[PATCH] cxgb4: Dynamically allocate memory in t4_memory_rw() and get_vpd_params()

[PATCH] cxgb4: Dynamically allocate memory in t4_memory_rw() and get_vpd_params()

[Vipul Pandya]

This patch changes memory allocation to reduce stack footprint

Signed-off-by: Jay Hernandez <jay@chelsio.com>
Signed-off-by: Vipul Pandya <vipul@chelsio.com>
---
 drivers/net/ethernet/chelsio/cxgb4/t4_hw.c |   43 +++++++++++++++++++--------
 1 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
index 35b81d8..137a244 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
@@ -408,7 +408,8 @@ static int t4_memory_rw(struct adapter *adap, int mtype, u32 addr, u32 len,
 			__be32 *buf, int dir)
 {
 	u32 pos, start, end, offset, memoffset;
-	int ret;
+	int ret = 0;
+	__be32 *data;
 
 	/*
 	 * Argument sanity checks ...
@@ -416,6 +417,10 @@ static int t4_memory_rw(struct adapter *adap, int mtype, u32 addr, u32 len,
 	if ((addr & 0x3) || (len & 0x3))
 		return -EINVAL;
 
+	data = vmalloc(MEMWIN0_APERTURE/sizeof(__be32));
+	if (!data)
+		return -ENOMEM;
+
 	/*
 	 * Offset into the region of memory which is being accessed
 	 * MEM_EDC0 = 0
@@ -438,7 +443,6 @@ static int t4_memory_rw(struct adapter *adap, int mtype, u32 addr, u32 len,
 	offset = (addr - start)/sizeof(__be32);
 
 	for (pos = start; pos < end; pos += MEMWIN0_APERTURE, offset = 0) {
-		__be32 data[MEMWIN0_APERTURE/sizeof(__be32)];
 
 		/*
 		 * If we're writing, copy the data from the caller's memory
@@ -452,7 +456,7 @@ static int t4_memory_rw(struct adapter *adap, int mtype, u32 addr, u32 len,
 			if (offset || len < MEMWIN0_APERTURE) {
 				ret = t4_mem_win_rw(adap, pos, data, 1);
 				if (ret)
-					return ret;
+					break;
 			}
 			while (offset < (MEMWIN0_APERTURE/sizeof(__be32)) &&
 			       len > 0) {
@@ -466,7 +470,7 @@ static int t4_memory_rw(struct adapter *adap, int mtype, u32 addr, u32 len,
 		 */
 		ret = t4_mem_win_rw(adap, pos, data, dir);
 		if (ret)
-			return ret;
+			break;
 
 		/*
 		 * If we're reading, copy the data into the caller's memory
@@ -480,7 +484,8 @@ static int t4_memory_rw(struct adapter *adap, int mtype, u32 addr, u32 len,
 			}
 	}
 
-	return 0;
+	vfree(data);
+	return ret;
 }
 
 int t4_memory_write(struct adapter *adap, int mtype, u32 addr, u32 len,
@@ -519,16 +524,21 @@ int get_vpd_params(struct adapter *adapter, struct vpd_params *p)
 	u32 cclk_param, cclk_val;
 	int i, ret;
 	int ec, sn;
-	u8 vpd[VPD_LEN], csum;
+	u8 *vpd, csum;
 	unsigned int vpdr_len, kw_offset, id_len;
 
-	ret = pci_read_vpd(adapter->pdev, VPD_BASE, sizeof(vpd), vpd);
+	vpd = vmalloc(VPD_LEN);
+	if (!vpd)
+		return -ENOMEM;
+
+	ret = pci_read_vpd(adapter->pdev, VPD_BASE, VPD_LEN, vpd);
 	if (ret < 0)
-		return ret;
+		goto out;
 
 	if (vpd[0] != PCI_VPD_LRDT_ID_STRING) {
 		dev_err(adapter->pdev_dev, "missing VPD ID string\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	id_len = pci_vpd_lrdt_size(vpd);
@@ -538,21 +548,24 @@ int get_vpd_params(struct adapter *adapter, struct vpd_params *p)
 	i = pci_vpd_find_tag(vpd, 0, VPD_LEN, PCI_VPD_LRDT_RO_DATA);
 	if (i < 0) {
 		dev_err(adapter->pdev_dev, "missing VPD-R section\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	vpdr_len = pci_vpd_lrdt_size(&vpd[i]);
 	kw_offset = i + PCI_VPD_LRDT_TAG_SIZE;
 	if (vpdr_len + kw_offset > VPD_LEN) {
 		dev_err(adapter->pdev_dev, "bad VPD-R length %u\n", vpdr_len);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 #define FIND_VPD_KW(var, name) do { \
 	var = pci_vpd_find_info_keyword(vpd, kw_offset, vpdr_len, name); \
 	if (var < 0) { \
 		dev_err(adapter->pdev_dev, "missing VPD keyword " name "\n"); \
-		return -EINVAL; \
+		ret = -EINVAL; \
+		goto out; \
 	} \
 	var += PCI_VPD_INFO_FLD_HDR_SIZE; \
 } while (0)
@@ -564,7 +577,8 @@ int get_vpd_params(struct adapter *adapter, struct vpd_params *p)
 	if (csum) {
 		dev_err(adapter->pdev_dev,
 			"corrupted VPD EEPROM, actual csum %u\n", csum);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	FIND_VPD_KW(ec, "EC");
@@ -587,6 +601,9 @@ int get_vpd_params(struct adapter *adapter, struct vpd_params *p)
 		      FW_PARAMS_PARAM_X(FW_PARAMS_PARAM_DEV_CCLK));
 	ret = t4_query_params(adapter, adapter->mbox, 0, 0,
 			      1, &cclk_param, &cclk_val);
+
+out:
+	vfree(vpd);
 	if (ret)
 		return ret;
 	p->cclk = cclk_val;
-- 
1.7.1

Re: [PATCH] cxgb4: Dynamically allocate memory in t4_memory_rw() and get_vpd_params()

[David Miller]

From: Vipul Pandya <vipul@chelsio.com>
Date: Wed,  3 Oct 2012 18:52:32 +0530

> This patch changes memory allocation to reduce stack footprint
> 
> Signed-off-by: Jay Hernandez <jay@chelsio.com>
> Signed-off-by: Vipul Pandya <vipul@chelsio.com>

Applied.