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diff --git a/Documentation/driver-api/crypto/iaa/iaa-crypto.rst b/Documentation/driver-api/crypto/iaa/iaa-crypto.rst new file mode 100644 index 0000000000..de587cf9cb --- /dev/null +++ b/Documentation/driver-api/crypto/iaa/iaa-crypto.rst @@ -0,0 +1,824 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========================================= +IAA Compression Accelerator Crypto Driver +========================================= + +Tom Zanussi <tom.zanussi@linux.intel.com> + +The IAA crypto driver supports compression/decompression compatible +with the DEFLATE compression standard described in RFC 1951, which is +the compression/decompression algorithm exported by this module. + +The IAA hardware spec can be found here: + + https://cdrdv2.intel.com/v1/dl/getContent/721858 + +The iaa_crypto driver is designed to work as a layer underneath +higher-level compression devices such as zswap. + +Users can select IAA compress/decompress acceleration by specifying +one of the supported IAA compression algorithms in whatever facility +allows compression algorithms to be selected. + +For example, a zswap device can select the IAA 'fixed' mode +represented by selecting the 'deflate-iaa' crypto compression +algorithm:: + + # echo deflate-iaa > /sys/module/zswap/parameters/compressor + +This will tell zswap to use the IAA 'fixed' compression mode for all +compresses and decompresses. + +Currently, there is only one compression modes available, 'fixed' +mode. + +The 'fixed' compression mode implements the compression scheme +specified by RFC 1951 and is given the crypto algorithm name +'deflate-iaa'. (Because the IAA hardware has a 4k history-window +limitation, only buffers <= 4k, or that have been compressed using a +<= 4k history window, are technically compliant with the deflate spec, +which allows for a window of up to 32k. Because of this limitation, +the IAA fixed mode deflate algorithm is given its own algorithm name +rather than simply 'deflate'). + + +Config options and other setup +============================== + +The IAA crypto driver is available via menuconfig using the following +path:: + + Cryptographic API -> Hardware crypto devices -> Support for Intel(R) IAA Compression Accelerator + +In the configuration file the option called CONFIG_CRYPTO_DEV_IAA_CRYPTO. + +The IAA crypto driver also supports statistics, which are available +via menuconfig using the following path:: + + Cryptographic API -> Hardware crypto devices -> Support for Intel(R) IAA Compression -> Enable Intel(R) IAA Compression Accelerator Statistics + +In the configuration file the option called CONFIG_CRYPTO_DEV_IAA_CRYPTO_STATS. + +The following config options should also be enabled:: + + CONFIG_IRQ_REMAP=y + CONFIG_INTEL_IOMMU=y + CONFIG_INTEL_IOMMU_SVM=y + CONFIG_PCI_ATS=y + CONFIG_PCI_PRI=y + CONFIG_PCI_PASID=y + CONFIG_INTEL_IDXD=m + CONFIG_INTEL_IDXD_SVM=y + +IAA is one of the first Intel accelerator IPs that can work in +conjunction with the Intel IOMMU. There are multiple modes that exist +for testing. Based on IOMMU configuration, there are 3 modes:: + + - Scalable + - Legacy + - No IOMMU + + +Scalable mode +------------- + +Scalable mode supports Shared Virtual Memory (SVM or SVA). It is +entered when using the kernel boot commandline:: + + intel_iommu=on,sm_on + +with VT-d turned on in BIOS. + +With scalable mode, both shared and dedicated workqueues are available +for use. + +For scalable mode, the following BIOS settings should be enabled:: + + Socket Configuration > IIO Configuration > Intel VT for Directed I/O (VT-d) > Intel VT for Directed I/O + + Socket Configuration > IIO Configuration > PCIe ENQCMD > ENQCMDS + + +Legacy mode +----------- + +Legacy mode is entered when using the kernel boot commandline:: + + intel_iommu=off + +or VT-d is not turned on in BIOS. + +If you have booted into Linux and not sure if VT-d is on, do a "dmesg +| grep -i dmar". If you don't see a number of DMAR devices enumerated, +most likely VT-d is not on. + +With legacy mode, only dedicated workqueues are available for use. + + +No IOMMU mode +------------- + +No IOMMU mode is entered when using the kernel boot commandline:: + + iommu=off. + +With no IOMMU mode, only dedicated workqueues are available for use. + + +Usage +===== + +accel-config +------------ + +When loaded, the iaa_crypto driver automatically creates a default +configuration and enables it, and assigns default driver attributes. +If a different configuration or set of driver attributes is required, +the user must first disable the IAA devices and workqueues, reset the +configuration, and then re-register the deflate-iaa algorithm with the +crypto subsystem by removing and reinserting the iaa_crypto module. + +The :ref:`iaa_disable_script` in the 'Use Cases' +section below can be used to disable the default configuration. + +See :ref:`iaa_default_config` below for details of the default +configuration. + +More likely than not, however, and because of the complexity and +configurability of the accelerator devices, the user will want to +configure the device and manually enable the desired devices and +workqueues. + +The userspace tool to help doing that is called accel-config. Using +accel-config to configure device or loading a previously saved config +is highly recommended. The device can be controlled via sysfs +directly but comes with the warning that you should do this ONLY if +you know exactly what you are doing. The following sections will not +cover the sysfs interface but assumes you will be using accel-config. + +The :ref:`iaa_sysfs_config` section in the appendix below can be +consulted for the sysfs interface details if interested. + +The accel-config tool along with instructions for building it can be +found here: + + https://github.com/intel/idxd-config/#readme + +Typical usage +------------- + +In order for the iaa_crypto module to actually do any +compression/decompression work on behalf of a facility, one or more +IAA workqueues need to be bound to the iaa_crypto driver. + +For instance, here's an example of configuring an IAA workqueue and +binding it to the iaa_crypto driver (note that device names are +specified as 'iax' rather than 'iaa' - this is because upstream still +has the old 'iax' device naming in place) :: + + # configure wq1.0 + + accel-config config-wq --group-id=0 --mode=dedicated --type=kernel --name="iaa_crypto" --device_name="crypto" iax1/wq1.0 + + # enable IAA device iax1 + + accel-config enable-device iax1 + + # enable wq1.0 on IAX device iax1 + + accel-config enable-wq iax1/wq1.0 + +Whenever a new workqueue is bound to or unbound from the iaa_crypto +driver, the available workqueues are 'rebalanced' such that work +submitted from a particular CPU is given to the most appropriate +workqueue available. Current best practice is to configure and bind +at least one workqueue for each IAA device, but as long as there is at +least one workqueue configured and bound to any IAA device in the +system, the iaa_crypto driver will work, albeit most likely not as +efficiently. + +The IAA crypto algorigthms is operational and compression and +decompression operations are fully enabled following the successful +binding of the first IAA workqueue to the iaa_crypto driver. + +Similarly, the IAA crypto algorithm is not operational and compression +and decompression operations are disabled following the unbinding of +the last IAA worqueue to the iaa_crypto driver. + +As a result, the IAA crypto algorithms and thus the IAA hardware are +only available when one or more workques are bound to the iaa_crypto +driver. + +When there are no IAA workqueues bound to the driver, the IAA crypto +algorithms can be unregistered by removing the module. + + +Driver attributes +----------------- + +There are a couple user-configurable driver attributes that can be +used to configure various modes of operation. They're listed below, +along with their default values. To