kernel/linux.git/drivers/mailbox/pcc.c, branch linux-6.0.y

mailbox: pcc: Reset pcc_chan_count to zero in case of PCC probe failure

2022-12-31T12:25:43+00:00

[ Upstream commit 6d7d3c287410c0ad499e478e2338dc3d7e3392b1 ] Currently, 'pcc_chan_count' is remains set to a non-zero value if PCC subspaces are parsed successfully but something else fail later during the initial PCC probing phase. This will result in pcc_mbox_request_channel trying to access the resources that are not initialised or allocated and may end up in a system crash. Reset pcc_chan_count to 0 when the PCC probe fails in order to prevent the possible issue as described above. Fixes: ce028702ddbc ("mailbox: pcc: Move bulk of PCCT parsing into pcc_mbox_probe") Signed-off-by: Huisong Li Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

mailbox: pcc: Fix an invalid-load caught by the address sanitizer

2022-05-21T16:41:30+00:00

`pcc_mailbox_probe` doesn't initialize all memory that has been allocated before the first time that one of it's members `txdone_irq` may be accessed. This leads to a an invalid load any time that this member is accessed: [ 2.429769] UBSAN: invalid-load in drivers/mailbox/pcc.c:684:22 [ 2.430324] UBSAN: invalid-load in drivers/mailbox/mailbox.c:486:12 [ 4.276782] UBSAN: invalid-load in drivers/acpi/cppc_acpi.c:314:45 Link: https://bugzilla.kernel.org/show_bug.cgi?id=215587 Fixes: ce028702ddbc ("mailbox: pcc: Move bulk of PCCT parsing into pcc_mbox_probe") Signed-off-by: Mario Limonciello Reviewed-by: Sudeep Holla Signed-off-by: Jassi Brar

mailbox: pcc: Handle all PCC subtypes correctly in pcc_mbox_irq

2022-01-12T05:47:33+00:00

Commit c45ded7e1135 ("mailbox: pcc: Add support for PCCT extended PCC subspaces(type 3/4)") enabled the type3/4 of PCCT, but the change in pcc_mbox_irq breaks the other PCC subtypes. The kernel reports a warning on an Ampere eMag server -->8 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.16.0-rc4 #127 Hardware name: MiTAC RAPTOR EV-883832-X3-0001/RAPTOR, BIOS 0.14 02/22/2019 Call trace: dump_backtrace+0x0/0x200 show_stack+0x20/0x30 dump_stack_lvl+0x68/0x84 dump_stack+0x18/0x34 __report_bad_irq+0x54/0x17c note_interrupt+0x330/0x428 handle_irq_event_percpu+0x90/0x98 handle_irq_event+0x4c/0x148 handle_fasteoi_irq+0xc4/0x188 generic_handle_domain_irq+0x44/0x68 gic_handle_irq+0x84/0x2ec call_on_irq_stack+0x28/0x34 do_interrupt_handler+0x88/0x90 el1_interrupt+0x48/0xb0 el1h_64_irq_handler+0x18/0x28 el1h_64_irq+0x7c/0x80 Fixes: c45ded7e1135 ("mailbox: pcc: Add support for PCCT extended PCC subspaces(type 3/4)") Reported-by: Justin He Tested-by: Justin He Signed-off-by: Sudeep Holla Signed-off-by: Jassi Brar

mailbox: pcc: Avoid using the uninitialized variable 'dev'

2022-01-12T05:47:33+00:00

Smatch static checker warns: | drivers/mailbox/pcc.c:292 pcc_mbox_request_channel() | error: uninitialized symbol 'dev'. Fix the same by using pr_err instead of dev_err as the variable 'dev' is uninitialized at that stage. Fixes: ce028702ddbc ("mailbox: pcc: Move bulk of PCCT parsing into pcc_mbox_probe") Cc: Jassi Brar Reported-by: Dan Carpenter Signed-off-by: Sudeep Holla Signed-off-by: Jassi Brar

mailbox: pcc: Move bulk of PCCT parsing into pcc_mbox_probe

2021-10-30T03:46:38+00:00

Move the PCCT subspace parsing and allocation into pcc_mbox_probe so that we can get rid of global PCC channel and mailbox controller data. It also helps to make use of devm_* APIs for all the allocations. Signed-off-by: Sudeep Holla Signed-off-by: Jassi Brar

mailbox: pcc: Add support for PCCT extended PCC subspaces(type 3/4)

2021-10-30T03:46:38+00:00

With all the plumbing in place to avoid accessing PCCT type and other fields directly from the PCCT table all the time, let us now add the support for extended PCC subspaces(type 3 and 4). Signed-off-by: Sudeep Holla Signed-off-by: Jassi Brar

mailbox: pcc: Drop handling invalid bit-width in {read,write}_register

2021-10-30T03:46:38+00:00

pcc_chan_reg_init now checks if the register bit width is within the list [8, 16, 32, 64] and flags error if that is not the case. Therefore there is no need to handling invalid bit-width in both read_register and write_register. We can drop that along with the return values for these 2 functions. Signed-off-by: Sudeep Holla Signed-off-by: Jassi Brar

mailbox: pcc: Avoid accessing PCCT table in pcc_send_data and pcc_mbox_irq

2021-10-30T03:46:38+00:00

Now that the con_priv is availvale solely for PCC mailbox controller driver, let us use the same to save the channel specific information in it so that we can it whenever required instead of parsing the PCCT table entries every time in both pcc_send_data and pcc_mbox_irq. We can now use the newly introduces PCC register bundle to simplify both saving of channel specific information and accessing them without repeated checks for the subspace type. Reviewed-by: Cristian Marussi Signed-off-by: Sudeep Holla Signed-off-by: Jassi Brar

mailbox: pcc: Add PCC register bundle and associated accessor functions

2021-10-30T03:46:38+00:00

Extended PCC subspaces introduces more registers into the PCCT. In order to consolidate access to these registers and to keep all the details contained in one place, let us introduce PCC register bundle that holds the ACPI Generic Address Structure as well as the virtual address for the same if it is mapped in the OS. It also contains the various masks used to access the register and the associated read, write and read-modify-write accessors. We can also clean up the initialisations by having a helper function for the same. Signed-off-by: Sudeep Holla Signed-off-by: Jassi Brar

mailbox: pcc: Rename doorbell ack to platform interrupt ack register

2021-10-30T03:46:38+00:00

The specification refers this register and associated bitmask as platform interrupt acknowledge register. Let us rename it so that it is easier to map and understand. Signed-off-by: Sudeep Holla Signed-off-by: Jassi Brar