dmaengine: idxd: Move dma_free_coherent() out of spinlocked context

[ Upstream commit e271c0ba3f919c48e90c64b703538fbb7865cb63 ]

Task may be rescheduled within dma_free_coherent(). So dma_free_coherent()
can't be called between spin_lock() and spin_unlock() to avoid Call Trace:
    Call Trace:
    <TASK>
    dump_stack_lvl+0x37/0x50
    __might_resched+0x16a/0x1c0
    vunmap+0x2c/0x70
    __iommu_dma_free+0x96/0x100
    idxd_device_evl_free+0xd5/0x100 [idxd]
    device_release_driver_internal+0x197/0x200
    unbind_store+0xa1/0xb0
    kernfs_fop_write_iter+0x120/0x1c0
    vfs_write+0x2d3/0x400
    ksys_write+0x63/0xe0
    do_syscall_64+0x44/0xa0
    entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Move it out of the context.

Fixes: 244da66cda35 ("dmaengine: idxd: setup event log configuration")
Signed-off-by: Rex Zhang <rex.zhang@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20231212022158.358619-2-rex.zhang@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 8f754f9..fa0f880 100644 (file)
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -802,6 +802,9 @@ err_bmap:
 
 static void idxd_device_evl_free(struct idxd_device *idxd)
 {
+       void *evl_log;
+       unsigned int evl_log_size;
+       dma_addr_t evl_dma;
        union gencfg_reg gencfg;
        union genctrl_reg genctrl;
        struct device *dev = &idxd->pdev->dev;
@@ -822,11 +825,15 @@ static void idxd_device_evl_free(struct idxd_device *idxd)
        iowrite64(0, idxd->reg_base + IDXD_EVLCFG_OFFSET);
        iowrite64(0, idxd->reg_base + IDXD_EVLCFG_OFFSET + 8);
 
-       dma_free_coherent(dev, evl->log_size, evl->log, evl->dma);
        bitmap_free(evl->bmap);
+       evl_log = evl->log;
+       evl_log_size = evl->log_size;
+       evl_dma = evl->dma;
        evl->log = NULL;
        evl->size = IDXD_EVL_SIZE_MIN;
        spin_unlock(&evl->lock);
+
+       dma_free_coherent(dev, evl_log_size, evl_log, evl_dma);
 }
 
 static void idxd_group_config_write(struct idxd_group *group)