starfive-tech/u-boot.git/arch/x86/include/asm/mp.h, branch rtthread_AMP

x86: Update the MP constants to avoid conflicts

2021-07-15T11:50:04+00:00

These constants conflict with error codes returned by the MP implementation when something is wrong. In particular, mp_first_cpu() returns MP_SELECT_BSP when running without multiprocessing enabled. Since this is -2, it is interpreted as an error by callers, which expect a positive CPU number for the first CPU. Correct this by using a different range for the pre-defined CPU numbers, above zero and out of the range of possible CPU values. For now it is safe to assume there are no more than 64K CPUs. This fixes the 'mtrr' command when CONFIG_SMP is not enabled. Signed-off-by: Simon Glass Reviewed-by: Bin Meng

common: Drop asm/global_data.h from common header

2021-02-02T20:33:42+00:00

Move this out of the common header and include it only where needed. In a number of cases this requires adding "struct udevice;" to avoid adding another large header or in other cases replacing / adding missing header files that had been pulled in, very indirectly. Finally, we have a few cases where we did not need to include at all, so remove that include. Signed-off-by: Simon Glass Signed-off-by: Tom Rini

x86: Drop unnecessary mp_init logic

2020-12-19T03:32:21+00:00

Now that sequence numbers are set up when devices are bound, this code is not needed. Also, we should use dev_seq() instead of req_seq. Update the whole file accordingly. Also fix up APL cpu while we are here. Signed-off-by: Simon Glass

x86: mp: Add more comments to the module

2020-07-20T01:46:48+00:00

Add a description of how this module works and also some missing function comments. Signed-off-by: Simon Glass Reviewed-by: Wolfgang Wallner Reviewed-by: Bin Meng

x86: Don't enable SMP in SPL

2020-07-20T01:46:46+00:00

SMP should be set up in U-Boot where possible, not SPL. Disable it in SPL. For 64-bit U-Boot we should find a way to allow SMP operations in U-Boot, but this is somewhat more complicated. For now that is disabled too. Signed-off-by: Simon Glass Reviewed-by: Bin Meng Reviewed-by: Wolfgang Wallner

x86: mp: Add iterators for CPUs

2020-07-20T01:46:46+00:00

It is convenient to iterate through the CPUs performing work on each one and processing the result. Add a few iterator functions which handle this. These can be used by any client code. It can call mp_run_on_cpus() on each CPU that is returned, handling them one at a time. Signed-off-by: Simon Glass Reviewed-by: Wolfgang Wallner Reviewed-by: Bin Meng

x86: mp: Park CPUs before running the OS

2020-07-20T01:46:46+00:00

With the new MP features the CPUs are no-longer parked when the OS is run. Fix this by calling a special function to park them, just before the OS is started. Signed-off-by: Simon Glass Reviewed-by: Wolfgang Wallner Reviewed-by: Bin Meng

x86: mp: Allow running functions on multiple CPUs

2020-07-20T01:46:45+00:00

Add a way to run a function on a selection of CPUs. This supports either a single CPU, all CPUs, just the main CPU or just the 'APs', in Intel terminology. It works by writing into a mailbox and then waiting for the CPUs to notice it, take action and indicate they are done. When SMP is not yet enabled, this just calls the function on the main CPU. Signed-off-by: Simon Glass Reviewed-by: Wolfgang Wallner Reviewed-by: Bin Meng

x86: mp: Support APs waiting for instructions

2020-07-20T01:46:45+00:00

At present the APs (non-boot CPUs) are inited once and then parked ready for the OS to use them. However in some cases we want to send new requests through, such as to change MTRRs and keep them consistent across CPUs. Change the last state of the flight plan to go into a wait loop, accepting instructions from the main CPU. Drop cpu_map since it is not used. Signed-off-by: Simon Glass Reviewed-by: Wolfgang Wallner Reviewed-by: Bin Meng

x86: mp_init: Avoid declarations in header files

2020-07-20T01:46:43+00:00

The functions used by the flight plan are declared in the header file but are not used in any other file. Move the flight plan steps down to just above where it is used so that we can make these function static. Signed-off-by: Simon Glass Reviewed-by: Wolfgang Wallner Reviewed-by: Bin Meng