kernel.git/drivers/net/ipa/gsi.c, branch linux-5.16.y

net: ipa: disable GSI interrupts while suspended

2021-08-04T09:12:05Z

Introduce new functions gsi_suspend() and gsi_resume(), which will disable the GSI interrupt handler after all endpoints are suspended and re-enable it before endpoints are resumed. This will ensure no GSI interrupt handler will fire when the hardware is suspended. Here's a little further explanation. There are seven GSI interrupt types, and most are disabled except when needed. - These two are not used (never enabled): GSI_INTER_EE_CH_CTRL GSI_INTER_EE_EV_CTRL - These two are only used to implement channel and event ring commands, and are only enabled while a command is underway: GSI_CH_CTRL GSI_EV_CTRL - The IEOB interrupt signals I/O completion. It will not fire when a channel is stopped (or "suspended"). GSI_IEOB - This interrupt is used to allocate or halt modem channels, and is only enabled while such a command is underway. GSI_GLOB_EE However it also is used to signal certain errors, and this could occur at any time. - The general interrupt signals general errors, and could occur at any time. GSI_GENERAL The purpose for this change is to ensure no global or general interrupts fire due to errors while the hardware is suspended. We enable the clock on resume, and at that time we can "handle" (at least report) these error conditions. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: move gsi_irq_init() code into setup

2021-08-04T09:12:05Z

The GSI IRQ handler could be triggered as soon as it is registered with request_irq(). The handler function, gsi_isr(), touches hardware, meaning the IPA clock must be operational. The IPA clock is not operating when the handler is registered (in gsi_irq_init()), so this is a problem. Move the call to request_irq() for the GSI interrupt handler into gsi_irq_setup(), which is called when the IPA clock is known to be operational (and furthermore, the GSI firmware will have been loaded). Request the IRQ at the end of that function, after all interrupt types have been disabled and masked. Move the matching free_irq() call into gsi_irq_teardown(), and get rid of the now empty gsi_irq_exit(), Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: have gsi_irq_setup() return an error code

2021-08-04T09:12:05Z

Change gsi_irq_setup() so it returns an error value, and introduce gsi_irq_teardown() as its inverse. Set the interrupt type (IRQ rather than MSI) in gsi_irq_setup(). Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: move some GSI setup functions

2021-08-04T09:12:05Z

Move gsi_irq_setup() and gsi_ring_setup() so they're defined right above gsi_setup() where they're called. This is a trivial movement of code to prepare for upcoming patches. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: move version check for channel suspend/resume

2021-08-04T09:12:05Z

Change the Boolean flags passed to __gsi_channel_start() and __gsi_channel_stop() so they represent whether the request is being made to implement suspend (versus stop) or resume (versus start). Then stop or start the channel for suspend/resume requests only if the hardware version indicates it should be done. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: use gsi->version for channel suspend/resume

2021-08-04T09:12:05Z

The GSI layer has the IPA version now, so there's no need for version-specific flags to be passed from IPA. One instance of this is in gsi_channel_suspend() and gsi_channel_resume(), which indicate whether or not the endpoint suspend is implemented by GSI stopping the channel. We can make that determination based on gsi->version, eliminating the need for a Boolean flag in those functions. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: kill the remaining conditional validation code

2021-07-26T21:38:11Z

There are only a few remaining spots that validate IPA code conditional on whether a symbol is defined at compile time. The checks are not expensive, so just build them always. This completes the removal of all CONFIG_VALIDATE/CONFIG_VALIDATION IPA code. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: introduce gsi_ring_setup()

2021-06-21T19:30:59Z

Prior to IPA v3.5.1, there is no HW_PARAM_2 GSI register, which we use to determine the number of channels and endpoints per execution environment. In that case, we will just assume the number supported is the maximum supported by the driver. Introduce gsi_ring_setup() to encapsulate the code that determines the number of channels and endpoints. Update GSI_EVT_RING_COUNT_MAX so it is big enough to handle any available channel for all supported hardware (IPA v4.9 can have 23 channels and 24 event rings). Signed-off-by: Alex Elder Acked-by: AngeloGioacchino Del Regno Signed-off-by: David S. Miller

net: ipa: inter-EE interrupts aren't always available

2021-06-21T19:30:59Z

The GSI inter-EE interrupts are not supported prior to IPA v3.5. Don't attempt to initialize them in gsi_irq_setup() for hardware that does not support them. Originally proposed by AngeloGioacchino Del Regno. Link: https://lore.kernel.org/netdev/20210211175015.200772-4-angelogioacchino.delregno@somainline.org Signed-off-by: Alex Elder Acked-by: AngeloGioacchino Del Regno Signed-off-by: David S. Miller

net: ipa: fix inter-EE IRQ register definitions

2021-05-06T23:32:10Z

In gsi_irq_setup(), two registers are written with the intention of disabling inter-EE channel and event IRQs. But the wrong registers are used (and defined); the ones used are read-only registers that indicate whether the interrupt condition is present. Define the mask registers instead of the status registers, and use them to disable the inter-EE interrupt types. Fixes: 46f748ccaf01 ("net: ipa: explicitly disallow inter-EE interrupts") Signed-off-by: Alex Elder Link: https://lore.kernel.org/r/20210505223636.232527-1-elder@linaro.org Signed-off-by: Jakub Kicinski