Kernel/E1000: Consolidate RX and TX buffer regions

Allocate all the RX buffers in one big memory region (and same for TX.)
This removes 38 lines from every crash dump (and just seems like a
reasonable idea in general.)

Kernel/Net/E1000NetworkAdapter.cpp

@@ -221,8 +221,8 @@ UNMAP_AFTER_INIT bool E1000NetworkAdapter::initialize()
 
 UNMAP_AFTER_INIT E1000NetworkAdapter::E1000NetworkAdapter(PCI::Address address, u8 irq)
     : PCI::Device(address, irq)
-    , m_rx_descriptors_region(MM.allocate_contiguous_kernel_region(page_round_up(sizeof(e1000_rx_desc) * number_of_rx_descriptors + 16), "E1000 RX", Region::Access::Read | Region::Access::Write))
-    , m_tx_descriptors_region(MM.allocate_contiguous_kernel_region(page_round_up(sizeof(e1000_tx_desc) * number_of_tx_descriptors + 16), "E1000 TX", Region::Access::Read | Region::Access::Write))
+    , m_rx_descriptors_region(MM.allocate_contiguous_kernel_region(page_round_up(sizeof(e1000_rx_desc) * number_of_rx_descriptors + 16), "E1000 RX Descriptors", Region::Access::Read | Region::Access::Write))
+    , m_tx_descriptors_region(MM.allocate_contiguous_kernel_region(page_round_up(sizeof(e1000_tx_desc) * number_of_tx_descriptors + 16), "E1000 TX Descriptors", Region::Access::Read | Region::Access::Write))
 {
     set_interface_name(pci_address());
 }
@@ -317,12 +317,14 @@ bool E1000NetworkAdapter::link_up()
 UNMAP_AFTER_INIT void E1000NetworkAdapter::initialize_rx_descriptors()
 {
     auto* rx_descriptors = (e1000_tx_desc*)m_rx_descriptors_region->vaddr().as_ptr();
+    constexpr auto rx_buffer_size = 8192;
+    constexpr auto rx_buffer_page_count = rx_buffer_size / PAGE_SIZE;
+
+    m_rx_buffer_region = MM.allocate_contiguous_kernel_region(rx_buffer_size * number_of_rx_descriptors, "E1000 RX buffers", Region::Access::Read | Region::Access::Write);
     for (size_t i = 0; i < number_of_rx_descriptors; ++i) {
         auto& descriptor = rx_descriptors[i];
-        auto region = MM.allocate_contiguous_kernel_region(8192, "E1000 RX buffer", Region::Access::Read | Region::Access::Write);
-        VERIFY(region);
-        m_rx_buffers_regions.append(region.release_nonnull());
-        descriptor.addr = m_rx_buffers_regions[i].physical_page(0)->paddr().get();
+        m_rx_buffers[i] = m_rx_buffer_region->vaddr().as_ptr() + rx_buffer_size * i;
+        descriptor.addr = m_rx_buffer_region->physical_page(rx_buffer_page_count * i)->paddr().get();
         descriptor.status = 0;
     }
 
@@ -338,12 +340,15 @@ UNMAP_AFTER_INIT void E1000NetworkAdapter::initialize_rx_descriptors()
 UNMAP_AFTER_INIT void E1000NetworkAdapter::initialize_tx_descriptors()
 {
     auto* tx_descriptors = (e1000_tx_desc*)m_tx_descriptors_region->vaddr().as_ptr();
+
+    constexpr auto tx_buffer_size = 8192;
+    constexpr auto tx_buffer_page_count = tx_buffer_size / PAGE_SIZE;
+    m_tx_buffer_region = MM.allocate_contiguous_kernel_region(tx_buffer_size * number_of_tx_descriptors, "E1000 TX buffers", Region::Access::Read | Region::Access::Write);
+
     for (size_t i = 0; i < number_of_tx_descriptors; ++i) {
         auto& descriptor = tx_descriptors[i];
-        auto region = MM.allocate_contiguous_kernel_region(8192, "E1000 TX buffer", Region::Access::Read | Region::Access::Write);
-        VERIFY(region);
-        m_tx_buffers_regions.append(region.release_nonnull());
-        descriptor.addr = m_tx_buffers_regions[i].physical_page(0)->paddr().get();
+        m_tx_buffers[i] = m_tx_buffer_region->vaddr().as_ptr() + tx_buffer_size * i;
+        descriptor.addr = m_tx_buffer_region->physical_page(tx_buffer_page_count * i)->paddr().get();
         descriptor.cmd = 0;
     }
 
@@ -422,7 +427,7 @@ void E1000NetworkAdapter::send_raw(ReadonlyBytes payload)
     auto* tx_descriptors = (e1000_tx_desc*)m_tx_descriptors_region->vaddr().as_ptr();
     auto& descriptor = tx_descriptors[tx_current];
     VERIFY(payload.size() <= 8192);
-    auto* vptr = (void*)m_tx_buffers_regions[tx_current].vaddr().as_ptr();
+    auto* vptr = (void*)m_tx_buffers[tx_current];
     memcpy(vptr, payload.data(), payload.size());
     descriptor.length = payload.size();
     descriptor.status = 0;
@@ -451,7 +456,7 @@ void E1000NetworkAdapter::receive()
         rx_current = (rx_current + 1) % number_of_rx_descriptors;
         if (!(rx_descriptors[rx_current].status & 1))
             break;
-        auto* buffer = m_rx_buffers_regions[rx_current].vaddr().as_ptr();
+        auto* buffer = m_rx_buffers[rx_current];
         u16 length = rx_descriptors[rx_current].length;
         VERIFY(length <= 8192);
         dbgln_if(E1000_DEBUG, "E1000: Received 1 packet @ {:p} ({} bytes)", buffer, length);

Kernel/Net/E1000NetworkAdapter.h

@@ -6,7 +6,6 @@
 
 #pragma once
 
-#include <AK/NonnullOwnPtrVector.h>
 #include <AK/OwnPtr.h>
 #include <Kernel/Bus/PCI/Access.h>
 #include <Kernel/Bus/PCI/Device.h>
@@ -77,21 +76,23 @@ protected:
 
     void receive();
 
+    static constexpr size_t number_of_rx_descriptors = 32;
+    static constexpr size_t number_of_tx_descriptors = 8;
+
     IOAddress m_io_base;
     VirtualAddress m_mmio_base;
     OwnPtr<Region> m_rx_descriptors_region;
     OwnPtr<Region> m_tx_descriptors_region;
-    NonnullOwnPtrVector<Region> m_rx_buffers_regions;
-    NonnullOwnPtrVector<Region> m_tx_buffers_regions;
+    OwnPtr<Region> m_rx_buffer_region;
+    OwnPtr<Region> m_tx_buffer_region;
+    Array<void*, number_of_rx_descriptors> m_rx_buffers;
+    Array<void*, number_of_tx_descriptors> m_tx_buffers;
     OwnPtr<Region> m_mmio_region;
     u8 m_interrupt_line { 0 };
     bool m_has_eeprom { false };
     bool m_use_mmio { false };
     EntropySource m_entropy_source;
 
-    static constexpr size_t number_of_rx_descriptors = 32;
-    static constexpr size_t number_of_tx_descriptors = 8;
-
     WaitQueue m_wait_queue;
 };
 }