[PATCH 1/2] Revert "drm/i915: Introduce private PAT management"

Michał Winiarski
2019-07-02T11:32:17Z

This reverts commit 4395890a48551982549d222d1923e2833dac47cf.

It's been over a year since this was merged, and the actual users of
intel_ppat_get / intel_ppat_put never materialized.

Time to remove it!

v2: Unbreak suspend (Chris)
v3: Rebase, drop fixes tag to avoid confusion

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 2 -
drivers/gpu/drm/i915/i915_gem_gtt.c | 279 +++++-----------------------
drivers/gpu/drm/i915/i915_gem_gtt.h | 36 ----
3 files changed, 42 insertions(+), 275 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 02dd9f9f3a89..09e09d26e67d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1489,8 +1489,6 @@ struct drm_i915_private {
DECLARE_HASHTABLE(mm_structs, 7);
struct mutex mm_lock;

- struct intel_ppat ppat;
-
/* Kernel Modesetting */

struct intel_crtc *plane_to_crtc_mapping[I915_MAX_PIPES];
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index ff1d5008a256..30e14eac47ac 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -3028,203 +3028,26 @@ static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
return 0;
}

-static struct intel_ppat_entry *
-__alloc_ppat_entry(struct intel_ppat *ppat, unsigned int index, u8 value)
+static void cnl_setup_private_ppat(struct drm_i915_private *dev_priv)
{
- struct intel_ppat_entry *entry = &ppat->entries[index];
-
- GEM_BUG_ON(index >= ppat->max_entries);
- GEM_BUG_ON(test_bit(index, ppat->used));
-
- entry->ppat = ppat;
- entry->value = value;
- kref_init(&entry->ref);
- set_bit(index, ppat->used);
- set_bit(index, ppat->dirty);
-
- return entry;
-}
-
-static void __free_ppat_entry(struct intel_ppat_entry *entry)
-{
- struct intel_ppat *ppat = entry->ppat;
- unsigned int index = entry - ppat->entries;
-
- GEM_BUG_ON(index >= ppat->max_entries);
- GEM_BUG_ON(!test_bit(index, ppat->used));
-
- entry->value = ppat->clear_value;
- clear_bit(index, ppat->used);
- set_bit(index, ppat->dirty);
-}
-
-/**
- * intel_ppat_get - get a usable PPAT entry
- * @i915: i915 device instance
- * @value: the PPAT value required by the caller
- *
- * The function tries to search if there is an existing PPAT entry which
- * matches with the required value. If perfectly matched, the existing PPAT
- * entry will be used. If only partially matched, it will try to check if
- * there is any available PPAT index. If yes, it will allocate a new PPAT
- * index for the required entry and update the HW. If not, the partially
- * matched entry will be used.
- */
-const struct intel_ppat_entry *
-intel_ppat_get(struct drm_i915_private *i915, u8 value)
-{
- struct intel_ppat *ppat = &i915->ppat;
- struct intel_ppat_entry *entry = NULL;
- unsigned int scanned, best_score;
- int i;
-
- GEM_BUG_ON(!ppat->max_entries);
-
- scanned = best_score = 0;
- for_each_set_bit(i, ppat->used, ppat->max_entries) {
- unsigned int score;
-
- score = ppat->match(ppat->entries[i].value, value);
- if (score > best_score) {
- entry = &ppat->entries[i];
- if (score == INTEL_PPAT_PERFECT_MATCH) {
- kref_get(&entry->ref);
- return entry;
- }
- best_score = score;
- }
- scanned++;
- }
-
- if (scanned == ppat->max_entries) {
- if (!entry)
- return ERR_PTR(-ENOSPC);
-
- kref_get(&entry->ref);
- return entry;
- }
-
- i = find_first_zero_bit(ppat->used, ppat->max_entries);
- entry = __alloc_ppat_entry(ppat, i, value);
- ppat->update_hw(i915);
- return entry;
-}
-
-static void release_ppat(struct kref *kref)
-{
- struct intel_ppat_entry *entry =
- container_of(kref, struct intel_ppat_entry, ref);
- struct drm_i915_private *i915 = entry->ppat->i915;
