2011-06-21 12:11:48

by Josh Boyer

Subject: [PATCH] crypto: crypto4xx - Perform read/modify/write on device control register

The Security function on the AMCC SoCs has multiple engines within a
single MMIO range. The crypto driver currently enables the 3DES
functionality by doing a blind write to the device control register.
This can unintentionally disable other functions like the PKA or TRNG
when the driver is loaded.

Perform a read/modify/write to enable the 3DES function instead.

Signed-off-by: Josh Boyer <[email protected]>

---

diff --git a/drivers/crypto/amcc/crypto4xx_core.c b/drivers/crypto/amcc/crypto4xx_core.c
index 1891252..1d103f9 100644
--- a/drivers/crypto/amcc/crypto4xx_core.c
+++ b/drivers/crypto/amcc/crypto4xx_core.c
@@ -51,6 +51,7 @@ static void crypto4xx_hw_init(struct crypto4xx_device *dev)
union ce_io_threshold io_threshold;
u32 rand_num;
union ce_pe_dma_cfg pe_dma_cfg;
+ u32 device_ctrl;

writel(PPC4XX_BYTE_ORDER, dev->ce_base + CRYPTO4XX_BYTE_ORDER_CFG);
/* setup pe dma, include reset sg, pdr and pe, then release reset */
@@ -84,7 +85,9 @@ static void crypto4xx_hw_init(struct crypto4xx_device *dev)
writel(ring_size.w, dev->ce_base + CRYPTO4XX_RING_SIZE);
ring_ctrl.w = 0;
writel(ring_ctrl.w, dev->ce_base + CRYPTO4XX_RING_CTRL);
- writel(PPC4XX_DC_3DES_EN, dev->ce_base + CRYPTO4XX_DEVICE_CTRL);
+ device_ctrl = readl(dev->ce_base + CRYPTO4XX_DEVICE_CTRL);
+ device_ctrl |= PPC4XX_DC_3DES_EN;
+ writel(device_ctrl, dev->ce_base + CRYPTO4XX_DEVICE_CTRL);
writel(dev->gdr_pa, dev->ce_base + CRYPTO4XX_GATH_RING_BASE);
writel(dev->sdr_pa, dev->ce_base + CRYPTO4XX_SCAT_RING_BASE);
part_ring_size.w = 0;

2011-06-27 07:33:29

by Herbert Xu

Subject: Re: [PATCH] crypto: crypto4xx - Perform read/modify/write on device control register

On Tue, Jun 21, 2011 at 08:13:21AM -0400, Josh Boyer wrote:
> The Security function on the AMCC SoCs has multiple engines within a
> single MMIO range. The crypto driver currently enables the 3DES
> functionality by doing a blind write to the device control register.
> This can unintentionally disable other functions like the PKA or TRNG
> when the driver is loaded.
>
> Perform a read/modify/write to enable the 3DES function instead.
>
> Signed-off-by: Josh Boyer <[email protected]>

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt