[PATCH 3/3] bsps/zynqmp: Add locking around JFFS2 NAND adapter

[Kinsey Moore]

The internal JFFS2 locking does not guarantee that delayed writes will
not step on other reads and writes to the device. This adds locking to
prevent that in the JFFS2 NAND interworking layer.
---
 bsps/aarch64/xilinx-zynqmp/jffs2_xnandpsu.c | 30 ++++++++++++++++++---
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/bsps/aarch64/xilinx-zynqmp/jffs2_xnandpsu.c b/bsps/aarch64/xilinx-zynqmp/jffs2_xnandpsu.c
index a64be91058..5fb00d5eeb 100644
--- a/bsps/aarch64/xilinx-zynqmp/jffs2_xnandpsu.c
+++ b/bsps/aarch64/xilinx-zynqmp/jffs2_xnandpsu.c
@@ -46,11 +46,13 @@
 #include <rtems/libio.h>
 #include <rtems/libcsupport.h>
 #include <rtems/malloc.h>
+#include <rtems/thread.h>
 #include <dev/nand/xnandpsu_bbm.h>
 
 typedef struct {
   rtems_jffs2_flash_control super;
   XNandPsu *nandpsu;
+  rtems_mutex access_lock;
 } flash_control;
 
 static flash_control *get_flash_control(rtems_jffs2_flash_control *super)
@@ -68,7 +70,9 @@ static int flash_read(
   XNandPsu *nandpsu = get_flash_control(super)->nandpsu;
   rtems_status_code sc;
 
+  rtems_mutex_lock(&(get_flash_control(super)->access_lock));
   sc = XNandPsu_Read(nandpsu, offset, size_of_buffer, buffer);
+  rtems_mutex_unlock(&(get_flash_control(super)->access_lock));
   if (sc) {
     return -EIO;
   }
@@ -85,7 +89,9 @@ static int flash_write(
   XNandPsu *nandpsu = get_flash_control(super)->nandpsu;
   rtems_status_code sc;
 
+  rtems_mutex_lock(&(get_flash_control(super)->access_lock));
   sc = XNandPsu_Write(nandpsu, offset, size_of_buffer, (void *)buffer);
+  rtems_mutex_unlock(&(get_flash_control(super)->access_lock));
   if (sc) {
     return -EIO;
   }
@@ -112,7 +118,9 @@ static int flash_erase(
   BlockIndex = (offset % DeviceSize) / BlockSize;
 
   /* Perform erase operation. */
+  rtems_mutex_lock(&(get_flash_control(super)->access_lock));
   sc = XNandPsu_EraseBlock(nandpsu, DeviceIndex, BlockIndex);
+  rtems_mutex_unlock(&(get_flash_control(super)->access_lock));
   if (sc ) {
     return -EIO;
   }
@@ -137,7 +145,9 @@ static int flash_block_is_bad(
 
   BlockIndex = offset / nandpsu->Geometry.BlockSize;
 
+  rtems_mutex_lock(&(get_flash_control(super)->access_lock));
   *bad = (XNandPsu_IsBlockBad(nandpsu, BlockIndex) == XST_SUCCESS);
+  rtems_mutex_unlock(&(get_flash_control(super)->access_lock));
   return 0;
 }
 
@@ -146,6 +156,7 @@ static int flash_block_mark_bad(
   uint32_t offset
 )
 {
+  rtems_status_code sc;
   XNandPsu *nandpsu = get_flash_control(super)->nandpsu;
   uint32_t BlockIndex;
 
@@ -155,7 +166,10 @@ static int flash_block_mark_bad(
 
   BlockIndex = offset / nandpsu->Geometry.BlockSize;
 
-  if ( XNandPsu_MarkBlockBad(nandpsu, BlockIndex) != XST_SUCCESS ) {
+  rtems_mutex_lock(&(get_flash_control(super)->access_lock));
+  sc = XNandPsu_MarkBlockBad(nandpsu, BlockIndex);
+  rtems_mutex_unlock(&(get_flash_control(super)->access_lock));
+  if ( sc != XST_SUCCESS ) {
     return -EIO;
   }
   return RTEMS_SUCCESSFUL;
@@ -189,6 +203,7 @@ static int flash_read_oob(
     return -ENOMEM;
   }
 
+  rtems_mutex_lock(&(get_flash_control(super)->access_lock));
   while (ooblen) {
     int rv = XNandPsu_ReadSpareBytes(nandpsu, PageIndex, spare_bytes);
     /* no guarantee oobbuf can hold all of spare bytes, so read and then copy */
@@ -198,6 +213,7 @@ static int flash_read_oob(
     }
 
     if (rv) {
+      rtems_mutex_unlock(&(get_flash_control(super)->access_lock));
       free(spare_bytes);
       return -EIO;
     }
@@ -208,6 +224,7 @@ static int flash_read_oob(
     ooblen -= readlen;
     oobbuf += readlen;
   }
+  rtems_mutex_unlock(&(get_flash_control(super)->access_lock));
   free(spare_bytes);
   return RTEMS_SUCCESSFUL;
 }
@@ -219,6 +236,7 @@ static int flash_write_oob(
   uint32_t ooblen
 )
 {
+  rtems_status_code sc;
   uint8_t *spare_bytes;
   uint8_t *buffer = oobbuf;
   XNandPsu *nandpsu = get_flash_control(super)->nandpsu;
@@ -252,11 +270,14 @@ static int flash_write_oob(
   /* Get page index */
   uint32_t PageIndex = offset / nandpsu->Geometry.BytesPerPage;
 
-  if ( XNandPsu_WriteSpareBytes(nandpsu, PageIndex, buffer) != XST_SUCCESS ) {
-    free(spare_bytes);
+  rtems_mutex_lock(&(get_flash_control(super)->access_lock));
+  sc = XNandPsu_WriteSpareBytes(nandpsu, PageIndex, buffer);
+  rtems_mutex_unlock(&(get_flash_control(super)->access_lock));
+  free(spare_bytes);
+
+  if ( sc != XST_SUCCESS ) {
     return -EIO;
   }
-  free(spare_bytes);
   return RTEMS_SUCCESSFUL;
 }
 
@@ -307,6 +328,7 @@ int xilinx_zynqmp_nand_jffs2_initialize(
 
   flash_instance.super.write_size = NandInstPtr->Geometry.BytesPerPage;
   flash_instance.nandpsu = NandInstPtr;
+  rtems_mutex_init(&flash_instance.access_lock, "XNandPsu JFFS2 adapter lock");
   mount_data.flash_control = &flash_instance.super;
   mount_data.compressor_control = &compressor_instance;
 
-- 
2.39.2