[PATCH 0/4] drivers/net: replace __get_free_pages() with kmalloc()

[PATCH 0/4] drivers/net: replace __get_free_pages() with kmalloc()

[Mike Rapoport (Microsoft)]

This is a (small) part of larger work of replacing page allocator calls
with kmalloc.

My initial intention a few month ago was to remove ugly casts [1], but then
willy pointed out that Linus objected to something like this [2] and it
looks like more than a decade old technical debt.

Largely, anything that doesn't need struct page (or a memdesc in the
future) should just use kmalloc() or kvmalloc() to allocate memory.
kmalloc() guarantees alignment, physical contiguity and working
virt_to_phys() and beside nicer API that returns void * on alloc and
doesn't require to know the allocation size on free, kmalloc() provides
better debugging capabilities than page allocator.

Another thing is that touching these allocation sites gives the reviewers
opportunity to see if a PAGE_SIZE buffer is actually needed or maybe
another size is appropriate.

For larger allocations that don't need physically contiguous memory
kvmalloc() can be a better option that __get_free_pages() because under
memory pressure it's is easier to allocate several order-0 pages than a
physically contiguous chunk with the same number of pages.

And last, but not least, removing needless calls to page allocator should
help with memdesc (aka project folio) conversion. There will be way less
places to audit to see if the user was actually using struct page.

Also in git:
https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git gfp-to-kmalloc/drivers-net-wireless

[1] https://lore.kernel.org/all/20251018093002.3660549-1-rppt@kernel.org/
[2] https://lore.kernel.org/all/CA+55aFwp4iy4rtX2gE2WjBGFL=NxMVnoFeHqYa2j1dYOMMGqxg@mail.gmail.com/

---
Changes in v2:
- split out wireless drivers from a larger set 
- use kzalloc() instead of kmalloc() + memset in b43legacy

v1: https://patch.msgid.link/20260630-b4-drivers-net-v1-0-672162a91f37@kernel.org

---
Mike Rapoport (Microsoft) (4):
      b43, b43legacy: debugfs: use kzalloc() to allocate formatting buffers
      libertas: debugfs: use kzalloc() to allocate formatting buffers
      mwifiex: debugfs: use kzalloc() to allocate formatting buffers
      wlcore: allocate aggregation and firmware log buffers with kzalloc()

 drivers/net/wireless/broadcom/b43/debugfs.c       | 12 ++---
 drivers/net/wireless/broadcom/b43legacy/debugfs.c | 12 ++---
 drivers/net/wireless/marvell/libertas/debugfs.c   | 39 ++++++--------
 drivers/net/wireless/marvell/mwifiex/debugfs.c    | 62 ++++++++++-------------
 drivers/net/wireless/ti/wlcore/main.c             | 14 +++--
 5 files changed, 59 insertions(+), 80 deletions(-)
---
base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
change-id: 20260630-b4-drivers-wireless-5294524fab46

Best regards,
--  
Sincerely yours,
Mike.

[PATCH 1/4] b43, b43legacy: debugfs: use kzalloc() to allocate formatting buffers

[Mike Rapoport (Microsoft)]

b43* debugfs functions allocate 16 KiB buffers for formatting debug output
text using __get_free_pages().

kzalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object and for 16 Kib
allocation kzalloc() will anyway delegate it to buddy.

Replace use of __get_free_pages() with kzalloc().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 drivers/net/wireless/broadcom/b43/debugfs.c       | 12 +++++-------
 drivers/net/wireless/broadcom/b43legacy/debugfs.c | 12 +++++-------
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/net/wireless/broadcom/b43/debugfs.c b/drivers/net/wireless/broadcom/b43/debugfs.c
index acddae68947a..31a1ff00c1a4 100644
--- a/drivers/net/wireless/broadcom/b43/debugfs.c
+++ b/drivers/net/wireless/broadcom/b43/debugfs.c
@@ -495,7 +495,6 @@ static ssize_t b43_debugfs_read(struct file *file, char __user *userbuf,
 	ssize_t ret;
 	char *buf;
 	const size_t bufsize = 1024 * 16; /* 16 kiB buffer */
-	const size_t buforder = get_order(bufsize);
 	int err = 0;
 
 	if (!count)
@@ -518,15 +517,14 @@ static ssize_t b43_debugfs_read(struct file *file, char __user *userbuf,
 	dfile = fops_to_dfs_file(dev, dfops);
 
