MdeModulePkg SataControllerDxe: Calculate ChannelCount based on PI value

Current code calculates ChannelCount based on CAP(NP) value.
It only works when the ports implemented number are <= CAP(NP),
for example, platform has CAP(NP) = 5 (means 6 ports) and ports
implemented are 0, 1, 2, 3, 4 and 5.

But we have some platform that has CAP(NP) = 1 (means 2 ports) and
ports implemented are 1 and 2, and has no port 0 implemented, then
current code does not work.

This patch updates the code to calculate ChannelCount based on PI value.

Cc: Amy Chan <amy.chan@intel.com>
Cc: Hong-chihX Hsueh <hong-chihx.hsueh@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Hao Wu <hao.a.wu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Hao Wu <hao.a.wu@intel.com>
Tested-by: Hong-chihX Hsueh <hong-chihx.hsueh@intel.com>

diff --git a/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.c b/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.c
index 7dc40f82e81977224b3da64884c2924766e9180b..d47e918f5757eff15ab5f056f1651635596aede6 100644 (file)
--- a/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.c
+++ b/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.c
@@ -366,6 +366,7 @@ SataControllerStart (
   UINT32                            Data32;\r
   UINTN                             TotalCount;\r
   UINT64                            Supports;\r
+  UINT8                             MaxPortNumber;\r
 \r
   DEBUG ((EFI_D_INFO, "SataControllerStart start\n"));\r
 \r
@@ -472,12 +473,31 @@ SataControllerStart (
     Private->DeviceCount          = IDE_MAX_DEVICES;\r
   } else if (IS_PCI_SATADPA (&PciData)) {\r
     //\r
-    // Read Host Capability Register(CAP) to get Number of Ports(NPS) and Supports Port Multiplier(SPM)\r
-    //   NPS is 0's based value indicating the maximum number of ports supported by the HBA silicon.\r
-    //   A maximum of 32 ports can be supported. A value of '0h', indicating one port, is the minimum requirement.\r
+    // Read Ports Implemented(PI) to calculate max port number (0 based).\r
+    //\r
+    Data32 = AhciReadReg (PciIo, R_AHCI_PI);\r
+    DEBUG ((DEBUG_INFO, "Ports Implemented(PI) = 0x%x\n", Data32));\r
+    if (Data32 == 0) {\r
+      Status = EFI_UNSUPPORTED;\r
+      goto Done;\r
+    }\r
+    MaxPortNumber = 31;\r
+    while (MaxPortNumber > 0) {\r
+      if (Data32 & (1 << MaxPortNumber)) {\r
+        break;\r
+      }\r
+      MaxPortNumber--;\r
+    }\r
+    //\r
+    // Make the ChannelCount equal to the max port number (0 based) plus 1.\r
+    //\r
+    Private->IdeInit.ChannelCount = MaxPortNumber + 1;\r
+\r
+    //\r
+    // Read HBA Capabilities(CAP) to get Supports Port Multiplier(SPM).\r
     //\r
     Data32 = AhciReadReg (PciIo, R_AHCI_CAP);\r
-    Private->IdeInit.ChannelCount = (UINT8) ((Data32 & B_AHCI_CAP_NPS) + 1);\r
+    DEBUG ((DEBUG_INFO, "HBA Capabilities(CAP) = 0x%x\n", Data32));\r
     Private->DeviceCount          = AHCI_MAX_DEVICES;\r
     if ((Data32 & B_AHCI_CAP_SPM) == B_AHCI_CAP_SPM) {\r
       Private->DeviceCount = AHCI_MULTI_MAX_DEVICES;\r

diff --git a/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.h b/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.h
index 436eff2dc673dc44c8a5c413026dde6592778068..7ffd3e218a61119e6bc056705b8e654b06f73e6d 100644 (file)
--- a/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.h
+++ b/MdeModulePkg/Bus/Pci/SataControllerDxe/SataController.h
@@ -44,6 +44,7 @@ extern EFI_COMPONENT_NAME2_PROTOCOL gSataControllerComponentName2;
 #define R_AHCI_CAP 0x0\r
 #define   B_AHCI_CAP_NPS (BIT4 | BIT3 | BIT2 | BIT1 | BIT0) // Number of Ports\r
 #define   B_AHCI_CAP_SPM BIT17                              // Supports Port Multiplier\r
+#define R_AHCI_PI  0xC\r
 \r
 ///\r
 /// AHCI each channel can have up to 1 device\r