[PATCH] EDAC/versalnet: Refactor memory controller initialization and cleanup
From: Shubhrajyoti Datta
Date: Tue Nov 04 2025 - 04:39:20 EST
Simplify the initialization and cleanup flow for Versal Net DDRMC
controllers in the EDAC driver by carving out the single controller init
into a separate function which allows for a much better and more
readable error handling and unwinding.
[ bp:
- do the kzalloc allocations first
- "publish" the structures only after they've been initialized
properly so that you don't need to unwind unnecessarily when
it fails later
- remove_versalnet() is now trivial
]
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://patch.msgid.link/20251104093932.3838876-1-shubhrajyoti.datta@xxxxxxx
---
drivers/edac/versalnet_edac.c | 174 +++++++++++++++++++---------------
1 file changed, 97 insertions(+), 77 deletions(-)
diff --git a/drivers/edac/versalnet_edac.c b/drivers/edac/versalnet_edac.c
index 2cbc13d9bd00..0b47ed7fed63 100644
--- a/drivers/edac/versalnet_edac.c
+++ b/drivers/edac/versalnet_edac.c
@@ -70,6 +70,8 @@
#define XDDR5_BUS_WIDTH_32 1
#define XDDR5_BUS_WIDTH_16 2
+#define MC_NAME_LEN 32
+
/**
* struct ecc_error_info - ECC error log information.
* @burstpos: Burst position.
@@ -760,7 +762,17 @@ static void versal_edac_release(struct device *dev)
kfree(dev);
}
-static int init_versalnet(struct mc_priv *priv, struct platform_device *pdev)
+static void remove_one_mc(struct mc_priv *priv, int i)
+{
+ struct mem_ctl_info *mci;
+
+ mci = priv->mci[i];
+ device_unregister(mci->pdev);
+ edac_mc_del_mc(mci->pdev);
+ edac_mc_free(mci);
+}
+
+static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i)
{
u32 num_chans, rank, dwidth, config;
struct edac_mc_layer layers[2];
@@ -768,102 +780,110 @@ static int init_versalnet(struct mc_priv *priv, struct platform_device *pdev)
struct device *dev;
enum dev_type dt;
char *name;
- int rc, i;
-
- for (i = 0; i < NUM_CONTROLLERS; i++) {
- config = priv->adec[CONF + i * ADEC_NUM];
- num_chans = FIELD_GET(MC5_NUM_CHANS_MASK, config);
- rank = 1 << FIELD_GET(MC5_RANK_MASK, config);
- dwidth = FIELD_GET(MC5_BUS_WIDTH_MASK, config);
-
- switch (dwidth) {
- case XDDR5_BUS_WIDTH_16:
- dt = DEV_X16;
- break;
- case XDDR5_BUS_WIDTH_32:
- dt = DEV_X32;
- break;
- case XDDR5_BUS_WIDTH_64:
- dt = DEV_X64;
- break;
- default:
- dt = DEV_UNKNOWN;
- }
+ int rc;
- if (dt == DEV_UNKNOWN)
- continue;
+ config = priv->adec[CONF + i * ADEC_NUM];
+ num_chans = FIELD_GET(MC5_NUM_CHANS_MASK, config);
+ rank = 1 << FIELD_GET(MC5_RANK_MASK, config);
+ dwidth = FIELD_GET(MC5_BUS_WIDTH_MASK, config);
+
+ switch (dwidth) {
+ case XDDR5_BUS_WIDTH_16:
+ dt = DEV_X16;
+ break;
+ case XDDR5_BUS_WIDTH_32:
+ dt = DEV_X32;
+ break;
+ case XDDR5_BUS_WIDTH_64:
+ dt = DEV_X64;
+ break;
+ default:
+ dt = DEV_UNKNOWN;
+ }
- /* Find the first enabled device and register that one. */
- layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
- layers[0].size = rank;
- layers[0].is_virt_csrow = true;