 	if (!dfile->buffer) {
-		buf = (char *)__get_free_pages(GFP_KERNEL, buforder);
+		buf = kzalloc(bufsize, GFP_KERNEL);
 		if (!buf) {
 			err = -ENOMEM;
 			goto out_unlock;
 		}
-		memset(buf, 0, bufsize);
 		ret = dfops->read(dev, buf, bufsize);
 		if (ret <= 0) {
-			free_pages((unsigned long)buf, buforder);
+			kfree(buf);
 			err = ret;
 			goto out_unlock;
 		}
@@ -538,7 +536,7 @@ static ssize_t b43_debugfs_read(struct file *file, char __user *userbuf,
 				      dfile->buffer,
 				      dfile->data_len);
 	if (*ppos >= dfile->data_len) {
-		free_pages((unsigned long)dfile->buffer, buforder);
+		kfree(dfile->buffer);
 		dfile->buffer = NULL;
 		dfile->data_len = 0;
 	}
@@ -577,7 +575,7 @@ static ssize_t b43_debugfs_write(struct file *file,
 		goto out_unlock;
 	}
 
-	buf = (char *)get_zeroed_page(GFP_KERNEL);
+	buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf) {
 		err = -ENOMEM;
 		goto out_unlock;
@@ -591,7 +589,7 @@ static ssize_t b43_debugfs_write(struct file *file,
 		goto out_freepage;
 
 out_freepage:
-	free_page((unsigned long)buf);
+	kfree(buf);
 out_unlock:
 	mutex_unlock(&dev->wl->mutex);
 
diff --git a/drivers/net/wireless/broadcom/b43legacy/debugfs.c b/drivers/net/wireless/broadcom/b43legacy/debugfs.c
index 3ad99124d522..a04d90d7307c 100644
--- a/drivers/net/wireless/broadcom/b43legacy/debugfs.c
+++ b/drivers/net/wireless/broadcom/b43legacy/debugfs.c
@@ -192,7 +192,6 @@ static ssize_t b43legacy_debugfs_read(struct file *file, char __user *userbuf,
 	ssize_t ret;
 	char *buf;
 	const size_t bufsize = 1024 * 16; /* 16 KiB buffer */
-	const size_t buforder = get_order(bufsize);
 	int err = 0;
 
 	if (!count)
@@ -215,12 +214,11 @@ static ssize_t b43legacy_debugfs_read(struct file *file, char __user *userbuf,
 	dfile = fops_to_dfs_file(dev, dfops);
 
 	if (!dfile->buffer) {
-		buf = (char *)__get_free_pages(GFP_KERNEL, buforder);
+		buf = kzalloc(bufsize, GFP_KERNEL);
 		if (!buf) {
 			err = -ENOMEM;
 			goto out_unlock;
 		}
-		memset(buf, 0, bufsize);
 		if (dfops->take_irqlock) {
 			spin_lock_irq(&dev->wl->irq_lock);
 			ret = dfops->read(dev, buf, bufsize);
@@ -228,7 +226,7 @@ static ssize_t b43legacy_debugfs_read(struct file *file, char __user *userbuf,
 		} else
 			ret = dfops->read(dev, buf, bufsize);
 		if (ret <= 0) {
-			free_pages((unsigned long)buf, buforder);
+			kfree(buf);
 			err = ret;
 			goto out_unlock;
 		}
@@ -240,7 +238,7 @@ static ssize_t b43legacy_debugfs_read(struct file *file, char __user *userbuf,
 				      dfile->buffer,
 				      dfile->data_len);
 	if (*ppos >= dfile->data_len) {
-		free_pages((unsigned long)dfile->buffer, buforder);
+		kfree(dfile->buffer);
 		dfile->buffer = NULL;
 		dfile->data_len = 0;
 	}
@@ -279,7 +277,7 @@ static ssize_t b43legacy_debugfs_write(struct file *file,
 		goto out_unlock;
 	}
 
-	buf = (char *)get_zeroed_page(GFP_KERNEL);
+	buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf) {
 		err = -ENOMEM;
 		goto out_unlock;
@@ -298,7 +296,7 @@ static ssize_t b43legacy_debugfs_write(struct file *file,
 		goto out_freepage;
 
 out_freepage:
-	free_page((unsigned long)buf);
+	kfree(buf);
 out_unlock:
 	mutex_unlock(&dev->wl->mutex);
 

-- 
2.53.0

[PATCH 2/4] libertas: debugfs: use kzalloc() to allocate formatting buffers

[Mike Rapoport (Microsoft)]

libertas debugfs functions allocate buffers for formatting debug
output text using get_zeroed_page().