set any of these attributes, echo +the appropriate values to the attribute file located under +/sys/bus/dsa/drivers/crypto/ + +The attribute settings at the time the IAA algorithms are registered +are captured in each algorithm's crypto_ctx and used for all compresses +and decompresses when using that algorithm. + +The available attributes are: + + - verify_compress + + Toggle compression verification. If set, each compress will be + internally decompressed and the contents verified, returning error + codes if unsuccessful. This can be toggled with 0/1:: + + echo 0 > /sys/bus/dsa/drivers/crypto/verify_compress + + The default setting is '1' - verify all compresses. + + - sync_mode + + Select mode to be used to wait for completion of each compresses + and decompress operation. + + The crypto async interface support implemented by iaa_crypto + provides an implementation that satisfies the interface but does + so in a synchronous manner - it fills and submits the IDXD + descriptor and then loops around waiting for it to complete before + returning. This isn't a problem at the moment, since all existing + callers (e.g. zswap) wrap any asynchronous callees in a + synchronous wrapper anyway. + + The iaa_crypto driver does however provide true asynchronous + support for callers that can make use of it. In this mode, it + fills and submits the IDXD descriptor, then returns immediately + with -EINPROGRESS. The caller can then either poll for completion + itself, which requires specific code in the caller which currently + nothing in the upstream kernel implements, or go to sleep and wait + for an interrupt signaling completion. This latter mode is + supported by current users in the kernel such as zswap via + synchronous wrappers. Although it is supported this mode is + significantly slower than the synchronous mode that does the + polling in the iaa_crypto driver previously mentioned. + + This mode can be enabled by writing 'async_irq' to the sync_mode + iaa_crypto driver attribute:: + + echo async_irq > /sys/bus/dsa/drivers/crypto/sync_mode + + Async mode without interrupts (caller must poll) can be enabled by + writing 'async' to it:: + + echo async > /sys/bus/dsa/drivers/crypto/sync_mode + + The mode that does the polling in the iaa_crypto driver can be + enabled by writing 'sync' to it:: + + echo sync > /sys/bus/dsa/drivers/crypto/sync_mode + + The default mode is 'sync'. + +.. _iaa_default_config: + +IAA Default Configuration +------------------------- + +When the iaa_crypto driver is loaded, each IAA device has a single +work queue configured for it, with the following attributes:: + + mode "dedicated" + threshold 0 + size Total WQ Size from WQCAP + priority 10 + type IDXD_WQT_KERNEL + group 0 + name "iaa_crypto" + driver_name "crypto" + +The devices and workqueues are also enabled and therefore the driver +is ready to be used without any additional configuration. + +The default driver attributes in effect when the driver is loaded are:: + + sync_mode "sync" + verify_compress 1 + +In order to change either the device/work queue or driver attributes, +the enabled devices and workqueues must first be disabled. In order +to have the new configuration applied to the deflate-iaa crypto +algorithm, it needs to be re-registered by removing and reinserting +the iaa_crypto module. The :ref:`iaa_disable_script` in the 'Use +Cases' section below can be used to disable the default configuration. + +Statistics +========== + +If the optional debugfs statistics support is enabled, the IAA crypto +driver will generate statistics which can be accessed in debugfs at:: + + # ls -al /sys/kernel/debug/iaa-crypto/ + total 0 + drwxr-xr-x 2 root root 0 Mar 3 09:35 . + drwx------ 47 root root 0 Mar 3 09:35 .. + -rw-r--r-- 1 root root 0 Mar 3 09:35 max_acomp_delay_ns + -rw-r--r-- 1 root root 0 Mar 3 09:35 max_adecomp_delay_ns + -rw-r--r-- 1 root root 0 Mar 3 09:35 max_comp_delay_ns + -rw-r--r-- 1 root root 0 Mar 3 09:35 max_decomp_delay_ns + -rw-r--r-- 1 root root 0 Mar 3 09:35 stats_reset + -rw-r--r-- 1 root root 0 Mar 3 09:35 total_comp_bytes_out + -rw-r--r-- 1 root root 0 Mar 3 09:35 total_comp_calls + -rw-r--r-- 1 root root 0 Mar 3 09:35 total_decomp_bytes_in + -rw-r--r-- 1 root root 0 Mar 3 09:35 total_decomp_calls + -rw-r--r-- 1 root root 0 Mar 3 09:35 wq_stats + +Most of the above statisticss are self-explanatory. The wq_stats file +shows per-wq stats, a set for each iaa device and wq in addition to +some global stats:: + + # cat wq_stats + global stats: + total_comp_calls: 100 + total_decomp_calls: 100 + total_comp_bytes_out: 22800 + total_decomp_bytes_in: 22800 + total_completion_einval_errors: 0 + total_completion_timeout_errors: 0 + total_completion_comp_buf_overflow_errors: 0 + + iaa device: + id: 1 + n_wqs: 1 + comp_calls: 0 + comp_bytes: 0 + decomp_calls: 0 + decomp_bytes: 0 + wqs: + name: iaa_crypto + comp_calls: 0 + comp_bytes: 0 + decomp_calls: 0 + decomp_bytes: 0 + + iaa device: + id: 3 + n_wqs: 1 + comp_calls: 0 + comp_bytes: 0 + decomp_calls: 0 + decomp_bytes: 0 + wqs: + name: iaa_crypto + comp_calls: 0 + comp_bytes: 0 + decomp_calls: 0 + decomp_bytes: 0 + + iaa device: + id: 5 + n_wqs: 1 + comp_calls: 100 + comp_bytes: 22800 + decomp_calls: 100 + decomp_bytes: 22800 + wqs: + name: iaa_crypto + comp_calls: 100 + comp_bytes: 22800 + decomp_calls: 100 + decomp_bytes: 22800 + +Writing 0 to 'stats_reset' resets all the stats, including the +per-device and per-wq stats:: + + # echo 0 > stats_reset + # cat wq_stats + global stats: + total_comp_calls: 0 + total_decomp_calls: 0 + total_comp_bytes_out: 0 + total_decomp_bytes_in: 0 + total_completion_einval_errors: 0 + total_completion_timeout_errors: 0 + total_completion_comp_buf_overflow_errors: 0 + ... + + +Use cases +========= + +Simple zswap test +----------------- + +For this example, the kernel should be configured according to the +dedicated mode options described above, and zswap should be enabled as +well:: + + CONFIG_ZSWAP=y + +This is a simple test that uses iaa_compress as the compressor for a +swap (zswap) device. It sets up the zswap device and then uses the +memory_memadvise program listed below to forcibly swap out and in a +specified number of pages, demonstrating both compress and decompress. + +The zswap test expects the work queues for each IAA device on the +system to be configured properly as a kernel workqueue with a +workqueue driver_name of "crypto". + +The first step is to make sure the iaa_crypto module is loaded:: + + modprobe iaa_crypto + +If the IAA devices and workqueues haven't previously been disabled and +reconfigured, then the default configuration should be in place and no +further IAA configuration is necessary. See :ref:`iaa_default_config` +below for details of the default configuration. + +If the default configuration is in place, you should see the iaa +devices and wq0s enabled:: + + # cat /sys/bus/dsa/devices/iax1/state + enabled + # cat /sys/bus/dsa/devices/iax1/wq1.0/state + enabled + +To demonstrate that the following steps work as expected, these +commands can be used to enable debug output:: + + # echo -n 'module iaa_crypto +p' > /sys/kernel/debug/dynamic_debug/control + # echo -n 'module idxd +p' > /sys/kernel/debug/dynamic_debug/control + +Use the following commands to enable zswap:: + + # echo 0 > /sys/module/zswap/parameters/enabled + # echo 50 > /sys/module/zswap/parameters/max_pool_percent + # echo deflate-iaa > /sys/module/zswap/parameters/compressor + # echo zsmalloc > /sys/module/zswap/parameters/zpool + # echo 1 > /sys/module/zswap/parameters/enabled + # echo 0 > /sys/module/zswap/parameters/same_filled_pages_enabled + # echo 100 > /proc/sys/vm/swappiness + # echo never > /sys/kernel/mm/transparent_hugepage/enabled + # echo 1 > /proc/sys/vm/overcommit_memory + +Now you can now run the zswap workload you want to measure. For +example, using the memory_memadvise code below, the following command +will swap in and out 100 pages:: + + ./memory_madvise 100 + + Allocating 