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drm/i915/guc: Don't GEM_BUG_ON on corrupted H2G CTB

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We should never BUG_ON on any corruption in CTB descriptor as
data there can be also modified by the GuC. Instead we can
use flag "is_in_error" to indicate that we will not process
any further messages over this CTB (until reset).

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200120191817.50164-1-michal.wajdeczko@intel.com
This commit is contained in:
Michal Wajdeczko 2020-01-20 19:18:17 +00:00 committed by Chris Wilson
parent 37f60b753b
commit 4c22abfbcb
1 changed files with 22 additions and 10 deletions
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32
drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
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@ -317,18 +317,25 @@ static int ct_write(struct intel_guc_ct *ct,
{
struct intel_guc_ct_buffer *ctb = &ct->ctbs[CTB_SEND];
struct guc_ct_buffer_desc *desc = ctb->desc;
u32 head = desc->head / 4; /* in dwords */
u32 tail = desc->tail / 4; /* in dwords */
u32 size = desc->size / 4; /* in dwords */
u32 used; /* in dwords */
u32 head = desc->head;
u32 tail = desc->tail;
u32 size = desc->size;
u32 used;
u32 header;
u32 *cmds = ctb->cmds;
unsigned int i;
GEM_BUG_ON(desc->size % 4);
GEM_BUG_ON(desc->head % 4);
GEM_BUG_ON(desc->tail % 4);
GEM_BUG_ON(tail >= size);
if (unlikely(desc->is_in_error))
return -EPIPE;
if (unlikely(!IS_ALIGNED(head | tail | size, 4) ||
(tail | head) >= size))
goto corrupted;
/* later calculations will be done in dwords */
head /= 4;
tail /= 4;
size /= 4;
/*
* tail == head condition indicates empty. GuC FW does not support
@ -367,12 +374,17 @@ static int ct_write(struct intel_guc_ct *ct,
cmds[tail] = action[i];
tail = (tail + 1) % size;
}
GEM_BUG_ON(tail > size);
/* now update desc tail (back in bytes) */
desc->tail = tail * 4;
GEM_BUG_ON(desc->tail > desc->size);
return 0;
corrupted:
CT_ERROR(ct, "Corrupted descriptor addr=%#x head=%u tail=%u size=%u\n",
desc->addr, desc->head, desc->tail, desc->size);
desc->is_in_error = 1;
return -EPIPE;
}
/**