These buffers can be allocated with kmalloc() as there's nothing special
about them to go directly to the page allocator.

kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.

Performance difference between kmalloc() and __get_free_pages() is not
measurable as both allocators take an object/page from a per-CPU list for
fast path allocations.

For the slow path the performance is anyway determined by the amount of
reclaim involved rather than by what allocator is used.

Replace use of get_zeroed_page() with kzalloc() and free_page() with
kfree().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 drivers/net/wireless/marvell/libertas/debugfs.c | 39 ++++++++++---------------
 1 file changed, 16 insertions(+), 23 deletions(-)

diff --git a/drivers/net/wireless/marvell/libertas/debugfs.c b/drivers/net/wireless/marvell/libertas/debugfs.c
index 9ebd69134940..9428f954837a 100644
--- a/drivers/net/wireless/marvell/libertas/debugfs.c
+++ b/drivers/net/wireless/marvell/libertas/debugfs.c
@@ -35,8 +35,7 @@ static ssize_t lbs_dev_info(struct file *file, char __user *userbuf,
 {
 	struct lbs_private *priv = file->private_data;
 	size_t pos = 0;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	ssize_t res;
 	if (!buf)
 		return -ENOMEM;
@@ -48,7 +47,7 @@ static ssize_t lbs_dev_info(struct file *file, char __user *userbuf,
 
 	res = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
 
-	free_page(addr);
+	kfree(buf);
 	return res;
 }
 
@@ -96,8 +95,7 @@ static ssize_t lbs_sleepparams_read(struct file *file, char __user *userbuf,
 	ssize_t ret;
 	size_t pos = 0;
 	struct sleep_params sp;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
@@ -113,7 +111,7 @@ static ssize_t lbs_sleepparams_read(struct file *file, char __user *userbuf,
 	ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
 
 out_unlock:
-	free_page(addr);
+	kfree(buf);
 	return ret;
 }
 
@@ -165,8 +163,7 @@ static ssize_t lbs_host_sleep_read(struct file *file, char __user *userbuf,
 	struct lbs_private *priv = file->private_data;
 	ssize_t ret;
 	size_t pos = 0;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
@@ -174,7 +171,7 @@ static ssize_t lbs_host_sleep_read(struct file *file, char __user *userbuf,
 
 	ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
 
-	free_page(addr);
+	kfree(buf);
 	return ret;
 }
 
@@ -228,7 +225,7 @@ static ssize_t lbs_threshold_read(uint16_t tlv_type, uint16_t event_mask,
 	u8 freq;
 	int events = 0;
 
-	buf = (char *)get_zeroed_page(GFP_KERNEL);
+	buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
@@ -261,7 +258,7 @@ static ssize_t lbs_threshold_read(uint16_t tlv_type, uint16_t event_mask,
 	kfree(subscribed);
 
  out_page:
-	free_page((unsigned long)buf);
+	kfree(buf);
 	return ret;
 }
 
@@ -436,8 +433,7 @@ static ssize_t lbs_rdmac_read(struct file *file, char __user *userbuf,
 	struct lbs_private *priv = file->private_data;
 	ssize_t pos = 0;
 	int ret;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	u32 val = 0;
 
 	if (!buf)
@@ -450,7 +446,7 @@ static ssize_t lbs_rdmac_read(struct file *file, char __user *userbuf,
 				priv->mac_offset, val);
 		ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
 	}
-	free_page(addr);
+	kfree(buf);
 	return ret;
 }
 
@@ -506,8 +502,7 @@ static ssize_t lbs_rdbbp_read(struct file *file, char __user *userbuf,
 	struct lbs_private *priv = file->private_data;
 	ssize_t pos = 0;
 	int ret;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	u32 val;
 
 	if (!buf)
@@ -520,7 +515,7 @@ static ssize_t lbs_rdbbp_read(struct file *file, char __user *userbuf,
 				priv->bbp_offset, val);
 		ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
 	}
-	free_page(addr);
+	kfree(buf);
 
 	return ret;
 }
@@ -578,8 +573,7 @@ static ssize_t lbs_rdrf_read(struct file *file, char __user *userbuf,
 	struct lbs_private *priv = file->private_data;
 	ssize_t pos = 0;
 	int ret;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	u32 val;
 
 	if (!buf)
@@ -592,7 +586,7 @@ static ssize_t lbs_rdrf_read(struct file *file, char __user *userbuf,
 				priv->rf_offset, val);
 		ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
 	}
-	free_page(addr);
+	kfree(buf);
 
 	return ret;
 }
@@ -812,8 +806,7 @@ static ssize_t lbs_debugfs_read(struct file *file, char __user *userbuf,
 	char *p;
 	int i;
 	struct debug_data *d;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
@@ -836,7 +829,7 @@ static ssize_t lbs_debugfs_read(struct file *file, char __user *userbuf,
 
 	res = simple_read_from_buffer(userbuf, count, ppos, p, pos);
 
