[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [XEN PATCH v8 19/22] xen/arm: ffa: support sharing large memory ranges
Adds support for sharing large memory ranges transmitted in fragments using FFA_MEM_FRAG_TX. The implementation is the bare minimum to be able to communicate with OP-TEE running as an SPMC at S-EL1. Adds a check that the SP supports the needed FF-A feature FFA_MEM_FRAG_TX. Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx> --- xen/arch/arm/tee/ffa.c | 253 ++++++++++++++++++++++++++++++++++++++--- 1 file changed, 240 insertions(+), 13 deletions(-) diff --git a/xen/arch/arm/tee/ffa.c b/xen/arch/arm/tee/ffa.c index 47ff899eca32..888e3f9265c2 100644 --- a/xen/arch/arm/tee/ffa.c +++ b/xen/arch/arm/tee/ffa.c @@ -356,6 +356,8 @@ struct ffa_ctx { /* FF-A version used by the guest */ uint32_t guest_vers; bool rx_is_free; + /* Currently used fragment states, struct mem_frag_state */ + struct list_head frag_list; /* Used shared memory objects, struct ffa_shm_mem */ struct list_head shm_list; /* Number of allocated shared memory object */ @@ -372,6 +374,18 @@ struct ffa_shm_mem { struct page_info *pages[]; }; +struct mem_frag_state { + struct list_head list; + struct ffa_shm_mem *shm; + uint32_t range_count; + unsigned int current_page_idx; + unsigned int frag_offset; + unsigned int range_offset; + const uint8_t *buf; + unsigned int buf_size; + struct ffa_address_range range; +}; + /* Negotiated FF-A version to use with the SPMC */ static uint32_t ffa_version __ro_after_init; @@ -535,6 +549,36 @@ static int32_t ffa_mem_share(uint32_t tot_len, uint32_t frag_len, } } +static int32_t ffa_mem_frag_tx(uint64_t handle, uint32_t frag_len, + uint16_t sender_id) +{ + struct arm_smccc_1_2_regs arg = { + .a0 = FFA_MEM_FRAG_TX, + .a1 = handle & UINT32_MAX, + .a2 = handle >> 32, + .a3 = frag_len, + .a4 = (uint32_t)sender_id << 16, + }; + struct arm_smccc_1_2_regs resp; + + arm_smccc_1_2_smc(&arg, &resp); + + switch ( resp.a0 ) + { + case FFA_ERROR: + if ( resp.a2 ) + return resp.a2; + else + return FFA_RET_NOT_SUPPORTED; + case FFA_SUCCESS_32: + return FFA_RET_OK; + case FFA_MEM_FRAG_RX: + return resp.a3; + default: + return FFA_RET_NOT_SUPPORTED; + } +} + static int32_t ffa_mem_reclaim(uint32_t handle_lo, uint32_t handle_hi, uint32_t flags) { @@ -609,6 +653,14 @@ static void set_regs_success(struct cpu_user_regs *regs, uint32_t w2, set_regs(regs, FFA_SUCCESS_32, 0, w2, w3, 0, 0, 0, 0); } +static void set_regs_frag_rx(struct cpu_user_regs *regs, uint32_t handle_lo, + uint32_t handle_hi, uint32_t frag_offset, + uint16_t sender_id) +{ + set_regs(regs, FFA_MEM_FRAG_RX, handle_lo, handle_hi, frag_offset, + (uint32_t)sender_id << 16, 0, 0, 0); +} + static void handle_version(struct cpu_user_regs *regs) { struct domain *d = current->domain; @@ -977,6 +1029,8 @@ static int share_shm(struct ffa_shm_mem *shm) paddr_t last_pa; unsigned int n; paddr_t pa; + bool first; + int ret; ASSERT(spin_is_locked(&ffa_tx_buffer_lock)); ASSERT(shm->page_count); @@ -1012,13 +1066,23 @@ static int share_shm(struct ffa_shm_mem *shm) tot_len = ADDR_RANGE_OFFSET(descr->mem_access_count, region_count, region_descr->address_range_count); - if ( tot_len > max_frag_len ) - return FFA_RET_NOT_SUPPORTED; + /* + * Sharing memory with secure world may have to be done with multiple + * calls depending on how many address ranges will be needed. If we're + * sharing