100 pages to swap in/out + Swapping out 100 pages + Swapping in 100 pages + Swapped out and in 100 pages + +You should see something like the following in the dmesg output:: + + [ 404.202972] idxd 0000:e7:02.0: iaa_comp_acompress: dma_map_sg, src_addr 223925c000, nr_sgs 1, req->src 00000000ee7cb5e6, req->slen 4096, sg_dma_len(sg) 4096 + [ 404.202973] idxd 0000:e7:02.0: iaa_comp_acompress: dma_map_sg, dst_addr 21dadf8000, nr_sgs 1, req->dst 000000008d6acea8, req->dlen 4096, sg_dma_len(sg) 8192 + [ 404.202975] idxd 0000:e7:02.0: iaa_compress: desc->src1_addr 223925c000, desc->src1_size 4096, desc->dst_addr 21dadf8000, desc->max_dst_size 4096, desc->src2_addr 2203543000, desc->src2_size 1568 + [ 404.202981] idxd 0000:e7:02.0: iaa_compress_verify: (verify) desc->src1_addr 21dadf8000, desc->src1_size 228, desc->dst_addr 223925c000, desc->max_dst_size 4096, desc->src2_addr 0, desc->src2_size 0 + ... + +Now that basic functionality has been demonstrated, the defaults can +be erased and replaced with a different configuration. To do that, +first disable zswap:: + + # echo lzo > /sys/module/zswap/parameters/compressor + # swapoff -a + # echo 0 > /sys/module/zswap/parameters/accept_threshold_percent + # echo 0 > /sys/module/zswap/parameters/max_pool_percent + # echo 0 > /sys/module/zswap/parameters/enabled + # echo 0 > /sys/module/zswap/parameters/enabled + +Then run the :ref:`iaa_disable_script` in the 'Use Cases' section +below to disable the default configuration. + +Finally turn swap back on:: + + # swapon -a + +Following all that the IAA device(s) can now be re-configured and +enabled as desired for further testing. Below is one example. + +The zswap test expects the work queues for each IAA device on the +system to be configured properly as a kernel workqueue with a +workqueue driver_name of "crypto". + +The below script automatically does that:: + + #!/bin/bash + + echo "IAA devices:" + lspci -d:0cfe + echo "# IAA devices:" + lspci -d:0cfe | wc -l + + # + # count iaa instances + # + iaa_dev_id="0cfe" + num_iaa=$(lspci -d:${iaa_dev_id} | wc -l) + echo "Found ${num_iaa} IAA instances" + + # + # disable iaa wqs and devices + # + echo "Disable IAA" + + for ((i = 1; i < ${num_iaa} * 2; i += 2)); do + echo disable wq iax${i}/wq${i}.0 + accel-config disable-wq iax${i}/wq${i}.0 + echo disable iaa iax${i} + accel-config disable-device iax${i} + done + + echo "End Disable IAA" + + # + # configure iaa wqs and devices + # + echo "Configure IAA" + for ((i = 1; i < ${num_iaa} * 2; i += 2)); do + accel-config config-wq --group-id=0 --mode=dedicated --size=128 --priority=10 --type=kernel --name="iaa_crypto" --driver_name="crypto" iax${i}/wq${i} + done + + echo "End Configure IAA" + + # + # enable iaa wqs and devices + # + echo "Enable IAA" + + for ((i = 1; i < ${num_iaa} * 2; i += 2)); do + echo enable iaa iaa${i} + accel-config enable-device iaa${i} + echo enable wq iaa${i}/wq${i}.0 + accel-config enable-wq iaa${i}/wq${i}.0 + done + + echo "End Enable IAA" + +When the workqueues are bound to the iaa_crypto driver, you should +see something similar to the following in dmesg output if you've +enabled debug output (echo -n 'module iaa_crypto +p' > +/sys/kernel/debug/dynamic_debug/control):: + + [ 60.752344] idxd 0000:f6:02.0: add_iaa_wq: added wq 000000004068d14d to iaa 00000000c9585ba2, n_wq 1 + [ 60.752346] iaa_crypto: rebalance_wq_table: nr_nodes=2, nr_cpus 160, nr_iaa 8, cpus_per_iaa 20 + [ 60.752347] iaa_crypto: rebalance_wq_table: iaa=0 + [ 60.752349] idxd 0000:6a:02.0: request_iaa_wq: getting wq from iaa_device 0000000042d7bc52 (0) + [ 60.752350] idxd 0000:6a:02.0: request_iaa_wq: returning unused wq 00000000c8bb4452 (0) from iaa device 0000000042d7bc52 (0) + [ 60.752352] iaa_crypto: rebalance_wq_table: assigned wq for cpu=0, node=0 = wq 00000000c8bb4452 + [ 60.752354] iaa_crypto: rebalance_wq_table: iaa=0 + [ 60.752355] idxd 0000:6a:02.0: request_iaa_wq: getting wq from iaa_device 0000000042d7bc52 (0) + [ 60.752356] idxd 0000:6a:02.0: request_iaa_wq: returning unused wq 00000000c8bb4452 (0) from iaa device 0000000042d7bc52 (0) + [ 60.752358] iaa_crypto: rebalance_wq_table: assigned wq for cpu=1, node=0 = wq 00000000c8bb4452 + [ 60.752359] iaa_crypto: rebalance_wq_table: iaa=0 + [ 60.752360] idxd 0000:6a:02.0: request_iaa_wq: getting wq from iaa_device 0000000042d7bc52 (0) + [ 60.752361] idxd 0000:6a:02.0: request_iaa_wq: returning unused wq 00000000c8bb4452 (0) from iaa device 0000000042d7bc52 (0) + [ 60.752362] iaa_crypto: rebalance_wq_table: assigned wq for cpu=2, node=0 = wq 00000000c8bb4452 + [ 60.752364] iaa_crypto: rebalance_wq_table: iaa=0 + . + . + . + +Once the workqueues and devices have been enabled, the IAA crypto +algorithms are enabled and available. When the IAA crypto algorithms +have been successfully enabled, you should see the following dmesg +output:: + + [ 64.893759] iaa_crypto: iaa_crypto_enable: iaa_crypto now ENABLED + +Now run the following zswap-specific setup commands to have zswap use +the 'fixed' compression mode:: + + echo 0 > /sys/module/zswap/parameters/enabled + echo 50 > /sys/module/zswap/parameters/max_pool_percent + echo deflate-iaa > /sys/module/zswap/parameters/compressor + echo zsmalloc > /sys/module/zswap/parameters/zpool + echo 1 > /sys/module/zswap/parameters/enabled + echo 0 > /sys/module/zswap/parameters/same_filled_pages_enabled + + echo 100 > /proc/sys/vm/swappiness + echo never > /sys/kernel/mm/transparent_hugepage/enabled + echo 1 > /proc/sys/vm/overcommit_memory + +Finally, you can now run the zswap workload you want to measure. For +example, using the code below, the following command will swap in and +out 100 pages:: + + ./memory_madvise 100 + + Allocating 100 pages to swap in/out + Swapping out 100 pages + Swapping in 100 pages + Swapped out and in 100 pages + +You should see something like the following in the dmesg output if +you've enabled debug output (echo -n 'module iaa_crypto +p' > +/sys/kernel/debug/dynamic_debug/control):: + + [ 404.202972] idxd 0000:e7:02.0: iaa_comp_acompress: dma_map_sg, src_addr 223925c000, nr_sgs 1, req->src 00000000ee7cb5e6, req->slen 4096, sg_dma_len(sg) 4096 + [ 404.202973] idxd 0000:e7:02.0: iaa_comp_acompress: dma_map_sg, dst_addr 21dadf8000, nr_sgs 1, req->dst 000000008d6acea8, req->dlen 4096, sg_dma_len(sg) 8192 + [ 404.202975] idxd 0000:e7:02.0: iaa_compress: desc->src1_addr 223925c000, desc->src1_size 4096, desc->dst_addr 21dadf8000, desc->max_dst_size 4096, desc->src2_addr 2203543000, desc->src2_size 1568 + [ 404.202981] idxd 0000:e7:02.0: iaa_compress_verify: (verify) desc->src1_addr 21dadf8000, desc->src1_size 228, desc->dst_addr 223925c000, desc->max_dst_size 4096, desc->src2_addr 0, desc->src2_size 0 + [ 409.203227] idxd 0000:e7:02.0: iaa_comp_adecompress: dma_map_sg, src_addr 21ddd8b100, nr_sgs 1, req->src 0000000084adab64, req->slen 228, sg_dma_len(sg) 228 + [ 409.203235] idxd 0000:e7:02.0: iaa_comp_adecompress: dma_map_sg, dst_addr 21ee3dc000, nr_sgs 1, req->dst 000000004e2990d0, req->dlen 4096, sg_dma_len(sg) 4096 + [ 409.203239] idxd 0000:e7:02.0: iaa_decompress: desc->src1_addr 21ddd8b100, desc->src1_size 228, desc->dst_addr 21ee3dc000, desc->max_dst_size 4096, desc->src2_addr 0, desc->src2_size 0 + [ 409.203254] idxd 0000:e7:02.0: iaa_comp_adecompress: dma_map_sg, src_addr 21ddd8b100, nr_sgs 1, req->src 0000000084adab64, req->slen 228, sg_dma_len(sg) 228 + [ 409.203256] idxd 0000:e7:02.0: iaa_comp_adecompress: dma_map_sg, dst_addr 21f1551000, nr_sgs 1, req->dst 000000004e2990d0, req->dlen 4096, sg_dma_len(sg) 4096 + [ 409.203257] idxd 0000:e7:02.0: iaa_decompress: desc->src1_addr 21ddd8b100, desc->src1_size 228, desc->dst_addr 21f1551000, desc->max_dst_size 4096, desc->src2_addr 0, desc->src2_size 0 + +In order to unregister the IAA crypto algorithms, and register new +ones using different parameters, any users of the current algorithm +should be stopped and the IAA workqueues and devices disabled. + +In the case of zswap, remove the IAA crypto algorithm as the +compressor and turn off swap (to remove all references to +iaa_crypto):: + + echo lzo > /sys/module/zswap/parameters/compressor + swapoff -a + + echo 0 > /sys/module/zswap/parameters/accept_threshold_percent + echo 0 > /sys/module/zswap/parameters/max_pool_percent + echo 0 > /sys/module/zswap/parameters/enabled + +Once zswap is disabled and no longer using iaa_crypto, the IAA wqs and +devices can be disabled. + +.. _iaa_disable_script: + +IAA disable script +------------------ + +The below script automatically does that:: + + #!