[PATCH v2 04/12] scsi: mpt3sas: Make MPI2_CONFIG_PAGE_SASIOUNIT_0::PhyData[] a flexible array

From: James Seo
Date: Sun Aug 06 2023 - 13:08:31 EST


This terminal 1-length variable array can be directly converted into
a C99 flexible array member.

As all users of MPI2_CONFIG_PAGE_SASIOUNIT_0 (Mpi2SasIOUnitPage0_t)
either calculate its size without depending on its sizeof() or do not
use PhyData[], no further source changes are required:

- mpt3sas_config.c:mpt3sas_config_get_number_hba_phys() fetches a
Mpi2SasIOUnitPage0_t for itself, but does not use PhyData[].

- mpt3sas_config.c:mpt3sas_config_get_sas_iounit_pg0() fetches a
Mpi2SasIOUnitPage0_t into a caller-provided buffer, and may fetch
and write PhyData[] into that buffer depending on its sz argument.
Its callers:

- mpt3sas_scsih.c:_scsih_update_vphys_after_reset(),
mpt3sas_scsih.c:_scsih_get_port_table_after_reset(),
mpt3sas_scsih.c:_scsih_sas_host_refresh(),
mpt3sas_scsih.c:_scsih_sas_host_add(), and
mpt3sas_transport.c:_transport_phy_enable() all calculate sz
independently of sizeof(Mpi2SasIOUnitPage0_t) and allocate a
suitable buffer before calling mpt3sas_config_get_sas_iounit_pg0()
and using PhyData[].

Signed-off-by: James Seo <james@xxxxxxxxxx>
---
drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h b/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h
index 55abfc00301e..07a8d7646b6d 100644
--- a/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h
+++ b/drivers/scsi/mpt3sas/mpi/mpi2_cnfg.h
@@ -2178,12 +2178,9 @@ typedef struct _MPI2_SAS_IO_UNIT0_PHY_DATA {
*pMpi2SasIOUnit0PhyData_t;

/*
- *Host code (drivers, BIOS, utilities, etc.) should leave this define set to
- *one and check the value returned for NumPhys at runtime.
+ *Host code (drivers, BIOS, utilities, etc.) should check the value returned
+ *for NumPhys at runtime before using PhyData[].
*/
-#ifndef MPI2_SAS_IOUNIT0_PHY_MAX
-#define MPI2_SAS_IOUNIT0_PHY_MAX (1)
-#endif

typedef struct _MPI2_CONFIG_PAGE_SASIOUNIT_0 {
MPI2_CONFIG_EXTENDED_PAGE_HEADER Header; /*0x00 */
@@ -2191,8 +2188,7 @@ typedef struct _MPI2_CONFIG_PAGE_SASIOUNIT_0 {
U8 NumPhys; /*0x0C */
U8 Reserved2;/*0x0D */
U16 Reserved3;/*0x0E */
- MPI2_SAS_IO_UNIT0_PHY_DATA
- PhyData[MPI2_SAS_IOUNIT0_PHY_MAX]; /*0x10 */
+ MPI2_SAS_IO_UNIT0_PHY_DATA PhyData[];/*0x10 */
} MPI2_CONFIG_PAGE_SASIOUNIT_0,
*PTR_MPI2_CONFIG_PAGE_SASIOUNIT_0,
Mpi2SasIOUnitPage0_t, *pMpi2SasIOUnitPage0_t;
--
2.39.2