fix: PRP list allocation

drivers/nvme/nvme.asm

@@ -454,29 +454,19 @@ proc get_log_page stdcall, pci:dword, prp1:dword, lid:byte
 
 endp
 
-proc build_prp_list stdcall, nprps:dword, buf_physical:dword, prp_list_ptr:dword
+proc build_prp_list stdcall, nprps:dword, buf:dword, prp_list_ptr:dword
 
 	push 	esi ebx edi
-	sub 	esp, 16
+	sub 	esp, 4
 
+	; stack:
+	; 	[esp]: virtual pointer to first PRP list
 	; here, we store the pointer to the very first
 	; PRP list so that free_prp_list can free the
 	; entire PRP list if something goes wrong, it
 	; also serves as our return value placeholder
 	mov 	dword [esp], 0
 
-	; store the number of PRPs here, we need to 
-	; cache the result here since we'll subtract
-	; nprps regularly. If we don't we will lose
-	; the value.
-	mov 	eax, [nprps]
-	mov 	dword [esp + 4], eax
-
-	; store consecutive PRP list buffer here, since
-	; we'll increment the PRP list pointer continuously
-	; its important to cache the value
-	mov 	dword [esp + 12], 0
-
 	xor 	edi, edi
 	xor 	esi, esi
 	mov 	ecx, [nprps]
@@ -484,16 +474,20 @@ proc build_prp_list stdcall, nprps:dword, buf_physical:dword, prp_list_ptr:dword
 
 	; we'll store consecutive PRP list buffers here, for example
 	; given 2 PRP lists, we allocate 2 continuous pages
+	push 	ecx
 	invoke  KernelAlloc, ecx ; store pointers to the PRP entries here
+	pop 	ecx
 	test 	eax, eax
 	jz 	.err
-	mov 	dword [esp + 12], eax
+	mov 	dword [esp], eax
 	mov 	edi, eax
 	mov 	eax, [prp_list_ptr]
 	mov 	dword [eax], edi
+	shr 	ecx, 1
+	stdcall memsetdz, edi, ecx
 	
-	; note we assume buf_physical is page-aligned
-	mov 	esi, [buf_physical]
+	; note we assume buf is page-aligned
+	mov 	esi, [buf]
 
 .build_prp_list:
 	; ensure we don't cross a page boundary
@@ -505,40 +499,41 @@ proc build_prp_list stdcall, nprps:dword, buf_physical:dword, prp_list_ptr:dword
 
 @@:
 	xor 	ecx, ecx
-	cmp 	dword [esp], 0
-	jz 	@f
+	cmp 	dword [esp], edi
+	je 	.loop
 
-	; we need to store the pointer of the newly allocated 
-	; PRP list to the previous PRP list last slot
-	mov 	eax, dword [esp + 8]
-	mov 	dword [eax + PAGE_SIZE - 8], esi
-	mov 	dword [eax + PAGE_SIZE - 4], 0
-	jmp 	.loop
-
-@@:
-	mov 	dword [esp], esi
+	; we need to store the pointer of the next
+	; PRP list to the previous PRP list last entry
+	mov 	eax, edi
+	invoke  GetPhysAddr
+	mov 	dword [edi - 8], eax
+	mov 	dword [edi - 4], 0
 
 .loop:
-	mov 	dword [edi + ecx * 4], esi
+	mov 	eax, esi
+	invoke  GetPhysAddr
+	mov 	dword [edi + ecx * 4], eax
 	mov 	dword [edi + ecx * 4 + 4], 0
-	DEBUGF  DBG_INFO, "PRP: %x\n", esi
+	DEBUGF  DBG_INFO, "PRP: %x\n", eax
 	add 	esi, PAGE_SIZE
 	inc 	ecx
 	cmp 	ecx, ebx
 	jne 	.loop
+
 	; check if we we need to build another PRP list
-	mov 	dword [esp + 8], edi
 	add 	edi, PAGE_SIZE
 	cmp 	ebx, PAGE_SIZE / 8
 	je 	.build_prp_list
+
+	; PRP list successfully created
 	mov 	eax, dword [esp]
 	invoke  GetPhysAddr
-	add 	esp, 16
+	add 	esp, 4
 	pop 	edi ebx esi
 	ret
 
 .err:
-	add 	esp, 16
+	add 	esp, 4
 	pop 	edi ebx esi
 	xor 	eax, eax
 	ret
@@ -607,12 +602,9 @@ proc alloc_dptr stdcall, ns:dword, prps_ptr:dword, numsectors:dword, prp_list_pt
 	inc 	eax
 
 @@:
-	mov 	edx, dword [buf]
-	and 	edx, not (PAGE_SIZE - 1)
-	add 	edx, PAGE_SIZE
-	xchg 	eax, edx
-	; push edx?
-	invoke  GetPhysAddr
+	mov 	eax, [buf]
+	and 	eax, not (PAGE_SIZE - 1)
+	add 	eax, PAGE_SIZE
 	stdcall build_prp_list, edx, eax, [prp_list_ptr]
 	test 	eax, eax
 	jz 	.err
@@ -1092,11 +1084,12 @@ proc nvme_init stdcall, pci:dword
 		test 	eax, eax
 		jz 	.exit_fail
 		mov 	edx, NVM_CMD_READ
-		mov 	dword [eax], 1
-		add 	edi, 4094
+		mov 	dword [eax], 17
+		;add 	edi, 4094
 		stdcall nvme_readwrite, [esi + pcidev.nsinfo], edi, 0, 0, eax
 		test 	eax, eax
 		jz 	.exit_fail
+		add 	edi, PAGE_SIZE
 	        DEBUGF  DBG_INFO, "STRING: %s\n", edi
 	end if
 	DEBUGF  DBG_INFO, "nvme%u: Successfully initialized driver\n", [esi + pcidev.num]