[PATCH] ppc/pnv: Add a HIOMAP erase command

["Cédric Le Goater" <clg@kaod.org>]

The OPAL test suite runs a read-erase-write test on the PNOR :

  https://github.com/open-power/op-test/blob/master/testcases/OpTestPNOR.py

which revealed that the IPMI HIOMAP handlers didn't support
HIOMAP_C_ERASE. Implement the sector erase command by writing 0xFF in
the PNOR memory region.

Reported-by: Klaus Heinrich Kiwi <klaus@linux.vnet.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 hw/ppc/pnv_bmc.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/pnv_bmc.c b/hw/ppc/pnv_bmc.c
index 2e1a03daa45a..0fb082fcb8ee 100644
--- a/hw/ppc/pnv_bmc.c
+++ b/hw/ppc/pnv_bmc.c
@@ -140,6 +140,29 @@ static uint16_t bytes_to_blocks(uint32_t bytes)
     return bytes >> BLOCK_SHIFT;
 }
 
+static uint32_t blocks_to_bytes(uint16_t blocks)
+{
+    return blocks << BLOCK_SHIFT;
+}
+
+#define IPMI_ERR_UNSPECIFIED            0xff
+
+static int hiomap_erase(PnvPnor *pnor, uint32_t offset, uint32_t size)
+{
+    MemTxResult result;
+    int i;
+
+    for (i = 0; i < size / 4; i++) {
+        result = memory_region_dispatch_write(&pnor->mmio, offset + i * 4,
+                                              0xFFFFFFFF, MO_32,
+                                              MEMTXATTRS_UNSPECIFIED);
+        if (result != MEMTX_OK) {
+            return -1;
+        }
+    }
+    return 0;
+}
+
 static void hiomap_cmd(IPMIBmcSim *ibs, uint8_t *cmd, unsigned int cmd_len,
                        RspBuffer *rsp)
 {
@@ -155,10 +178,16 @@ static void hiomap_cmd(IPMIBmcSim *ibs, uint8_t *cmd, unsigned int cmd_len,
     switch (cmd[2]) {
     case HIOMAP_C_MARK_DIRTY:
     case HIOMAP_C_FLUSH:
-    case HIOMAP_C_ERASE:
     case HIOMAP_C_ACK:
         break;
 
+    case HIOMAP_C_ERASE:
+        if (hiomap_erase(pnor, blocks_to_bytes(cmd[5] << 8 | cmd[4]),
+                        blocks_to_bytes(cmd[7] << 8 | cmd[6]))) {
+            rsp_buffer_set_error(rsp, IPMI_ERR_UNSPECIFIED);
+        }
+        break;
+
     case HIOMAP_C_GET_INFO:
         rsp_buffer_push(rsp, 2);  /* Version 2 */
         rsp_buffer_push(rsp, BLOCK_SHIFT); /* block size */
-- 
2.25.4