drm/i915: Canonicalize stolen memory calculations

Move the better constructs/comments from i915_gem_stolen.c to
early-quirks.c and increase readability in preparation of only
having one set of functions.

- intel_stolen_base -> gen3_stolen_base
- use phys_addr_t instead of u32 for address for future proofing

v2:
- Print the invalid register values (Chris)
  (Omitting the register prefix as it's visible from backtrace.)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

3 files changed, 109 insertions, 132 deletions

diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index bca14c8..70e0ab6 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -223,36 +223,19 @@ static void __init intel_remapping_check(int num, int slot, int func)
  * despite the efforts of the "RAM buffer" approach, which simply rounds
  * memory boundaries up to 64M to try to catch space that may decode
  * as RAM and so is not suitable for MMIO.
- *
- * And yes, so far on current devices the base addr is always under 4G.
  */
-static u32 __init intel_stolen_base(int num, int slot, int func, size_t stolen_size)
-{
-	u32 base;
-
-	/*
-	 * For the PCI IDs in this quirk, the stolen base is always
-	 * in 0x5c, aka the BDSM register (yes that's really what
-	 * it's called).
-	 */
-	base = read_pci_config(num, slot, func, 0x5c);
-	base &= ~((1<<20) - 1);
-
-	return base;
-}
 
 #define KB(x)	((x) * 1024UL)
 #define MB(x)	(KB (KB (x)))
-#define GB(x)	(MB (KB (x)))
 
 static size_t __init i830_tseg_size(void)
 {
-	u8 tmp = read_pci_config_byte(0, 0, 0, I830_ESMRAMC);
+	u8 esmramc = read_pci_config_byte(0, 0, 0, I830_ESMRAMC);
 
-	if (!(tmp & TSEG_ENABLE))
+	if (!(esmramc & TSEG_ENABLE))
 		return 0;
 
-	if (tmp & I830_TSEG_SIZE_1M)
+	if (esmramc & I830_TSEG_SIZE_1M)
 		return MB(1);
 	else
 		return KB(512);
@@ -260,27 +243,26 @@ static size_t __init i830_tseg_size(void)
 
 static size_t __init i845_tseg_size(void)
 {
-	u8 tmp = read_pci_config_byte(0, 0, 0, I845_ESMRAMC);
+	u8 esmramc = read_pci_config_byte(0, 0, 0, I845_ESMRAMC);
+	u8 tseg_size = esmramc & I845_TSEG_SIZE_MASK;
 
-	if (!(tmp & TSEG_ENABLE))
+	if (!(esmramc & TSEG_ENABLE))
 		return 0;
 
-	switch (tmp & I845_TSEG_SIZE_MASK) {
-	case I845_TSEG_SIZE_512K:
-		return KB(512);
-	case I845_TSEG_SIZE_1M:
-		return MB(1);
+	switch (tseg_size) {
+	case I845_TSEG_SIZE_512K:	return KB(512);
+	case I845_TSEG_SIZE_1M:		return MB(1);
 	default:
-		WARN_ON(1);
-		return 0;
+		WARN(1, "Unknown ESMRAMC value: %x!\n", esmramc);
 	}
+	return 0;
 }
 
 static size_t __init i85x_tseg_size(void)
 {
-	u8 tmp = read_pci_config_byte(0, 0, 0, I85X_ESMRAMC);
+	u8 esmramc = read_pci_config_byte(0, 0, 0, I85X_ESMRAMC);
 
-	if (!(tmp & TSEG_ENABLE))
+	if (!(esmramc & TSEG_ENABLE))
 		return 0;
 
 	return MB(1);
@@ -300,174 +282,166 @@ static size_t __init i85x_mem_size(void)
  * On 830/845/85x the stolen memory base isn't available in any
  * register. We need to calculate it as TOM-TSEG_SIZE-stolen_size.
  */
-static u32 __init i830_stolen_base(int num, int slot, int func, size_t stolen_size)
+static phys_addr_t __init i830_stolen_base(int num, int slot, int func,
+					   size_t stolen_size)
 {
-	return i830_mem_size() - i830_tseg_size() - stolen_size;
+	return (phys_addr_t)i830_mem_size() - i830_tseg_size() - stolen_size;
 }
 
-static u32 __init i845_stolen_base(int num, int slot, int func, size_t stolen_size)
+static phys_addr_t __init i845_stolen_base(int num, int slot, int func,
+					   size_t stolen_size)
 {
-	return i830_mem_size() - i845_tseg_size() - stolen_size;
+	return (phys_addr_t)i830_mem_size() - i845_tseg_size() - stolen_size;
 }
 
