0x3000, NULL, NULL},
+	{D_ALL, _MMIO(MCHBAR_MIRROR_BASE_SNB), 0x40000, NULL, NULL},
+	{D_ALL, _MMIO(VGT_PVINFO_PAGE), VGT_PVINFO_SIZE,
+		pvinfo_mmio_read, pvinfo_mmio_write},
+	{D_ALL, LGC_PALETTE(PIPE_A, 0), 1024, NULL, NULL},
+	{D_ALL, LGC_PALETTE(PIPE_B, 0), 1024, NULL, NULL},
+	{D_ALL, LGC_PALETTE(PIPE_C, 0), 1024, NULL, NULL},
+};
 
-	WARN_ON(!IS_ALIGNED(offset, 4));
+static struct gvt_mmio_block *find_mmio_block(struct intel_gvt *gvt,
+					      unsigned int offset)
+{
+	unsigned long device = intel_gvt_get_device_type(gvt);
+	struct gvt_mmio_block *block = gvt_mmio_blocks;
+	int i;
 
-	hash_for_each_possible(gvt->mmio.mmio_info_table, e, node, offset) {
-		if (e->offset == offset)
-			return e;
+	for (i = 0; i < ARRAY_SIZE(gvt_mmio_blocks); i++, block++) {
+		if (!(device & block->device))
+			continue;
+		if (offset >= INTEL_GVT_MMIO_OFFSET(block->offset) &&
+		    offset < INTEL_GVT_MMIO_OFFSET(block->offset) + block->size)
+			return block;
 	}
 	return NULL;
 }
@@ -3056,3 +3069,94 @@ bool intel_gvt_in_force_nonpriv_whitelist(struct intel_gvt *gvt,
 {
 	return in_whitelist(offset);
 }
+
+/**
+ * intel_vgpu_mmio_reg_rw - emulate tracked mmio registers
+ * @vgpu: a vGPU
+ * @offset: register offset
+ * @pdata: data buffer
+ * @bytes: data length
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ */
+int intel_vgpu_mmio_reg_rw(struct intel_vgpu *vgpu, unsigned int offset,
+			   void *pdata, unsigned int bytes, bool is_read)
+{
+	struct intel_gvt *gvt = vgpu->gvt;
+	struct intel_gvt_mmio_info *mmio_info;
+	struct gvt_mmio_block *mmio_block;
+	gvt_mmio_func func;
+	int ret;
+
+	if (WARN_ON(bytes > 4))
+		return -EINVAL;
+
+	/*
+	 * Handle special MMIO blocks.
+	 */
+	mmio_block = find_mmio_block(gvt, offset);
+	if (mmio_block) {
+		func = is_read ? mmio_block->read : mmio_block->write;
+		if (func)
+			return func(vgpu, offset, pdata, bytes);
+		goto default_rw;
+	}
+
+	/*
+	 * Normal tracked MMIOs.
+	 */
+	mmio_info = find_mmio_info(gvt, offset);
+	if (!mmio_info) {
+		if (!vgpu->mmio.disable_warn_untrack)
+			gvt_vgpu_err("untracked MMIO %08x len %d\n",
+				     offset, bytes);
+		goto default_rw;
+	}
+
+	if (WARN_ON(bytes > mmio_info->size))
+		return -EINVAL;
+
+	if (is_read)
+		return mmio_info->read(vgpu, offset, pdata, bytes);
+	else {
+		u64 ro_mask = mmio_info->ro_mask;
+		u32 old_vreg = 0, old_sreg = 0;
+		u64 data = 0;
+
+		if (intel_gvt_mmio_has_mode_mask(gvt, mmio_info->offset)) {
+			old_vreg = vgpu_vreg(vgpu, offset);
+			old_sreg = vgpu_sreg(vgpu, offset);
+		}
+
+		if (likely(!ro_mask))
+			ret = mmio_info->write(vgpu, offset, pdata, bytes);
+		else if (!~ro_mask) {
+			gvt_vgpu_err("try to write RO reg %x\n", offset);
+			return 0;
+		} else {
+			/* keep the RO bits in the virtual register */
+			memcpy(&data, pdata, bytes);
+			data &= ~ro_mask;
+			data |= vgpu_vreg(vgpu, offset) & ro_mask;
+			ret = mmio_info->write(vgpu, offset, &data, bytes);
+		}
+
+		/* higher 16bits of mode ctl regs are mask bits for change */
+		if (intel_gvt_mmio_has_mode_mask(gvt, mmio_info->offset)) {
+			u32 mask = vgpu_vreg(vgpu, offset) >> 16;
+
+			vgpu_vreg(vgpu, offset) = (old_vreg & ~mask)
+					| (vgpu_vreg(vgpu, offset) & mask);
+			vgpu_sreg(vgpu, offset) = (old_sreg & ~mask)
+					| (vgpu_sreg(vgpu, offset) & mask);
+		}
+	}
+
+	return ret;
+
+default_rw:
+	return is_read ?
+		intel_vgpu_default_mmio_read(vgpu, offset, pdata, bytes) :
+		intel_vgpu_default_mmio_write(vgpu, offset, pdata, bytes);
+}