Hi Jens,
> On 17 Jul 2023, at 09:20, Jens Wiklander <jens.wiklan...@linaro.org> wrote:
>
> When initializing the FF-A mediator map the RX and TX buffers shared with
> the SPMC.
>
> These buffer are later used to to transmit data that cannot be passed in
> registers only.
>
> Adds a check that the SP supports the needed FF-A features
> FFA_RXTX_MAP_64 and FFA_RXTX_UNMAP.
>
> Signed-off-by: Jens Wiklander <jens.wiklan...@linaro.org>
Reviewed-by: Bertrand Marquis <bertrand.marq...@arm.com>
Cheers
Bertrand
> ---
> xen/arch/arm/tee/ffa.c | 50 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/xen/arch/arm/tee/ffa.c b/xen/arch/arm/tee/ffa.c
> index e05d58cf7755..f8ccaabc568d 100644
> --- a/xen/arch/arm/tee/ffa.c
> +++ b/xen/arch/arm/tee/ffa.c
> @@ -12,6 +12,7 @@
> #include <xen/errno.h>
> #include <xen/init.h>
> #include <xen/lib.h>
> +#include <xen/mm.h>
> #include <xen/sched.h>
> #include <xen/sizes.h>
> #include <xen/types.h>
> @@ -67,6 +68,12 @@
> */
> #define FFA_PAGE_SIZE SZ_4K
>
> +/*
> + * The number of pages used for each of the RX and TX buffers shared with
> + * the SPMC.
> + */
> +#define FFA_RXTX_PAGE_COUNT 1
> +
> /*
> * Flags and field values used for the MSG_SEND_DIRECT_REQ/RESP:
> * BIT(31): Framework or partition message
> @@ -161,6 +168,13 @@ struct ffa_ctx {
> /* Negotiated FF-A version to use with the SPMC */
> static uint32_t __ro_after_init ffa_version;
>
> +/*
> + * Our rx/tx buffers shared with the SPMC. FFA_RXTX_PAGE_COUNT is the
> + * number of pages used in each of these buffers.
> + */
> +static void *ffa_rx __read_mostly;
> +static void *ffa_tx __read_mostly;
> +
> static bool ffa_get_version(uint32_t *vers)
> {
> const struct arm_smccc_1_2_regs arg = {
> @@ -231,6 +245,12 @@ static bool check_mandatory_feature(uint32_t id)
> return !ret;
> }
>
> +static int32_t ffa_rxtx_map(paddr_t tx_addr, paddr_t rx_addr,
> + uint32_t page_count)
> +{
> + return ffa_simple_call(FFA_RXTX_MAP_64, tx_addr, rx_addr, page_count, 0);
> +}
> +
> static uint16_t get_vm_id(const struct domain *d)
> {
> /* +1 since 0 is reserved for the hypervisor in FF-A */
> @@ -394,6 +414,7 @@ static int ffa_relinquish_resources(struct domain *d)
> static bool ffa_probe(void)
> {
> uint32_t vers;
> + int e;
> unsigned int major_vers;
> unsigned int minor_vers;
>
> @@ -441,12 +462,39 @@ static bool ffa_probe(void)
> * TODO: Rework the code to allow domain to use a subset of the
> * features supported.
> */
> - if ( !check_mandatory_feature(FFA_MSG_SEND_DIRECT_REQ_32) )
> + if (
> + !check_mandatory_feature(FFA_RXTX_MAP_64) ||
> + !check_mandatory_feature(FFA_RXTX_UNMAP) ||
> + !check_mandatory_feature(FFA_MSG_SEND_DIRECT_REQ_32) )
> + return false;
> +
> + ffa_rx = alloc_xenheap_pages(get_order_from_pages(FFA_RXTX_PAGE_COUNT),
> 0);
> + if ( !ffa_rx )
> return false;
>
> + ffa_tx = alloc_xenheap_pages(get_order_from_pages(FFA_RXTX_PAGE_COUNT),
> 0);
> + if ( !ffa_tx )
> + goto err_free_ffa_rx;
> +
> + e = ffa_rxtx_map(__pa(ffa_tx), __pa(ffa_rx), FFA_RXTX_PAGE_COUNT);
> + if ( e )
> + {
> + printk(XENLOG_ERR "ffa: Failed to map rxtx: error %d\n", e);
> + goto err_free_ffa_tx;
> + }
> ffa_version = vers;
>
> return true;
> +
> +err_free_ffa_tx:
> + free_xenheap_pages(ffa_tx, 0);
> + ffa_tx = NULL;
> +err_free_ffa_rx:
> + free_xenheap_pages(ffa_rx, 0);
> + ffa_rx = NULL;
> + ffa_version = 0;
> +
> + return false;
> }
>
> static const struct tee_mediator_ops ffa_ops =
> --
> 2.34.1
>
