Make storage alignement use cache alignement macros

Introduce STORAGE_ALIGN_DOWN, STORAGE_PAD (using new CACHE_PAD) and
STORAGE_OVERLAP (using new CACHE_OVERLAP), make them useful only when
PROC_NEEDS_CACHEALIGN and STORAGE_NEEDS_ALIGN are defined

Modify PP and nano2g system-target.h accordingly

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25336 a1c6a512-1295-4272-9138-f99709370657

apps/buffering.c

@@ -755,8 +755,7 @@ static void reset_handle(int handle_id)
         return;
 
     /* Align to desired storage alignment */
-    alignment_pad = (h->offset - (size_t)(&buffer[h->start]))
-                    & STORAGE_ALIGN_MASK;
+    alignment_pad = STORAGE_OVERLAP(h->offset - (size_t)(&buffer[h->start]));
     h->ridx = h->widx = h->data = ringbuf_add(h->start, alignment_pad);
 
     if (h == cur_handle)
@@ -1022,8 +1021,8 @@ int bufopen(const char *file, size_t offset, enum data_type type,
         adjusted_offset = 0;
 
     /* Reserve extra space because alignment can move data forward */
-    struct memory_handle *h = add_handle(size-adjusted_offset+STORAGE_ALIGN_MASK,
-                                         can_wrap, false);
+    size_t padded_size = STORAGE_PAD(size-adjusted_offset);
+    struct memory_handle *h = add_handle(padded_size, can_wrap, false);
     if (!h)
     {
         DEBUGF("%s(): failed to add handle\n", __func__);
@@ -1045,8 +1044,7 @@ int bufopen(const char *file, size_t offset, enum data_type type,
         h->start = buf_widx;
 
         /* Align to desired storage alignment */
-        alignment_pad = (adjusted_offset - (size_t)(&buffer[buf_widx]))
-                        & STORAGE_ALIGN_MASK;
+        alignment_pad = STORAGE_OVERLAP(adjusted_offset - (size_t)(&buffer[buf_widx]));
         buf_widx = ringbuf_add(buf_widx, alignment_pad);
     }
 
@@ -1582,7 +1580,7 @@ bool buffering_reset(char *buf, size_t buflen)
 
     buffer = buf;
     /* Preserve alignment when wrapping around */
-    buffer_len = buflen & ~STORAGE_ALIGN_MASK;
+    buffer_len = STORAGE_ALIGN_DOWN(buflen);
     guard_buffer = buf + buflen;
 
     buf_widx = 0;

firmware/export/config.h

@@ -914,23 +914,6 @@ Lyre prototype 1 */
 
 #endif /* HAVE_USBSTACK */
 
-/* Storage alignment: the mask specifies a mask of bits which should be
- * clear in addresses used for storage_{read,write}_sectors(). This is
- * only relevant for buffers that will contain one or more whole sectors.
- */ 
-
-/* PP502x DMA requires an alignment of at least 16 bytes */
-#ifdef HAVE_ATA_DMA
-#ifdef  CPU_PP502x
-#define STORAGE_ALIGN_MASK 15
-#endif
-#endif /* HAVE_ATA_DMA */
-
-/* by default no alignment is required */
-#ifndef STORAGE_ALIGN_MASK
-#define STORAGE_ALIGN_MASK 0
-#endif
-
 /* This attribute can be used to enable to detection of plugin file handles leaks.
  * When enabled, the plugin core will monitor open/close/creat and when the plugin exits
  * will display an error message if the plugin leaked some file handles */

firmware/export/config/ipodnano2g.h

@@ -219,6 +219,5 @@
 //#define IPOD_ACCESSORY_PROTOCOL
 //#define HAVE_SERIAL
 
-#define STORAGE_ALIGN_MASK 15
 #define USB_WRITE_BUFFER_SIZE (1024*64)
 

firmware/export/system.h

@@ -312,6 +312,16 @@ static inline void cpucache_flush(void)
 /* Aligns a buffer pointer and size to proper boundaries */
 #define CACHEALIGN_BUFFER(start, size) \
     ALIGN_BUFFER((start), (size), CACHEALIGN_SIZE)
+/* Pad a size so the buffer can be aligned later */
+#define CACHE_PAD(x) ((x) + CACHEALIGN_SIZE - 1)
+/* Number of bytes in the last cacheline assuming buffer of size x is aligned */
+#define CACHE_OVERLAP(x) (x & (CACHEALIGN_SIZE - 1))
+
+#ifdef NEEDS_STORAGE_ALIGN
+#define STORAGE_ALIGN_DOWN(x) CACHEALIGN_DOWN(x)
+#define STORAGE_PAD(x) CACHE_PAD(x)
+#define STORAGE_OVERLAP(x) CACHE_OVERLAP(x)
+#endif
 
 #else /* ndef PROC_NEEDS_CACHEALIGN */
 
@@ -323,9 +333,17 @@ static inline void cpucache_flush(void)
 #define CACHEALIGN_DOWN(x) (x)
 /* Make no adjustments */
 #define CACHEALIGN_BUFFER(start, size)
+#define CACHE_PAD(x) (x)
+#define CACHE_OVERLAP(x) 0
 
 #endif /* PROC_NEEDS_CACHEALIGN */
 
+#if !defined(PROC_NEEDS_CACHEALIGN) || !defined(NEEDS_STORAGE_ALIGN)
+#define STORAGE_ALIGN_DOWN(x) (x)
+#define STORAGE_PAD(x) (x)
+#define STORAGE_OVERLAP(x) 0
+#endif
+
 /* Double-cast to avoid 'dereferencing type-punned pointer will
  * break strict aliasing rules' B.S. */
 #define PUN_PTR(type, p) ((type)(intptr_t)(p))

firmware/target/arm/s5l8700/system-target.h

@@ -29,6 +29,11 @@
 #define CPUFREQ_NORMAL  47923200
 #define CPUFREQ_MAX    191692800
 
+/* DMA engine needs aligned addresses */
+#define PROC_NEEDS_CACHEALIGN
+#define CACHEALIGN_BITS (4) /* 2^4 = 16 bytes */
+#define NEEDS_STORAGE_ALIGN
+
 #define inl(a) (*(volatile unsigned long *) (a))
 #define outl(a,b) (*(volatile unsigned long *) (b) = (a))
 #define inb(a) (*(volatile unsigned char *) (a))

firmware/target/arm/system-target.h

@@ -22,6 +22,7 @@
 #ifndef SYSTEM_TARGET_H
 #define SYSTEM_TARGET_H
 
+#include "config.h"
 #include "system-arm.h"
 
 #ifdef CPU_PP
@@ -162,6 +163,10 @@ static inline void wake_core(int core)
 #define PROC_NEEDS_CACHEALIGN
 #define CACHEALIGN_BITS (4) /* 2^4 = 16 bytes */
 
+#if defined(CPU_PP502x) && defined(HAVE_ATA_DMA)
+#define NEEDS_STORAGE_ALIGN
+#endif
+
 /** cache functions **/
 #ifndef BOOTLOADER
 #define HAVE_CPUCACHE_INVALIDATE