2 files changed, 97 insertions, 0 deletions
diff --git a/tools/rmq/kmod/Makefile b/tools/rmq/kmod/Makefile
new file mode 100644
index 0000000..2fde4ef
--- /dev/null
+++ b/tools/rmq/kmod/Makefile
@@ -0,0 +1,7 @@
+obj-m += wpr2_reset_kmod.o
+
+all:
+	make -C /lib/modules/$(shell uname -r)/build M=$(CURDIR) modules
+
+clean:
+	make -C /lib/modules/$(shell uname -r)/build M=$(CURDIR) clean
diff --git a/tools/rmq/kmod/wpr2_reset_kmod.c b/tools/rmq/kmod/wpr2_reset_kmod.c
new file mode 100644
index 0000000..523fac7
--- /dev/null
+++ b/tools/rmq/kmod/wpr2_reset_kmod.c
@@ -0,0 +1,90 @@
+/* wpr2_reset_kmod - kernel module that clears GPU WPR2 registers via BAR0 ioremap.
+ *
+ * When nvidia.ko is unloaded without a clean GSP teardown, GSP firmware stays
+ * resident in WPR2 (a write-protected FB region described by
+ * PFB_PRI_MMU_WPR2_ADDR_LO/HI). Every subsequent RmInitAdapter then fails with
+ * "unexpected WPR2 already up" and FLR does not help (GSP survives warm resets).
+ *
+ * This module ioremaps GPU BAR0 and pokes WPR2_ADDR_LO/HI to zero so the next
+ * driver load takes the normal (clean) GSP boot path. Equivalent to the effect
+ * of FWSEC-SB + Booter Unload teardown, minus running the ucodes.
+ *
+ * Usage: sudo insmod wpr2_reset_kmod.ko [pci_bdf=0000:01:00.0]
+ *        result printed via pr_info (check dmesg)
+ */
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+
+#define NV_PFB_PRI_MMU_WPR2_ADDR_LO 0x1fa824
+#define NV_PFB_PRI_MMU_WPR2_ADDR_HI 0x1fa828
+
+static char *pci_bdf = "0000:01:00.0";
+module_param(pci_bdf, charp, 0444);
+MODULE_PARM_DESC(pci_bdf, "PCI BDF of the GPU (default 0000:01:00.0)");
+
+static int __init wpr2_reset_init(void)
+{
+    struct pci_dev *pdev = NULL;
+    unsigned int bus, dev, fn;
+    void __iomem *bar0;
+    u32 lo_before, hi_before, lo_after, hi_after;
+
+    if (sscanf(pci_bdf, "0000:%x:%x.%u", &bus, &dev, &fn) != 3) {
+        pr_err("wpr2_reset: bad pci_bdf %s\n", pci_bdf);
+        return -EINVAL;
+    }
+    pdev = pci_get_domain_bus_and_slot(0, bus, PCI_DEVFN(dev, fn));
+    if (!pdev) {
+        pr_err("wpr2_reset: device %s not found\n", pci_bdf);
+        return -ENODEV;
+    }
+    if (!pci_resource_start(pdev, 0)) {
+        pr_err("wpr2_reset: BAR0 not assigned\n");
+        pci_dev_put(pdev);
+        return -ENODEV;
+    }
+
+    if (pci_enable_device(pdev)) {
+        pr_err("wpr2_reset: pci_enable_device failed\n");
+        pci_dev_put(pdev);
+        return -EIO;
+    }
+    pci_set_master(pdev);
+    bar0 = ioremap_wc(pci_resource_start(pdev, 0), pci_resource_len(pdev, 0));
+    if (!bar0) {
+        pr_err("wpr2_reset: ioremap failed\n");
+        pci_dev_put(pdev);
+        return -ENOMEM;
+    }
+
+    lo_before = readl(bar0 + NV_PFB_PRI_MMU_WPR2_ADDR_LO);
+    hi_before = readl(bar0 + NV_PFB_PRI_MMU_WPR2_ADDR_HI);
+    pr_info("wpr2_reset: before LO=0x%08x HI=0x%08x\n", lo_before, hi_before);
+
+    writel(0, bar0 + NV_PFB_PRI_MMU_WPR2_ADDR_LO);
+    writel(0, bar0 + NV_PFB_PRI_MMU_WPR2_ADDR_HI);
+
+    lo_after = readl(bar0 + NV_PFB_PRI_MMU_WPR2_ADDR_LO);
+    hi_after = readl(bar0 + NV_PFB_PRI_MMU_WPR2_ADDR_HI);
+    pr_info("wpr2_reset: after  LO=0x%08x HI=0x%08x\n", lo_after, hi_after);
+
+    if (hi_after == 0)
+        pr_info("wpr2_reset: WPR2 cleared, clean GSP boot now possible\n");
+    else
+        pr_info("wpr2_reset: write dropped (PLM?) - WPR2 still up\n");
+
+    iounmap(bar0);
+    pci_dev_put(pdev);
+    return hi_after ? -EINVAL : 0;
+}
+
+static void __exit wpr2_reset_exit(void)
+{
+    pr_info("wpr2_reset: unloaded\n");
+}
+
+module_init(wpr2_reset_init);
+module_exit(wpr2_reset_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Clear GPU WPR2 registers to unstick GSP boot");