-
- __free_ppat_entry(entry);
- entry->ppat->update_hw(i915);
-}
-
-/**
- * intel_ppat_put - put back the PPAT entry got from intel_ppat_get()
- * @entry: an intel PPAT entry
- *
- * Put back the PPAT entry got from intel_ppat_get(). If the PPAT index of the
- * entry is dynamically allocated, its reference count will be decreased. Once
- * the reference count becomes into zero, the PPAT index becomes free again.
- */
-void intel_ppat_put(const struct intel_ppat_entry *entry)
-{
- struct intel_ppat *ppat = entry->ppat;
- unsigned int index = entry - ppat->entries;
-
- GEM_BUG_ON(!ppat->max_entries);
-
- kref_put(&ppat->entries[index].ref, release_ppat);
-}
-
-static void cnl_private_pat_update_hw(struct drm_i915_private *dev_priv)
-{
- struct intel_ppat *ppat = &dev_priv->ppat;
- int i;
-
- for_each_set_bit(i, ppat->dirty, ppat->max_entries) {
- I915_WRITE(GEN10_PAT_INDEX(i), ppat->entries[i].value);
- clear_bit(i, ppat->dirty);
- }
-}
-
-static void bdw_private_pat_update_hw(struct drm_i915_private *dev_priv)
-{
- struct intel_ppat *ppat = &dev_priv->ppat;
- u64 pat = 0;
- int i;
-
- for (i = 0; i < ppat->max_entries; i++)
- pat |= GEN8_PPAT(i, ppat->entries[i].value);
-
- bitmap_clear(ppat->dirty, 0, ppat->max_entries);
-
- I915_WRITE(GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
- I915_WRITE(GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
-}
-
-static unsigned int bdw_private_pat_match(u8 src, u8 dst)
-{
- unsigned int score = 0;
- enum {
- AGE_MATCH = BIT(0),
- TC_MATCH = BIT(1),
- CA_MATCH = BIT(2),
- };
-
- /* Cache attribute has to be matched. */
- if (GEN8_PPAT_GET_CA(src) != GEN8_PPAT_GET_CA(dst))
- return 0;
-
- score |= CA_MATCH;
-
- if (GEN8_PPAT_GET_TC(src) == GEN8_PPAT_GET_TC(dst))
- score |= TC_MATCH;
-
- if (GEN8_PPAT_GET_AGE(src) == GEN8_PPAT_GET_AGE(dst))
- score |= AGE_MATCH;
-
- if (score == (AGE_MATCH | TC_MATCH | CA_MATCH))
- return INTEL_PPAT_PERFECT_MATCH;
-
- return score;
-}
-
-static unsigned int chv_private_pat_match(u8 src, u8 dst)
-{
- return (CHV_PPAT_GET_SNOOP(src) == CHV_PPAT_GET_SNOOP(dst)) ?
- INTEL_PPAT_PERFECT_MATCH : 0;
-}
-
-static void cnl_setup_private_ppat(struct intel_ppat *ppat)
-{
- ppat->max_entries = 8;
- ppat->update_hw = cnl_private_pat_update_hw;
- ppat->match = bdw_private_pat_match;
- ppat->clear_value = GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3);
-
- __alloc_ppat_entry(ppat, 0, GEN8_PPAT_WB | GEN8_PPAT_LLC);
- __alloc_ppat_entry(ppat, 1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC);
- __alloc_ppat_entry(ppat, 2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC);
- __alloc_ppat_entry(ppat, 3, GEN8_PPAT_UC);
- __alloc_ppat_entry(ppat, 4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0));
- __alloc_ppat_entry(ppat, 5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1));
- __alloc_ppat_entry(ppat, 6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2));
- __alloc_ppat_entry(ppat, 7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
+ I915_WRITE(GEN10_PAT_INDEX(0), GEN8_PPAT_WB | GEN8_PPAT_LLC);
+ I915_WRITE(GEN10_PAT_INDEX(1), GEN8_PPAT_WC | GEN8_PPAT_LLCELLC);
+ I915_WRITE(GEN10_PAT_INDEX(2), GEN8_PPAT_WT | GEN8_PPAT_LLCELLC);
+ I915_WRITE(GEN10_PAT_INDEX(3), GEN8_PPAT_UC);
+ I915_WRITE(GEN10_PAT_INDEX(4), GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0));
+ I915_WRITE(GEN10_PAT_INDEX(5), GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1));
+ I915_WRITE(GEN10_PAT_INDEX(6), GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2));
+ I915_WRITE(GEN10_PAT_INDEX(7), GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
}

