Re: [PATCH net-next v5 05/14] net: fman: Map the base address once
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2022-10-17 15:15:37
Also in:
linuxppc-dev, lkml, netdev
Hi Sean, On Sat, Sep 3, 2022 at 12:00 AM Sean Anderson [off-list ref] wrote:
We don't need to remap the base address from the resource twice (once in mac_probe() and again in set_fman_mac_params()). We still need the resource to get the end address, but we can use a single function call to get both at once. While we're at it, use platform_get_mem_or_io and devm_request_resource to map the resource. I think this is the more "correct" way to do things here, since we use the pdev resource, instead of creating a new one. It's still a bit tricky, since we need to ensure that the resource is a child of the fman region when it gets requested. Signed-off-by: Sean Anderson <redacted> Acked-by: Camelia Groza <redacted>
Thanks for your patch, which is now commit 262f2b782e255b79
("net: fman: Map the base address once") in v6.1-rc1.
quoted hunk ↗ jump to hunk
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth_sysfs.c +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth_sysfs.c@@ -18,7 +18,7 @@ static ssize_t dpaa_eth_show_addr(struct device *dev, if (mac_dev) return sprintf(buf, "%llx", - (unsigned long long)mac_dev->res->start); + (unsigned long long)mac_dev->vaddr);
On 32-bit:
warning: cast from pointer to integer of different size
[-Wpointer-to-int-cast]
Obviously you should cast to "uintptr_t" or "unsigned long" instead,
and change the "%llx" to "%p" or "%lx"...
However, taking a closer look:
1. The old code exposed a physical address to user space, the new
code exposes the mapped virtual address.
Is that change intentional?
2. Virtual addresses are useless in user space.
Moreover, addresses printed by "%p" are obfuscated, as this is
considered a security issue. Likewise for working around this by
casting to an integer.
What's the real purpose of dpaa_eth_show_addr()?
Perhaps it should be removed?
else
return sprintf(buf, "none");
}
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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