Adds support in the mediator to map and unmap the RX and TX buffers
provided by the guest using the two FF-A functions FFA_RXTX_MAP and
FFA_RXTX_UNMAP.
These buffer are later used to to transmit data that cannot be passed in
registers only.
Signed-off-by: Jens Wiklander <jens.wiklan...@linaro.org>
---
xen/arch/arm/ffa.c | 127 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 127 insertions(+)
diff --git a/xen/arch/arm/ffa.c b/xen/arch/arm/ffa.c
index a829379ad176..5e7211f0b4f6 100644
--- a/xen/arch/arm/ffa.c
+++ b/xen/arch/arm/ffa.c
@@ -196,10 +196,17 @@ struct ffa_partition_info_1_1 {
};
struct ffa_ctx {
+ void *rx;
+ const void *tx;
+ struct page_info *rx_pg;
+ struct page_info *tx_pg;
+ unsigned int page_count;
uint32_t guest_vers;
+ bool tx_is_mine;
bool interrupted;
};
+
/* Negotiated FF-A version to use with the SPMC */
static uint32_t ffa_version __read_mostly;
@@ -384,6 +391,11 @@ static void set_regs(struct cpu_user_regs *regs,
register_t v0, register_t v1,
set_user_reg(regs, 7, v7);
}
+static void set_regs_error(struct cpu_user_regs *regs, uint32_t error_code)
+{
+ set_regs(regs, FFA_ERROR, 0, error_code, 0, 0, 0, 0, 0);
+}
+
static void set_regs_success(struct cpu_user_regs *regs, uint32_t w2,
uint32_t w3)
{
@@ -405,6 +417,99 @@ static void handle_version(struct cpu_user_regs *regs)
set_regs(regs, vers, 0, 0, 0, 0, 0, 0, 0);
}
+static uint32_t handle_rxtx_map(uint32_t fid, register_t tx_addr,
+ register_t rx_addr, uint32_t page_count)
+{
+ uint32_t ret = FFA_RET_INVALID_PARAMETERS;
+ struct domain *d = current->domain;
+ struct ffa_ctx *ctx = d->arch.ffa;
+ struct page_info *tx_pg;
+ struct page_info *rx_pg;
+ p2m_type_t t;
+ void *rx;
+ void *tx;
+
+ if ( !smccc_is_conv_64(fid) )
+ {
+ tx_addr &= UINT32_MAX;
+ rx_addr &= UINT32_MAX;
+ }
+
+ /* For now to keep things simple, only deal with a single page */
+ if ( page_count != 1 )
+ return FFA_RET_NOT_SUPPORTED;
+
+ /* Already mapped */
+ if ( ctx->rx )
+ return FFA_RET_DENIED;
+
+ tx_pg = get_page_from_gfn(d, gfn_x(gaddr_to_gfn(tx_addr)), &t, P2M_ALLOC);
+ if ( !tx_pg )
+ return FFA_RET_INVALID_PARAMETERS;
+ /* Only normal RAM for now */
+ if ( !p2m_is_ram(t) )
+ goto err_put_tx_pg;
+
+ rx_pg = get_page_from_gfn(d, gfn_x(gaddr_to_gfn(rx_addr)), &t, P2M_ALLOC);
+ if ( !tx_pg )
+ goto err_put_tx_pg;
+ /* Only normal RAM for now */
+ if ( !p2m_is_ram(t) )
+ goto err_put_rx_pg;
+
+ tx = __map_domain_page_global(tx_pg);
+ if ( !tx )
+ goto err_put_rx_pg;
+
+ rx = __map_domain_page_global(rx_pg);
+ if ( !rx )
+ goto err_unmap_tx;
+
+ ctx->rx = rx;
+ ctx->tx = tx;
+ ctx->rx_pg = rx_pg;
+ ctx->tx_pg = tx_pg;
+ ctx->page_count = 1;
+ ctx->tx_is_mine = true;
+ return FFA_RET_OK;
+
+err_unmap_tx:
+ unmap_domain_page_global(tx);
+err_put_rx_pg:
+ put_page(rx_pg);
+err_put_tx_pg:
+ put_page(tx_pg);
+
+ return ret;
+}
+
+static void rxtx_unmap(struct ffa_ctx *ctx)
+{
+ unmap_domain_page_global(ctx->rx);
+ unmap_domain_page_global(ctx->tx);
+ put_page(ctx->rx_pg);
+ put_page(ctx->tx_pg);
+ ctx->rx = NULL;
+ ctx->tx = NULL;
+ ctx->rx_pg = NULL;
+ ctx->tx_pg = NULL;
+ ctx->page_count = 0;
+ ctx->tx_is_mine = false;
+}
+
+static uint32_t handle_rxtx_unmap(void)
+{
+ struct domain *d = current->domain;
+ struct ffa_ctx *ctx = d->arch.ffa;
+
+ if ( !ctx->rx )
+ return FFA_RET_INVALID_PARAMETERS;
+
+ rxtx_unmap(ctx);
+
+ return FFA_RET_OK;
+}
+
static void handle_msg_send_direct_req(struct cpu_user_regs *regs, uint32_t
fid)
{
struct arm_smccc_1_2_regs arg = { .a0 = fid, };
@@ -469,6 +574,7 @@ bool ffa_handle_call(struct cpu_user_regs *regs, uint32_t
fid)
{
struct domain *d = current->domain;
struct ffa_ctx *ctx = d->arch.ffa;
+ int e;
if ( !ctx )
return false;
@@ -481,6 +587,24 @@ bool ffa_handle_call(struct cpu_user_regs *regs, uint32_t
fid)
case FFA_ID_GET:
set_regs_success(regs, get_vm_id(d), 0);
return true;
+ case FFA_RXTX_MAP_32:
+#ifdef CONFIG_ARM_64
+ case FFA_RXTX_MAP_64:
+#endif
+ e = handle_rxtx_map(fid, get_user_reg(regs, 1), get_user_reg(regs, 2),
+ get_user_reg(regs, 3));
+ if ( e )
+ set_regs_error(regs, e);
+ else
+ set_regs_success(regs, 0, 0);
+ return true;
+ case FFA_RXTX_UNMAP:
+ e = handle_rxtx_unmap();
+ if ( e )
+ set_regs_error(regs, e);
+ else
+ set_regs_success(regs, 0, 0);
+ return true;
case FFA_MSG_SEND_DIRECT_REQ_32:
#ifdef CONFIG_ARM_64
case FFA_MSG_SEND_DIRECT_REQ_64:
@@ -556,6 +680,9 @@ int ffa_relinquish_resources(struct domain *d)
get_vm_id(d), subscr_vm_destroyed[n], res);
}
+ if ( ctx->rx )
+ rxtx_unmap(ctx);
+
XFREE(d->arch.ffa);
return 0;
--
2.31.1