-static u32 __init i85x_stolen_base(int num, int slot, int func, size_t stolen_size)
+static phys_addr_t __init i85x_stolen_base(int num, int slot, int func,
+					   size_t stolen_size)
 {
-	return i85x_mem_size() - i85x_tseg_size() - stolen_size;
+	return (phys_addr_t)i85x_mem_size() - i85x_tseg_size() - stolen_size;
 }
 
-static u32 __init i865_stolen_base(int num, int slot, int func, size_t stolen_size)
+static phys_addr_t __init i865_stolen_base(int num, int slot, int func,
+					   size_t stolen_size)
 {
+	u16 toud;
+
 	/*
 	 * FIXME is the graphics stolen memory region
 	 * always at TOUD? Ie. is it always the last
 	 * one to be allocated by the BIOS?
 	 */
-	return read_pci_config_16(0, 0, 0, I865_TOUD) << 16;
+	toud = read_pci_config_16(0, 0, 0, I865_TOUD);
+
+	return (phys_addr_t)toud << 16;
+}
+
+static phys_addr_t __init gen3_stolen_base(int num, int slot, int func,
+					   size_t stolen_size)
+{
+	u32 bsm;
+
+	/* Almost universally we can find the Graphics Base of Stolen Memory
+	 * at register BSM (0x5c) in the igfx configuration space. On a few
+	 * (desktop) machines this is also mirrored in the bridge device at
+	 * different locations, or in the MCHBAR.
+	 */
+	bsm = read_pci_config(num, slot, func, INTEL_BSM);
+
+	return (phys_addr_t)bsm & INTEL_BSM_MASK;
 }
 
 static size_t __init i830_stolen_size(int num, int slot, int func)
 {
-	size_t stolen_size;
 	u16 gmch_ctrl;
+	u16 gms;
 
 	gmch_ctrl = read_pci_config_16(0, 0, 0, I830_GMCH_CTRL);
-
-	switch (gmch_ctrl & I830_GMCH_GMS_MASK) {
-	case I830_GMCH_GMS_STOLEN_512:
-		stolen_size = KB(512);
-		break;
-	case I830_GMCH_GMS_STOLEN_1024:
-		stolen_size = MB(1);
-		break;
-	case I830_GMCH_GMS_STOLEN_8192:
-		stolen_size = MB(8);
-		break;
-	case I830_GMCH_GMS_LOCAL:
-		/* local memory isn't part of the normal address space */
-		stolen_size = 0;
-		break;
+	gms = gmch_ctrl & I830_GMCH_GMS_MASK;
+
+	switch (gms) {
+	case I830_GMCH_GMS_STOLEN_512:	return KB(512);
+	case I830_GMCH_GMS_STOLEN_1024:	return MB(1);
+	case I830_GMCH_GMS_STOLEN_8192:	return MB(8);
+	/* local memory isn't part of the normal address space */
+	case I830_GMCH_GMS_LOCAL:	return 0;
 	default:
-		return 0;
+		WARN(1, "Unknown GMCH_CTRL value: %x!\n", gmch_ctrl);
 	}
 
-	return stolen_size;
+	return 0;
 }
 
 static size_t __init gen3_stolen_size(int num, int slot, int func)
 {
-	size_t stolen_size;
 	u16 gmch_ctrl;
+	u16 gms;
 
