[PATCH V8 4/5] libsas: Align SMP req/resp to dma_get_cache_alignment()

From: Huacai Chen
Date: Tue Oct 17 2017 - 04:06:57 EST


In non-coherent DMA mode, kernel uses cache flushing operations to
maintain I/O coherency, so libsas's SMP request/response should be
aligned to ARCH_DMA_MINALIGN. Otherwise, If a DMA buffer and a kernel
structure share a same cache line, and if the kernel structure has
dirty data, cache_invalidate (no writeback) will cause data corruption.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
---
drivers/scsi/libsas/sas_expander.c | 93 +++++++++++++++++++++++---------------
1 file changed, 57 insertions(+), 36 deletions(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 6b4fd23..124a44b 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -164,17 +164,17 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,

/* ---------- Allocations ---------- */

-static inline void *alloc_smp_req(int size)
+static inline void *alloc_smp_req(int size, int align)
{
- u8 *p = kzalloc(size, GFP_KERNEL);
+ u8 *p = kzalloc(ALIGN(size, align), GFP_KERNEL);
if (p)
p[0] = SMP_REQUEST;
return p;
}

-static inline void *alloc_smp_resp(int size)
+static inline void *alloc_smp_resp(int size, int align)
{
- return kzalloc(size, GFP_KERNEL);
+ return kzalloc(ALIGN(size, align), GFP_KERNEL);
}

static char sas_route_char(struct domain_device *dev, struct ex_phy *phy)
@@ -403,15 +403,17 @@ static int sas_ex_phy_discover_helper(struct domain_device *dev, u8 *disc_req,
int sas_ex_phy_discover(struct domain_device *dev, int single)
{
struct expander_device *ex = &dev->ex_dev;
- int res = 0;
+ int res = 0, align;
u8 *disc_req;
u8 *disc_resp;

- disc_req = alloc_smp_req(DISCOVER_REQ_SIZE);
+ align = dma_get_cache_alignment(&dev->phy->dev);
+
+ disc_req = alloc_smp_req(DISCOVER_REQ_SIZE, align);
if (!disc_req)
return -ENOMEM;

- disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
+ disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE, align);
if (!disc_resp) {
kfree(disc_req);
return -ENOMEM;
@@ -480,14 +482,15 @@ static int sas_ex_general(struct domain_device *dev)
{
u8 *rg_req;
struct smp_resp *rg_resp;
- int res;
- int i;
+ int i, res, align;

- rg_req = alloc_smp_req(RG_REQ_SIZE);
+ align = dma_get_cache_alignment(&dev->phy->dev);
+
+ rg_req = alloc_smp_req(RG_REQ_SIZE, align);
if (!rg_req)
return -ENOMEM;

- rg_resp = alloc_smp_resp(RG_RESP_SIZE);
+ rg_resp = alloc_smp_resp(RG_RESP_SIZE, align);
if (!rg_resp) {
kfree(rg_req);
return -ENOMEM;
@@ -552,13 +555,15 @@ static int sas_ex_manuf_info(struct domain_device *dev)
{
u8 *mi_req;
u8 *mi_resp;
- int res;
+ int res, align;

- mi_req = alloc_smp_req(MI_REQ_SIZE);
+ align = dma_get_cache_alignment(&dev->phy->dev);
+
+ mi_req = alloc_smp_req(MI_REQ_SIZE, align);
if (!mi_req)
return -ENOMEM;

- mi_resp = alloc_smp_resp(MI_RESP_SIZE);
+ mi_resp = alloc_smp_resp(MI_RESP_SIZE, align);
if (!mi_resp) {
kfree(mi_req);
return -ENOMEM;
@@ -593,13 +598,15 @@ int sas_smp_phy_control(struct domain_device *dev, int phy_id,
{
u8 *pc_req;
u8 *pc_resp;
- int res;
+ int res, align;
+
+ align = dma_get_cache_alignment(&dev->phy->dev);

- pc_req = alloc_smp_req(PC_REQ_SIZE);
+ pc_req = alloc_smp_req(PC_REQ_SIZE, align);
if (!pc_req)
return -ENOMEM;

- pc_resp = alloc_smp_resp(PC_RESP_SIZE);
+ pc_resp = alloc_smp_resp(PC_RESP_SIZE, align);
if (!pc_resp) {
kfree(pc_req);
return -ENOMEM;
@@ -664,17 +671,19 @@ static int sas_dev_present_in_domain(struct asd_sas_port *port,
#define RPEL_RESP_SIZE 32
int sas_smp_get_phy_events(struct sas_phy *phy)
{
- int res;
+ int res, align;
u8 *req;
u8 *resp;
struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
struct domain_device *dev = sas_find_dev_by_rphy(rphy);

- req = alloc_smp_req(RPEL_REQ_SIZE);
+ align = dma_get_cache_alignment(&phy->dev);
+
+ req = alloc_smp_req(RPEL_REQ_SIZE, align);
if (!req)
return -ENOMEM;

- resp = alloc_smp_resp(RPEL_RESP_SIZE);
+ resp = alloc_smp_resp(RPEL_RESP_SIZE, align);
if (!resp) {
kfree(req);
return -ENOMEM;
@@ -709,7 +718,8 @@ int sas_get_report_phy_sata(struct domain_device *dev, int phy_id,
struct smp_resp *rps_resp)
{
int res;
- u8 *rps_req = alloc_smp_req(RPS_REQ_SIZE);
+ int align = dma_get_cache_alignment(&dev->phy->dev);
+ u8 *rps_req = alloc_smp_req(RPS_REQ_SIZE, align);
u8 *resp = (u8 *)rps_resp;

if (!rps_req)
@@ -1398,7 +1408,7 @@ static int sas_check_parent_topology(struct domain_device *child)
static int sas_configure_present(struct domain_device *dev, int phy_id,
u8 *sas_addr, int *index, int *present)
{
- int i, res = 0;
+ int i, res = 0, align;
struct expander_device *ex = &dev->ex_dev;
struct ex_phy *phy = &ex->ex_phy[phy_id];
u8 *rri_req;
@@ -1406,12 +1416,13 @@ static int sas_configure_present(struct domain_device *dev, int phy_id,

*present = 0;
*index = 0;
+ align = dma_get_cache_alignment(&dev->phy->dev);

- rri_req = alloc_smp_req(RRI_REQ_SIZE);
+ rri_req = alloc_smp_req(RRI_REQ_SIZE, align);
if (!rri_req)
return -ENOMEM;

- rri_resp = alloc_smp_resp(RRI_RESP_SIZE);
+ rri_resp = alloc_smp_resp(RRI_RESP_SIZE, align);
if (!rri_resp) {
kfree(rri_req);
return -ENOMEM;
@@ -1472,15 +1483,17 @@ static int sas_configure_present(struct domain_device *dev, int phy_id,
static int sas_configure_set(struct domain_device *dev, int phy_id,
u8 *sas_addr, int index, int include)
{
- int res;
+ int res, align;
u8 *cri_req;
u8 *cri_resp;

- cri_req = alloc_smp_req(CRI_REQ_SIZE);
+ align = dma_get_cache_alignment(&dev->phy->dev);
+
+ cri_req = alloc_smp_req(CRI_REQ_SIZE, align);
if (!cri_req)
return -ENOMEM;

- cri_resp = alloc_smp_resp(CRI_RESP_SIZE);
+ cri_resp = alloc_smp_resp(CRI_RESP_SIZE, align);
if (!cri_resp) {
kfree(cri_req);
return -ENOMEM;
@@ -1689,10 +1702,12 @@ int sas_discover_root_expander(struct domain_device *dev)
static int sas_get_phy_discover(struct domain_device *dev,
int phy_id, struct smp_resp *disc_resp)
{
- int res;
+ int res, align;
u8 *disc_req;

- disc_req = alloc_smp_req(DISCOVER_REQ_SIZE);
+ align = dma_get_cache_alignment(&dev->phy->dev);
+
+ disc_req = alloc_smp_req(DISCOVER_REQ_SIZE, align);
if (!disc_req)
return -ENOMEM;

@@ -1715,10 +1730,12 @@ static int sas_get_phy_discover(struct domain_device *dev,
static int sas_get_phy_change_count(struct domain_device *dev,
int phy_id, int *pcc)
{
- int res;
+ int res, align;
struct smp_resp *disc_resp;

- disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
+ align = dma_get_cache_alignment(&dev->phy->dev);
+
+ disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE, align);
if (!disc_resp)
return -ENOMEM;

@@ -1733,11 +1750,13 @@ static int sas_get_phy_change_count(struct domain_device *dev,
static int sas_get_phy_attached_dev(struct domain_device *dev, int phy_id,
u8 *sas_addr, enum sas_device_type *type)
{
- int res;
+ int res, align;
struct smp_resp *disc_resp;
struct discover_resp *dr;

- disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE);
+ align = dma_get_cache_alignment(&dev->phy->dev);
+
+ disc_resp = alloc_smp_resp(DISCOVER_RESP_SIZE, align);
if (!disc_resp)
return -ENOMEM;
dr = &disc_resp->disc;
@@ -1787,15 +1806,17 @@ static int sas_find_bcast_phy(struct domain_device *dev, int *phy_id,

static int sas_get_ex_change_count(struct domain_device *dev, int *ecc)
{
- int res;
+ int res, align;
u8 *rg_req;
struct smp_resp *rg_resp;

- rg_req = alloc_smp_req(RG_REQ_SIZE);
+ align = dma_get_cache_alignment(&dev->phy->dev);
+
+ rg_req = alloc_smp_req(RG_REQ_SIZE, align);
if (!rg_req)
return -ENOMEM;

- rg_resp = alloc_smp_resp(RG_RESP_SIZE);
+ rg_resp = alloc_smp_resp(RG_RESP_SIZE, align);
if (!rg_resp) {
kfree(rg_req);
return -ENOMEM;
--
2.7.0