[PATCH v2 07/11] bus: rifsc: introduce RIFSC firewall controller driver
Gatien CHEVALLIER
gatien.chevallier at foss.st.com
Wed Jul 26 03:32:31 PDT 2023
On 7/26/23 12:26, Simon Horman wrote:
> On Tue, Jul 25, 2023 at 06:41:00PM +0200, Gatien Chevallier wrote:
>
> ...
>
>> diff --git a/drivers/bus/stm32_rifsc.c b/drivers/bus/stm32_rifsc.c
>
> ...
>
>> +static int stm32_rif_acquire_semaphore(struct stm32_firewall_controller *stm32_firewall_controller,
>> + int id)
>> +{
>> + void __iomem *addr = stm32_firewall_controller->mmio + RIFSC_RISC_PER0_SEMCR + 0x8 * id;
>> +
>> + __set_bit(SEMCR_MUTEX, addr);
>
> Hi Gatien,
>
> Sparse seem a bit unhappy about this.
>
> .../stm32_rifsc.c:83:9: warning: cast removes address space '__iomem' of expression
> .../stm32_rifsc.c:83:9: warning: incorrect type in argument 2 (different address spaces)
> .../stm32_rifsc.c:83:9: expected unsigned long volatile *addr
> .../stm32_rifsc.c:83:9: got void [noderef] __iomem *addr
> .../stm32_rifsc.c:83:9: warning: incorrect type in argument 2 (different address spaces)
> .../stm32_rifsc.c:83:9: expected unsigned long volatile *addr
> .../stm32_rifsc.c:83:9: got void [noderef] __iomem *addr
>
> But it's not immediately apparent to me what a good solution is.
>
Hi Simon,
This is indeed incorrect, set_bit is used to modify bit fields, not
writing to a register. I'll change to writel, as in
stm32_rif_release_semaphore(). Thank you for pointing this out.
Best regards,
Gatien
>> +
>> + /* Check that CID1 has the semaphore */
>> + if (stm32_rifsc_is_semaphore_available(addr) ||
>> + FIELD_GET(RIFSC_RISC_SCID_MASK, readl(addr)) != RIF_CID1)
>> + return -EACCES;
>> +
>> + return 0;
>> +}
>
> ...
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