 	gmch_ctrl = read_pci_config_16(0, 0, 0, I830_GMCH_CTRL);
-
-	switch (gmch_ctrl & I855_GMCH_GMS_MASK) {
-	case I855_GMCH_GMS_STOLEN_1M:
-		stolen_size = MB(1);
-		break;
-	case I855_GMCH_GMS_STOLEN_4M:
-		stolen_size = MB(4);
-		break;
-	case I855_GMCH_GMS_STOLEN_8M:
-		stolen_size = MB(8);
-		break;
-	case I855_GMCH_GMS_STOLEN_16M:
-		stolen_size = MB(16);
-		break;
-	case I855_GMCH_GMS_STOLEN_32M:
-		stolen_size = MB(32);
-		break;
-	case I915_GMCH_GMS_STOLEN_48M:
-		stolen_size = MB(48);
-		break;
-	case I915_GMCH_GMS_STOLEN_64M:
-		stolen_size = MB(64);
-		break;
-	case G33_GMCH_GMS_STOLEN_128M:
-		stolen_size = MB(128);
-		break;
-	case G33_GMCH_GMS_STOLEN_256M:
-		stolen_size = MB(256);
-		break;
-	case INTEL_GMCH_GMS_STOLEN_96M:
-		stolen_size = MB(96);
-		break;
-	case INTEL_GMCH_GMS_STOLEN_160M:
-		stolen_size = MB(160);
-		break;
-	case INTEL_GMCH_GMS_STOLEN_224M:
-		stolen_size = MB(224);
-		break;
-	case INTEL_GMCH_GMS_STOLEN_352M:
-		stolen_size = MB(352);
-		break;
+	gms = gmch_ctrl & I855_GMCH_GMS_MASK;
+
+	switch (gms) {
+	case I855_GMCH_GMS_STOLEN_1M:	return MB(1);
+	case I855_GMCH_GMS_STOLEN_4M:	return MB(4);
+	case I855_GMCH_GMS_STOLEN_8M:	return MB(8);
+	case I855_GMCH_GMS_STOLEN_16M:	return MB(16);
+	case I855_GMCH_GMS_STOLEN_32M:	return MB(32);
+	case I915_GMCH_GMS_STOLEN_48M:	return MB(48);
+	case I915_GMCH_GMS_STOLEN_64M:	return MB(64);
+	case G33_GMCH_GMS_STOLEN_128M:	return MB(128);
+	case G33_GMCH_GMS_STOLEN_256M:	return MB(256);
+	case INTEL_GMCH_GMS_STOLEN_96M:	return MB(96);
+	case INTEL_GMCH_GMS_STOLEN_160M:return MB(160);
+	case INTEL_GMCH_GMS_STOLEN_224M:return MB(224);
+	case INTEL_GMCH_GMS_STOLEN_352M:return MB(352);
 	default:
-		stolen_size = 0;
-		break;
+		WARN(1, "Unknown GMCH_CTRL value: %x!\n", gmch_ctrl);
 	}
 
-	return stolen_size;
+	return 0;
 }
 
 static size_t __init gen6_stolen_size(int num, int slot, int func)
 {
 	u16 gmch_ctrl;
+	u16 gms;
 
 	gmch_ctrl = read_pci_config_16(num, slot, func, SNB_GMCH_CTRL);
-	gmch_ctrl >>= SNB_GMCH_GMS_SHIFT;
-	gmch_ctrl &= SNB_GMCH_GMS_MASK;
+	gms = (gmch_ctrl >> SNB_GMCH_GMS_SHIFT) & SNB_GMCH_GMS_MASK;
 
-	return gmch_ctrl << 25; /* 32 MB units */
+	return (size_t)gms * MB(32);
 }
 
 static size_t __init gen8_stolen_size(int num, int slot, int func)
 {
 	u16 gmch_ctrl;
+	u16 gms;
 
 	gmch_ctrl = read_pci_config_16(num, slot, func, SNB_GMCH_CTRL);
-	gmch_ctrl >>= BDW_GMCH_GMS_SHIFT;
-	gmch_ctrl &= BDW_GMCH_GMS_MASK;
-	return gmch_ctrl << 25; /* 32 MB units */
+	gms = (gmch_ctrl >> BDW_GMCH_GMS_SHIFT) & BDW_GMCH_GMS_MASK;
+
+	return (size_t)gms * MB(32);
 }
 
 static size_t __init chv_stolen_size(int num, int slot, int func)
 {
 	u16 gmch_ctrl;
+	u16 gms;
 
 	gmch_ctrl = read_pci_config_16(num, slot, func, SNB_GMCH_CTRL);
-	gmch_ctrl >>= SNB_GMCH_GMS_SHIFT;
-	gmch_ctrl &= SNB_GMCH_GMS_MASK;
+	gms = (gmch_ctrl >> SNB_GMCH_GMS_SHIFT) & SNB_GMCH_GMS_MASK;
 
 	/*
 	 * 0x0  to 0x10: 32MB increments starting at 0MB
 	 * 0x11 to 0x16: 4MB increments starting at 8MB
 	 * 0x17 to 0x1d: 4MB increments start at 36MB
 	 */
-	if (gmch_ctrl < 0x11)
-		return gmch_ctrl << 25;
-	else if (gmch_ctrl < 0x17)
-		return (gmch_ctrl - 0x11 + 2) << 22;
+	if (gms < 0x11)
+		return (size_t)gms * MB(32);
+	else if (gms < 0x17)
+		return (size_t)(gms - 0x11 + 2) * MB(4);
 	else
-		return (gmch_ctrl - 0x17 + 9) << 22;
+		return (size_t)(gms - 0x17 + 9) * MB(4);
 }
 
