From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hydra.sisk.pl (hydra.sisk.pl [212.160.235.94]) by ozlabs.org (Postfix) with ESMTP id BEBE32C0204 for ; Tue, 20 Aug 2013 22:16:57 +1000 (EST) From: "Rafael J. Wysocki" To: Sudeep KarkadaNagesha Subject: Re: [PATCH v4 03/19] powerpc: refactor of_get_cpu_node to support other architectures Date: Tue, 20 Aug 2013 14:27:28 +0200 Message-ID: <3703987.W8AZjrDbn0@vostro.rjw.lan> In-Reply-To: <1376991021-12160-4-git-send-email-Sudeep.KarkadaNagesha@arm.com> References: <1374492747-13879-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1376991021-12160-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1376991021-12160-4-git-send-email-Sudeep.KarkadaNagesha@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: Jonas Bonn , devicetree@vger.kernel.org, Michal Simek , linux-pm@vger.kernel.org, Sudeep KarkadaNagesha , Viresh Kumar , linux-kernel@vger.kernel.org, Rob Herring , Greg Kroah-Hartman , Grant Likely , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tuesday, August 20, 2013 10:30:05 AM Sudeep KarkadaNagesha wrote: > From: Sudeep KarkadaNagesha > > Currently different drivers requiring to access cpu device node are > parsing the device tree themselves. Since the ordering in the DT need > not match the logical cpu ordering, the parsing logic needs to consider > that. However, this has resulted in lots of code duplication and in some > cases even incorrect logic. > > It's better to consolidate them by adding support for getting cpu > device node for a given logical cpu index in DT core library. However > logical to physical index mapping can be architecture specific. > > PowerPC has it's own implementation to get the cpu node for a given > logical index. > > This patch refactors the current implementation of of_get_cpu_node. > This in preparation to move the implementation to DT core library. > It separates out the logical to physical mapping so that a default > matching of the physical id to the logical cpu index can be added > when moved to common code. Architecture specific code can override it. > > Cc: Rob Herring > Cc: Grant Likely > Cc: Benjamin Herrenschmidt > Signed-off-by: Sudeep KarkadaNagesha This needs an ACK from Ben to go anywhere. Thanks, Rafael > --- > arch/powerpc/kernel/prom.c | 76 ++++++++++++++++++++++++++++------------------ > 1 file changed, 47 insertions(+), 29 deletions(-) > > diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c > index eb23ac9..f7b8c0b 100644 > --- a/arch/powerpc/kernel/prom.c > +++ b/arch/powerpc/kernel/prom.c > @@ -865,45 +865,63 @@ static int __init prom_reconfig_setup(void) > __initcall(prom_reconfig_setup); > #endif > > +bool arch_match_cpu_phys_id(int cpu, u64 phys_id) > +{ > + return (int)phys_id == get_hard_smp_processor_id(cpu); > +} > + > +static bool __of_find_n_match_cpu_property(struct device_node *cpun, > + const char *prop_name, int cpu, unsigned int *thread) > +{ > + const __be32 *cell; > + int ac, prop_len, tid; > + u64 hwid; > + > + ac = of_n_addr_cells(cpun); > + cell = of_get_property(cpun, prop_name, &prop_len); > + if (!cell) > + return false; > + prop_len /= sizeof(*cell); > + for (tid = 0; tid < prop_len; tid++) { > + hwid = of_read_number(cell, ac); > + if (arch_match_cpu_phys_id(cpu, hwid)) { > + if (thread) > + *thread = tid; > + return true; > + } > + cell += ac; > + } > + return false; > +} > + > /* Find the device node for a given logical cpu number, also returns the cpu > * local thread number (index in ibm,interrupt-server#s) if relevant and > * asked for (non NULL) > */ > struct device_node *of_get_cpu_node(int cpu, unsigned int *thread) > { > - int hardid; > - struct device_node *np; > + struct device_node *cpun, *cpus; > > - hardid = get_hard_smp_processor_id(cpu); > + cpus = of_find_node_by_path("/cpus"); > + if (!cpus) { > + pr_warn("Missing cpus node, bailing out\n"); > + return NULL; > + } > > - for_each_node_by_type(np, "cpu") { > - const u32 *intserv; > - unsigned int plen, t; > + for_each_child_of_node(cpus, cpun) { > + if (of_node_cmp(cpun->type, "cpu")) > + continue; > > - /* Check for ibm,ppc-interrupt-server#s. If it doesn't exist > - * fallback to "reg" property and assume no threads > + /* Check for non-standard "ibm,ppc-interrupt-server#s" property > + * for thread ids on PowerPC. If it doesn't exist fallback to > + * standard "reg" property. > */ > - intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", > - &plen); > - if (intserv == NULL) { > - const u32 *reg = of_get_property(np, "reg", NULL); > - if (reg == NULL) > - continue; > - if (*reg == hardid) { > - if (thread) > - *thread = 0; > - return np; > - } > - } else { > - plen /= sizeof(u32); > - for (t = 0; t < plen; t++) { > - if (hardid == intserv[t]) { > - if (thread) > - *thread = t; > - return np; > - } > - } > - } > + if (__of_find_n_match_cpu_property(cpun, > + "ibm,ppc-interrupt-server#s", cpu, thread)) > + return cpun; > + > + if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread)) > + return cpun; > } > return NULL; > } > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.