From 29d258542f900a55791ec2ca8b15e4f9da083a14 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marek=20Beh=C3=BAn?= Date: Sat, 31 Aug 2024 11:20:35 +0200 Subject: [PATCH] firmware: turris-mox-rwtm: Use macro constant instead of hardcoded 4096 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The 4096 bytes limit in mox_hwrng_read() is due to the DMA buffer being allocated to one PAGE_SIZE bytes. Use new local macro constant RWTM_DMA_BUFFER_SIZE at allocation time and when used in mox_hwrng_read(). Use SZ_4K instead of PAGE_SIZE. Although PAGE_SIZE is never set to a larger value on Armada 3720, it theoretically could, and this would be a waste of space. Signed-off-by: Marek Behún Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240831092050.23093-2-kabel@kernel.org Signed-off-by: Arnd Bergmann --- drivers/firmware/turris-mox-rwtm.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/firmware/turris-mox-rwtm.c b/drivers/firmware/turris-mox-rwtm.c index 3e7f186d239a2..67d7b65da1741 100644 --- a/drivers/firmware/turris-mox-rwtm.c +++ b/drivers/firmware/turris-mox-rwtm.c @@ -11,14 +11,18 @@ #include #include #include +#include #include #include #include #include +#include #include #define DRIVER_NAME "turris-mox-rwtm" +#define RWTM_DMA_BUFFER_SIZE SZ_4K + /* * The macros and constants below come from Turris Mox's rWTM firmware code. * This firmware is open source and it's sources can be found at @@ -287,8 +291,7 @@ static int mox_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait) struct armada_37xx_rwtm_tx_msg msg; int ret; - if (max > 4096) - max = 4096; + max = min(max, RWTM_DMA_BUFFER_SIZE); msg.command = MBOX_CMD_GET_RANDOM; msg.args[0] = 1; @@ -479,8 +482,8 @@ static int turris_mox_rwtm_probe(struct platform_device *pdev) return -ENOMEM; rwtm->dev = dev; - rwtm->buf = dmam_alloc_coherent(dev, PAGE_SIZE, &rwtm->buf_phys, - GFP_KERNEL); + rwtm->buf = dmam_alloc_coherent(dev, RWTM_DMA_BUFFER_SIZE, + &rwtm->buf_phys, GFP_KERNEL); if (!rwtm->buf) return -ENOMEM; -- 2.39.5