[PATCH v14 10/44] arm64: RMI: Add support for SRO
Aneesh Kumar K.V
aneesh.kumar at kernel.org
Mon May 18 23:02:11 PDT 2026
Steven Price <steven.price at arm.com> writes:
> +static unsigned long donate_req_to_size(unsigned long donatereq)
> +{
> + unsigned long unit_size = RMI_DONATE_SIZE(donatereq);
> +
> + switch (unit_size) {
> + case 0:
> + return PAGE_SIZE;
> + case 1:
> + return PMD_SIZE;
> + case 2:
> + return PUD_SIZE;
> + case 3:
> + return P4D_SIZE;
> + }
> + unreachable();
> +}
>
> +
> +static void rmi_smccc_invoke(struct arm_smccc_1_2_regs *regs_in,
> + struct arm_smccc_1_2_regs *regs_out)
> +{
> + struct arm_smccc_1_2_regs regs = *regs_in;
> + unsigned long status;
> +
> + do {
> + arm_smccc_1_2_invoke(®s, regs_out);
> + status = RMI_RETURN_STATUS(regs_out->a0);
> + } while (status == RMI_BUSY || status == RMI_BLOCKED);
> +}
> +
> +int free_delegated_page(phys_addr_t phys)
> +{
> + if (WARN_ON(rmi_undelegate_page(phys))) {
> + /* Undelegate failed: leak the page */
> + return -EBUSY;
> + }
> +
> + free_page((unsigned long)phys_to_virt(phys));
> +
> + return 0;
> +}
> +
> +static int rmi_sro_ensure_capacity(struct rmi_sro_state *sro,
> + unsigned long count)
> +{
> + if (WARN_ON_ONCE(sro->addr_count > RMI_MAX_ADDR_LIST))
> + return -EOVERFLOW;
> +
> + if (count > RMI_MAX_ADDR_LIST - sro->addr_count)
> + return -ENOSPC;
> +
> + return 0;
> +}
> +
> +static int rmi_sro_donate_contig(struct rmi_sro_state *sro,
> + unsigned long sro_handle,
> + unsigned long donatereq,
> + struct arm_smccc_1_2_regs *out_regs,
> + gfp_t gfp)
> +{
> + unsigned long unit_size = RMI_DONATE_SIZE(donatereq);
> + unsigned long unit_size_bytes = donate_req_to_size(donatereq);
> + unsigned long count = RMI_DONATE_COUNT(donatereq);
> + unsigned long state = RMI_DONATE_STATE(donatereq);
> + unsigned long size = unit_size_bytes * count;
> + unsigned long addr_range;
>
Looking at above and the related code, I am wondering whether we should
use u64 instead of unsigned long for everything that the specification
defines as 64-bit.
-aneesh
More information about the linux-arm-kernel
mailing list