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linux/drivers/gpu/drm/xe/display/ext/i915_irq.c
Ilia Levi 4d79a1266d
drm/xe: Make irq enabled flag atomic
The irq.enabled flag was protected by a spin lock (irq.lock).
By making it atomic we no longer need to wait for the spin lock in
irq handlers. This will become especially useful for MSI-X irq
handlers to prevent lock contention between different interrupts.

Signed-off-by: Ilia Levi <ilia.levi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241210173506.202150-1-ilia.levi@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2024-12-11 13:20:53 -05:00

63 lines
1.7 KiB
C

// SPDX-License-Identifier: MIT
/*
* Copyright © 2023 Intel Corporation
*/
#include "i915_irq.h"
#include "i915_reg.h"
#include "intel_uncore.h"
void gen2_irq_reset(struct intel_uncore *uncore, struct i915_irq_regs regs)
{
intel_uncore_write(uncore, regs.imr, 0xffffffff);
intel_uncore_posting_read(uncore, regs.imr);
intel_uncore_write(uncore, regs.ier, 0);
/* IIR can theoretically queue up two events. Be paranoid. */
intel_uncore_write(uncore, regs.iir, 0xffffffff);
intel_uncore_posting_read(uncore, regs.iir);
intel_uncore_write(uncore, regs.iir, 0xffffffff);
intel_uncore_posting_read(uncore, regs.iir);
}
/*
* We should clear IMR at preinstall/uninstall, and just check at postinstall.
*/
void gen2_assert_iir_is_zero(struct intel_uncore *uncore, i915_reg_t reg)
{
struct xe_device *xe = container_of(uncore, struct xe_device, uncore);
u32 val = intel_uncore_read(uncore, reg);
if (val == 0)
return;
drm_WARN(&xe->drm, 1,
"Interrupt register 0x%x is not zero: 0x%08x\n",
i915_mmio_reg_offset(reg), val);
intel_uncore_write(uncore, reg, 0xffffffff);
intel_uncore_posting_read(uncore, reg);
intel_uncore_write(uncore, reg, 0xffffffff);
intel_uncore_posting_read(uncore, reg);
}
void gen2_irq_init(struct intel_uncore *uncore, struct i915_irq_regs regs,
u32 imr_val, u32 ier_val)
{
gen2_assert_iir_is_zero(uncore, regs.iir);
intel_uncore_write(uncore, regs.ier, ier_val);
intel_uncore_write(uncore, regs.imr, imr_val);
intel_uncore_posting_read(uncore, regs.imr);
}
bool intel_irqs_enabled(struct xe_device *xe)
{
return atomic_read(&xe->irq.enabled);
}
void intel_synchronize_irq(struct xe_device *xe)
{
synchronize_irq(to_pci_dev(xe->drm.dev)->irq);
}