From 2b9f8d7f37679aefbbe38b945b8a1e987228613c Mon Sep 17 00:00:00 2001
From: Abdur-Rahman Mansoor <armansoor@missingno.dev>
Date: Tue, 4 Jun 2024 14:44:06 -0400
Subject: [PATCH] feat: implement `create_io_completion_queue`

---
 drivers/nvme/nvme.asm | 28 ++++++++++++++++++++++++++++
 drivers/nvme/nvme.inc |  2 ++
 2 files changed, 30 insertions(+)

diff --git a/drivers/nvme/nvme.asm b/drivers/nvme/nvme.asm
index 174c2ee..652ff9d 100644
--- a/drivers/nvme/nvme.asm
+++ b/drivers/nvme/nvme.asm
@@ -128,6 +128,34 @@ proc nvme_identify stdcall, pci:dword, slot:dword, nsid:dword, dptr:dword, cid:w
 
 endp
 
+; See page 101 of the NVMe 1.4 specification for reference
+proc create_io_completion_queue stdcall, pci:dword, prp1:dword, qid:word, ien:byte
+	
+		push 	esi ebx
+		mov 	esi, [pci]
+
+		xor 	ebx, ebx
+		movzx   eax, [ien]
+		and 	eax, 10b
+		or 		ebx, eax
+		movzx 	eax, byte [esi + pcidev.pc]
+		and 	eax, 0x1
+		or 		ebx, eax ; CDW.PC
+		mov 	esi, [esi + pcidev.sq_ptr]
+		stdcall memset, esi, 0, sizeof.SQ_ENTRY
+		mov 	dword [esi + SQ_ENTRY.cdw11], ebx
+		mov 	bx, [qid] ; CDW10.QID
+		or 		ebx, (sizeof.CQ_ENTRY shl 16) ; CDW10.QSIZE
+		mov 	dword [esi + SQ_ENTRY.cdw10], ebx
+		mov 	ebx, [prp1]
+		mov 	dword [esi + SQ_ENTRY.dptr], ebx
+		stdcall sqytdbl_write, [pci], [qid], 0 ; setting last param to 0 for now, change later
+
+		pop 	ebx esi
+		ret
+
+endp
+
 proc detect_nvme
 
       	invoke  GetPCIList
diff --git a/drivers/nvme/nvme.inc b/drivers/nvme/nvme.inc
index 6dbf271..a1fc5ef 100644
--- a/drivers/nvme/nvme.inc
+++ b/drivers/nvme/nvme.inc
@@ -237,6 +237,8 @@ struct pcidev
 	sq_ptr 			dd ?
 	cq_ptr 			dd ?
 	dstrd 	        dd ?
+	pc 	            db ?
+				    rb 3 ; align
 ends
 TOTAL_PCIDEVS = 4
 TOTAL_PCIDEVS_MALLOC_SZ = TOTAL_PCIDEVS * sizeof.pcidev