Re: [PATCH 04/16] remoteproc/pru: Add PRU remoteproc driver

From: Roger Quadros <rogerq@ti.com>
To: Dimitar Dimitrov <dinuxbg@gmail.com>
Cc: ohad@wizery.com, bjorn.andersson@linaro.org, tony@atomide.com,
	robh+dt@kernel.org, bcousson@baylibre.com, ssantosh@kernel.org,
	s-anna@ti.com, nsekhar@ti.com, t-kristo@ti.com, nsaulnier@ti.com,
	jreeder@ti.com, m-karicheri2@ti.com, woods.technical@gmail.com,
	linux-omap@vger.kernel.org, linux-remoteproc@vger.kernel.org,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [PATCH 04/16] remoteproc/pru: Add PRU remoteproc driver
Date: Tue, 4 Dec 2018 10:47:48 +0200	[thread overview]
Message-ID: <5C063F34.5080301@ti.com> (raw)
In-Reply-To: <308735274.C9ZyqtqOL8@tpdeb>

On 30/11/18 23:39, Dimitar Dimitrov wrote:
> On Monday, 12/26/2018, 9:52:37 EET Roger Quadros wrote:
>> +/*
>> + * Convert PRU device address (instruction space) to kernel virtual address
>> + *
>> + * A PRU does not have an unified address space. Each PRU has its very own
>> + * private Instruction RAM, and its device address is identical to that of
>> + * its primary Data RAM device address.
>> + */
>> +static void *pru_i_da_to_va(struct pru_rproc *pru, u32 da, int len)
>> +{
>> +       u32 offset;
>> +       void *va = NULL;
>> +
>> +       if (len <= 0)
>> +               return NULL;
> 
> Could you please clear the upper 4 bits the of IRAM device address, in order 
> to support binutils ELF images? Here is an example line to add here:
> 
> +       /* GNU binutils do not support multiple address spaces. The 
> +        * default linker script from the official GNU pru-ld places 
> +        * IRAM at an arbitrary high offset, in order to differentiate it 
> +        * from DRAM. Hence we need to strip the artificial offset 
> +        * from the IRAM address. 
> +        */ 
> +       da &= ~0xf0000000u; 
> +
> 

OK. Thanks.
> 
>> +
>> +       if (da >= pru->iram_da &&
>> +           da + len <= pru->iram_da + pru->mem_regions[PRU_MEM_IRAM].size { 
>> +               offset = da - pru->iram_da;
>> +               va = (__force void *)(pru->mem_regions[PRU_MEM_IRAM].va +
>> +                                     offset);
>> +       }
>> +
>> +       return va;
>> +}
> 
> 

cheers,
-roger

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