Re: [PATCH 1/4] crypto: nintendo-aes - add a new AES driver
From: Joel Stanley <joel@jms.id.au>
Date: 2021-09-22 02:02:25
Also in:
linux-crypto, linuxppc-dev, lkml
On Tue, 21 Sept 2021 at 21:47, Emmanuel Gil Peyrot [off-list ref] wrote:
quoted hunk ↗ jump to hunk
This engine implements AES in CBC mode, using 128-bit keys only. It is present on both the Wii and the Wii U, and is apparently identical in both consoles. The hardware is capable of firing an interrupt when the operation is done, but this driver currently uses a busy loop, I’m not too sure whether it would be preferable to switch, nor how to achieve that. It also supports a mode where no operation is done, and thus could be used as a DMA copy engine, but I don’t know how to expose that to the kernel or whether it would even be useful. In my testing, on a Wii U, this driver reaches 80.7 MiB/s, while the aes-generic driver only reaches 30.9 MiB/s, so it is a quite welcome speedup. This driver was written based on reversed documentation, see: https://wiibrew.org/wiki/Hardware/AES Signed-off-by: Emmanuel Gil Peyrot <redacted> Tested-by: Emmanuel Gil Peyrot <redacted> # on Wii U --- drivers/crypto/Kconfig | 11 ++ drivers/crypto/Makefile | 1 + drivers/crypto/nintendo-aes.c | 273 ++++++++++++++++++++++++++++++++++ 3 files changed, 285 insertions(+) create mode 100644 drivers/crypto/nintendo-aes.cdiff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig index 9a4c275a1335..adc94ad7462d 100644 --- a/drivers/crypto/Kconfig +++ b/drivers/crypto/Kconfig@@ -871,4 +871,15 @@ config CRYPTO_DEV_SA2UL source "drivers/crypto/keembay/Kconfig" +config CRYPTO_DEV_NINTENDO + tristate "Support for the Nintendo Wii U AES engine" + depends on WII || WIIU || COMPILE_TEST
This current seteup will allow the driver to be compile tested for
non-powerpc, which will fail on the dcbf instructions.
Perhaps use this instead:
depends on WII || WIIU || (COMPILE_TEST && PPC)
quoted hunk ↗ jump to hunk
+ select CRYPTO_AES + help + Say 'Y' here to use the Nintendo Wii or Wii U on-board AES + engine for the CryptoAPI AES algorithm. + + To compile this driver as a module, choose M here: the module + will be called nintendo-aes. + endif # CRYPTO_HWdiff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile index fa22cb19e242..004dae7bbf39 100644 --- a/drivers/crypto/Makefile +++ b/drivers/crypto/Makefile@@ -22,6 +22,7 @@ obj-$(CONFIG_CRYPTO_DEV_MARVELL) += marvell/ obj-$(CONFIG_CRYPTO_DEV_MXS_DCP) += mxs-dcp.o obj-$(CONFIG_CRYPTO_DEV_NIAGARA2) += n2_crypto.o n2_crypto-y := n2_core.o n2_asm.o +obj-$(CONFIG_CRYPTO_DEV_NINTENDO) += nintendo-aes.o obj-$(CONFIG_CRYPTO_DEV_NX) += nx/ obj-$(CONFIG_CRYPTO_DEV_OMAP) += omap-crypto.o obj-$(CONFIG_CRYPTO_DEV_OMAP_AES) += omap-aes-driver.odiff --git a/drivers/crypto/nintendo-aes.c b/drivers/crypto/nintendo-aes.c new file mode 100644 index 000000000000..79ae77500999 --- /dev/null +++ b/drivers/crypto/nintendo-aes.c@@ -0,0 +1,273 @@ +/* + * Copyright (C) 2021 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details.
The kernel uses the SDPX header instead of pasting the text.
+static int
+do_crypt(const void *src, void *dst, u32 len, u32 flags)
+{
+ u32 blocks = ((len >> 4) - 1) & AES_CTRL_BLOCK;
+ u32 status;
+ u32 counter = OP_TIMEOUT;
+ u32 i;
+
+ /* Flush out all of src, we can’t know whether any of it is in cache */
+ for (i = 0; i < len; i += 32)
+ __asm__("dcbf 0, %0" : : "r" (src + i));
+ __asm__("sync" : : : "memory");This could be flush_dcache_range, from asm/cacheflush.h
+
+ /* Set the addresses for DMA */
+ iowrite32be(virt_to_phys((void *)src), base + AES_SRC);
+ iowrite32be(virt_to_phys(dst), base + AES_DEST);
+
+ /* Start the operation */
+ iowrite32be(flags | blocks, base + AES_CTRL);
+
+ /* TODO: figure out how to use interrupts here, this will probably
+ * lower throughput but let the CPU do other things while the AES
+ * engine is doing its work. */
+ do {
+ status = ioread32be(base + AES_CTRL);
+ cpu_relax();
+ } while ((status & AES_CTRL_EXEC) && --counter);You could add a msleep in here? Consider using readl_poll_timeout(). Cheers, Joel
+
+ /* Do we ever get called with dst ≠ src? If so we have to invalidate
+ * dst in addition to the earlier flush of src. */
+ if (unlikely(dst != src)) {
+ for (i = 0; i < len; i += 32)
+ __asm__("dcbi 0, %0" : : "r" (dst + i));
+ __asm__("sync" : : : "memory");
+ }
+
+ return counter ? 0 : 1;
+}