On Wed, 21 May 2008 21:46:24 +0900 FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote: > On Wed, 21 May 2008 20:22:18 +0800 > Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote: > > > On Wed, May 21, 2008 at 09:09:58PM +0900, FUJITA Tomonori wrote: > > > > > > OK, thanks. So it's about hardware requrement. Let me make sure if I > > > understand crypto alignment issue. > > > > > > __crt_ctx needs ARCH_KMALLOC_MINALIGN alignment only because of crypto > > > hardware. If I misunderstand it, can you answer my question in the > > > previous mail (it's the part that you cut)? That is, why does > > > __crt_ctx need ARCH_KMALLOC_MINALIGN alignment with software > > > algorithms. > > > > Because the same structure is used for all algorithms! > > No, you misunderstand my question. I meant, software algorithms don't > need ARCH_KMALLOC_MINALIGN alignment for __crt_ctx and if we are fine > with using the ALIGN hack for crypto hardware every time (like > aes_ctx_common), crypto doesn't need ARCH_KMALLOC_MINALIGN alignment > for __crt_ctx. Is this right? > > > > > > Why is this so hard to understand? > > Because there are few architecture that defines > ARCH_KMALLOC_MINALIGN. So if crypto hardware needs alignement, it's > likely the hardware alignement is larger than __crt_ctx alignment. As > a result, you have to use ALIGN_PTR. So It's hard to understand using > ARCH_KMALLOC_MINALIGN here. I don't know about crypto hardware, but I > wonder if we can use a static alignment like 64 bytes here, which may > work for most of crypto hardware. Or if there are not many users of Oops, scratch the static alignment. It's impossible. > crypto hardware, it may be fine to use ALIGN_PTR for the hardware. I still wonder it's acceptable or not. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
