Kernel: Don't reset AHCI ports during boot unless requested

Instead of blindly resetting every AHCI port, let's just reset only the
controller by default. The user can still request to reset everything
with a new kernel boot argument called ahci_reset_mode which is set
by default to "controller", so the code will only invoke an HBA reset.

This kernel boot argument can be set to 3 different values:
1. "controller" - reset the HBA and skip resetting AHCI ports
2. "none" - don't reset anything, so we rely on the firmware to
initialize the AHCI HBA and ports for us.
3. "complete" - reset the AHCI HBA and ports.

1 files changed, 7 insertions, 4 deletions

diff --git a/Kernel/Storage/AHCIController.cpp b/Kernel/Storage/AHCIController.cpp
index 1068ea104a..d2b0570469 100644
--- a/Kernel/Storage/AHCIController.cpp
+++ b/Kernel/Storage/AHCIController.cpp
@@ -28,6 +28,7 @@
 #include <AK/OwnPtr.h>
 #include <AK/RefPtr.h>
 #include <AK/Types.h>
+#include <Kernel/CommandLine.h>
 #include <Kernel/Storage/AHCIController.h>
 #include <Kernel/Storage/SATADiskDevice.h>
 #include <Kernel/VM/MemoryManager.h>
@@ -144,11 +145,13 @@ AHCIController::~AHCIController()
 
 void AHCIController::initialize()
 {
-    if (!reset()) {
-        dmesgln("{}: AHCI controller reset failed", pci_address());
-        return;
+    if (kernel_command_line().ahci_reset_mode() != AHCIResetMode::None) {
+        if (!reset()) {
+            dmesgln("{}: AHCI controller reset failed", pci_address());
+            return;
+        }
+        dmesgln("{}: AHCI controller reset", pci_address());
     }
-    dmesgln("{}: AHCI controller reset", pci_address());
     dbgln("{}: AHCI command list entries count - {}", pci_address(), hba_capabilities().max_command_list_entries_count);
     hba().control_regs.ghc = 0x80000000; // Ensure that HBA knows we are AHCI aware.
     PCI::enable_interrupt_line(pci_address());