From 3742ae23a16b1f7abe052bf22275b2c97daad71a Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Sat, 13 May 2023 18:12:34 +0200
Subject: [PATCH] kernel/ATA: Read the Busmaster base port and verify it

---
 kernel/src/arch/x86_64/disk/ATA.cpp | 8 ++++++++
 kernel/src/arch/x86_64/disk/ATA.h   | 1 +
 2 files changed, 9 insertions(+)

diff --git a/kernel/src/arch/x86_64/disk/ATA.cpp b/kernel/src/arch/x86_64/disk/ATA.cpp
index 1fb852cf..dec6f2a5 100644
--- a/kernel/src/arch/x86_64/disk/ATA.cpp
+++ b/kernel/src/arch/x86_64/disk/ATA.cpp
@@ -187,6 +187,14 @@ namespace ATA
         m_io_base = io_base_address;
         m_control_base = control_port_base_address + 2;
 
+        auto io_busmaster = m_controller->device().getBAR(4);
+        if (!io_busmaster.is_iospace())
+        {
+            kwarnln("ata: Channel %d's busmaster base BAR is not in IO space", m_channel_index);
+            return false;
+        }
+        m_busmaster_base = io_busmaster.port() + (u16)(m_channel_index * 8u);
+
         if (m_is_pci_native_mode) m_interrupt_line = PCI::read8(m_controller->device().address, PCI::InterruptLine);
         else
             m_interrupt_line = m_channel_index ? 15 : 14;
diff --git a/kernel/src/arch/x86_64/disk/ATA.h b/kernel/src/arch/x86_64/disk/ATA.h
index c7f9a720..45770de4 100644
--- a/kernel/src/arch/x86_64/disk/ATA.h
+++ b/kernel/src/arch/x86_64/disk/ATA.h
@@ -120,6 +120,7 @@ namespace ATA
 
         u16 m_io_base;
         u16 m_control_base;
+        u16 m_busmaster_base;
 
         u8 m_current_drive = (u8)-1;