/bin/bash + + echo "IAA devices:" + lspci -d:0cfe + echo "# IAA devices:" + lspci -d:0cfe | wc -l + + # + # count iaa instances + # + iaa_dev_id="0cfe" + num_iaa=$(lspci -d:${iaa_dev_id} | wc -l) + echo "Found ${num_iaa} IAA instances" + + # + # disable iaa wqs and devices + # + echo "Disable IAA" + + for ((i = 1; i < ${num_iaa} * 2; i += 2)); do + echo disable wq iax${i}/wq${i}.0 + accel-config disable-wq iax${i}/wq${i}.0 + echo disable iaa iax${i} + accel-config disable-device iax${i} + done + + echo "End Disable IAA" + +Finally, at this point the iaa_crypto module can be removed, which +will unregister the current IAA crypto algorithms:: + + rmmod iaa_crypto + + +memory_madvise.c (gcc -o memory_memadvise memory_madvise.c):: + + #include <stdio.h> + #include <stdlib.h> + #include <string.h> + #include <unistd.h> + #include <sys/mman.h> + #include <linux/mman.h> + + #ifndef MADV_PAGEOUT + #define MADV_PAGEOUT 21 /* force pages out immediately */ + #endif + + #define PG_SZ 4096 + + int main(int argc, char **argv) + { + int i, nr_pages = 1; + int64_t *dump_ptr; + char *addr, *a; + int loop = 1; + + if (argc > 1) + nr_pages = atoi(argv[1]); + + printf("Allocating %d pages to swap in/out\n", nr_pages); + + /* allocate pages */ + addr = mmap(NULL, nr_pages * PG_SZ, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); + *addr = 1; + + /* initialize data in page to all '*' chars */ + memset(addr, '*', nr_pages * PG_SZ); + + printf("Swapping out %d pages\n", nr_pages); + + /* Tell kernel to swap it out */ + madvise(addr, nr_pages * PG_SZ, MADV_PAGEOUT); + + while (loop > 0) { + /* Wait for swap out to finish */ + sleep(5); + + a = addr; + + printf("Swapping in %d pages\n", nr_pages); + + /* Access the page ... this will swap it back in again */ + for (i = 0; i < nr_pages; i++) { + if (a[0] != '*') { + printf("Bad data from decompress!!!!!\n"); + + dump_ptr = (int64_t *)a; + for (int j = 0; j < 100; j++) { + printf(" page %d data: %#llx\n", i, *dump_ptr); + dump_ptr++; + } + } + + a += PG_SZ; + } + + loop --; + } + + printf("Swapped out and in %d pages\n", nr_pages); + +Appendix +======== + +.. _iaa_sysfs_config: + +IAA sysfs config interface +-------------------------- + +Below is a description of the IAA sysfs interface, which as mentioned +in the main document, should only be used if you know exactly what you +are doing. Even then, there's no compelling reason to use it directly +since accel-config can do everything the sysfs interface can and in +fact accel-config is based on it under the covers. + +The 'IAA config path' is /sys/bus/dsa/devices and contains +subdirectories representing each IAA device, workqueue, engine, and +group. Note that in the sysfs interface, the IAA devices are actually +named using iax e.g. iax1, iax3, etc. (Note that IAA devices are the +odd-numbered devices; the even-numbered devices are DSA devices and +can be ignored for IAA). + +The 'IAA device bind path' is /sys/bus/dsa/drivers/idxd/bind and is +the file that is written to enable an IAA device. + +The 'IAA workqueue bind path' is /sys/bus/dsa/drivers/crypto/bind and +is the file that is written to enable an IAA workqueue. + +Similarly /sys/bus/dsa/drivers/idxd/unbind and +/sys/bus/dsa/drivers/crypto/unbind are used to disable IAA devices and +workqueues. + +The basic sequence of commands needed to set up the IAA devices and +workqueues is: + +For each device:: + 1) Disable any workqueues enabled on the device. For example to + disable workques 0 and 1 on IAA device 3:: + + # echo wq3.0 > /sys/bus/dsa/drivers/crypto/unbind + # echo wq3.1 > /sys/bus/dsa/drivers/crypto/unbind + + 2) Disable the device. For example to disable IAA device 3:: + + # echo iax3 > /sys/bus/dsa/drivers/idxd/unbind + + 3) configure the desired workqueues. For example, to configure + workqueue 3 on IAA device 3:: + + # echo dedicated > /sys/bus/dsa/devices/iax3/wq3.3/mode + # echo 128 > /sys/bus/dsa/devices/iax3/wq3.3/size + # echo 0 > /sys/bus/dsa/devices/iax3/wq3.3/group_id + # echo 10 > /sys/bus/dsa/devices/iax3/wq3.3/priority + # echo "kernel" > /sys/bus/dsa/devices/iax3/wq3.3/type + # echo "iaa_crypto" > /sys/bus/dsa/devices/iax3/wq3.3/name + # echo "crypto" > /sys/bus/dsa/devices/iax3/wq3.3/driver_name + + 4) Enable the device. For example to enable IAA device 3:: + + # echo iax3 > /sys/bus/dsa/drivers/idxd/bind + + 5) Enable the desired workqueues on the device. For example to + enable workques 0 and 1 on IAA device 3:: + + # echo wq3.0 > /sys/bus/dsa/drivers/crypto/bind + # echo wq3.1 > /sys/bus/dsa/drivers/crypto/bind diff --git a/Documentation/driver-api/crypto/iaa/index.rst b/Documentation/driver-api/crypto/iaa/index.rst new file mode 100644 index 0000000000..aa6837e272 --- /dev/null +++ b/Documentation/driver-api/crypto/iaa/index.rst @@ -0,0 +1,20 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================================= +IAA (Intel Analytics Accelerator) +================================= + +IAA provides hardware compression and decompression via the crypto +API. + +.. toctree:: + :maxdepth: 1 + + iaa-crypto + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/driver-api/crypto/index.rst b/Documentation/driver-api/crypto/index.rst new file mode 100644 index 0000000000..fb9709b98b --- /dev/null +++ b/Documentation/driver-api/crypto/index.rst @@ -0,0 +1,20 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============== +Crypto Drivers +============== + +Documentation for crypto drivers that may need more involved setup and +configuration. + +.. toctree:: + :maxdepth: 1 + + iaa/index + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/driver-api/device-io.rst b/Documentation/driver-api/device-io.rst index 2c7abd234f..d55384b106 100644 --- a/Documentation/driver-api/device-io.rst +++ b/Documentation/driver-api/device-io.rst @@ -408,11 +408,12 @@ functions for details on the CPU side of things. ioremap_uc() ------------ -ioremap_uc() behaves like ioremap() except that on the x86 architecture without -'PAT' mode, it marks memory as uncached even when the MTRR has designated -it as cacheable, see Documentation/arch/x86/pat.rst. +ioremap_uc() is only meaningful on old x86-32 systems with the PAT extension, +and on ia64 with its slightly unconventional ioremap() behavior, everywhere +elss ioremap_uc() defaults to return NULL. -Portable drivers should avoid the use of ioremap_uc(). + +Portable drivers should avoid the use of ioremap_uc(), use ioremap() instead. ioremap_cache() --------------- diff --git a/Documentation/driver-api/dpll.rst b/Documentation/driver-api/dpll.rst index e3d593841a..ea8d16600e 100644 --- a/Documentation/driver-api/dpll.rst +++ b/Documentation/driver-api/dpll.rst @@ -545,7 +545,7 @@ In such scenario, dpll device input signal shall be also configurable to drive dpll with signal recovered from the PHY netdevice. This is done by exposing a pin to the netdevice - attaching pin to the netdevice itself with -``netdev_dpll_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)``. +``dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)``. Exposed pin id handle ``DPLL_A_PIN_ID`` is then identifiable by the user as it is attached to rtnetlink respond to get ``RTM_NEWLINK`` command in nested attribute ``IFLA_DPLL_PIN``. diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index f549a68951..eba8516053 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -9,11 +9,8 @@ of device drivers. This document is an only somewhat organized