Currently, an interrupt can be triggered during a GPU reset, which can lead to GPU hangs and NULL pointer dereference in an interrupt context as shown in the following trace:

[ 314.035040] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000c0 [ 314.043822] Mem abort info: [ 314.046606] ESR = 0x0000000096000005 [ 314.050347] EC = 0x25: DABT (current EL), IL = 32 bits [ 314.055651] SET = 0, FnV = 0 [ 314.058695] EA = 0, S1PTW = 0 [ 314.061826] FSC = 0x05: level 1 translation fault [ 314.066694] Data abort info: [ 314.069564] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 [ 314.075039] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 314.080080] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 314.085382] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000102728000 [ 314.091814] [00000000000000c0] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 314.100511] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP [ 314.106770] Modules linked in: v3d i2c_brcmstb vc4 snd_soc_hdmi_codec gpu_sched drm_shmem_helper drm_display_helper cec drm_dma_helper drm_kms_helper drm drm_panel_orientation_quirks snd_soc_core snd_compress snd_pcm_dmaengine snd_pcm snd_timer snd backlight [ 314.129654] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.25+rpt-rpi-v8 #1 Debian 1:6.12.25-1+rpt1 [ 314.139388] Hardware name: Raspberry Pi 4 Model B Rev 1.4 (DT) [ 314.145211] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 314.152165] pc : v3d_irq+0xec/0x2e0 [v3d] [ 314.156187] lr : v3d_irq+0xe0/0x2e0 [v3d] [ 314.160198] sp : ffffffc080003ea0 [ 314.163502] x29: ffffffc080003ea0 x28: ffffffec1f184980 x27: 021202b000000000 [ 314.170633] x26: ffffffec1f17f630 x25: ffffff8101372000 x24: ffffffec1f17d9f0 [ 314.177764] x23: 000000000000002a x22: 000000000000002a x21: ffffff8103252000 [ 314.184895] x20: 0000000000000001 x19: 00000000deadbeef x18: 0000000000000000 [ 314.192026] x17: ffffff94e51d2000 x16: ffffffec1dac3cb0 x15: c306000000000000 [ 314.199156] x14: 0000000000000000 x13: b2fc982e03cc5168 x12: 0000000000000001 [ 314.206286] x11: ffffff8103f8bcc0 x10: ffffffec1f196868 x9 : ffffffec1dac3874 [ 314.213416] x8 : 0000000000000000 x7 : 0000000000042a3a x6 : ffffff810017a180 [ 314.220547] x5 : ffffffec1ebad400 x4 : ffffffec1ebad320 x3 : 00000000000bebeb [ 314.227677] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 [ 314.234807] Call trace: [ 314.237243] v3d_irq+0xec/0x2e0 [v3d] [ 314.240906] __handle_irq_event_percpu+0x58/0x218 [ 314.245609] handle_irq_event+0x54/0xb8 [ 314.249439] handle_fasteoi_irq+0xac/0x240 [ 314.253527] handle_irq_desc+0x48/0x68 [ 314.257269] generic_handle_domain_irq+0x24/0x38 [ 314.261879] gic_handle_irq+0x48/0xd8 [ 314.265533] call_on_irq_stack+0x24/0x58 [ 314.269448] do_interrupt_handler+0x88/0x98 [ 314.273624] el1_interrupt+0x34/0x68 [ 314.277193] el1h_64_irq_handler+0x18/0x28 [ 314.281281] el1h_64_irq+0x64/0x68 [ 314.284673] default_idle_call+0x3c/0x168 [ 314.288675] do_idle+0x1fc/0x230 [ 314.291895] cpu_startup_entry+0x3c/0x50 [ 314.295810] rest_init+0xe4/0xf0 [ 314.299030] start_kernel+0x5e8/0x790 [ 314.302684] __primary_switched+0x80/0x90 [ 314.306691] Code: 940029eb 360ffc13 f9442ea0 52800001 (f9406017) [ 314.312775] ---[ end trace 0000000000000000 ]--- [ 314.317384] Kernel panic - not syncing: Oops: Fatal exception in interrupt [ 314.324249] SMP: stopping secondary CPUs [ 314.328167] Kernel Offset: 0x2b9da00000 from 0xffffffc080000000 [ 314.334076] PHYS_OFFSET: 0x0 [ 314.336946] CPU features: 0x08,00002013,c0200000,0200421b [ 314.342337] Memory Limit: none [ 314.345382] ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---

Before resetting the GPU, it's necessary to disable all interrupts and deal with any interrupt handler still in-flight. Otherwise, the GPU might reset with jobs still running, or yet, an interrupt could be handled during the reset.