 struct intel_stolen_funcs {
 	size_t (*size)(int num, int slot, int func);
-	u32 (*base)(int num, int slot, int func, size_t size);
+	phys_addr_t (*base)(int num, int slot, int func, size_t size);
 };
 
 static size_t __init gen9_stolen_size(int num, int slot, int func)
 {
 	u16 gmch_ctrl;
+	u16 gms;
 
 	gmch_ctrl = read_pci_config_16(num, slot, func, SNB_GMCH_CTRL);
-	gmch_ctrl >>= BDW_GMCH_GMS_SHIFT;
-	gmch_ctrl &= BDW_GMCH_GMS_MASK;
+	gms = (gmch_ctrl >> BDW_GMCH_GMS_SHIFT) & BDW_GMCH_GMS_MASK;
 
-	if (gmch_ctrl < 0xf0)
-		return gmch_ctrl << 25; /* 32 MB units */
+	/* 0x0  to 0xef: 32MB increments starting at 0MB */
+	/* 0xf0 to 0xfe: 4MB increments starting at 4MB */
+	if (gms < 0xf0)
+		return (size_t)gms * MB(32);
 	else
-		/* 4MB increments starting at 0xf0 for 4MB */
-		return (gmch_ctrl - 0xf0 + 1) << 22;
+		return (size_t)(gms - 0xf0 + 1) * MB(4);
 }
 
 typedef size_t (*stolen_size_fn)(int num, int slot, int func);
@@ -493,27 +467,27 @@ static const struct intel_stolen_funcs i865_stolen_funcs __initconst = {
 };
 
 static const struct intel_stolen_funcs gen3_stolen_funcs __initconst = {
-	.base = intel_stolen_base,
+	.base = gen3_stolen_base,
 	.size = gen3_stolen_size,
 };
 
 static const struct intel_stolen_funcs gen6_stolen_funcs __initconst = {
-	.base = intel_stolen_base,
+	.base = gen3_stolen_base,
 	.size = gen6_stolen_size,
 };
 
 static const struct intel_stolen_funcs gen8_stolen_funcs __initconst = {
-	.base = intel_stolen_base,
+	.base = gen3_stolen_base,
 	.size = gen8_stolen_size,
 };
 
 static const struct intel_stolen_funcs gen9_stolen_funcs __initconst = {
-	.base = intel_stolen_base,
+	.base = gen3_stolen_base,
 	.size = gen9_stolen_size,
 };
 
 static const struct intel_stolen_funcs chv_stolen_funcs __initconst = {
-	.base = intel_stolen_base,
+	.base = gen3_stolen_base,
 	.size = chv_stolen_size,
 };
 
@@ -554,7 +528,7 @@ static void __init intel_graphics_stolen(int num, int slot, int func)
 {
 	size_t size;
 	int i;
-	u32 start;
+	phys_addr_t start;
 	u16 device, subvendor, subdevice;
 
 	device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID);
@@ -569,8 +543,8 @@ static void __init intel_graphics_stolen(int num, int slot, int func)
 			size = stolen_funcs->size(num, slot, func);
 			start = stolen_funcs->base(num, slot, func, size);
 			if (size && start) {
-				printk(KERN_INFO "Reserving Intel graphics stolen memory at 0x%x-0x%x\n",
-				       start, start + (u32)size - 1);
+				printk(KERN_INFO "Reserving Intel graphics stolen memory at 0x%llx-0x%llx\n",
+				       start, start + size - 1);
 				/* Mark this space as reserved */
 				e820_add_region(start, size, E820_RESERVED);
 				sanitize_e820_map(e820.map,
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index b7ce963..68fde8f 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -109,9 +109,9 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev)
 	if (INTEL_INFO(dev)->gen >= 3) {
 		u32 bsm;
 
-		pci_read_config_dword(dev->pdev, BSM, &bsm);
+		pci_read_config_dword(dev->pdev, INTEL_BSM, &bsm);
 
-		base = bsm & BSM_MASK;
+		base = bsm & INTEL_BSM_MASK;
 	} else if (IS_I865G(dev)) {
 		u16 toud = 0;
 
diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index 595f85c..b1755f8 100644
--- a/include/drm/i915_drm.h
+++ b/include/drm/i915_drm.h
@@ -92,4 +92,7 @@ extern bool i915_gpu_turbo_disable(void);
 #define    I845_TSEG_SIZE_512K	(2 << 1)
 #define    I845_TSEG_SIZE_1M	(3 << 1)
 
+#define INTEL_BSM 0x5c
+#define   INTEL_BSM_MASK (0xFFFF << 20)
+
 #endif				/* _I915_DRM_H_ */