On Fri, Jan 09, 2015 at 02:53:53AM +0000, tthayer@xxxxxxxxxxxxxxxxxxxxx wrote: > From: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx> > > This patch enables the ECC for On-Chip RAM on machine > startup. The ECC has to be enabled before data is > is stored in memory otherwise the ECC will fail on > reads. Where else is this OCRAM used? If we need the ECC to be enabled before use, a module_init call that seems to be unrelated to any other usage doesn't seem right to me. Hopefully I've just misunderstood something here. > > Signed-off-by: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx> > --- > v2: Split OCRAM ECC portion separately. Addition of iounmap() > and reorganization of gen_pool_free. Remove defconfig from patch. > > v3/4: No change > > v5: Remove ocram.h, use io.h instead of clk-provider.h > Check prop in correct place. Add ECC EN defines. > > v6: Implement OCRAM discovery changes from community. Add > of_node_put(). Remove be32_to_cpup(). Use __init() which > allows removal of .init_machine(). Update year in header. > --- > arch/arm/mach-socfpga/Makefile | 1 + > arch/arm/mach-socfpga/ocram.c | 97 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 98 insertions(+) > create mode 100644 arch/arm/mach-socfpga/ocram.c > > diff --git a/arch/arm/mach-socfpga/Makefile b/arch/arm/mach-socfpga/Makefile > index 142609e..1552ca5 100644 > --- a/arch/arm/mach-socfpga/Makefile > +++ b/arch/arm/mach-socfpga/Makefile > @@ -5,3 +5,4 @@ > obj-y := socfpga.o > obj-$(CONFIG_SMP) += headsmp.o platsmp.o > obj-$(CONFIG_EDAC_ALTERA_L2C) += l2_cache.o > +obj-$(CONFIG_EDAC_ALTERA_OCRAM) += ocram.o > diff --git a/arch/arm/mach-socfpga/ocram.c b/arch/arm/mach-socfpga/ocram.c > new file mode 100644 > index 0000000..1f12a38 > --- /dev/null > +++ b/arch/arm/mach-socfpga/ocram.c > @@ -0,0 +1,97 @@ > +/* > + * Copyright Altera Corporation (C) 2015. All rights reserved. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope 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. > + * > + * You should have received a copy of the GNU General Public License along with > + * this program. If not, see <http://www.gnu.org/licenses/>. > + */ > +#include <linux/io.h> > +#include <linux/genalloc.h> > +#include <linux/module.h> > +#include <linux/of_address.h> > +#include <linux/of_platform.h> > + > +#define ALTR_OCRAM_CLEAR_ECC 0x00000018 > +#define ALTR_OCRAM_ECC_EN 0x00000019 > + > +static int __init socfpga_init_ocram_ecc(void) > +{ > + struct device_node *np; > + struct resource res; > + u32 iram_addr; > + void __iomem *mapped_ocr_edac_addr; > + resource_size_t size; > + struct gen_pool *gp; > + int ret; > + > + /* Get the size of the on-chip RAM */ > + np = of_find_compatible_node(NULL, NULL, "mmio-sram"); > + if (!np) { > + pr_err("%s: Unable to find mmio-sram in dtb\n", __func__); > + return -ENODEV; > + } > + > + ret = of_address_to_resource(np, 0, &res); > + if (ret) { > + of_node_put(np); > + pr_err("%s: Problem getting SRAM address in dtb\n", __func__); > + return -ENODEV; > + } > + size = resource_size(&res); > + of_node_put(np); > + > + /* Find the OCRAM EDAC device tree node */ > + np = of_find_compatible_node(NULL, NULL, "altr,ocram-edac"); > + if (!np) { > + pr_err("%s: Unable to find altr,ocram-edac\n", __func__); > + return -ENODEV; > + } > + > + mapped_ocr_edac_addr = of_iomap(np, 0); > + if (!mapped_ocr_edac_addr) { > + of_node_put(np); > + pr_err("%s: Unable to map OCRAM ecc regs.\n", __func__); > + return -ENODEV; > + } > + > + gp = of_get_named_gen_pool(np, "iram", 0); > + if (!gp) { > + of_node_put(np); > + pr_err("%s: OCRAM cannot find gen pool\n", __func__); > + return -ENODEV; > + } > + of_node_put(np); > + > + iram_addr = gen_pool_alloc(gp, size / sizeof(size_t)); Why divide by sizeof(size_t) here? As far as I am aware, resource_size gives you a size in bytes... > + if (iram_addr == 0) { > + pr_err("%s: cannot alloc from gen pool\n", __func__); > + return -ENODEV; > + } > + > + /* Clear any pending OCRAM ECC interrupts, then enable ECC */ > + writel(ALTR_OCRAM_CLEAR_ECC, mapped_ocr_edac_addr); > + writel(ALTR_OCRAM_ECC_EN, mapped_ocr_edac_addr); > + > + memset((void *)iram_addr, 0, size); ...and here we write size bytes, not (size / sizeof(size_t)) bytes, so we're poking memory we weren't allocated. How is this memory mapped exactly? Is memset safe? Thanks, Mark. > + > + gen_pool_free(gp, iram_addr, size / sizeof(size_t)); > + > + iounmap(mapped_ocr_edac_addr); > + > + return 0; > +} > + > +static void __exit socfpga_exit_ocram_ecc(void) > +{ > +} > + > +module_init(socfpga_init_ocram_ecc); > +module_exit(socfpga_exit_ocram_ecc); > -- > 1.7.9.5 > > -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
