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drm/i915/uncore: fix race around i915->params.mmio_debug

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Only check the conditions for unclaimed reg debug once to avoid locking
problems when i915->params.mmio_debug changes between header and footer.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8749
Cc: Lee Shawn C <shawn.c.lee@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/a53fb0fd84c4627398ccd4304b35db05603b89b6.1690886109.git.jani.nikula@intel.com
This commit is contained in:
Jani Nikula 2023-08-01 15:32:50 +03:00
parent 7afe234064
commit d823445b09
1 changed files with 12 additions and 9 deletions
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21
drivers/gpu/drm/i915/intel_uncore.c
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@ -1925,27 +1925,26 @@ __unclaimed_previous_reg_debug(struct intel_uncore *uncore,
i915_mmio_reg_offset(reg));
}
static inline void
static inline bool __must_check
unclaimed_reg_debug_header(struct intel_uncore *uncore,
const i915_reg_t reg, const bool read)
{
if (likely(!uncore->i915->params.mmio_debug) || !uncore->debug)
return;
return false;
/* interrupts are disabled and re-enabled around uncore->lock usage */
lockdep_assert_held(&uncore->lock);
spin_lock(&uncore->debug->lock);
__unclaimed_previous_reg_debug(uncore, reg, read);
return true;
}
static inline void
unclaimed_reg_debug_footer(struct intel_uncore *uncore,
const i915_reg_t reg, const bool read)
{
if (likely(!uncore->i915->params.mmio_debug) || !uncore->debug)
return;
/* interrupts are disabled and re-enabled around uncore->lock usage */
lockdep_assert_held(&uncore->lock);
@ -2008,13 +2007,15 @@ __gen2_read(64)
#define GEN6_READ_HEADER(x) \
u32 offset = i915_mmio_reg_offset(reg); \
unsigned long irqflags; \
bool unclaimed_reg_debug; \
u##x val = 0; \
assert_rpm_wakelock_held(uncore->rpm); \
spin_lock_irqsave(&uncore->lock, irqflags); \
unclaimed_reg_debug_header(uncore, reg, true)
unclaimed_reg_debug = unclaimed_reg_debug_header(uncore, reg, true)
#define GEN6_READ_FOOTER \
unclaimed_reg_debug_footer(uncore, reg, true); \
if (unclaimed_reg_debug) \
unclaimed_reg_debug_footer(uncore, reg, true); \
spin_unlock_irqrestore(&uncore->lock, irqflags); \
trace_i915_reg_rw(false, reg, val, sizeof(val), trace); \
return val
@ -2112,13 +2113,15 @@ __gen2_write(32)
#define GEN6_WRITE_HEADER \
u32 offset = i915_mmio_reg_offset(reg); \
unsigned long irqflags; \
bool unclaimed_reg_debug; \
trace_i915_reg_rw(true, reg, val, sizeof(val), trace); \
assert_rpm_wakelock_held(uncore->rpm); \
spin_lock_irqsave(&uncore->lock, irqflags); \
unclaimed_reg_debug_header(uncore, reg, false)
unclaimed_reg_debug = unclaimed_reg_debug_header(uncore, reg, false)
#define GEN6_WRITE_FOOTER \
unclaimed_reg_debug_footer(uncore, reg, false); \
if (unclaimed_reg_debug) \
unclaimed_reg_debug_footer(uncore, reg, false); \
spin_unlock_irqrestore(&uncore->lock, irqflags)
#define __gen6_write(x) \