From: Josh Boyer <jwboyer@linux•vnet.ibm.com>
To: Stephen Neuendorffer <stephen.neuendorffer@xilinx•com>
Cc: linuxppc-dev@ozlabs•org
Subject: Re: [PATCH 1/2] [v3][POWERPC] refactor dcr code
Date: Sat, 19 Apr 2008 09:35:00 -0500 [thread overview]
Message-ID: <20080419093500.752c1930@zod.rchland.ibm.com> (raw)
In-Reply-To: <20080418215513.ACA0C17F007A@mail131-dub.bigfish.com>
On Fri, 18 Apr 2008 14:55:03 -0700
Stephen Neuendorffer <stephen.neuendorffer@xilinx•com> wrote:
> Previously, dcr support was configured at compile time to either using
> MMIO or native dcr instructions. Although this works for most
> platforms, it fails on FPGA platforms:
>
> 1) Systems may include more than one dcr bus.
> 2) Systems may be native dcr capable and still use memory mapped dcr interface.
>
> This patch provides runtime support based on the device trees for the
> case where CONFIG_PPC_DCR_MMIO and CONFIG_PPC_DCR_NATIVE are both
> selected. Previously, this was a poorly defined configuration, which
> happened to provide NATIVE support. The runtime selection is made
> based on the dcr controller having a 'dcr-access-method' attribute
> in the device tree. If only one of the above options is selected,
> then the code uses #defines to select only the used code in order to
> avoid introducing overhead in existing usage.
>
> Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx•com>
Hi Stephen,
Sorry for the late review. See some comments below. Mostly minor
stuff and I think the general direction here is good.
> diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
> index 437e48d..d3de0ff 100644
> --- a/arch/powerpc/sysdev/dcr.c
> +++ b/arch/powerpc/sysdev/dcr.c
> @@ -23,6 +23,68 @@
> #include <asm/prom.h>
> #include <asm/dcr.h>
>
> +#if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
> +
> +bool dcr_map_ok_generic(dcr_host_t host)
> +{
> + if (host.type == INVALID)
> + return 0;
> + else if (host.type == NATIVE)
> + return dcr_map_ok_native(host.host.native);
> + else
> + return dcr_map_ok_mmio(host.host.mmio);
> +}
> +EXPORT_SYMBOL_GPL(dcr_map_ok_generic);
> +
> +dcr_host_t dcr_map_generic(struct device_node *dev,
> + unsigned int dcr_n,
> + unsigned int dcr_c)
> +{
> + dcr_host_t host;
> + const char *prop = of_get_property(dev, "dcr-access-method", NULL);
> +
> + if (!strcmp(prop, "native")) {
> + host.type = NATIVE;
> + host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
> + } else if (!strcmp(prop, "mmio")) {
> + host.type = MMIO;
> + host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
> + } else
> + host.type = INVALID;
> +
> + return host;
> +}
> +EXPORT_SYMBOL_GPL(dcr_map_generic);
> +
> +void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
> +{
> + if (host.type == NATIVE)
> + dcr_unmap_native(host.host.native, dcr_c);
> + else
> + dcr_unmap_mmio(host.host.mmio, dcr_c);
What happens if host.type == INVALID? Same question for the other
accessors in dcr_*_generic.
<snip>
> diff --git a/include/asm-powerpc/dcr-generic.h b/include/asm-powerpc/dcr-generic.h
> new file mode 100644
> index 0000000..0ee74fb
> --- /dev/null
> +++ b/include/asm-powerpc/dcr-generic.h
> @@ -0,0 +1,49 @@
<snip>
> +enum host_type_t {MMIO, NATIVE, INVALID};
Should these be DCR_HOST_MMIO, DCR_HOST_NATIVE, DCR_HOST_INVALID?