collection of some of those interfaces — it will hopefully get better over time! The available subsections can be seen below. -.. class:: toc-title - - Table of contents - .. toctree:: + :caption: Table of contents :maxdepth: 2 driver-model/index @@ -81,10 +78,8 @@ available subsections can be seen below. backlight/lp855x-driver.rst connector console - dcdbas eisa isa - isapnp io-mapping io_ordering generic-counter @@ -115,6 +110,9 @@ available subsections can be seen below. hte/index wmi dpll + wbrf + crypto/index + tee .. only:: subproject and html diff --git a/Documentation/driver-api/media/camera-sensor.rst b/Documentation/driver-api/media/camera-sensor.rst index 6456145f96..b4920b34ce 100644 --- a/Documentation/driver-api/media/camera-sensor.rst +++ b/Documentation/driver-api/media/camera-sensor.rst @@ -9,8 +9,8 @@ This document covers the in-kernel APIs only. For the best practices on userspace API implementation in camera sensor drivers, please see :ref:`media_using_camera_sensor_drivers`. -CSI-2 and parallel (BT.601 and BT.656) busses ---------------------------------------------- +CSI-2, parallel and BT.656 buses +-------------------------------- Please see :ref:`transmitter-receiver`. @@ -60,7 +60,8 @@ management over the pipeline. Camera sensor drivers are responsible for controlling the power state of the device they otherwise control as well. They shall use runtime PM to manage power states. Runtime PM shall be enabled at probe time and disabled at remove -time. Drivers should enable runtime PM autosuspend. +time. Drivers should enable runtime PM autosuspend. Also see +:ref:`async sub-device registration <media-registering-async-subdevs>`. The runtime PM handlers shall handle clocks, regulators, GPIOs, and other system resources required to power the sensor up and down. For drivers that diff --git a/Documentation/driver-api/media/drivers/ccs/mk-ccs-regs b/Documentation/driver-api/media/drivers/ccs/mk-ccs-regs index 2a4edc7e05..3d3152b458 100755 --- a/Documentation/driver-api/media/drivers/ccs/mk-ccs-regs +++ b/Documentation/driver-api/media/drivers/ccs/mk-ccs-regs @@ -82,14 +82,6 @@ for my $fh ($H, $LH) { print $fh "/* $license */\n$copyright$note\n"; } -sub bit_def($) { - my $bit = shift @_; - - return "BIT($bit)" if defined $kernel; - return "(1U << $bit)" if $bit =~ /^[a-zA-Z0-9_]+$/; - return "(1U << ($bit))"; -} - print $H <<EOF #ifndef __${uc_header}__ #define __${uc_header}__ @@ -97,23 +89,63 @@ print $H <<EOF EOF ; -print $H "#include <linux/bits.h>\n\n" if defined $kernel; - print $H <<EOF -#define CCS_FL_BASE 16 +#include <linux/bits.h> + +#include <media/v4l2-cci.h> + EOF - ; + if defined $kernel; + +print $H "#define CCS_FL_BASE " . + (defined $kernel ? "CCI_REG_PRIVATE_SHIFT" : 16) . "\n"; + +my $flag = -1; +my $all_flags; + +sub bit_def($) { + my $bit = shift @_; + + if (defined $kernel) { + return "BIT$bit" if $bit =~ /^\(.*\)$/; + return "BIT($bit)"; + } + return "(1U << $bit)"; +} + +sub flag_str($$) { + my ($flag, $check) = @_; -print $H "#define CCS_FL_16BIT " . bit_def("CCS_FL_BASE") . "\n"; -print $H "#define CCS_FL_32BIT " . bit_def("CCS_FL_BASE + 1") . "\n"; -print $H "#define CCS_FL_FLOAT_IREAL " . bit_def("CCS_FL_BASE + 2") . "\n"; -print $H "#define CCS_FL_IREAL " . bit_def("CCS_FL_BASE + 3") . "\n"; + $$flag++; + + my $flag_str = !$$flag ? "CCS_FL_BASE" : "(CCS_FL_BASE + $$flag)"; + + $flag_str = bit_def($flag_str); + + $$check .= " | " if defined $$check; + + $$check .= $flag_str; + + return $flag_str; +} + +if (! defined $kernel) { + print $H "#define CCS_FL_16BIT " . flag_str(\$flag, \$all_flags) . "\n"; + print $H "#define CCS_FL_32BIT " . flag_str(\$flag, \$all_flags) . "\n"; +} + +print $H "#define CCS_FL_FLOAT_IREAL " . flag_str(\$flag, \$all_flags) . "\n"; +print $H "#define CCS_FL_IREAL " . flag_str(\$flag, \$all_flags) . "\n"; +print $H "#define CCS_BUILD_BUG \\ + BUILD_BUG_ON(~CCI_REG_PRIVATE_MASK & ($all_flags))\n" + if defined $kernel; print $H <<EOF + #define CCS_R_ADDR(r) ((r) & 0xffff) EOF - ; + if ! defined $kernel; print $A <<EOF #include <stdint.h> @@ -189,12 +221,12 @@ sub tabconv($) { return (join "\n", @l) . "\n"; } -sub elem_size(@) { +sub elem_bits(@) { my @flags = @_; - return 2 if grep /^16$/, @flags; - return 4 if grep /^32$/, @flags; - return 1; + return 16 if grep /^16$/, @flags; + return 32 if grep /^32$/, @flags; + return 8; } sub arr_size($) { @@ -296,9 +328,13 @@ while (<$R>) { next if $#{$this{args}} + 1 != scalar keys %{$this{argparams}}; - my $reg_formula = "($this{addr}"; + my $reg_formula = "$this{addr}"; my $lim_formula; + chop $reg_formula; + + $reg_formula = "(" . $reg_formula if $this{flagstring} ne ""; + foreach my $arg (@{$this{args}}) { my $d = $h->{$arg}->{discontig}; my $times = $h->{$arg}->{elsize} != 1 ? @@ -315,11 +351,13 @@ while (<$R>) { $lim_formula .= (defined $lim_formula ? " + " : "") . "($arg)$times"; } - $reg_formula .= ")\n"; + $reg_formula .= ")"; $lim_formula =~ s/^\(([a-z0-9]+)\)$/$1/i; print $H tabconv sprintf("#define %-62s %s", "CCS_R_" . (uc $this{name}) . - $this{arglist}, $reg_formula); + $this{arglist}, $reg_formula . + (($this{flagstring} eq "") ? "" : + " | " . $this{flagstring} . ")") . "\n"); print $H tabconv $hdr_data; undef $hdr_data; @@ -369,16 +407,23 @@ while (<$R>) { $name =~ s/[,\.-]/_/g; my $flagstring = ""; - my $size = elem_size(@flags); - $flagstring .= "| CCS_FL_16BIT " if $size eq "2"; - $flagstring .= "| CCS_FL_32BIT " if $size eq "4"; + my $bits = elem_bits(@flags); + if (! defined $kernel) { + $flagstring .= "| CCS_FL_16BIT " if $bits == 16; + $flagstring .= "| CCS_FL_32BIT " if $bits == 32; + } $flagstring .= "| CCS_FL_FLOAT_IREAL " if grep /^float_ireal$/, @flags; $flagstring .= "| CCS_FL_IREAL " if grep /^ireal$/, @flags; $flagstring =~ s/^\| //; $flagstring =~ s/ $//; $flagstring = "($flagstring)" if $flagstring =~ /\|/; my $base_addr = $addr; - $addr = "($addr | $flagstring)" if $flagstring ne ""; + $addr = "CCI_REG$bits($addr)" if defined $kernel; + + if ($flagstring ne "" && !@$args) { + $addr = "($addr | $flagstring)"; + $flagstring = ""; + } my $arglist = @$args ? "(" . (join ", ", @$args) . ")" : ""; $hdr_data .= sprintf "#define %-62s %s\n", "CCS_R_" . (uc $name), $addr @@ -388,11 +433,12 @@ while (<$R>) { %this = ( name => $name, addr => $addr, + flagstring => $flagstring, base_addr => $base_addr, argparams => {}, args => $args, arglist => $arglist, - elsize => $size, + elsize => $bits / 8, ); if (!@$args) { diff --git a/Documentation/driver-api/media/index.rst b/Documentation/driver-api/media/index.rst index 08e2065674..d5593182a3 100644 --- a/Documentation/driver-api/media/index.rst +++ b/Documentation/driver-api/media/index.rst @@ -20,13 +20,8 @@ Documentation/userspace-api/media/index.rst - for the userspace APIs used on media devices. -.. only:: html - - .. class:: toc-title - - Table of Contents - .. toctree:: + :caption: Table of Contents :maxdepth: 5 :numbered: diff --git a/Documentation/driver-api/media/tx-rx.rst b/Documentation/driver-api/media/tx-rx.rst index e1e9258dd8..29d66a47b5 100644 --- a/Documentation/driver-api/media/tx-rx.rst +++ b/Documentation/driver-api/media/tx-rx.rst @@ -6,8 +6,8 @@ Pixel data transmitter and receiver drivers =========================================== V4L2 supports various devices that transmit and receive pixel data. Examples of -these devices include a camera sensor, a TV tuner and a parallel or a CSI-2 -receiver in an SoC. +these devices include a camera sensor, a TV tuner and a parallel, a BT.656 or a +CSI-2 receiver in an SoC. Bus types --------- @@ -22,12 +22,13 @@ the host SoC. It is defined by the `MIPI alliance`_. .. _`MIPI alliance`: https://www.mipi.org/ -Parallel -^^^^^^^^ +Parallel and BT.656 +^^^^^^^^^^^^^^^^^^^ -`BT.601`_ and `BT.656`_ are the most common parallel busses. +The parallel and `BT.656`_ buses transport one bit of data on each clock cycle +per data line. The parallel bus uses synchronisation and other additional +signals whereas BT.656 embeds