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[73.185.129.58]) by smtp.gmail.com with ESMTPSA id g8-20020a02c548000000b0032b5e78bfcbsm1757115jaj.135.2022.05.21.17.32.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 21 May 2022 17:32:28 -0700 (PDT) From: Alex Elder To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: mka@chromium.org, evgreen@chromium.org, bjorn.andersson@linaro.org, quic_cpratapa@quicinc.com, quic_avuyyuru@quicinc.com, quic_jponduru@quicinc.com, quic_subashab@quicinc.com, elder@kernel.org, netdev@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next v2 2/9] net: ipa: support hard aggregation limits Date: Sat, 21 May 2022 19:32:16 -0500 Message-Id: <20220522003223.1123705-3-elder@linaro.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220522003223.1123705-1-elder@linaro.org> References: <20220522003223.1123705-1-elder@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Add a new flag for AP receive endpoints that indicates whether a "hard limit" is used as a criterion for closing aggregation. Add comments explaining the difference between "hard" and "soft" aggregation limits. Pass a flag to ipa_aggr_size_kb() so it computes the proper aggregation size value whether using hard or soft limits. Move that function earlier in "ipa_endpoint.c" so it can be used without a forward-reference. Update ipa_endpoint_data_valid_one() so it validates endpoints whose data indicate a hard aggregation limit is used, and so it reports set aggregation flags for endpoints without aggregation enabled. Signed-off-by: Alex Elder --- drivers/net/ipa/ipa_endpoint.c | 89 +++++++++++++++++++++------------- drivers/net/ipa/ipa_endpoint.h | 15 +++++- 2 files changed, 69 insertions(+), 35 deletions(-) diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c index 3ad97fbf6884e..6079670bd8605 100644 --- a/drivers/net/ipa/ipa_endpoint.c +++ b/drivers/net/ipa/ipa_endpoint.c @@ -81,6 +81,24 @@ static u32 aggr_byte_limit_max(enum ipa_version version) return field_max(aggr_byte_limit_fmask(false)); } +/* Compute the aggregation size value to use for a given buffer size */ +static u32 ipa_aggr_size_kb(u32 rx_buffer_size, bool aggr_hard_limit) +{ + /* A hard aggregation limit will not be crossed; aggregation closes + * if saving incoming data would cross the hard byte limit boundary. + * + * With a soft limit, aggregation closes *after* the size boundary + * has been crossed. In that case the limit must leave enough space + * after that limit to receive a full MTU of data plus overhead. + */ + if (!aggr_hard_limit) + rx_buffer_size -= IPA_MTU + IPA_RX_BUFFER_OVERHEAD; + + /* The byte limit is encoded as a number of kilobytes */ + + return rx_buffer_size / SZ_1K; +} + static bool ipa_endpoint_data_valid_one(struct ipa *ipa, u32 count, const struct ipa_gsi_endpoint_data *all_data, const struct ipa_gsi_endpoint_data *data) @@ -93,7 +111,9 @@ static bool ipa_endpoint_data_valid_one(struct ipa *ipa, u32 count, return true; if (!data->toward_ipa) { + const struct ipa_endpoint_rx *rx_config; u32 buffer_size; + u32 aggr_size; u32 limit; if (data->endpoint.filter_support) { @@ -107,8 +127,10 @@ static bool ipa_endpoint_data_valid_one(struct ipa *ipa, u32 count, if (data->ee_id != GSI_EE_AP) return true; - buffer_size = data->endpoint.config.rx.buffer_size; + rx_config = &data->endpoint.config.rx; + /* The buffer size must hold an MTU plus overhead */ + buffer_size = rx_config->buffer_size; limit = IPA_MTU + IPA_RX_BUFFER_OVERHEAD; if (buffer_size < limit) { dev_err(dev, "RX buffer size too small for RX endpoint %u (%u < %u)\n", @@ -116,27 +138,39 @@ static bool ipa_endpoint_data_valid_one(struct ipa *ipa, u32 count, return false; } - /* For an endpoint supporting receive aggregation, the - * aggregation byte limit defines the point at which an - * aggregation window will close. It is programmed into the - * IPA hardware as a number of KB. We don't use "hard byte - * limit" aggregation, so we need to supply enough space in - * a receive buffer to hold a complete MTU plus normal skb - * overhead *after* that aggregation byte limit has been - * crossed. - * - * This check just ensures the receive buffer size doesn't - * exceed what's representable in the aggregation limit field. + if (!data->endpoint.config.aggregation) { + bool