I worry about the generic nature of the names.
josh
next prev parent reply other threads:[~2008-04-19 14:39 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1206401313-1625-1-git-send-email-stephen.neuendorffer@xilinx.com>
2008-03-28 16:23 ` [PATCH 1/5] [v2][POWERPC] refactor dcr code Stephen Neuendorffer
2008-03-30 22:02 ` Benjamin Herrenschmidt
2008-04-01 20:16 ` Stephen Neuendorffer
2008-04-04 22:02 ` Stephen Neuendorffer
2008-04-04 22:10 ` Benjamin Herrenschmidt
2008-04-18 21:49 ` Stephen Neuendorffer
2008-04-18 21:55 ` [PATCH 1/2] [v3][POWERPC] " Stephen Neuendorffer
2008-04-19 2:30 ` Grant Likely
2008-04-19 3:04 ` Benjamin Herrenschmidt
2008-04-19 14:35 ` Josh Boyer [this message]
2008-04-21 3:56 ` Stephen Neuendorffer
2008-04-21 13:03 ` Josh Boyer
2008-05-05 17:56 ` [PATCH 0/4] [v4][POWERPC] " Stephen Neuendorffer
[not found] ` <1210010201-28436-1-git-send-email-stephen.neuendorffer@xilinx.com>
2008-05-05 17:56 ` [PATCH 1/4] " Stephen Neuendorffer
2008-05-06 0:12 ` Benjamin Herrenschmidt
2008-05-06 3:40 ` Stephen Rothwell
2008-05-06 4:02 ` Benjamin Herrenschmidt
2008-05-06 17:34 ` Stephen Neuendorffer
2008-05-06 17:40 ` Josh Boyer
2008-05-06 18:29 ` [PATCH 1/4] [v5][POWERPC] " Stephen Neuendorffer
[not found] ` <1210010201-28436-2-git-send-email-stephen.neuendorffer@xilinx.com>
2008-05-05 17:56 ` [PATCH 2/4] [POWERPC] Xilinx: Virtex: Enable dcr for MMIO and NATIVE Stephen Neuendorffer
2008-05-06 0:11 ` Benjamin Herrenschmidt
2008-05-06 17:33 ` [PATCH 2/4] [POWERPC] Xilinx: Virtex: Enable dcr for MMIO andNATIVE Stephen Neuendorffer
[not found] ` <1210010201-28436-3-git-send-email-stephen.neuendorffer@xilinx.com>
2008-05-05 17:56 ` [PATCH 3/4] [POWERPC] Xilinx: Framebuffer: remove platform device support Stephen Neuendorffer
[not found] ` <1210010201-28436-4-git-send-email-stephen.neuendorffer@xilinx.com>
2008-05-05 17:56 ` [PATCH 4/4] [POWERPC] Xilinx: Framebuffer: Use dcr infrastructure Stephen Neuendorffer
2008-05-06 4:55 ` Grant Likely
2008-05-06 6:14 ` David Gibson
2008-05-06 10:56 ` Segher Boessenkool
2008-05-08 1:57 ` David Gibson
2008-05-06 17:43 ` [PATCH 4/4] [POWERPC] Xilinx: Framebuffer: Use dcrinfrastructure Stephen Neuendorffer
2008-05-08 1:59 ` David Gibson
2008-05-08 4:46 ` [PATCH 4/4] [POWERPC] Xilinx: Framebuffer: Usedcrinfrastructure Stephen Neuendorffer
2008-05-08 7:01 ` David Gibson
[not found] ` <1208555704-8978-1-git-send-email-stephen.neuendorffer@xilinx.com>
2008-04-18 21:55 ` [PATCH 2/2] [POWERPC] Xilinx: Virtex: Enable dcr for MMIO and NATIVE Stephen Neuendorffer
2008-04-19 2:31 ` Grant Likely
[not found] ` <1206721429-18276-1-git-send-email-stephen.neuendorffer@xilinx.com>
2008-03-28 16:23 ` [PATCH 2/5] " Stephen Neuendorffer
[not found] ` <1206721429-18276-2-git-send-email-stephen.neuendorffer@xilinx.com>
2008-03-28 16:23 ` [PATCH 3/5] [POWERPC] explicit dcr support Stephen Neuendorffer
2008-03-30 22:04 ` Benjamin Herrenschmidt
[not found] ` <1206721429-18276-3-git-send-email-stephen.neuendorffer@xilinx.com>
2008-03-28 16:23 ` [PATCH 4/5] [POWERPC] Xilinx: Framebuffer: Use dcr infrastructure Stephen Neuendorffer
[not found] ` <1206721429-18276-4-git-send-email-stephen.neuendorffer@xilinx.com>
2008-03-28 16:23 ` [PATCH 5/5] [RFC][PPC] Use DCR for arch ppc, and enable MMIO and NATIVE for virtex Stephen Neuendorffer
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