;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;                                                                 ;;
;; Copyright (C) KolibriOS team 2004-2024. All rights reserved.    ;;
;; Distributed under terms of the GNU General Public License       ;;
;;                                                                 ;;
;;          GNU GENERAL PUBLIC LICENSE                             ;;
;;             Version 2, June 1991                                ;;
;;                                                                 ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

format PE DLL native
entry START

API_VERSION     equ 0  ;debug
SRV_GETVERSION  equ 0
__DEBUG__ = 1
__DEBUG_LEVEL__ = 1
DRIVER_VERSION = 1
DBG_INFO = 1

section ".flat" code readable writable executable
include "../proc32.inc"
include "../struct.inc"
include "../macros.inc"
include "../fdo.inc"
include "../pci.inc"
include "../peimport.inc"
include "nvme.inc"

proc START c, reason:dword

        cmp     [reason], DRV_ENTRY
        jne     .err

.entry:
		DEBUGF  DBG_INFO, "Detecting NVMe hardware...\n"
        call    detect_nvme
		mov 	eax, dword [p_nvme_devices]
		test 	eax, eax
        jz      .err ; no NVMe device found?

		mov 	eax, dword [eax]
		stdcall nvme_init, dword [eax + pcidev.bus], dword [eax + pcidev.devfn]
		test    eax, eax
		jz      .err ; failed to initialize controller?

        invoke  RegService, my_service, service_proc
        ret

.err:
		DEBUGF  DBG_INFO, "(NVMe) Cleaning up...\n"
		call    nvme_cleanup
        xor     eax, eax
        ret

endp

proc service_proc stdcall, ioctl:dword

        mov     ebx, [ioctl]
        mov     eax, [ebx+IOCTL.io_code]
        cmp     eax, SRV_GETVERSION
        jne     @F

        mov     eax, [ebx+IOCTL.output]
        cmp     [ebx+IOCTL.out_size], 4
        jne     @F
        mov     dword [eax], API_VERSION
        xor     eax, eax
        ret
@@:
        or      eax, -1
        ret

endp

proc memset stdcall, p_data:dword, val:byte, sz:dword

		mov     bh, byte [val]
		xor     ecx, ecx 
@@:
		mov     byte [p_data + ecx], bh
		inc     ecx
		cmp     ecx, dword [sz]
		jne     @b
		xor     eax, eax
		ret

endp

; Submit a Command in the Admin Submission Queue
proc submit_asq stdcall, p_sq:dword

		xor 	eax, eax
		ret

endp

proc nvme_identify stdcall, nsid:dword, dptr:dword, cns:byte

		sub     esp, sizeof.SQ_ENTRY
		stdcall memset, esp, 0, sizeof.SQ_ENTRY

		mov     eax, dword [nsid]
		mov     dword [esp + SQ_ENTRY.nsid], eax
		mov     eax, dword [dptr]
		mov     dword [esp + SQ_ENTRY.dptr], eax
		mov     dword [esp + SQ_ENTRY.cdw0], ADM_CMD_IDENTIFY ; TODO: setting CID to 0 for now but later on keep a unique list of identifiers
		mov     ah, byte [cns]
		mov     byte [esp + SQ_ENTRY.cdw10], ah
		stdcall submit_asq, esp

		add     esp, sizeof.SQ_ENTRY
		xor     eax, eax
		ret

endp

proc detect_nvme

        invoke  GetPCIList
		mov 	edx, eax

.check_dev:
		mov 	ebx, dword [eax + PCIDEV.class]
		and		ebx, 0x00ffff00 ; retrieve class/subclass code only
		cmp 	ebx, 0x00010800 ; Mass Storage Controller - Non-Volatile Memory Controller
		je		.found_dev

.next_dev:
		mov		eax, dword [eax + PCIDEV.fd]
		cmp		eax, edx
		jne 	.check_dev
		ret

.found_dev:
		if __DEBUG__
			movzx   ebx, byte [eax + PCIDEV.devfn]
			shr     ebx, 3 ; get rid of 3 lowest bits (function code), the rest bits is device code
			movzx   ecx, byte [eax + PCIDEV.devfn]
			and     ecx, 00000111b ; get only 3 lowest bits (function code)
			DEBUGF  DBG_INFO, "PCI(%u.%u.%u): Detected NVMe device...\n", [eax + PCIDEV.bus], ebx, ecx
		end if
		push    eax
		mov     eax, dword [pcidevs_len] 	
		cmp 	eax, MAX_NVM_PCIDEVS
		jne 	@f
		pop 	eax
		ret

