1 files changed, 75 insertions, 0 deletions
diff --git a/pci.c b/pci.c
new file mode 100644
index 0000000..16569ae
--- /dev/null
+++ b/pci.c
@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/mman.h>
+
+#include "pci.h"
+
+struct pci_access *pci;
+struct pci_dev *dev;
+
+void find_device(char *name,
+                 unsigned int vendor,
+                 unsigned int device)
+{
+    struct pci_filter filter;
+    struct pci_dev *d;
+
+    if (!pci) {
+        pci = pci_alloc();
+        if (!pci) {
+            fprintf(stderr, "libpci alloc failed\n");
+            exit(1);
+        }
+        pci_init(pci);
+        pci_scan_bus(pci);
+    }
+
+    pci_filter_init(pci, &filter);
+    filter.vendor = vendor;
+    filter.device = device;
+
+    for (d = pci->devices; d != NULL; d = d->next) {
+        if (!pci_filter_match(&filter, d))
+            continue;
+        dev = d;
+        fprintf(stderr, "%s found at %02x:%02x.%x\n",
+                name, dev->bus, dev->dev, dev->func);
+        return;
+    }
+    fprintf(stderr, "%s not found\n", name);
+    exit(1);
+}
+
+void *mmap_bar(int nr)
+{
+    char filename[128];
+    size_t size;
+    int fd;
+    void *bar;
+
+    snprintf(filename, sizeof(filename),
+             "/sys/bus/pci/devices/%04x:%02x:%02x.%x/resource%d",
+             dev->domain, dev->bus, dev->dev, dev->func, nr);
+    size = dev->size[nr];
+    fd = open(filename, O_RDWR);
+    if (fd < 0) {
+        fprintf(stderr, "open %s: %s\n", filename, strerror(errno));
+        exit(1);
+    }
+    bar = mmap(NULL, size, PROT_WRITE | PROT_READ, MAP_SHARED, fd, 0);
+    if (bar == MAP_FAILED) {
+        fprintf(stderr, "mmap %s: %s\n", filename, strerror(errno));
+        exit(1);
+    }
+    if (size >= (1 << 20)) {
+        fprintf(stderr, "bar %d mapped (%zd MB)\n", nr, size >> 20);
+    } else {
+        fprintf(stderr, "bar %d mapped (%zd bytes)\n", nr, size);
+    }
+    return bar;
+}