-	free_page(addr);
+	kfree(buf);
 	return res;
 }
 

-- 
2.53.0

[PATCH 3/4] mwifiex: debugfs: use kzalloc() to allocate formatting buffers

[Mike Rapoport (Microsoft)]

mwifiex debugfs functions allocate buffers for formatting debug output
text using get_zeroed_page().

These buffers can be allocated with kmalloc() as there's nothing special
about them to go directly to the page allocator.

kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.

Performance difference between kmalloc() and __get_free_pages() is not
measurable as both allocators take an object/page from a per-CPU list for
fast path allocations.

For the slow path the performance is anyway determined by the amount of
reclaim involved rather than by what allocator is used.

Replace use of get_zeroed_page() with kzalloc() and free_page() with
kfree().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 drivers/net/wireless/marvell/mwifiex/debugfs.c | 62 +++++++++++---------------
 1 file changed, 27 insertions(+), 35 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/debugfs.c b/drivers/net/wireless/marvell/mwifiex/debugfs.c
index 9deaf59dcb62..573768b6ad91 100644
--- a/drivers/net/wireless/marvell/mwifiex/debugfs.c
+++ b/drivers/net/wireless/marvell/mwifiex/debugfs.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/debugfs.h>
+#include <linux/slab.h>
 
 #include "main.h"
 #include "11n.h"
@@ -67,8 +68,8 @@ mwifiex_info_read(struct file *file, char __user *ubuf,
 	struct net_device *netdev = priv->netdev;
 	struct netdev_hw_addr *ha;
 	struct netdev_queue *txq;
-	unsigned long page = get_zeroed_page(GFP_KERNEL);
-	char *p = (char *) page, fmt[64];
+	char *page = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	char *p = page, fmt[64];
 	struct mwifiex_bss_info info;
 	ssize_t ret;
 	int i = 0;
@@ -133,11 +134,10 @@ mwifiex_info_read(struct file *file, char __user *ubuf,
 	}
 	p += sprintf(p, "\n");
 
-	ret = simple_read_from_buffer(ubuf, count, ppos, (char *) page,
-				      (unsigned long) p - page);
+	ret = simple_read_from_buffer(ubuf, count, ppos, page, p - page);
 
 free_and_exit:
-	free_page(page);
+	kfree(page);
 	return ret;
 }
 
@@ -168,8 +168,8 @@ mwifiex_getlog_read(struct file *file, char __user *ubuf,
 {
 	struct mwifiex_private *priv =
 		(struct mwifiex_private *) file->private_data;
-	unsigned long page = get_zeroed_page(GFP_KERNEL);
-	char *p = (char *) page;
+	char *page = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	char *p = page;
 	ssize_t ret;
 	struct mwifiex_ds_get_stats stats;
 
@@ -220,11 +220,10 @@ mwifiex_getlog_read(struct file *file, char __user *ubuf,
 		     stats.bcn_miss_cnt);
 
 
-	ret = simple_read_from_buffer(ubuf, count, ppos, (char *) page,
-				      (unsigned long) p - page);
+	ret = simple_read_from_buffer(ubuf, count, ppos, page, p - page);
 
 free_and_exit:
-	free_page(page);
+	kfree(page);
 	return ret;
 }
 
@@ -247,8 +246,8 @@ mwifiex_histogram_read(struct file *file, char __user *ubuf,
 	ssize_t ret;
 	struct mwifiex_histogram_data *phist_data;
 	int i, value;
-	unsigned long page = get_zeroed_page(GFP_KERNEL);
-	char *p = (char *)page;
+	char *page = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	char *p = page;
 
 	if (!p)
 		return -ENOMEM;
@@ -309,11 +308,10 @@ mwifiex_histogram_read(struct file *file, char __user *ubuf,
 				i, value);
 	}
 
-	ret = simple_read_from_buffer(ubuf, count, ppos, (char *)page,
-				      (unsigned long)p - page);
+	ret = simple_read_from_buffer(ubuf, count, ppos, page, p - page);
 
 free_and_exit:
-	free_page(page);
+	kfree(page);
 	return ret;
 }
 
@@ -383,8 +381,8 @@ mwifiex_debug_read(struct file *file, char __user *ubuf,
 {
 	struct mwifiex_private *priv =
 		(struct mwifiex_private *) file->private_data;
-	unsigned long page = get_zeroed_page(GFP_KERNEL);
-	char *p = (char *) page;
+	char *page = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	char *p = page;
 	ssize_t ret;
 
 	if (!p)
@@ -396,11 +394,10 @@ mwifiex_debug_read(struct file *file, char __user *ubuf,
 
 	p += mwifiex_debug_info_to_buffer(priv, p, &info);
 
-	ret = simple_read_from_buffer(ubuf, count, ppos, (char *) page,
-				      (unsigned long) p - page);
+	ret = simple_read_from_buffer(ubuf, count, ppos, page, p - page);
 
 free_and_exit:
-	free_page(page);
+	kfree(page);
 	return ret;
 }
 
@@ -457,8 +454,7 @@ mwifiex_regrdwr_read(struct file *file, char __user *ubuf,
 {
 	struct mwifiex_private *priv =
 		(struct mwifiex_private *) file->private_data;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *) addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	int pos = 0, ret = 0;
 	u32 reg_value;
 
@@ -497,7 +493,7 @@ mwifiex_regrdwr_read(struct file *file, char __user *ubuf,
 	ret = simple_read_from_buffer(ubuf, count, ppos, buf, pos);
 
 done:
-	free_page(addr);
+	kfree(buf);
 	return ret;
 }
 
@@ -511,8 +507,7 @@ mwifiex_debug_mask_read(struct file *file, char __user *ubuf,
 {
 	struct mwifiex_private *priv =
 		(struct mwifiex_private *)file->private_data;
-	unsigned long page = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)page;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	size_t ret = 0;
 	int pos = 0;
 
@@ -523,7 +518,7 @@ mwifiex_debug_mask_read(struct file *file, char __user *ubuf,
 			priv->adapter->debug_mask);
 	ret = simple_read_from_buffer(ubuf, count, ppos, buf, pos);
 
-	free_page(page);
+	kfree(buf);
 	return ret;
 }
 
@@ -652,8 +647,7 @@ mwifiex_memrw_read(struct file *file, char __user *ubuf,
 		   size_t count, loff_t *ppos)
 {
 	struct mwifiex_private *priv = (void *)file->private_data;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	int ret, pos = 0;
 
 	if (!buf)
@@ -663,7 +657,7 @@ mwifiex_memrw_read(struct file *file, char __user *ubuf,
 			priv->mem_rw.value);
 	ret = simple_read_from_buffer(ubuf, count, ppos, buf, pos);
 
-	free_page(addr);
+	kfree(buf);
 	return ret;
 }
 
@@ -719,8 +713,7 @@ mwifiex_rdeeprom_read(struct file *file, char __user *ubuf,
 {
 	struct mwifiex_private *priv =
 		(struct mwifiex_private *) file->private_data;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *) addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	int pos, ret, i;
 	u8 value[MAX_EEPROM_DATA];
 
@@ -749,7 +742,7 @@ mwifiex_rdeeprom_read(struct file *file, char __user *ubuf,
 done:
 	ret = simple_read_from_buffer(ubuf, count, ppos, buf, pos);
 out_free:
-	free_page(addr);
+	kfree(buf);
 	return ret;
 }
 
@@ -820,8 +813,7 @@ mwifiex_hscfg_read(struct file *file, char __user *ubuf,
 		   size_t count, loff_t *ppos)
 {
 	struct mwifiex_private *priv = (void *)file->private_data;
-	unsigned long addr = get_zeroed_page(GFP_KERNEL);
-	char *buf = (char *)addr;
+	char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	int pos, ret;
 	struct mwifiex_ds_hs_cfg hscfg;
 
@@ -836,7 +828,7 @@ mwifiex_hscfg_read(struct file *file, char __user *ubuf,
 
 	ret = simple_read_from_buffer(ubuf, count, ppos, buf, pos);
 
-	free_page(addr);
+	kfree(buf);
 	return ret;
 }
 

-- 
2.53.0

[PATCH 4/4] wlcore: allocate aggregation and firmware log buffers with kzalloc()

[Mike Rapoport (Microsoft)]

wlcore_alloc_hw() uses __get_free_pages() to  allocate TX aggregation
and firmware log buffers used for software data staging.

