From d172666be29dc597e616ca1891a54872e0da395a Mon Sep 17 00:00:00 2001
From: Abdur-Rahman Mansoor <armansoor@missingno.dev>
Date: Sat, 25 May 2024 20:37:42 -0400
Subject: [PATCH] wip: setup controller configuration

---
 drivers/nvme/nvme.asm | 30 ++++++++++++++++++++++++------
 drivers/nvme/nvme.inc |  2 ++
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/nvme.asm b/drivers/nvme/nvme.asm
index b507664..6e85d29 100644
--- a/drivers/nvme/nvme.asm
+++ b/drivers/nvme/nvme.asm
@@ -231,6 +231,10 @@ proc nvme_init stdcall, pci:dword
 			DEBUGF DBG_INFO, "(NVMe) CAP (0-31): 0x%x\n", ebx
 			mov    ebx, dword [eax + NVME_MMIO.CAP + 4]
 			DEBUGF DBG_INFO, "(NVMe) CAP (32-63): 0x%x\n", ebx
+			mov    ebx, dword [eax + NVME_MMIO.CC]
+			DEBUGF DBG_INFO, "(NVMe) CC: 0x%x\n", ebx
+			mov    ebx, dword [eax + NVME_MMIO.CSTS]
+			DEBUGF DBG_INFO, "(NVMe) CSTS: 0x%x\n", ebx
 		end if
 
 		mov      ebx, dword [eax + NVME_MMIO.CAP]
@@ -244,8 +248,25 @@ proc nvme_init stdcall, pci:dword
 		test 	 ebx, CAP_CSS_NVM_CMDSET
 		jz       .exit_fail
 
-		; Reset controller
+		; Reset controller before we configure it
 		stdcall nvme_controller_reset, [pci]
+		mov 	eax, [pci]
+		mov 	eax, [eax + pcidev.mmio_ptr]
+		mov 	ebx, dword [eax + NVME_MMIO.CC]
+		and 	ebx, CAP_MPSMAX
+		shr 	ebx, 20
+		cmp 	ebx, NVM_MPS
+		jl		.exit_fail
+
+		; Configure IOSQES, IOCQES, MPS, CSS
+		mov 	ebx, dword [eax + NVME_MMIO.CC]
+		or 	    ebx, (4 shl 16) or (6 shl 20)
+		and 	ebx, not (CC_MPS or CC_CSS)
+		mov		dword [eax + NVME_MMIO.CC], ebx 
+
+		; Configure Admin Queue Attributes
+
+		; Configure Admin Submission/Completion Queue Base Address
 
         xor     eax, eax
         inc     eax
@@ -266,15 +287,12 @@ proc nvme_controller_reset stdcall, pci:dword
 		push 	ebx
 		mov 	ebx, dword [pci]
 		mov 	ebx, dword [ebx + pcidev.mmio_ptr]
-		mov 	eax, dword [ebx + NVME_MMIO.CC]
-		and 	eax, 0xfffffffe ; CC.EN = 0
-		mov 	dword [ebx + NVME_MMIO.CC], eax
+		and 	dword [ebx + NVME_MMIO.CC], 0xfffffffe
 		stdcall nvme_wait, [pci]
 
 ; Wait for controller to be brought to idle state, CSTS.RDY should be cleared to 0 when this happens
 .wait:
-		mov 	eax, dword [ebx + NVME_MMIO.CSTS]
-		test    eax, CSTS_RDY
+		test    dword [ebx + NVME_MMIO.CSTS], CSTS_RDY
 		jnz 	.wait
 		DEBUGF  DBG_INFO, "(NVMe) Successfully reset controller...\n"
 		pop 	ebx
diff --git a/drivers/nvme/nvme.inc b/drivers/nvme/nvme.inc
index 152cdc3..3863bf1 100644
--- a/drivers/nvme/nvme.inc
+++ b/drivers/nvme/nvme.inc
@@ -11,6 +11,8 @@
 ; Supported NVMe Controller Version
 NVM_SUPPORTED_CONTROLLER_VERSION = 0x00010400 ; (v1.4)
 
+NVM_MPS = 0
+
 ; Opcodes for NVM commands
 NVM_CMD_FLUSH = 0x00 
 NVM_CMD_WRITE = 0x01