From mboxrd@z Thu Jan 1 00:00:00 1970 From: nm@ti.com (Nishanth Menon) Date: Fri, 9 May 2014 08:36:27 -0500 Subject: [PATCH 3/5] irqchip: crossbar: Skip some irqs from getting mapped to crossbar In-Reply-To: <536CD7BE.5020407@ti.com> References: <1399299527-10955-1-git-send-email-r.sricharan@ti.com> <1399299527-10955-4-git-send-email-r.sricharan@ti.com> <536BD9D8.4080905@ti.com> <20140508203659.GA5620@kahuna> <536C0DC4.7090309@ti.com> <536C2071.8040502@ti.com> <536CD01F.2070506@ti.com> <536CD7BE.5020407@ti.com> Message-ID: <536CD9DB.4010508@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 05/09/2014 08:27 AM, Santosh Shilimkar wrote: > On Friday 09 May 2014 08:54 AM, Nishanth Menon wrote: >> On 05/08/2014 11:22 PM, Joel Fernandes wrote: >>> On Thu, May 8, 2014 at 7:25 PM, Santosh Shilimkar >>> wrote: >> [...] >>> Ok, thanks for pointing to the post. >>> >> >> >> Yep - thanks Santosh for clarifying this. Now, we still have the >> issues that I pointed out in [1] - without resolving which, we should >> not enable crossbar for dra74x/72x. >> >> A. taking example of PMU >> interrupts = >> this wont work. instead the crossbar driver needs some sort of a hint >> to know that it should not map these on crossbar register instead >> assign GIC mapping directly. >> >> I propose doing the following >> #define GIC_CROSSBAR_PASSTHROUGH(irq_no) ((irq_no) | (0x1 << 31)) >> >> and dts will define the following: >> interrupts = >> >> This will also work for the other cases (B.2, B.3) >> >> For B.2: L3_APP_IRQ: >> instead of: >> interrupts = >> we do: >> interrupts = >> >> For B.3: NMI >> interrupts = >> > We can't do add a flag to generic interrupt controller flags since its > very specific to cross-bar. > >> xlate is easy -> >> >> diff --git a/drivers/irqchip/irq-crossbar.c >> b/drivers/irqchip/irq-crossbar.c >> index de021638..fd09ab4 100644 >> --- a/drivers/irqchip/irq-crossbar.c >> +++ b/drivers/irqchip/irq-crossbar.c >> @@ -112,6 +112,10 @@ static int crossbar_domain_xlate(struct >> irq_domain *d, >> { >> unsigned long ret; >> >> + /* Check to see if direct GIC mapping is required */ >> + if (intspec[1] & BIT(31)) >> + return intspec[1] & ~BIT[31]; >> + >> ret = get_prev_map_irq(intspec[1]); >> if (!IS_ERR_VALUE(ret)) >> goto found; >> >> But then, crossbar_domain_map and crossbar_domain_unmap need hints as >> well to know that there is no corresponding crossbar registers. >> Have'nt thought through that yet. Looking to hear about opinions here. >> >> > May be we need additional property like reserved to take care of 1:1 > map. > > ti,irqs-direct-map = <131 132>; > We already have equivalents for these -> reserved and skip. Problem is how does crossbar driver know the difference between direct maps and crossbar value? 6 is one of those reserved ones. dts for a device says: interrupts = Now, xlate gets intspec[1] = 6. 6 is valid crossbar number PRM_IRQ_MPU, however GIC 6 is mapped to WD_TIMER_MPU_C1_IRQ_WARN -> you need to be able to get a hint that this is direct mapping dts intended. in the "6" example: How do i get PRM_IRQ_MPU? interrupts = How do I get WD_TIMER_MPU_C1_IRQ_WARN? interrupts = ????? - that wont work as crossbar driver thinks it is crossbar 6 (PRM_IRQ_MPU) -- Regards, Nishanth Menon