@@:
		mov     ebx, dword [p_nvme_devices]
		test    ebx, ebx
		jnz		@f
		invoke  KernelAlloc, MAX_NVM_PCIDEVS_BYTES
		test 	eax, eax
		jz 		.err
		mov     dword [ebx], eax 

@@:
		mov 	ecx, dword [pcidevs_len]
		inc 	ecx
		mov 	dword [pcidevs_len], ecx
		invoke  KernelAlloc, sizeof.pcidev
		test 	eax, eax
		jz 		.err

		mov 	dword [p_nvme_devices + ecx * 4], eax
		mov 	ebx, eax
		pop		eax
		mov 	ecx, dword [eax + PCIDEV.bus]
		mov 	dword [ebx + pcidev.bus], ecx
		mov 	ecx, dword [eax + PCIDEV.devfn]
		mov 	dword [ebx + pcidev.devfn], ecx
		jmp		.check_dev

.err:
		DEBUGF DBG_INFO, "error initializing NVMe driver: unable to allocate memory\n"
		pop    eax
		ret

endp

proc device_is_compat, bus:dword, devfn:dword

		invoke   PciRead32, [bus], [devfn], PCI_header00.base_addr_0
		and      eax, 0xfffffff0
		test     eax, eax
		jz       .exit_fail

		invoke   MapIoMem, eax, sizeof.NVME_REG_MAP, PG_SW+PG_NOCACHE
		test     eax, eax
		jz       .exit_fail
		mov      [p_mmap], eax

.exit_fail:
		DEBUGF DBG_INFO, "(NVMe) Device is incompatible\n"
	
endp

; nvme_init: Initializes the NVMe controller 
proc nvme_init, bus:dword, devfn:dword

		test     eax, eax
		jz       .exit_fail
		mov      eax, dword [p_mmap]
		mov      ebx, dword [eax + NVME_REG_MAP.CAP]
		DEBUGF   DBG_INFO, "(NVMe) Maximum queue entries supported: %u\n", bx
		test     ebx, CAP_CQR
		jz       .cqr_not_req
		DEBUGF   DBG_INFO, "(NVMe) Contiguous queues required\n"

.cqr_not_req:
		mov      ebx, dword [eax + NVME_REG_MAP.CAP + 4]
		mov      ecx, ebx
		test     ebx, CAP_CSS_NVM_CMDSET
		jz       .exit_fail

		if __DEBUG__
			and      ebx, CAP_MPSMIN
			and      ecx, CAP_MPSMAX
			shr      ebx, 16
			shr      ecx, 16
			DEBUGF   DBG_INFO, "(NVMe) Memory page size minimum: %u\n", ebx
			DEBUGF   DBG_INFO, "(NVMe) Memory page size maximum: %u\n", ecx

			mov      ebx, dword [eax + NVME_REG_MAP.CC]
			mov      ecx, ebx
			and      ebx, CC_IOSQES
			and      ecx, CC_IOCQES
			shl      ebx, 16
			shl      ecx, 16

			; TODO: Change entry sizes to their appropriate values
			DEBUGF   DBG_INFO, "(NVMe) I/O Submission Queue entry Size: %u\n", ebx
			DEBUGF   DBG_INFO, "(NVMe) I/O completion queue entry size: %u\n", ecx
		end if

        xor     eax, eax
        inc     eax
        ret

.exit_fail:
		DEBUGF  DBG_INFO, "ERROR: failed to initialize NVMe controller\n"
		xor 	eax, eax
		ret

endp

proc nvme_cleanup

		xor 	ecx, ecx
		mov 	eax, dword [p_nvme_devices]
		test 	eax, eax
		jz 		.last

@@:
		mov 	ebx, dword [eax + ecx * 4]
		invoke  KernelFree, ebx
		inc 	ecx
		cmp 	ecx, dword [pcidevs_len]
		jl	 	@b
		mov 	eax, dword [p_ident]
		test 	eax, eax
		jz 		.last
		invoke  KernelFree, eax

.last:
		ret

endp

; uninitialized data
align 4
		p_mmap              dd ?
		p_ident             dd ?

;all initialized data place here
align 4
		p_nvme_devices dd 0
		pcidevs_len  dd 0
		my_service   db "NVMe",0  ;max 16 chars include zero
		include_debug_strings

align 4
data fixups
end data