synchronisation. -.. _`BT.601`: https://en.wikipedia.org/wiki/Rec._601 .. _`BT.656`: https://en.wikipedia.org/wiki/ITU-R_BT.656 Transmitter drivers @@ -90,8 +91,8 @@ where pixel rate on the camera sensor's pixel array which is indicated by the :ref:`V4L2_CID_PIXEL_RATE <v4l2-cid-pixel-rate>` control. -LP-11 and LP-111 modes -^^^^^^^^^^^^^^^^^^^^^^ +LP-11 and LP-111 states +^^^^^^^^^^^^^^^^^^^^^^^ As part of transitioning to high speed mode, a CSI-2 transmitter typically briefly sets the bus to LP-11 or LP-111 state, depending on the PHY. This period @@ -105,7 +106,7 @@ in software, especially when there is no interrupt telling something is happening. One way to address this is to configure the transmitter side explicitly to LP-11 -or LP-111 mode, which requires support from the transmitter hardware. This is +or LP-111 state, which requires support from the transmitter hardware. This is not universally available. Many devices return to this state once streaming is stopped while the state after power-on is LP-00 or LP-000. @@ -116,11 +117,11 @@ transitioning to streaming state, but not yet start streaming. Similarly, the to call ``.post_streamoff()`` for each successful call of ``.pre_streamon()``. In the context of CSI-2, the ``.pre_streamon()`` callback is used to transition -the transmitter to the LP-11 or LP-111 mode. This also requires powering on the +the transmitter to the LP-11 or LP-111 state. This also requires powering on the device, so this should be only done when it is needed. -Receiver drivers that do not need explicit LP-11 or LP-111 mode setup are waived -from calling the two callbacks. +Receiver drivers that do not need explicit LP-11 or LP-111 state setup are +waived from calling the two callbacks. Stopping the transmitter ^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/Documentation/driver-api/media/v4l2-subdev.rst b/Documentation/driver-api/media/v4l2-subdev.rst index e56b50b3f2..1db2ba27c5 100644 --- a/Documentation/driver-api/media/v4l2-subdev.rst +++ b/Documentation/driver-api/media/v4l2-subdev.rst @@ -181,6 +181,8 @@ You can unregister a sub-device using: Afterwards the subdev module can be unloaded and :c:type:`sd <v4l2_subdev>`->dev == ``NULL``. +.. _media-registering-async-subdevs: + Registering asynchronous sub-devices ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -195,6 +197,11 @@ performed using the :c:func:`v4l2_async_unregister_subdev` call. Subdevices registered this way are stored in a global list of subdevices, ready to be picked up by bridge drivers. +Drivers must complete all initialization of the sub-device before +registering it using :c:func:`v4l2_async_register_subdev`, including +enabling runtime PM. This is because the sub-device becomes accessible +as soon as it gets registered. + Asynchronous sub-device notifiers ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -562,8 +569,8 @@ device configuration. This is often implemented as e.g. an array of struct v4l2_mbus_framefmt, one entry for each pad, and similarly for crop and compose rectangles. -In addition to the active configuration, each subdev file handle has an array of -struct v4l2_subdev_pad_config, managed by the V4L2 core, which contains the try +In addition to the active configuration, each subdev file handle has a struct +v4l2_subdev_state, managed by the V4L2 core, which contains the try configuration. To simplify the subdev drivers the V4L2 subdev API now optionally supports a diff --git a/Documentation/driver-api/mei/index.rst b/Documentation/driver-api/mei/index.rst index 3a22b522ee..eae6f18f18 100644 --- a/Documentation/driver-api/mei/index.rst +++ b/Documentation/driver-api/mei/index.rst @@ -9,13 +9,8 @@ Intel(R) Management Engine Interface (Intel(R) MEI) **Copyright** |copy| 2019 Intel Corporation -.. only:: html - - .. class:: toc-title - - Table of Contents - .. toctree:: + :caption: Table of Contents :maxdepth: 3 mei diff --git a/Documentation/driver-api/mtd/spi-nor.rst b/Documentation/driver-api/mtd/spi-nor.rst index c22f8c0f79..148fa42887 100644 --- a/Documentation/driver-api/mtd/spi-nor.rst +++ b/Documentation/driver-api/mtd/spi-nor.rst @@ -2,64 +2,204 @@ SPI NOR framework ================= -Part I - Why do we need this framework? ---------------------------------------- - -SPI bus controllers (drivers/spi/) only deal with streams of bytes; the bus -controller operates agnostic of the specific device attached. However, some -controllers (such as Freescale's QuadSPI controller) cannot easily handle -arbitrary streams of bytes, but rather are designed specifically for SPI NOR. - -In particular, Freescale's QuadSPI controller must know the NOR commands to -find the right LUT sequence. Unfortunately, the SPI subsystem has no notion of -opcodes, addresses, or data payloads; a SPI controller simply knows to send or -receive bytes (Tx and Rx). Therefore, we must define a new layering scheme under -which the controller driver is aware of the opcodes, addressing, and other -details of the SPI NOR protocol. - -Part II - How does the framework work? --------------------------------------- - -This framework just adds a new layer between the MTD and the SPI bus driver. -With this new layer, the SPI NOR controller driver does not depend on the -m25p80 code anymore. - -Before this framework, the layer is like:: - - MTD - ------------------------ - m25p80 - ------------------------ - SPI bus driver - ------------------------ - SPI NOR chip - -After this framework, the layer is like:: - - MTD - ------------------------ - SPI NOR framework - ------------------------ - m25p80 - ------------------------ - SPI bus driver - ------------------------ - SPI NOR chip - -With the SPI NOR controller driver (Freescale QuadSPI), it looks like:: - - MTD - ------------------------ - SPI NOR framework - ------------------------ - fsl-quadSPI - ------------------------ - SPI NOR chip - -Part III - How can drivers use the framework? ---------------------------------------------- - -The main API is spi_nor_scan(). Before you call the hook, a driver should -initialize the necessary fields for spi_nor{}. Please see -drivers/mtd/spi-nor/spi-nor.c for detail. Please also refer to spi-fsl-qspi.c -when you want to write a new driver for a SPI NOR controller. +How to propose a new flash addition +----------------------------------- + +Most SPI NOR flashes comply with the JEDEC JESD216 +Serial Flash Discoverable Parameter (SFDP) standard. SFDP describes +the functional and feature capabilities of serial flash devices in a +standard set of internal read-only parameter tables. + +The SPI NOR driver queries the SFDP tables in order to determine the +flash's parameters and settings. If the flash defines the SFDP tables +it's likely that you won't need a flash entry at all, and instead +rely on the generic flash driver which probes the flash solely based +on its SFDP data. All one has to do is to specify the "jedec,spi-nor" +compatible in the device tree. + +There are cases however where you need to define an explicit flash +entry. This typically happens when the flash has settings or support +that is not covered by the SFDP tables (e.g. Block Protection), or +when the flash contains mangled SFDP data. If the later, one needs +to implement the ``spi_nor_fixups`` hooks in order to amend the SFDP +parameters with the correct values. + +Minimum testing requirements +----------------------------- + +Do all the tests from below and paste them in the commit's comments +section, after the ``---`` marker. + +1) Specify the controller that you used to test the flash and specify + the frequency at which the flash was operated, e.g.:: + + This flash is populated on the X board and was tested at Y + frequency using the Z (put compatible) SPI controller. + +2) Dump the sysfs entries and print the md5/sha1/sha256 SFDP checksum:: + + root@1:~# cat /sys/bus/spi/devices/spi0.0/spi-nor/partname + sst26vf064b + root@1:~# cat /sys/bus/spi/devices/spi0.0/spi-nor/jedec_id + bf2643 + root@1:~# cat /sys/bus/spi/devices/spi0.0/spi-nor/manufacturer + sst + root@1:~# xxd -p /sys/bus/spi/devices/spi0.0/spi-nor/sfdp + 53464450060102ff00060110300000ff81000106000100ffbf0001180002 + 0001fffffffffffffffffffffffffffffffffd20f1ffffffff0344eb086b + 083b80bbfeffffffffff00ffffff440b0c200dd80fd810d820914824806f + 1d81ed0f773830b030b0f7ffffff29c25cfff030c080ffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffff0004fff37f0000f57f0000f9ff + 7d00f57f0000f37f0000ffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff + ffffbf2643ffb95ffdff30f260f332ff0a122346ff0f19320f1919ffffff + ffffffff00669938ff05013506040232b03072428de89888a585c09faf5a + ffff06ec060c0003080bffffffffff07ffff0202ff060300fdfd040700fc + 0300fefe0202070e + root@1:~# sha256sum /sys/bus/spi/devices/spi0.0/spi-nor/sfdp + 428f34d0461876f189ac97f93e68a05fa6428c6650b3b7baf736a921e5898ed1 /sys/bus/spi/devices/spi0.0/spi-nor/sfdp + + Please dump the SFDP tables using ``xxd -p``. It enables us to do + the reverse operation and convert the hexdump to binary with + ``xxd -rp``. Dumping the SFDP data with ``hexdump -Cv`` is accepted, + but less desirable. + +3) Dump debugfs data:: + + root@1:~# cat /sys/kernel/debug/spi-nor/spi0.0/capabilities + Supported read modes by the flash + 1S-1S-1S + opcode 0x03 + mode cycles 0 + dummy cycles 0 + 1S-1S-1S (fast read) + opcode 0x0b + mode cycles 0 + dummy cycles 8 + 1S-1S-2S + opcode 0x3b + mode cycles 0 + dummy cycles 8 + 1S-2S-2S + opcode 0xbb + mode cycles 4 + dummy cycles 0 + 1S-1S-4S + opcode 0x6b + mode cycles 0 + dummy cycles 8 + 1S-4S-4S + opcode 0xeb + mode cycles 2 + dummy cycles 4 + 4S-4S-4S + opcode 0x0b + mode cycles 2 + dummy cycles 4 + + Supported page program modes by the flash + 1S-1S-1S + opcode 0x02 + + root@1:~# cat /sys/kernel/debug/spi-nor/spi0.0/params + name sst26vf064b + id bf 26 43 bf 26 43 + size 8.00 MiB + write size 1 + page size 256 + address nbytes 3 + flags HAS_LOCK | HAS_16BIT_SR | SOFT_RESET | SWP_IS_VOLATILE + + opcodes + read 0xeb + dummy cycles 6 + erase 0x20 + program 0x02 + 8D extension none + + protocols + read 1S-4S-4S + write 1S-1S-1S + register 1S-1S-1S + + erase commands + 20 (4.00 KiB) [0] + d8 (8.00 KiB) [1] + d8 (32.0 KiB) [2] + d8 (64.0 KiB) [3] + c7 (8.00 MiB) + + sector map + region (in hex) | erase mask | flags + ------------------+------------+---------- + 00000000-00007fff | [01 ] | + 00008000-0000ffff | [0 2 ] | + 00010000-007effff | [0 3] | + 007f0000-007f7fff | [0 2 ] | + 007f8000-007fffff | [01 ] | + +4) Use `mtd-utils <https://git.infradead.org/mtd-utils.git>`__ + and verify that erase, read and page program operations work fine:: + + root@1:~# dd if=/dev/urandom of=./spi_test bs=1M count=2 + 2+0 records in + 2+0 records out + 2097152 bytes (2.1 MB, 2.0 MiB) copied, 0.848566 s, 2.5 MB/s + + root@1:~# mtd_debug erase /dev/mtd0 0 2097152 + Erased 2097152 bytes from address 0x00000000 in flash + + root@1:~# mtd_debug read /dev/mtd0 0 2097152 spi_read + Copied 2097152 bytes from address 0x00000000 in flash to spi_read + + root@1:~# hexdump spi_read + 0000000 ffff ffff ffff ffff ffff ffff ffff ffff + * + 0200000 + + root@1:~# sha256sum spi_read + 4bda3a28f4ffe603c0ec1258c0034d65a1a0d35ab7bd523a834608adabf03cc5 spi_read + + root@1:~# mtd_debug write /dev/mtd0 0 2097152 spi_test + Copied 2097152 bytes from spi_test to address 0x00000000 in flash + + root@1:~# mtd_debug read /dev/mtd0 0 2097152 spi_read + Copied 2097152 bytes from address 0x00000000 in flash to spi_read + + root@1:~# sha256sum spi* + c444216a6ba2a4a66cccd60a0dd062bce4b865dd52b200ef5e21838c4b899ac8 spi_read + c444216a6ba2a4a66cccd60a0dd062bce4b865dd52b200ef5e21838c4b899ac8 spi_test + + If the flash comes erased by default and the previous erase was ignored, + we won't catch it, thus test the erase again:: + + root@1:~# mtd_debug erase /dev/mtd0 0 2097152 + Erased 2097152 bytes from address 0x00000000 in flash + + root@1:~# mtd_debug read /dev/mtd0 0 2097152 spi_read + Copied 2097152 bytes from address 0x00000000 in flash to spi_read + + root@1:~# sha256sum spi* + 4bda3a28f4ffe603c0ec1258c0034d65a1a0d35ab7bd523a834608adabf03cc5 spi_read + c444216a6ba2a4a66cccd60a0dd062bce4b865dd52b200ef5e21838c4b899ac8 spi_test + + Dump some other relevant data:: + + root@1:~# mtd_debug info /dev/mtd0 + mtd.type = MTD_NORFLASH + mtd.flags = MTD_CAP_NORFLASH + mtd.size = 8388608 (8M) + mtd.erasesize = 4096 (4K) + mtd.writesize = 1 + mtd.oobsize = 0 + regions = 0 diff --git a/Documentation/driver-api/nvmem.rst b/Documentation/driver-api/nvmem.rst index de221e91c8..5d9500d21e 100644 --- a/Documentation/driver-api/nvmem.rst +++ b/Documentation/driver-api/nvmem.rst @@ -41,7 +41,7 @@ A NVMEM provider can register with NVMEM core by supplying relevant nvmem configuration to nvmem_register(), on success core would return a valid nvmem_device pointer. -nvmem_unregister(nvmem) is used to unregister a previously registered provider. +nvmem_unregister() is used to unregister a previously registered provider. For example, a simple nvram case:: @@ -200,3 +200,9 @@ and let you add cells dynamically. Another use case for layouts is the post processing of cells. With layouts, it is possible to associate a custom post processing hook to a cell. It even possible to add this hook to cells not created by the layout itself. + +9. Internal kernel API +====================== + +.. kernel-doc:: drivers/nvmem/core.c + :export: diff --git a/Documentation/driver-api/pci/index.rst b/Documentation/driver-api/pci/index.rst index c6cf1fef61..a38e475cdb 100644 --- a/Documentation/driver-api/pci/index.rst +++ b/Documentation/driver-api/pci/index.rst @@ -4,11 +4,8 @@ The Linux PCI driver implementer's API guide ============================================ -.. class:: toc-title - - Table of contents - .. toctree:: + :caption: Table of contents :maxdepth: 2 pci diff --git a/Documentation/driver-api/pwm.rst b/Documentation/driver-api/pwm.rst index bb264490a8..3c28ccc4b6 100644 --- a/Documentation/driver-api/pwm.rst +++ b/Documentation/driver-api/pwm.rst @@ -41,11 +41,20 @@ the getter, devm_pwm_get() and devm_fwnode_pwm_get(), also exist. After being requested, a PWM has to be configured using:: - int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state); + int pwm_apply_might_sleep(struct pwm_device *pwm, struct pwm_state *state); This API controls both the PWM period/duty_cycle config and the enable/disable state. +PWM devices can be used from atomic context, if the PWM does not sleep. You +can check if this the case with:: + + bool pwm_might_sleep(struct pwm_device *pwm); + +If false, the PWM can also be configured from atomic context with:: + + int pwm_apply_atomic(struct pwm_device *pwm, struct pwm_state *state); + As a consumer, don't rely on the output's state for a disabled PWM. If it's easily possible, drivers are supposed to emit the inactive state, but some drivers cannot. If you rely on getting the inactive state, use .duty_cycle=0, @@ -57,13 +66,13 @@ If supported by the driver, the signal can be optimized, for example to improve EMI by phase shifting the individual channels of a chip. The pwm_config(), pwm_enable() and pwm_disable() functions are just wrappers -around pwm_apply_state() and should not be used if the user wants to change +around pwm_apply_might_sleep() and should not be used if the user wants to change several parameter at once. For example, if you see pwm_config() and pwm_{enable,disable}() calls in the same function, this probably means you -should switch to pwm_apply_state(). +should switch to pwm_apply_might_sleep(). The PWM user API also allows one to query the PWM state that was passed to the -last invocation of pwm_apply_state() using pwm_get_state(). Note this is +last invocation of pwm_apply_might_sleep() using pwm_get_state(). Note this is different to what the driver has actually implemented if the request cannot be satisfied exactly with the hardware in use. There is currently no way for consumers to get the actually implemented settings. diff --git