PCI XHCI allocate only necessary pages

kernel/amd64/mm.c

@@ -14,6 +14,7 @@
 #define AMD64_PG_PRESENT (1 << 0)
 #define AMD64_PG_RW      (1 << 1)
 #define AMD64_PG_USER    (1 << 2)
+#define AMD64_PG_PWT     (1 << 3)
 #define AMD64_PG_PCD     (1 << 4)
 #define AMD64_PG_HUGE    (1 << 7)
 
@@ -98,7 +99,7 @@ static uint64_t mm_resolve_flags (uint32_t generic) {
   flags |= ((generic & MM_PG_PRESENT) ? AMD64_PG_PRESENT : 0);
   flags |= ((generic & MM_PG_RW) ? AMD64_PG_RW : 0);
   flags |= ((generic & MM_PG_USER) ? AMD64_PG_USER : 0);
-  flags |= ((generic & MM_PG_NOCACHE ? AMD64_PG_PCD : 0));
+  flags |= ((generic & MM_PG_NOCACHE ? (AMD64_PG_PCD | AMD64_PG_PWT) : 0));
 
   return flags;
 }

kernel/device/pci.c

@@ -128,6 +128,38 @@ uint8_t pci_find_cap (uint8_t bus, uint8_t slot, uint8_t func, uint8_t cap_id) {
   return 0;
 }
 
+uint64_t pci_get_bar_size (uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset) {
+  uint32_t bar = pci_read32 (bus, slot, func, offset);
+
+  pci_write32 (bus, slot, func, offset, 0xFFFFFFFF);
+
+  uint32_t mask = pci_read32 (bus, slot, func, offset);
+
+  pci_write32 (bus, slot, func, offset, bar);
+
+  if (mask == 0)
+    return 0;
+
+  uint64_t full_mask;
+  if ((bar & PCI_BAR_MEM32) || (bar & PCI_BAR_MEM64)) {
+    full_mask = mask & ~0xF;
+
+    if ((bar & PCI_BAR_MEM64)) {
+      uint32_t bar_hi = pci_read32 (bus, slot, func, offset + 4);
+      pci_write32 (bus, slot, func, offset + 4, 0xFFFFFFFF);
+      uint32_t mask_hi = pci_read32 (bus, slot, func, offset + 4);
+      pci_write32 (bus, slot, func, offset + 4, bar_hi);
+
+      full_mask |= ((uint64_t)mask_hi << 32);
+    }
+  } else {
+    full_mask = mask & ~0x3;
+    full_mask |= 0xFFFFFFFF00000000ULL;
+  }
+
+  return (~full_mask) + 1;
+}
+
 bool pci_msi_init (uint8_t bus, uint8_t slot, uint8_t func, uint8_t vec, uint32_t lapic_id) {
   struct limine_hhdm_response* hhdm = limine_hhdm_request.response;
 

kernel/device/pci.h

@@ -82,6 +82,8 @@ uint8_t pci_find_cap (uint8_t bus, uint8_t slot, uint8_t func, uint8_t cap_id);
 
 bool pci_msi_init (uint8_t bus, uint8_t slot, uint8_t func, uint8_t vec, uint32_t lapic_id);
 
+uint64_t pci_get_bar_size (uint8_t bus, uint8_t slot, uint8_t func, uint8_t bar_offset);
+
 extern const struct pci_vendor pci_vendors[];
 
 extern const struct pci_device_id pci_device_names[];

kernel/device/pci_xhci.c

@@ -42,8 +42,11 @@ bool pci_xhci_init (struct proc* proc, struct reschedule_ctx* rctx, struct pci_i
   }
 
   uintptr_t xhci_phys = 0;
+  size_t map_pages = 0;
 
   uint32_t bar0 = pci_read32 (pci_info.bus, pci_info.slot, pci_info.func, PCI_BAR0);
+  map_pages = pci_get_bar_size (pci_info.bus, pci_info.slot, pci_info.func, PCI_BAR0);
+  map_pages = div_align_up (map_pages, PAGE_SIZE);
 
   if ((bar0 & PCI_BAR_MEM64)) {
     uint32_t bar1 = pci_read32 (pci_info.bus, pci_info.slot, pci_info.func, PCI_BAR1);
@@ -61,7 +64,9 @@ bool pci_xhci_init (struct proc* proc, struct reschedule_ctx* rctx, struct pci_i
 
   uintptr_t xhci_base = xhci_phys + (uintptr_t)hhdm->offset;
 
-  for (size_t page = 0; page < 8; page++) {
+  DEBUG ("BAR size = %zu pages\n", map_pages);
+
+  for (size_t page = 0; page < map_pages; page++) {
     mm_map_kernel_page (xhci_phys + page * PAGE_SIZE, xhci_base + page * PAGE_SIZE,
                         MM_PG_RW | MM_PG_PRESENT | MM_PG_NOCACHE);
   }

kernel/device/xhci.c

@@ -188,6 +188,27 @@ static void xhci_event_dispatch (struct xhci* xhci, struct xhci_trb* event, uint
 
     DEBUG ("cmd completion: code=%u,slot=%u\n", cmpl_code, slot_id);
   } break;
+  case XHCI_TRB_PORT_STS_CHNG: {
+    uint8_t port = ((event->param >> 24) & 0xFF) - 1;
+
+    uint32_t portsc = xhci_portsc_read (xhci, port);
+    DEBUG ("Status change on port %u: 0x%08x\n", port, portsc);
+
+    /* ack. PED + PR */
+    portsc &= ~((1 << 1) | (1 << 4));
+
+    xhci_portsc_write (xhci, port, portsc);
+
+    if ((portsc & (1 << 17))) {
+      if ((portsc & (1 << 0)))
+        DEBUG ("Device attached to port %u!\n", port);
+      else
+        DEBUG ("Device detached from port %u!\n", port);
+    }
+
+    if ((portsc & (1 << 21)))
+      DEBUG ("Port %u reset done\n", port);
+  } break;
   default:
     DEBUG ("Unhandled event type %u at %u\n", type, xhci->event_ring_idx);
     break;