/* The GGTT and PPGTT need a private PPAT setup in order to handle cacheability
* bits. When using advanced contexts each context stores its own PAT, but
* writing this data shouldn't be harmful even in those cases. */
-static void bdw_setup_private_ppat(struct intel_ppat *ppat)
+static void bdw_setup_private_ppat(struct drm_i915_private *dev_priv)
{
- ppat->max_entries = 8;
- ppat->update_hw = bdw_private_pat_update_hw;
- ppat->match = bdw_private_pat_match;
- ppat->clear_value = GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3);
+ u64 pat;

- if (!HAS_PPGTT(ppat->i915)) {
+ if (!HAS_PPGTT(dev_priv)) {
/* Spec: "For GGTT, there is NO pat_sel[2:0] from the entry,
* so RTL will always use the value corresponding to
* pat_sel = 000".
@@ -3238,26 +3061,25 @@ static void bdw_setup_private_ppat(struct intel_ppat *ppat)
* So we can still hold onto all our assumptions wrt cpu
* clflushing on LLC machines.
*/
- __alloc_ppat_entry(ppat, 0, GEN8_PPAT_UC);
- return;
+ pat = GEN8_PPAT(0, GEN8_PPAT_UC);
+ } else {
+ pat = GEN8_PPAT(0, GEN8_PPAT_WB | GEN8_PPAT_LLC) | /* for normal objects, no eLLC */
+ GEN8_PPAT(1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC) | /* for something pointing to ptes? */
+ GEN8_PPAT(2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC) | /* for scanout with eLLC */
+ GEN8_PPAT(3, GEN8_PPAT_UC) | /* Uncached objects, mostly for scanout */
+ GEN8_PPAT(4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0)) |
+ GEN8_PPAT(5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1)) |
+ GEN8_PPAT(6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2)) |
+ GEN8_PPAT(7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
}

- __alloc_ppat_entry(ppat, 0, GEN8_PPAT_WB | GEN8_PPAT_LLC); /* for normal objects, no eLLC */
- __alloc_ppat_entry(ppat, 1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC); /* for something pointing to ptes? */
- __alloc_ppat_entry(ppat, 2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC); /* for scanout with eLLC */
- __alloc_ppat_entry(ppat, 3, GEN8_PPAT_UC); /* Uncached objects, mostly for scanout */
- __alloc_ppat_entry(ppat, 4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0));
- __alloc_ppat_entry(ppat, 5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1));
- __alloc_ppat_entry(ppat, 6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2));
- __alloc_ppat_entry(ppat, 7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
+ I915_WRITE(GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
+ I915_WRITE(GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
}

-static void chv_setup_private_ppat(struct intel_ppat *ppat)
+static void chv_setup_private_ppat(struct drm_i915_private *dev_priv)
{
- ppat->max_entries = 8;
- ppat->update_hw = bdw_private_pat_update_hw;
- ppat->match = chv_private_pat_match;
- ppat->clear_value = CHV_PPAT_SNOOP;
+ u64 pat;

/*
* Map WB on BDW to snooped on CHV.
@@ -3278,14 +3100,17 @@ static void chv_setup_private_ppat(struct intel_ppat *ppat)
* in order to keep the global status page working.
*/

- __alloc_ppat_entry(ppat, 0, CHV_PPAT_SNOOP);
- __alloc_ppat_entry(ppat, 1, 0);
- __alloc_ppat_entry(ppat, 2, 0);
- __alloc_ppat_entry(ppat, 3, 0);
- __alloc_ppat_entry(ppat, 4, CHV_PPAT_SNOOP);
- __alloc_ppat_entry(ppat, 5, CHV_PPAT_SNOOP);
- __alloc_ppat_entry(ppat, 6, CHV_PPAT_SNOOP);
- __alloc_ppat_entry(ppat, 7, CHV_PPAT_SNOOP);
+ pat = GEN8_PPAT(0, CHV_PPAT_SNOOP) |
+ GEN8_PPAT(1, 0) |
+ GEN8_PPAT(2, 0) |
+ GEN8_PPAT(3, 0) |
+ GEN8_PPAT(4, CHV_PPAT_SNOOP) |
+ GEN8_PPAT(5, CHV_PPAT_SNOOP) |
+ GEN8_PPAT(6, CHV_PPAT_SNOOP) |
+ GEN8_PPAT(7, CHV_PPAT_SNOOP);
+
+ I915_WRITE(GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
+ I915_WRITE(GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
}

