dmaengine: idxd: setup event log configuration

Add setup of event log feature for supported device. Event log addresses
error reporting that was lacking in gen 1 DSA devices where a second error
event does not get reported when a first event is pending software
handling. The event log allows a circular buffer that the device can push
error events to. It is up to the user to create a large enough event log
ring in order to capture the expected events. The evl size can be set in
the device sysfs attribute. By default 64 entries are supported as minimal
when event log is enabled.

Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-4-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 88 insertions, 1 deletions

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 5f321f3b4242..230fe9bb56ae 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -752,6 +752,83 @@ void idxd_device_clear_state(struct idxd_device *idxd)
 	spin_unlock(&idxd->dev_lock);
 }
 
+static int idxd_device_evl_setup(struct idxd_device *idxd)
+{
+	union gencfg_reg gencfg;
+	union evlcfg_reg evlcfg;
+	union genctrl_reg genctrl;
+	struct device *dev = &idxd->pdev->dev;
+	void *addr;
+	dma_addr_t dma_addr;
+	int size;
+	struct idxd_evl *evl = idxd->evl;
+
+	if (!evl)
+		return 0;
+
+	size = evl_size(idxd);
+	/*
+	 * Address needs to be page aligned. However, dma_alloc_coherent() provides
+	 * at minimal page size aligned address. No manual alignment required.
+	 */
+	addr = dma_alloc_coherent(dev, size, &dma_addr, GFP_KERNEL);
+	if (!addr)
+		return -ENOMEM;
+
+	memset(addr, 0, size);
+
+	spin_lock(&evl->lock);
+	evl->log = addr;
+	evl->dma = dma_addr;
+	evl->log_size = size;
+
+	memset(&evlcfg, 0, sizeof(evlcfg));
+	evlcfg.bits[0] = dma_addr & GENMASK(63, 12);
+	evlcfg.size = evl->size;
+
+	iowrite64(evlcfg.bits[0], idxd->reg_base + IDXD_EVLCFG_OFFSET);
+	iowrite64(evlcfg.bits[1], idxd->reg_base + IDXD_EVLCFG_OFFSET + 8);
+
+	genctrl.bits = ioread32(idxd->reg_base + IDXD_GENCTRL_OFFSET);
+	genctrl.evl_int_en = 1;
+	iowrite32(genctrl.bits, idxd->reg_base + IDXD_GENCTRL_OFFSET);
+
+	gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
+	gencfg.evl_en = 1;
+	iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
+
+	spin_unlock(&evl->lock);
+	return 0;
+}
+
+static void idxd_device_evl_free(struct idxd_device *idxd)
+{
+	union gencfg_reg gencfg;
+	union genctrl_reg genctrl;
+	struct device *dev = &idxd->pdev->dev;
+	struct idxd_evl *evl = idxd->evl;
+
+	gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
+	if (!gencfg.evl_en)
+		return;
+
+	spin_lock(&evl->lock);
+	gencfg.evl_en = 0;
+	iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
+
+	genctrl.bits = ioread32(idxd->reg_base + IDXD_GENCTRL_OFFSET);
+	genctrl.evl_int_en = 0;
+	iowrite32(genctrl.bits, idxd->reg_base + IDXD_GENCTRL_OFFSET);
+
+	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);
+	evl->log = NULL;
+	evl->size = IDXD_EVL_SIZE_MIN;
+	spin_unlock(&evl->lock);
+}
+
 static void idxd_group_config_write(struct idxd_group *group)
 {
 	struct idxd_device *idxd = group->idxd;
@@ -1451,15 +1528,24 @@ int idxd_device_drv_probe(struct idxd_dev *idxd_dev)
 	if (rc < 0)
 		return -ENXIO;
 
+	rc = idxd_device_evl_setup(idxd);
+	if (rc < 0) {
+		idxd->cmd_status = IDXD_SCMD_DEV_EVL_ERR;
+		return rc;
+	}
+
 	/* Start device */
 	rc = idxd_device_enable(idxd);
-	if (rc < 0)
+	if (rc < 0) {
+		idxd_device_evl_free(idxd);
 		return rc;
+	}
 
 	/* Setup DMA device without channels */
 	rc = idxd_register_dma_device(idxd);
 	if (rc < 0) {
 		idxd_device_disable(idxd);
+		idxd_device_evl_free(idxd);
 		idxd->cmd_status = IDXD_SCMD_DEV_DMA_ERR;
 		return rc;
 	}
@@ -1488,6 +1574,7 @@ void idxd_device_drv_remove(struct idxd_dev *idxd_dev)
 	idxd_device_disable(idxd);
 	if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
 		idxd_device_reset(idxd);
+	idxd_device_evl_free(idxd);
 }
 
 static enum idxd_dev_type dev_types[] = {