result = true; + + /* No aggregation; check for bogus aggregation data */ + if (rx_config->aggr_hard_limit) { + dev_err(dev, "hard limit with no aggregation for RX endpoint %u\n", + data->endpoint_id); + result = false; + } + + if (rx_config->aggr_close_eof) { + dev_err(dev, "close EOF with no aggregation for RX endpoint %u\n", + data->endpoint_id); + result = false; + } + + return result; /* Nothing more to check */ + } + + /* For an endpoint supporting receive aggregation, the byte + * limit defines the point at which aggregation closes. This + * check ensures the receive buffer size doesn't result in a + * limit that exceeds what's representable in the aggregation + * byte limit field. */ - if (data->endpoint.config.aggregation) { - limit += SZ_1K * aggr_byte_limit_max(ipa->version); - if (buffer_size - NET_SKB_PAD > limit) { - dev_err(dev, "RX buffer size too large for aggregated RX endpoint %u (%u > %u)\n", - data->endpoint_id, - buffer_size - NET_SKB_PAD, limit); + aggr_size = ipa_aggr_size_kb(buffer_size - NET_SKB_PAD, + rx_config->aggr_hard_limit); + limit = aggr_byte_limit_max(ipa->version); + if (aggr_size > limit) { + dev_err(dev, "aggregated size too large for RX endpoint %u (%u KB > %u KB)\n", + data->endpoint_id, aggr_size, limit); - return false; - } + return false; } return true; /* Nothing more to check for RX */ @@ -670,18 +704,6 @@ static void ipa_endpoint_init_mode(struct ipa_endpoint *endpoint) iowrite32(val, endpoint->ipa->reg_virt + offset); } -/* Compute the aggregation size value to use for a given buffer size */ -static u32 ipa_aggr_size_kb(u32 rx_buffer_size) -{ - /* We don't use "hard byte limit" aggregation, so we define the - * aggregation limit such that our buffer has enough space *after* - * that limit to receive a full MTU of data, plus overhead. - */ - rx_buffer_size -= IPA_MTU + IPA_RX_BUFFER_OVERHEAD; - - return rx_buffer_size / SZ_1K; -} - /* Encoded values for AGGR endpoint register fields */ static u32 aggr_byte_limit_encoded(enum ipa_version version, u32 limit) { @@ -753,7 +775,8 @@ static void ipa_endpoint_init_aggr(struct ipa_endpoint *endpoint) val |= u32_encode_bits(IPA_GENERIC, AGGR_TYPE_FMASK); buffer_size = rx_config->buffer_size; - limit = ipa_aggr_size_kb(buffer_size - NET_SKB_PAD); + limit = ipa_aggr_size_kb(buffer_size - NET_SKB_PAD, + rx_config->aggr_hard_limit); val |= aggr_byte_limit_encoded(version, limit); limit = IPA_AGGR_TIME_LIMIT; diff --git a/drivers/net/ipa/ipa_endpoint.h b/drivers/net/ipa/ipa_endpoint.h index 3ab62fb892ec6..1e72a9695d3d9 100644 --- a/drivers/net/ipa/ipa_endpoint.h +++ b/drivers/net/ipa/ipa_endpoint.h @@ -59,21 +59,32 @@ struct ipa_endpoint_tx { * struct ipa_endpoint_rx - Endpoint configuration for RX endpoints * @buffer_size: requested receive buffer size (bytes) * @pad_align: power-of-2 boundary to which packet payload is aligned + * @aggr_hard_limit: whether aggregation closes before or after boundary * @aggr_close_eof: whether aggregation closes on end-of-frame * @holb_drop: whether to drop packets to avoid head-of-line blocking * + * The actual size of the receive buffer is rounded up if necessary + * to be a power-of-2 number of pages. + * * With each packet it transfers, the IPA hardware can perform certain * transformations of its packet data. One of these is adding pad bytes * to the end of the packet data so the result ends on a power-of-2 boundary. * * It is also able to aggregate multiple packets into a single receive buffer. * Aggregation is "open" while a buffer is being filled, and "closes" when - * certain criteria are met. One of those criteria is the sender indicating - * a "frame" consisting of several transfers has ended. + * certain criteria are met. + * + * Insufficient space available in the receive buffer can close aggregation. + * The aggregation byte limit defines the point (in units of 1024 bytes) in + * the buffer where aggregation closes. With a "soft" aggregation limit, + * aggregation closes when a packet written to the buffer *crosses* that + * aggregation limit. With a "hard" aggregation limit, aggregation will + * close *before* writing a packet that would cross that boundary. */ struct ipa_endpoint_rx { u32 buffer_size; u32 pad_align; + bool aggr_hard_limit; bool aggr_close_eof; bool holb_drop; };