static void gen6_gmch_remove(struct i915_address_space *vm)
@@ -3298,27 +3123,12 @@ static void gen6_gmch_remove(struct i915_address_space *vm)

static void setup_private_pat(struct drm_i915_private *dev_priv)
{
- struct intel_ppat *ppat = &dev_priv->ppat;
- int i;
-
- ppat->i915 = dev_priv;
-
if (INTEL_GEN(dev_priv) >= 10)
- cnl_setup_private_ppat(ppat);
+ cnl_setup_private_ppat(dev_priv);
else if (IS_CHERRYVIEW(dev_priv) || IS_GEN9_LP(dev_priv))
- chv_setup_private_ppat(ppat);
+ chv_setup_private_ppat(dev_priv);
else
- bdw_setup_private_ppat(ppat);
-
- GEM_BUG_ON(ppat->max_entries > INTEL_MAX_PPAT_ENTRIES);
-
- for_each_clear_bit(i, ppat->used, ppat->max_entries) {
- ppat->entries[i].value = ppat->clear_value;
- ppat->entries[i].ppat = ppat;
- set_bit(i, ppat->dirty);
- }
-
- ppat->update_hw(dev_priv);
+ bdw_setup_private_ppat(dev_priv);
}

static int gen8_gmch_probe(struct i915_ggtt *ggtt)
@@ -3697,13 +3507,8 @@ void i915_gem_restore_gtt_mappings(struct drm_i915_private *i915)
{
ggtt_restore_mappings(&i915->ggtt);

- if (INTEL_GEN(i915) >= 8) {
- struct intel_ppat *ppat = &i915->ppat;
-
- bitmap_set(ppat->dirty, 0, ppat->max_entries);
- i915->ppat.update_hw(i915);
- return;
- }
+ if (INTEL_GEN(i915) >= 8)
+ setup_private_pat(i915);
}

static struct scatterlist *
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 028be3b44d07..d0e0905acbbb 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -160,11 +160,6 @@ typedef u64 gen8_ppgtt_pml4e_t;
#define GEN8_PPAT_ELLC_OVERRIDE (0<<2)
#define GEN8_PPAT(i, x) ((u64)(x) << ((i) * 8))

-#define GEN8_PPAT_GET_CA(x) ((x) & 3)
-#define GEN8_PPAT_GET_TC(x) ((x) & (3 << 2))
-#define GEN8_PPAT_GET_AGE(x) ((x) & (3 << 4))
-#define CHV_PPAT_GET_SNOOP(x) ((x) & (1 << 6))
-
#define GEN8_PDE_IPS_64K BIT(11)
#define GEN8_PDE_PS_2M BIT(7)

@@ -619,37 +614,6 @@ i915_vm_to_ppgtt(struct i915_address_space *vm)
return container_of(vm, struct i915_ppgtt, vm);
}

-#define INTEL_MAX_PPAT_ENTRIES 8
-#define INTEL_PPAT_PERFECT_MATCH (~0U)
-
-struct intel_ppat;
-
-struct intel_ppat_entry {
- struct intel_ppat *ppat;
- struct kref ref;
- u8 value;
-};
-
-struct intel_ppat {
- struct intel_ppat_entry entries[INTEL_MAX_PPAT_ENTRIES];
- DECLARE_BITMAP(used, INTEL_MAX_PPAT_ENTRIES);
- DECLARE_BITMAP(dirty, INTEL_MAX_PPAT_ENTRIES);
- unsigned int max_entries;
- u8 clear_value;
- /*
- * Return a score to show how two PPAT values match,
- * a INTEL_PPAT_PERFECT_MATCH indicates a perfect match
- */
- unsigned int (*match)(u8 src, u8 dst);
- void (*update_hw)(struct drm_i915_private *i915);
-
- struct drm_i915_private *i915;
-};
-
-const struct intel_ppat_entry *
-intel_ppat_get(struct drm_i915_private *i915, u8 value);
-void intel_ppat_put(const struct intel_ppat_entry *entry);
-
int i915_ggtt_probe_hw(struct drm_i915_private *dev_priv);
int i915_ggtt_init_hw(struct drm_i915_private *dev_priv);
int i915_ggtt_enable_hw(struct drm_i915_private *dev_priv);
--
2.21.0