Staging
v0.8.1
Revision f383219674b72f390911c60e1d8ae95e32622398 authored by James Hogan on 19 April 2016, 08:25:06 UTC, committed by Ralf Baechle on 13 May 2016, 13:30:25 UTC
For XPA kernels build_update_entries() uses $1 (at) as a scratch
register, but doesn't arrange for it to be preserved, so it will always
be clobbered by the TLB refill exception. Although this register
normally has a very short lifetime that doesn't cross memory accesses,
TLB refills due to instruction fetches (either on a page boundary or
after preemption) could clobber live data, and its easy to reproduce
the clobber with a little bit of assembler code.

Note that the use of a hardware page table walker will partly mask the
problem, as the TLB refill handler will not always be invoked.

This is fixed by avoiding the use of the extra scratch register. The
pte_high parts (going into the lower half of the EntryLo registers) are
loaded and manipulated separately so as to keep the PTE pointer around
for the other halves (instead of storing in the scratch register), and
the pte_low parts (going into the high half of the EntryLo registers)
are masked with 0x00ffffff using an ext instruction (instead of loading
0x00ffffff into the scratch register and AND'ing).

[paul.burton@imgtec.com:
  - Rebase atop other TLB work.
  - Use ext instead of an sll, srl sequence.
  - Use cpu_has_xpa instead of #ifdefs.
  - Modify commit subject to include "mm".]

Fixes: c5b367835cfc ("MIPS: Add support for XPA.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13120/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
1 parent 7b2cb64
Raw File
drm_atomic.h
/*
 * Copyright (C) 2014 Red Hat
 * Copyright (C) 2014 Intel Corp.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 * Rob Clark <robdclark@gmail.com>
 * Daniel Vetter <daniel.vetter@ffwll.ch>
 */

#ifndef DRM_ATOMIC_H_
#define DRM_ATOMIC_H_

#include <drm/drm_crtc.h>

struct drm_atomic_state * __must_check
drm_atomic_state_alloc(struct drm_device *dev);
void drm_atomic_state_clear(struct drm_atomic_state *state);
void drm_atomic_state_free(struct drm_atomic_state *state);

int  __must_check
drm_atomic_state_init(struct drm_device *dev, struct drm_atomic_state *state);
void drm_atomic_state_default_clear(struct drm_atomic_state *state);
void drm_atomic_state_default_release(struct drm_atomic_state *state);

struct drm_crtc_state * __must_check
drm_atomic_get_crtc_state(struct drm_atomic_state *state,
			  struct drm_crtc *crtc);
int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
		struct drm_crtc_state *state, struct drm_property *property,
		uint64_t val);
struct drm_plane_state * __must_check
drm_atomic_get_plane_state(struct drm_atomic_state *state,
			   struct drm_plane *plane);
int drm_atomic_plane_set_property(struct drm_plane *plane,
		struct drm_plane_state *state, struct drm_property *property,
		uint64_t val);
struct drm_connector_state * __must_check
drm_atomic_get_connector_state(struct drm_atomic_state *state,
			       struct drm_connector *connector);
int drm_atomic_connector_set_property(struct drm_connector *connector,
		struct drm_connector_state *state, struct drm_property *property,
		uint64_t val);

/**
 * drm_atomic_get_existing_crtc_state - get crtc state, if it exists
 * @state: global atomic state object
 * @crtc: crtc to grab
 *
 * This function returns the crtc state for the given crtc, or NULL
 * if the crtc is not part of the global atomic state.
 */
static inline struct drm_crtc_state *
drm_atomic_get_existing_crtc_state(struct drm_atomic_state *state,
				   struct drm_crtc *crtc)
{
	return state->crtc_states[drm_crtc_index(crtc)];
}

/**
 * drm_atomic_get_existing_plane_state - get plane state, if it exists
 * @state: global atomic state object
 * @plane: plane to grab
 *
 * This function returns the plane state for the given plane, or NULL
 * if the plane is not part of the global atomic state.
 */
static inline struct drm_plane_state *
drm_atomic_get_existing_plane_state(struct drm_atomic_state *state,
				    struct drm_plane *plane)
{
	return state->plane_states[drm_plane_index(plane)];
}

/**
 * drm_atomic_get_existing_connector_state - get connector state, if it exists
 * @state: global atomic state object
 * @connector: connector to grab
 *
 * This function returns the connector state for the given connector,
 * or NULL if the connector is not part of the global atomic state.
 */
static inline struct drm_connector_state *
drm_atomic_get_existing_connector_state(struct drm_atomic_state *state,
					struct drm_connector *connector)
{
	int index = drm_connector_index(connector);

	if (index >= state->num_connector)
		return NULL;

	return state->connector_states[index];
}

int __must_check
drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
			     struct drm_display_mode *mode);
int __must_check
drm_atomic_set_mode_prop_for_crtc(struct drm_crtc_state *state,
				  struct drm_property_blob *blob);
int __must_check
drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state,
			      struct drm_crtc *crtc);
void drm_atomic_set_fb_for_plane(struct drm_plane_state *plane_state,
				 struct drm_framebuffer *fb);
int __must_check
drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
				  struct drm_crtc *crtc);
int __must_check
drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
				   struct drm_crtc *crtc);
int __must_check
drm_atomic_add_affected_planes(struct drm_atomic_state *state,
			       struct drm_crtc *crtc);

void drm_atomic_legacy_backoff(struct drm_atomic_state *state);

void
drm_atomic_clean_old_fb(struct drm_device *dev, unsigned plane_mask, int ret);

int __must_check drm_atomic_check_only(struct drm_atomic_state *state);
int __must_check drm_atomic_commit(struct drm_atomic_state *state);
int __must_check drm_atomic_async_commit(struct drm_atomic_state *state);

#define for_each_connector_in_state(state, connector, connector_state, __i) \
	for ((__i) = 0;							\
	     (__i) < (state)->num_connector &&				\
	     ((connector) = (state)->connectors[__i],			\
	     (connector_state) = (state)->connector_states[__i], 1); 	\
	     (__i)++)							\
		for_each_if (connector)

#define for_each_crtc_in_state(state, crtc, crtc_state, __i)	\
	for ((__i) = 0;						\
	     (__i) < (state)->dev->mode_config.num_crtc &&	\
	     ((crtc) = (state)->crtcs[__i],			\
	     (crtc_state) = (state)->crtc_states[__i], 1);	\
	     (__i)++)						\
		for_each_if (crtc_state)

#define for_each_plane_in_state(state, plane, plane_state, __i)		\
	for ((__i) = 0;							\
	     (__i) < (state)->dev->mode_config.num_total_plane &&	\
	     ((plane) = (state)->planes[__i],				\
	     (plane_state) = (state)->plane_states[__i], 1);		\
	     (__i)++)							\
		for_each_if (plane_state)
static inline bool
drm_atomic_crtc_needs_modeset(struct drm_crtc_state *state)
{
	return state->mode_changed || state->active_changed ||
	       state->connectors_changed;
}


#endif /* DRM_ATOMIC_H_ */
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