physically contiguous memory we will only need one range but + * we will also need to deal with the worst case where all physical + * pages are non-contiguous. For the first batch of address ranges we + * call ffa_mem_share() and for all that follows ffa_mem_frag_tx(). + * + * We use frag_len to keep track of how far into the transmit buffer we + * have gone. + */ addr_range = region_descr->address_range_array; frag_len = ADDR_RANGE_OFFSET(descr->mem_access_count, region_count, 1); last_pa = page_to_maddr(shm->pages[0]); init_range(addr_range, last_pa); + first = true; for ( n = 1; n < shm->page_count; last_pa = pa, n++ ) { pa = page_to_maddr(shm->pages[n]); @@ -1028,12 +1092,34 @@ static int share_shm(struct ffa_shm_mem *shm) continue; } - frag_len += sizeof(*addr_range); - addr_range++; + if ( frag_len == max_frag_len ) + { + if ( first ) + { + ret = ffa_mem_share(tot_len, frag_len, 0, 0, &shm->handle); + first = false; + } + else + { + ret = ffa_mem_frag_tx(shm->handle, frag_len, shm->sender_id); + } + if ( ret <= 0 ) + return ret; + frag_len = sizeof(*addr_range); + addr_range = buf; + } + else + { + frag_len += sizeof(*addr_range); + addr_range++; + } init_range(addr_range, pa); } - return ffa_mem_share(tot_len, frag_len, 0, 0, &shm->handle); + if ( first ) + return ffa_mem_share(tot_len, frag_len, 0, 0, &shm->handle); + else + return ffa_mem_frag_tx(shm->handle, frag_len, shm->sender_id); } static int read_mem_transaction(uint32_t ffa_vers, const void *buf, size_t blen, @@ -1110,8 +1196,53 @@ static int read_mem_transaction(uint32_t ffa_vers, const void *buf, size_t blen, return 0; } +static int add_mem_share_frag(struct mem_frag_state *s, unsigned int offs, + unsigned int frag_len) +{ + struct domain *d = current->domain; + unsigned int o = offs; + unsigned int l; + int ret; + + if ( frag_len < o ) + return FFA_RET_INVALID_PARAMETERS; + + /* Fill up the first struct ffa_address_range */ + l = min_t(unsigned int, frag_len - o, sizeof(s->range) - s->range_offset); + memcpy((uint8_t *)&s->range + s->range_offset, s->buf + o, l); + s->range_offset += l; + o += l; + if ( s->range_offset != sizeof(s->range) ) + goto out; + s->range_offset = 0; + + while ( true ) + { + ret = get_shm_pages(d, s->shm, &s->range, 1, s->current_page_idx, + &s->current_page_idx); + if ( ret ) + return ret; + if ( s->range_count == 1 ) + return 0; + s->range_count--; + if ( frag_len - o < sizeof(s->range) ) + break; + memcpy(&s->range, s->buf + o, sizeof(s->range)); + o += sizeof(s->range); + } + + /* Collect any remaining bytes for the next struct ffa_address_range */ + s->range_offset = frag_len - o; + memcpy(&s->range, s->buf + o, frag_len - o); +out: + s->frag_offset += frag_len; + + return s->frag_offset; +} + static void handle_mem_share(struct cpu_user_regs *regs) { + static uint64_t next_handle = FFA_HANDLE_HYP_FLAG; uint32_t tot_len = get_user_reg(regs, 1); uint32_t frag_len = get_user_reg(regs, 2); uint64_t addr = get_user_reg(regs, 3); @@ -1146,13 +1277,6 @@ static void handle_mem_share(struct cpu_user_regs *regs) goto out_set_ret; } - /* We currently only support a single fragment */ - if ( frag_len != tot_len ) - { - ret = FFA_RET_NOT_SUPPORTED; - goto out_set_ret; - } - spin_lock(&ctx->lock); if ( frag_len > ctx->page_count * FFA_PAGE_SIZE ) @@ -1218,6 +1342,36 @@ static void handle_mem_share(struct cpu_user_regs *regs) shm->sender_id = trans.sender_id; shm->ep_id = read_atomic(&mem_access->access_perm.endpoint_id); + if ( frag_len != tot_len ) + { + struct mem_frag_state *s = xzalloc(struct mem_frag_state); + + if ( !s ) + { + ret = FFA_RET_NO_MEMORY; + goto out; + } + s->shm = shm; + s->range_count = range_count; + s->buf = ctx->tx; + s->buf_size = FFA_RXTX_PAGE_COUNT * FFA_PAGE_SIZE; + ret = add_mem_share_frag(s, sizeof(*region_descr) + region_offs, + frag_len); + if ( ret <= 0 ) + { + xfree(s); + if ( ret < 0 ) + goto out; + } + else + { + shm->handle = next_handle++; + uint64_to_regpair(&handle_hi, &handle_lo, shm->handle); + list_add_tail(&s->list, &ctx->frag_list); + } + goto out_unlock; + } + /* * Check that the Composite memory region descriptor fits. */ @@ -1256,7 +1410,75 @@ out_unlock: spin_unlock(&ctx->lock); out_set_ret: - if ( ret == 0) + if ( ret > 0 ) + set_regs_frag_rx(regs, handle_lo, handle_hi, ret, trans.sender_id); + else if ( ret == 0) + set_regs_success(regs, handle_lo, handle_hi); + else + set_regs_error(regs, ret); +} + +static struct mem_frag_state *find_frag_state(struct ffa_ctx *ctx, + uint64_t handle) +{ + struct mem_frag_state *s; + + list_for_each_entry(s, &ctx->frag_list, list) + if ( s->shm->handle == handle ) + return s; + + return NULL; +} + +static void handle_mem_frag_tx(struct cpu_user_regs *regs) +{ + struct domain *d = current->domain; + struct ffa_ctx *ctx = d->arch.tee; + uint32_t frag_len = get_user_reg(regs, 3); + uint32_t handle_lo = get_user_reg(regs, 1); + uint32_t handle_hi = get_user_reg(regs, 2); + uint64_t handle = regpair_to_uint64(handle_hi, handle_lo); + struct mem_frag_state *s; + uint16_t sender_id = 0; + int ret; + + spin_lock(&ctx->lock); + s = find_frag_state(ctx, handle); + if ( !s ) + { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + sender_id = s->shm->sender_id; + + if ( frag_len > s->buf_size ) + { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_free_s; + } + + ret = add_mem_share_frag(s, 0, frag_len); + if ( ret < 0 ) + goto out_free_s; + + /* Note that share_shm() uses our tx buffer */ + spin_lock(&ffa_tx_buffer_lock); + ret = share_shm(s->shm); + spin_unlock(&ffa_tx_buffer_lock); + if ( ret < 0 ) + goto out_free_s; + list_add_tail(&s->shm->list, &ctx->shm_list); +out_free_s: + if ( ret < 0 ) + free_ffa_shm_mem(ctx, s->shm); + list_del(&s->list); + xfree(s); +out: + spin_unlock(&ctx->lock); + + if ( ret > 0 ) + set_regs_frag_rx(regs, handle_lo, handle_hi, ret, sender_id); + else if ( ret == 0) set_regs_success(regs, handle_lo, handle_hi); else set_regs_error(regs, ret); @@ -1369,6 +1591,9 @@ static bool ffa_handle_call(struct cpu_user_regs *regs) else set_regs_success(regs, 0, 0); return true; + case FFA_MEM_FRAG_TX: + handle_mem_frag_tx(regs); + return true; default: gprintk(XENLOG_ERR, "ffa: unhandled fid 0x%x\n", fid); @@ -1410,6 +1635,7 @@ static int ffa_domain_init(struct domain *d) } } + INIT_LIST_HEAD(&ctx->frag_list); INIT_LIST_HEAD(&ctx->shm_list); d->arch.tee = ctx; @@ -1586,6 +1812,7 @@ static bool ffa_probe(void) !check_mandatory_feature(FFA_MEM_SHARE_64) || !check_mandatory_feature(FFA_RXTX_UNMAP) || !check_mandatory_feature(FFA_MEM_SHARE_32) || + !check_mandatory_feature(FFA_MEM_FRAG_TX) || !check_mandatory_feature(FFA_MEM_RECLAIM) || !check_mandatory_feature(FFA_MSG_SEND_DIRECT_REQ_32) ) return false; -- 2.34.1
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