[PATCH v5 34.2/71] x86/gpu: Implement stolen memory size early quirk for CHV

ville.syrjala
2014-05-08T19:19:58Z

From: Damien Lespiau <damien.lespiau@intel.com>

CHV uses the same bits as SNB/VLV to code the Graphics Mode Select field
(GFX stolen memory size) with the addition of finer granularity modes:
4MB increments from 0x11 (8MB) to 0x1d.

Values strictly above 0x1d are either reserved or not supported.

v2: 4MB increments, not 8MB. 32MB has been omitted from the list of new
values (Ville Syrjälä)

v3: Also correctly interpret GGMS (GTT Graphics Memory Size) (Ville
Syrjälä)

v4: Don't assign a value that needs 20bits or more to a u16 (Rafael
Barbalho)

[vsyrjala: v5: Split from i915 changes and add chv_stolen_funcs]

Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Rafael Barbalho <rafael.barbalho@intel.com>
Tested-by: Rafael Barbalho <rafael.barbalho@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---

Note to x86 folks: This depends on INTEL_CHV_IDS() which is part of some
other i915 patch, so I think it would be easiest to merge this through
Daniel's tree.

arch/x86/kernel/early-quirks.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index 6e2537c..8323575 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -428,6 +428,26 @@ static size_t gen8_stolen_size(int num, int slot, int func)
return gmch_ctrl << 25; /* 32 MB units */
}

+static size_t __init chv_stolen_size(int num, int slot, int func)
+{
+ u16 gmch_ctrl;
+
+ gmch_ctrl = read_pci_config_16(num, slot, func, SNB_GMCH_CTRL);
+ gmch_ctrl >>= SNB_GMCH_GMS_SHIFT;
+ gmch_ctrl &= 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;
+ else
+ return (gmch_ctrl - 0x17 + 9) << 22;
+}

struct intel_stolen_funcs {
size_t (*size)(int num, int slot, int func);
@@ -469,6 +489,11 @@ static const struct intel_stolen_funcs gen8_stolen_funcs = {
.size = gen8_stolen_size,
};

+static const struct intel_stolen_funcs chv_stolen_funcs = {
+ .base = intel_stolen_base,
+ .size = chv_stolen_size,
+};
+
static struct pci_device_id intel_stolen_ids[] __initdata = {
INTEL_I830_IDS(&i830_stolen_funcs),
INTEL_I845G_IDS(&i845_stolen_funcs),
@@ -495,7 +520,8 @@ static struct pci_device_id intel_stolen_ids[] __initdata = {
INTEL_HSW_D_IDS(&gen6_stolen_funcs),
INTEL_HSW_M_IDS(&gen6_stolen_funcs),
INTEL_BDW_M_IDS(&gen8_stolen_funcs),
- INTEL_BDW_D_IDS(&gen8_stolen_funcs)
+ INTEL_BDW_D_IDS(&gen8_stolen_funcs),
+ INTEL_CHV_IDS(&chv_stolen_funcs),
};

static void __init intel_graphics_stolen(int num, int slot, int func)
--
1.8.3.2