On 15/11/2016 13:17, Praveen Paneri wrote:
Hi Chris,
On Tuesday 15 November 2016 03:37 PM, Chris Wilson wrote:
On Tue, Nov 15, 2016 at 09:36:34AM +0000, Tvrtko Ursulin wrote:
On 15/11/2016 06:40, Praveen Paneri wrote:
Decoupled MMIO is an alternative way to access forcewake domain
registers, which requires less cycles for a single read/write and
avoids frequent software forcewake.
This certainly gives advantage over the forcewake as this new
mechanism “decouples” CPU cycles and allow them to complete even
when GT is in a CPD (frequency change) or C6 state.
This can co-exist with forcewake and we will continue to use forcewake
as appropriate. E.g. 64-bit register writes to avoid writing 2 dwords
separately and land into funny situations.
v2:
- Moved platform check out of the function and got rid of duplicate
functions to find out decoupled power domain (Chris)
- Added a check for forcewake already held and skipped decoupled
access (Chris)
- Skipped writing 64 bit registers through decoupled MMIO (Chris)
v3:
- Improved commit message with more info on decoupled mmio (Tvrtko)
- Changed decoupled operation to enum and used u32 instead of
uint_32 data type for register offset (Tvrtko)
- Moved HAS_DECOUPLED_MMIO to device info (Tvrtko)
- Added lookup table for converting fw_engine to pd_engine (Tvrtko)
- Improved __gen9_decoupled_read and __gen9_decoupled_write
routines (Tvrtko)
v4:
- Fixed alignment and variable names (Chris)
- Write GEN9_DECOUPLED_REG0_DW1 register in just one go (Zhe Wang)
Signed-off-by: Zhe Wang <zhe1.wang@xxxxxxxxx>
Signed-off-by: Praveen Paneri <praveen.paneri@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.h | 18 +++++-
drivers/gpu/drm/i915/i915_pci.c | 1 +
drivers/gpu/drm/i915/i915_reg.h | 7 +++
drivers/gpu/drm/i915/intel_uncore.c | 109
++++++++++++++++++++++++++++++++++++
4 files changed, 134 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h
b/drivers/gpu/drm/i915/i915_drv.h
index 4e7148a..158f05c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -549,6 +549,18 @@ enum forcewake_domains {
#define FW_REG_READ (1)
#define FW_REG_WRITE (2)
+enum decoupled_power_domain {
+ GEN9_DECOUPLED_PD_BLITTER = 0,
+ GEN9_DECOUPLED_PD_RENDER,
+ GEN9_DECOUPLED_PD_MEDIA,
+ GEN9_DECOUPLED_PD_ALL
+};
+
+enum decoupled_ops {
+ GEN9_DECOUPLED_OP_WRITE = 0,
+ GEN9_DECOUPLED_OP_READ
+};
+
enum forcewake_domains
intel_uncore_forcewake_for_reg(struct drm_i915_private *dev_priv,
i915_reg_t reg, unsigned int op);
@@ -683,7 +695,8 @@ struct intel_csr {
func(cursor_needs_physical); \
func(hws_needs_physical); \
func(overlay_needs_physical); \
- func(supports_tv)
+ func(supports_tv); \
+ func(has_decoupled_mmio)
struct sseu_dev_info {
u8 slice_mask;
@@ -2652,6 +2665,9 @@ struct drm_i915_cmd_table {
#define GT_FREQUENCY_MULTIPLIER 50
#define GEN9_FREQ_SCALER 3
+#define HAS_DECOUPLED_MMIO(dev) (INTEL_INFO(dev)->has_decoupled_mmio \
+ && IS_BXT_REVID(dev, BXT_REVID_C0, REVID_FOREVER))
+
Looks like I've missed this before, but Would you mind renaming the
dev argument to dev_priv?
And whilst you are there, fix up the code to set
info->has_decoupled_mmio = false when santizing.
-Chris
but dev_priv->info is declared as const.
Look in intel_device_info_runtime_init for how it is currently done
(mkwrite_device_info).
Regards,
Tvrtko
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