a/Documentation/driver-api/soundwire/stream.rst b/Documentation/driver-api/soundwire/stream.rst index b432a2de45..2a794484f6 100644 --- a/Documentation/driver-api/soundwire/stream.rst +++ b/Documentation/driver-api/soundwire/stream.rst @@ -324,12 +324,12 @@ framework, this stream state is linked to .hw_params() operation. int sdw_stream_add_master(struct sdw_bus * bus, struct sdw_stream_config * stream_config, - struct sdw_ports_config * ports_config, + const struct sdw_ports_config * ports_config, struct sdw_stream_runtime * stream); int sdw_stream_add_slave(struct sdw_slave * slave, struct sdw_stream_config * stream_config, - struct sdw_ports_config * ports_config, + const struct sdw_ports_config * ports_config, struct sdw_stream_runtime * stream); diff --git a/Documentation/driver-api/surface_aggregator/ssh.rst b/Documentation/driver-api/surface_aggregator/ssh.rst index b955b67383..58a7573199 100644 --- a/Documentation/driver-api/surface_aggregator/ssh.rst +++ b/Documentation/driver-api/surface_aggregator/ssh.rst @@ -39,7 +39,7 @@ Note that the standard disclaimer for this subsystem also applies to this document: All of this has been reverse-engineered and may thus be erroneous and/or incomplete. -All CRCs used in the following are two-byte ``crc_ccitt_false(0xffff, ...)``. +All CRCs used in the following are two-byte ``crc_itu_t(0xffff, ...)``. All multi-byte values are little-endian, there is no implicit padding between values. diff --git a/Documentation/driver-api/tee.rst b/Documentation/driver-api/tee.rst new file mode 100644 index 0000000000..5eaeb81039 --- /dev/null +++ b/Documentation/driver-api/tee.rst @@ -0,0 +1,66 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=============================================== +TEE (Trusted Execution Environment) driver API +=============================================== + +Kernel provides a TEE bus infrastructure where a Trusted Application is +represented as a device identified via Universally Unique Identifier (UUID) and +client drivers register a table of supported device UUIDs. + +TEE bus infrastructure registers following APIs: + +match(): + iterates over the client driver UUID table to find a corresponding + match for device UUID. If a match is found, then this particular device is + probed via corresponding probe API registered by the client driver. This + process happens whenever a device or a client driver is registered with TEE + bus. + +uevent(): + notifies user-space (udev) whenever a new device is registered on + TEE bus for auto-loading of modularized client drivers. + +TEE bus device enumeration is specific to underlying TEE implementation, so it +is left open for TEE drivers to provide corresponding implementation. + +Then TEE client driver can talk to a matched Trusted Application using APIs +listed in include/linux/tee_drv.h. + +TEE client driver example +------------------------- + +Suppose a TEE client driver needs to communicate with a Trusted Application +having UUID: ``ac6a4085-0e82-4c33-bf98-8eb8e118b6c2``, so driver registration +snippet would look like:: + + static const struct tee_client_device_id client_id_table[] = { + {UUID_INIT(0xac6a4085, 0x0e82, 0x4c33, + 0xbf, 0x98, 0x8e, 0xb8, 0xe1, 0x18, 0xb6, 0xc2)}, + {} + }; + + MODULE_DEVICE_TABLE(tee, client_id_table); + + static struct tee_client_driver client_driver = { + .id_table = client_id_table, + .driver = { + .name = DRIVER_NAME, + .bus = &tee_bus_type, + .probe = client_probe, + .remove = client_remove, + }, + }; + + static int __init client_init(void) + { + return driver_register(&client_driver.driver); + } + + static void __exit client_exit(void) + { + driver_unregister(&client_driver.driver); + } + + module_init(client_init); + module_exit(client_exit); diff --git a/Documentation/driver-api/wbrf.rst b/Documentation/driver-api/wbrf.rst new file mode 100644 index 0000000000..f48bfa0298 --- /dev/null +++ b/Documentation/driver-api/wbrf.rst @@ -0,0 +1,78 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +================================= +WBRF - Wifi Band RFI Mitigations +================================= + +Due to electrical and mechanical constraints in certain platform designs +there may be likely interference of relatively high-powered harmonics of +the GPU memory clocks with local radio module frequency bands used by +certain Wifi bands. + +To mitigate possible RFI interference producers can advertise the +frequencies in use and consumers can use this information to avoid using +these frequencies for sensitive features. + +When a platform is known to have this issue with any contained devices, +the platform designer will advertise the availability of this feature via +ACPI devices with a device specific method (_DSM). +* Producers with this _DSM will be able to advertise the frequencies in use. +* Consumers with this _DSM will be able to register for notifications of +frequencies in use. + +Some general terms +================== + +Producer: such component who can produce high-powered radio frequency +Consumer: such component who can adjust its in-use frequency in +response to the radio frequencies of other components to mitigate the +possible RFI. + +To make the mechanism function, those producers should notify active use +of their particular frequencies so that other consumers can make relative +internal adjustments as necessary to avoid this resonance. + +ACPI interface +============== + +Although initially used by for wifi + dGPU use cases, the ACPI interface +can be scaled to any type of device that a platform designer discovers +can cause interference. + +The GUID used for the _DSM is 7B7656CF-DC3D-4C1C-83E9-66E721DE3070. + +3 functions are available in this _DSM: + +* 0: discover # of functions available +* 1: record RF bands in use +* 2: retrieve RF bands in use + +Driver programming interface +============================ + +.. kernel-doc:: drivers/platform/x86/amd/wbrf.c + +Sample Usage +============= + +The expected flow for the producers: +1. During probe, call `acpi_amd_wbrf_supported_producer` to check if WBRF +can be enabled for the device. +2. On using some frequency band, call `acpi_amd_wbrf_add_remove` with 'add' +param to get other consumers properly notified. +3. Or on stopping using some frequency band, call +`acpi_amd_wbrf_add_remove` with 'remove' param to get other consumers notified. + +The expected flow for the consumers: +1. During probe, call `acpi_amd_wbrf_supported_consumer` to check if WBRF +can be enabled for the device. +2. Call `amd_wbrf_register_notifier` to register for notification +of frequency band change(add or remove) from other producers. +3. Call the `amd_wbrf_retrieve_freq_band` initally to retrieve +current active frequency bands considering some producers may broadcast +such information before the consumer is up. +4. On receiving a notification for frequency band change, run +`amd_wbrf_retrieve_freq_band` again to retrieve the latest +active frequency bands. +5. During driver cleanup, call `amd_wbrf_unregister_notifier` to +unregister the notifier. diff --git a/Documentation/driver-api/dcdbas.rst b/Documentation/userspace-api/dcdbas.rst index 309cc57a7c..309cc57a7c 100644 --- a/Documentation/driver-api/dcdbas.rst +++ b/Documentation/userspace-api/dcdbas.rst diff --git a/Documentation/driver-api/isapnp.rst b/Documentation/userspace-api/isapnp.rst index 8d0840ac84..d6fceb19b8 100644 --- a/Documentation/driver-api/isapnp.rst +++ b/Documentation/userspace-api/isapnp.rst @@ -1,11 +1,11 @@ -========================================================== -ISA Plug & Play support by Jaroslav Kysela <perex@suse.cz> -========================================================== +======================= +ISA Plug & Play support +======================= Interface /proc/isapnp ====================== -The interface has been removed. See pnp.txt for more details. +The interface was removed in kernel 2.5.53. See pnp.rst for more details. Interface /proc/bus/isapnp ========================== |