From de94fe74ac65d2dc46764642b9b5247affcde6c9 Mon Sep 17 00:00:00 2001
From: CleverMouse <theclevermouse@yandex.ru>
Date: Mon, 14 Jan 2013 09:24:25 +0000
Subject: [PATCH] make caching for PnP disks really work

git-svn-id: svn://kolibrios.org@3164 a494cfbc-eb01-0410-851d-a64ba20cac60
---
 kernel/trunk/blkdev/disk.inc       |  4 ++--
 kernel/trunk/blkdev/disk_cache.inc | 29 +++++++++++++++++++++++------
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/kernel/trunk/blkdev/disk.inc b/kernel/trunk/blkdev/disk.inc
index 72289d1586..8df1dd3d6f 100644
--- a/kernel/trunk/blkdev/disk.inc
+++ b/kernel/trunk/blkdev/disk.inc
@@ -626,8 +626,8 @@ disk_default_flush:
 
 ; The default implementation of DISKFUNC.adjust_cache_size.
 disk_default_adjust_cache_size:
-        mov     eax, [esp+4]
-        ret     4
+        mov     eax, [esp+8]
+        ret     8
 
 ; This is an internal function called from 'disk_media_changed' when a new media
 ; is detected. It creates the list of partitions for the media.
diff --git a/kernel/trunk/blkdev/disk_cache.inc b/kernel/trunk/blkdev/disk_cache.inc
index 059c32388f..496a6f9e3b 100644
--- a/kernel/trunk/blkdev/disk_cache.inc
+++ b/kernel/trunk/blkdev/disk_cache.inc
@@ -135,7 +135,7 @@ end virtual
         push    esp
         push    edx
         push    [.sector_lo+12]
-        mov     ecx, [.cache]
+        mov     ecx, [.cache+16]
         mov     eax, edi
         shl     eax, 9
         add     eax, [ecx+DISKCACHE.data]
@@ -317,7 +317,7 @@ end virtual
 
 .yes_in_cache_write:
 
-        mov     dword [esi+4], 2        ; write - differs from hd
+        mov     dword [esi+8], 2        ; write - differs from hd
 
         shl     edi, 9
         mov     ecx, [.cache]
@@ -373,11 +373,12 @@ find_empty_slot64:
 ; This function is intended to replace the old 'write_cache' function.
 proc write_cache64 uses ecx edx esi edi, disk:dword
 locals
-cache_chain_started     dd      ?
+cache_chain_started     dd      0
 cache_chain_size        dd      ?
 cache_chain_pos         dd      ?
 cache_chain_ptr         dd      ?
 endl
+saved_esi_pos = 16+12 ; size of local variables + size of registers before esi
 ; If there is no cache for this disk, nothing to do.
         cmp     [esi+DISKCACHE.pointer], 0
         jz      .flush
@@ -465,7 +466,7 @@ endl
 .write_cache_chain:
         pusha
         mov     edi, [cache_chain_pos]
-        mov     ecx, [ebp-12]
+        mov     ecx, [ebp-saved_esi_pos]
         shl     edi, 9
         add     edi, [ecx+DISKCACHE.data]
         mov     ecx, [cache_chain_size]
@@ -549,7 +550,7 @@ disk_init_cache:
 
         mov     eax, [esi+DISK.SysCache.data_size]
         push    ebx
-        call    calculate_for_hd
+        call    calculate_for_hd64
         pop     ebx
         add     eax, [esi+DISK.SysCache.pointer]
         mov     [esi+DISK.SysCache.data], eax
@@ -564,7 +565,7 @@ disk_init_cache:
 
         mov     eax, [esi+DISK.AppCache.data_size]
         push    ebx
-        call    calculate_for_hd
+        call    calculate_for_hd64
         pop     ebx
         add     eax, [esi+DISK.AppCache.pointer]
         mov     [esi+DISK.AppCache.data], eax
@@ -590,6 +591,22 @@ disk_init_cache:
         mov     al, 1
         ret
 
+calculate_for_hd64:
+        push    eax
+        mov     ebx, eax
+        shr     eax, 9
+        lea     eax, [eax*3]
+        shl     eax, 2
+        sub     ebx, eax
+        shr     ebx, 9
+        mov     ecx, ebx
+        shl     ebx, 9
+        pop     eax
+        sub     eax, ebx
+        dec     ecx
+        ret
+
+
 ; This internal function is called from disk_media_dereference to free the
 ; allocated cache, if there is one.
 ; esi = pointer to DISK structure