libflash/ipmi-hiomap: Fix blocks count issue

[ Upstream commit 7f29116 ]

We convert data size to block count and pass block count to BMC.
If data size is not block aligned then we endup sending block count
less than actual data. BMC will write partial data to flash memory.

Sample log :
[  594.388458416,7] HIOMAP: Marked flash dirty at 0x42010 for 8
[  594.398756487,7] HIOMAP: Flushed writes
[  594.409596439,7] HIOMAP: Marked flash dirty at 0x42018 for 3970
[  594.419897507,7] HIOMAP: Flushed writes

In this case HIOMAP sent data with block count=0 and hence BMC didn't
flush data to flash.

Lets fix this issue by adjusting block count before sending it to BMC.

Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: skiboot-stable@lists.ozlabs.org
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>

libflash/ipmi-hiomap.c

@@ -49,6 +49,21 @@ static inline uint16_t bytes_to_blocks(struct ipmi_hiomap *ctx, uint32_t bytes)
 	return bytes >> ctx->block_size_shift;
 }
 
+static inline uint16_t bytes_to_blocks_align_up(struct ipmi_hiomap *ctx,
+						uint32_t pos, uint32_t len)
+{
+	uint32_t block_size = 1 << ctx->block_size_shift;
+	uint32_t delta = pos & (block_size - 1);
+	uint32_t aligned = ALIGN_UP((len + delta), block_size);
+	uint32_t blocks = aligned >> ctx->block_size_shift;
+	/* Our protocol can handle block count < sizeof(u16) */
+	uint32_t mask = ((1 << 16) - 1);
+
+	assert(!(blocks & ~mask));
+
+	return blocks & mask;
+}
+
 /* Call under ctx->lock */
 static int hiomap_protocol_ready(struct ipmi_hiomap *ctx)
 {
@@ -321,7 +336,7 @@ static int hiomap_window_move(struct ipmi_hiomap *ctx, uint8_t command,
 
 	range = (struct hiomap_v2_range *)&req[2];
 	range->offset = cpu_to_le16(bytes_to_blocks(ctx, pos));
-	range->size = cpu_to_le16(bytes_to_blocks(ctx, len));
+	range->size = cpu_to_le16(bytes_to_blocks_align_up(ctx, pos, len));
 
 	msg = ipmi_mkmsg(IPMI_DEFAULT_INTERFACE,
 		         bmc_platform->sw->ipmi_oem_hiomap_cmd,
@@ -384,7 +399,7 @@ static int hiomap_mark_dirty(struct ipmi_hiomap *ctx, uint64_t offset,
 	pos = offset - ctx->current.cur_pos;
 	range = (struct hiomap_v2_range *)&req[2];
 	range->offset = cpu_to_le16(bytes_to_blocks(ctx, pos));
-	range->size = cpu_to_le16(bytes_to_blocks(ctx, size));
+	range->size = cpu_to_le16(bytes_to_blocks_align_up(ctx, pos, size));
 
 	msg = ipmi_mkmsg(IPMI_DEFAULT_INTERFACE,
 		         bmc_platform->sw->ipmi_oem_hiomap_cmd,
@@ -494,7 +509,7 @@ static int hiomap_erase(struct ipmi_hiomap *ctx, uint64_t offset,
 	pos = offset - ctx->current.cur_pos;
 	range = (struct hiomap_v2_range *)&req[2];
 	range->offset = cpu_to_le16(bytes_to_blocks(ctx, pos));
-	range->size = cpu_to_le16(bytes_to_blocks(ctx, size));
+	range->size = cpu_to_le16(bytes_to_blocks_align_up(ctx, pos, size));
 
 	msg = ipmi_mkmsg(IPMI_DEFAULT_INTERFACE,
 		         bmc_platform->sw->ipmi_oem_hiomap_cmd,