drm/i915: Move ioremap_wc tracking onto VMA
authorChris Wilson <chris@chris-wilson.co.uk>
Thu, 28 Apr 2016 08:56:39 +0000 (09:56 +0100)
committerChris Wilson <chris@chris-wilson.co.uk>
Thu, 28 Apr 2016 11:17:32 +0000 (12:17 +0100)
commit8ef8561f2c8a5e3c8cfd84a1a755dcabc1440235
tree5346e4fd7122d31ea9cb6443c8225addefdf9d45
parentce7fda2e15afa7996ee922c8619ea514dff6f66f
drm/i915: Move ioremap_wc tracking onto VMA

By tracking the iomapping on the VMA itself, we can share that area
between multiple users. Also by only revoking the iomapping upon
unbinding from the mappable portion of the GGTT, we can keep that iomap
across multiple invocations (e.g. execlists context pinning).

Note that by moving the iounnmap tracking to the VMA, we actually end up
fixing a leak of the iomapping in intel_fbdev.

v1.5: Rebase prompted by Tvrtko
v2: Drop dev_priv parameter, we can recover the i915_ggtt from the vma.
v3: Move handling of ioremap space exhaustion to vmap_purge and also
allow vmallocs to recover old iomaps. Add Tvrtko's kerneldoc.
v4: Fix a use-after-free in shrinker and rearrange i915_vma_iomap
v5: Back to i915_vm_to_ggtt
v6: Use i915_vma_pin_iomap and i915_vma_unpin_iomap to mark critical
sections and ensure the VMA cannot be reaped whilst mapped.
v7: Move i915_vma_iounmap so that consumers of the API are not tempted,
and add iomem annotations

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461833819-3991-5-git-send-email-chris@chris-wilson.co.uk
drivers/gpu/drm/i915/i915_gem.c
drivers/gpu/drm/i915/i915_gem_gtt.c
drivers/gpu/drm/i915/i915_gem_gtt.h
drivers/gpu/drm/i915/i915_gem_shrinker.c
drivers/gpu/drm/i915/intel_fbdev.c