- layers[1].type = EDAC_MC_LAYER_CHANNEL;
- layers[1].size = num_chans;
- layers[1].is_virt_csrow = false;
+ if (dt == DEV_UNKNOWN)
+ return 0;
- rc = -ENOMEM;
- mci = edac_mc_alloc(i, ARRAY_SIZE(layers), layers,
- sizeof(struct mc_priv));
- if (!mci) {
- edac_printk(KERN_ERR, EDAC_MC, "Failed memory allocation for MC%d\n", i);
- goto err_alloc;
- }
+ /* Find the first enabled device and register that one. */
+ layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
+ layers[0].size = rank;
+ layers[0].is_virt_csrow = true;
+ layers[1].type = EDAC_MC_LAYER_CHANNEL;
+ layers[1].size = num_chans;
+ layers[1].is_virt_csrow = false;
+
+ rc = -ENOMEM;
+ name = kzalloc(MC_NAME_LEN, GFP_KERNEL);
+ if (!name)
+ return rc;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ goto err_name_free;
+
+ mci = edac_mc_alloc(i, ARRAY_SIZE(layers), layers, sizeof(struct mc_priv));
+ if (!mci) {
+ edac_printk(KERN_ERR, EDAC_MC, "Failed memory allocation for MC%d\n", i);
+ goto err_dev_free;
+ }
- priv->mci[i] = mci;
- priv->dwidth = dt;
+ sprintf(name, "versal-net-ddrmc5-edac-%d", i);
- dev = kzalloc_obj(*dev);
- dev->release = versal_edac_release;
- name = kmalloc(32, GFP_KERNEL);
- sprintf(name, "versal-net-ddrmc5-edac-%d", i);
- dev->init_name = name;
- rc = device_register(dev);
- if (rc)
- goto err_alloc;
+ dev->init_name = name;
+ dev->release = versal_edac_release;
- mci->pdev = dev;
+ rc = device_register(dev);
+ if (rc)
+ goto err_mc_free;
- platform_set_drvdata(pdev, priv);
+ mci->pdev = dev;
+ mc_init(mci, dev);
- mc_init(mci, dev);
- rc = edac_mc_add_mc(mci);
- if (rc) {
- edac_printk(KERN_ERR, EDAC_MC, "Failed to register MC%d with EDAC core\n", i);
- goto err_alloc;
- }
+ rc = edac_mc_add_mc(mci);
+ if (rc) {
+ edac_printk(KERN_ERR, EDAC_MC, "Failed to register MC%d with EDAC core\n", i);
+ goto err_unreg;
}
- return 0;
-err_alloc:
- while (i--) {
- mci = priv->mci[i];
- if (!mci)
- continue;
-
- if (mci->pdev) {
- device_unregister(mci->pdev);
- edac_mc_del_mc(mci->pdev);
- }
+ priv->mci[i] = mci;
+ priv->dwidth = dt;
- edac_mc_free(mci);
- }
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+
+err_unreg:
+ device_unregister(mci->pdev);
+err_mc_free:
+ edac_mc_free(mci);
+err_dev_free:
+ kfree(dev);
+err_name_free:
+ kfree(name);
return rc;
}
-static void remove_versalnet(struct mc_priv *priv)
+static int init_versalnet(struct mc_priv *priv, struct platform_device *pdev)
{
- struct mem_ctl_info *mci;
- int i;
+ int rc, i;
for (i = 0; i < NUM_CONTROLLERS; i++) {
- device_unregister(priv->mci[i]->pdev);
- mci = edac_mc_del_mc(priv->mci[i]->pdev);
- if (!mci)
- return;
+ rc = init_one_mc(priv, pdev, i);
+ if (rc) {
+ while (i--)
+ remove_one_mc(priv, i);
- edac_mc_free(mci);
+ return rc;
+ }
}
+ return 0;
+}
+
+static void remove_versalnet(struct mc_priv *priv)
+{
+ for (int i = 0; i < NUM_CONTROLLERS; i++)
+ remove_one_mc(priv, i);
}
static int mc_probe(struct platform_device *pdev)
--
2.51.0
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette