[PATCH RESEND v2] dma-buf: heaps: use max3 in dma_heap_ioctl

[PATCH RESEND v2] dma-buf: heaps: use max3 in dma_heap_ioctl

[Thorsten Blum]

Replace two nested max() calls with a single max3() in dma_heap_ioctl().

Reviewed-by: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Changes in v2:
- Include minmax.h as suggested by T.J. Mercier
- v1: https://lore.kernel.org/lkml/20260427172519.417333-3-thorsten.blum@linux.dev/
---
 drivers/dma-buf/dma-heap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
index ac5f8685a649..d49188893608 100644
--- a/drivers/dma-buf/dma-heap.c
+++ b/drivers/dma-buf/dma-heap.c
@@ -13,6 +13,7 @@
 #include <linux/err.h>
 #include <linux/export.h>
 #include <linux/list.h>
+#include <linux/minmax.h>
 #include <linux/nospec.h>
 #include <linux/syscalls.h>
 #include <linux/uaccess.h>
@@ -153,7 +154,7 @@ static long dma_heap_ioctl(struct file *file, unsigned int ucmd,
 		in_size = 0;
 	if ((ucmd & kcmd & IOC_OUT) == 0)
 		out_size = 0;
-	ksize = max(max(in_size, out_size), drv_size);
+	ksize = max3(in_size, out_size, drv_size);
 
 	/* If necessary, allocate buffer for ioctl argument */
 	if (ksize > sizeof(stack_kdata)) {

Claude review: dma-buf: heaps: use max3 in dma_heap_ioctl

[Claude Code Review Bot]

Patch Review

**Status: Clean**

The patch does two things:

1. Adds `#include <linux/minmax.h>` (line 16 after patch), which provides the `max3` macro. This is correctly placed in alphabetical order among the existing includes.

2. Replaces the nested `max()` calls:
```c
-	ksize = max(max(in_size, out_size), drv_size);
+	ksize = max3(in_size, out_size, drv_size);
```

All three variables are declared as `unsigned int` at line 138:
```c
unsigned int in_size, out_size, drv_size, ksize;
```

This makes the `max3` call type-safe with no risk of signed/unsigned comparison issues.

The change is functionally equivalent and slightly more readable. No concerns.

**Reviewed-by: Already has R-b from T.J. Mercier.**

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Generated by Claude Code Patch Reviewer

Claude review: dma-buf: heaps: use max3 in dma_heap_ioctl

[Claude Code Review Bot]

Overall Series Review

Subject: dma-buf: heaps: use max3 in dma_heap_ioctl
Author: Thorsten Blum <thorsten.blum@linux.dev>
Patches: 1
Reviewed: 2026-05-18T16:01:29.053378

---

This is a single-patch series that is a straightforward, correct cleanup. It replaces `max(max(in_size, out_size), drv_size)` with `max3(in_size, out_size, drv_size)` and adds the corresponding `#include <linux/minmax.h>` header. The change is purely cosmetic — it improves readability with no functional change. All three arguments are the same type (`unsigned int`), so there are no type-promotion concerns with `max3`.

Already has a Reviewed-by from T.J. Mercier.

**Verdict: Looks good. No issues found.**

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Generated by Claude Code Patch Reviewer