These buffer can be allocated with kmalloc() as there's nothing special
about them to go directly to the page allocator.

kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.

Performance difference between kmalloc() and __get_free_pages() is not
measurable as both allocators take an object/page from a per-CPU list for
fast path allocations.

For the slow path the performance is anyway determined by the amount of
reclaim involved rather than by what allocator is used.

Replace use of __get_free_pages() with kzalloc() and free_pages() with
kfree().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 drivers/net/wireless/ti/wlcore/main.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
index be583ae331c0..5595f7a1fc0c 100644
--- a/drivers/net/wireless/ti/wlcore/main.c
+++ b/drivers/net/wireless/ti/wlcore/main.c
@@ -6354,7 +6354,6 @@ struct ieee80211_hw *wlcore_alloc_hw(size_t priv_size, u32 aggr_buf_size,
 	struct ieee80211_hw *hw;
 	struct wl1271 *wl;
 	int i, j, ret;
-	unsigned int order;
 
 	hw = ieee80211_alloc_hw(sizeof(*wl), &wl1271_ops);
 	if (!hw) {
@@ -6434,8 +6433,7 @@ struct ieee80211_hw *wlcore_alloc_hw(size_t priv_size, u32 aggr_buf_size,
 	mutex_init(&wl->flush_mutex);
 	init_completion(&wl->nvs_loading_complete);
 
-	order = get_order(aggr_buf_size);
-	wl->aggr_buf = (u8 *)__get_free_pages(GFP_KERNEL, order);
+	wl->aggr_buf = kmalloc(round_up(aggr_buf_size, PAGE_SIZE), GFP_KERNEL);
 	if (!wl->aggr_buf) {
 		ret = -ENOMEM;
 		goto err_wq;
@@ -6449,7 +6447,7 @@ struct ieee80211_hw *wlcore_alloc_hw(size_t priv_size, u32 aggr_buf_size,
 	}
 
 	/* Allocate one page for the FW log */
-	wl->fwlog = (u8 *)get_zeroed_page(GFP_KERNEL);
+	wl->fwlog = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!wl->fwlog) {
 		ret = -ENOMEM;
 		goto err_dummy_packet;
@@ -6474,13 +6472,13 @@ struct ieee80211_hw *wlcore_alloc_hw(size_t priv_size, u32 aggr_buf_size,
 	kfree(wl->mbox);
 
 err_fwlog:
-	free_page((unsigned long)wl->fwlog);
+	kfree(wl->fwlog);
 
 err_dummy_packet:
 	dev_kfree_skb(wl->dummy_packet);
 
 err_aggr:
-	free_pages((unsigned long)wl->aggr_buf, order);
+	kfree(wl->aggr_buf);
 
 err_wq:
 	destroy_workqueue(wl->freezable_wq);
@@ -6509,9 +6507,9 @@ int wlcore_free_hw(struct wl1271 *wl)
 
 	kfree(wl->buffer_32);
 	kfree(wl->mbox);
-	free_page((unsigned long)wl->fwlog);
+	kfree(wl->fwlog);
 	dev_kfree_skb(wl->dummy_packet);
-	free_pages((unsigned long)wl->aggr_buf, get_order(wl->aggr_buf_size));
+	kfree(wl->aggr_buf);
 
 	wl1271_debugfs_exit(wl);
 

-- 
2.53.0

Re: [PATCH 3/4] mwifiex: debugfs: use kzalloc() to allocate formatting buffers

[Francesco Dolcini]

+Jeff

Jeff: this is relevant also for nxpwifi.

On Wed, Jul 01, 2026 at 04:59:12PM +0300, Mike Rapoport (Microsoft) wrote:
> mwifiex debugfs functions allocate buffers for formatting debug output
> text using get_zeroed_page().
> 
> These buffers can be allocated with kmalloc() as there's nothing special
> about them to go directly to the page allocator.
> 
> kmalloc() provides a better API that does not require ugly casts and
> kfree() does not need to know the size of the freed object.
> 
> Performance difference between kmalloc() and __get_free_pages() is not
> measurable as both allocators take an object/page from a per-CPU list for
> fast path allocations.
> 
> For the slow path the performance is anyway determined by the amount of
> reclaim involved rather than by what allocator is used.
> 
> Replace use of get_zeroed_page() with kzalloc() and free_page() with
> kfree().
> 
> Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>