Cc: stable@vger.kernel.org Fixes: 57692c94dcbe ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+") Signed-off-by: Maíra Canal mcanal@igalia.com --- drivers/gpu/drm/v3d/v3d_drv.h | 8 ++++++++ drivers/gpu/drm/v3d/v3d_gem.c | 2 ++ drivers/gpu/drm/v3d/v3d_irq.c | 37 +++++++++++++++++++++++++---------- 3 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h index b51f0b648a08..411e47702f8a 100644 --- a/drivers/gpu/drm/v3d/v3d_drv.h +++ b/drivers/gpu/drm/v3d/v3d_drv.h @@ -101,6 +101,12 @@ enum v3d_gen { V3D_GEN_71 = 71, };

+enum v3d_irq { + V3D_CORE_IRQ, + V3D_HUB_IRQ, + V3D_MAX_IRQS, +}; + struct v3d_dev { struct drm_device drm;

@@ -112,6 +118,8 @@ struct v3d_dev {

bool single_irq_line;

+ int irq[V3D_MAX_IRQS]; + struct v3d_perfmon_info perfmon_info;

void __iomem *hub_regs; diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c index d7d16da78db3..37bf5eecdd2c 100644 --- a/drivers/gpu/drm/v3d/v3d_gem.c +++ b/drivers/gpu/drm/v3d/v3d_gem.c @@ -134,6 +134,8 @@ v3d_reset(struct v3d_dev *v3d) if (false) v3d_idle_axi(v3d, 0);

+ v3d_irq_disable(v3d); + v3d_idle_gca(v3d); v3d_reset_sms(v3d); v3d_reset_v3d(v3d); diff --git a/drivers/gpu/drm/v3d/v3d_irq.c b/drivers/gpu/drm/v3d/v3d_irq.c index 2cca5d3a26a2..a515a301e480 100644 --- a/drivers/gpu/drm/v3d/v3d_irq.c +++ b/drivers/gpu/drm/v3d/v3d_irq.c @@ -260,7 +260,7 @@ v3d_hub_irq(int irq, void *arg) int v3d_irq_init(struct v3d_dev *v3d) { - int irq1, ret, core; + int irq, ret, core;

INIT_WORK(&v3d->overflow_mem_work, v3d_overflow_mem_work);

@@ -271,17 +271,24 @@ v3d_irq_init(struct v3d_dev *v3d) V3D_CORE_WRITE(core, V3D_CTL_INT_CLR, V3D_CORE_IRQS(v3d->ver)); V3D_WRITE(V3D_HUB_INT_CLR, V3D_HUB_IRQS(v3d->ver));

- irq1 = platform_get_irq_optional(v3d_to_pdev(v3d), 1); - if (irq1 == -EPROBE_DEFER) - return irq1; - if (irq1 > 0) { - ret = devm_request_irq(v3d->drm.dev, irq1, + irq = platform_get_irq_optional(v3d_to_pdev(v3d), 1); + if (irq == -EPROBE_DEFER) + return irq; + if (irq > 0) { + v3d->irq[V3D_CORE_IRQ] = irq; + + ret = devm_request_irq(v3d->drm.dev, v3d->irq[V3D_CORE_IRQ], v3d_irq, IRQF_SHARED, "v3d_core0", v3d); if (ret) goto fail; - ret = devm_request_irq(v3d->drm.dev, - platform_get_irq(v3d_to_pdev(v3d), 0), + + irq = platform_get_irq(v3d_to_pdev(v3d), 0); + if (irq < 0) + return irq; + v3d->irq[V3D_HUB_IRQ] = irq; + + ret = devm_request_irq(v3d->drm.dev, v3d->irq[V3D_HUB_IRQ], v3d_hub_irq, IRQF_SHARED, "v3d_hub", v3d); if (ret) @@ -289,8 +296,12 @@ v3d_irq_init(struct v3d_dev *v3d) } else { v3d->single_irq_line = true;

- ret = devm_request_irq(v3d->drm.dev, - platform_get_irq(v3d_to_pdev(v3d), 0), + irq = platform_get_irq(v3d_to_pdev(v3d), 0); + if (irq < 0) + return irq; + v3d->irq[V3D_CORE_IRQ] = irq; + + ret = devm_request_irq(v3d->drm.dev, v3d->irq[V3D_CORE_IRQ], v3d_irq, IRQF_SHARED, "v3d", v3d); if (ret) @@ -331,6 +342,12 @@ v3d_irq_disable(struct v3d_dev *v3d) V3D_CORE_WRITE(core, V3D_CTL_INT_MSK_SET, ~0); V3D_WRITE(V3D_HUB_INT_MSK_SET, ~0);

+ /* Finish any interrupt handler still in flight. */ + for (int i = 0; i < V3D_MAX_IRQS; i++) { + if (v3d->irq[i]) + synchronize_irq(v3d->irq[i]); + } + /* Clear any pending interrupts we might have left. */ for (core = 0; core < v3d->cores; core++) V3D_CORE_WRITE(core, V3D_CTL_INT_CLR, V3D_CORE_IRQS(v3d->ver));