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2021-01-12lib: sbi: Allow platforms to provide root domain memory regionsAnup Patel1-8/+8
Currently, the root domain memory regions are fixed in generic code but some of the platforms may want to explicitly define memory regions for the root domain. This patch adds optional domains_root_regions() platform callback which platforms can use to provide platform specific root domain memory regions. Due to this changes, the root domain should also undergo all sanity checks (just like regular domain) so we use sbi_domain_register() to register root domain. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2021-01-07lib: utils: Fix shakti uart implementationVijai Kumar K1-2/+6
Fix uart_putc implementation. Due to a bug in the IP, this went unnoticed. Use macros instead of magic numbers to make the code more readable. Signed-off-by: Vijai Kumar K <vijai@behindbytes.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-01-07lib: sbi: Allow custom local TLB flush functionAnup Patel3-51/+33
Currently, we have fixed TLB flush types supported by the remote TLB library. This approach is not flexible and does not allow custom local TLB flush function. For example, after updating PMP entries on a set of HARTs at runtime, we have to flush TLB on these HARTs as well. To support custom local TLB flush function, we replace the "type" field of "struct sbi_tlb_info" with a local TLB flush function pointer. We also provide definitions of standard TLB flush operations (such as fence_i, sfence.vma, hfence.vvma, hfence.gvma, etc). Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2021-01-07lib: sbi: Introduce sbi_trap_exit() APIAnup Patel1-0/+20
We introduce sbi_trap_exit() API which can help non-firmware (i.e. generic or platform) code to force exit trap/interrupt handling and resume execution at context pointed by parameter "const struct sbi_trap_regs *regs". This new sbi_trap_exit() API will help Keystone Enclave project to resume execution of enclave from custom SBI call handler. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2021-01-07lib: sbi: Replace args with trap registers in ecall handlerAnup Patel6-55/+59
We had added args pointer in ecall handler to ensure that ecall handler only implements functionality and does not deal with SBI calling convention. This also helped us to keep SBI calling convention related code in one place at sbi_ecall_handler(). The Keystone Enclavce project needs access to the trap regsiters in their ecall handler so that they can context switch enclaves in custom SBI calls. To help the Keystone Enclave project, we replace the args pointer in ecall handler parameter with a const pointer to trap registers. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-24lib: sbi: Fix sign-extension in sbi_misaligned_load_handler()Anup Patel1-1/+1
The misaligned load emulation does not sign-extend values correctly due to missing sign typecast in value passed to the SET_RD() macro. A very easy way to reproduce this issue is to load 16-bit value 0xff1e from a byte aligned address using LH instruction on hardware lacking misaligned load/store. This patch fixes sbi_misaligned_load_handler() for above issue. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-16lib: sbi: Remove domain_get() platform callback functionAnup Patel1-75/+3
The domain_get() platform callback function is now redundant because fdt_domain_populate() register new domain explicitly using the sbi_domain_register() function. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-16lib: utils: Remove fdt_domain_get() functionAnup Patel1-47/+36
The fdt_domain_get() function is now redundant because the fdt_domains_populate() function can explicitly register new domains using the sbi_domain_register() function. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-16lib: sbi: Add function to register new domainAnup Patel1-0/+71
We add sbi_domain_register() function to help platform code register a new domain explicitly instead of depending on domain_get() platform callback. This function will eventually help us completely remove the domain_get() platform callback. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-16lib: utils: Allow FDT domain iteration functions to failAnup Patel1-47/+68
We extend fdt_iterate_each_domain() and fdt_iterate_each_memregion() functions to allow underlying iteration function to fail. This will help us catch more domain misconfiguration issues at boot time. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-13lib: utils/libfdt: Upgrade to v1.6.0 releaseDimitri John Ledkov11-154/+356
Sync with libfdt v1.6.0 release source codes. Signed-off-by: Dimitri John Ledkov <xnox@ubuntu.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-12-04lib: utils: Add helper routines to populate domains from FDTAnup Patel2-0/+446
We add various helper routines to populate domains, iterate domains, iterate domain memregions, and parse HART to domain assignment from the FDT. These helper routines can be used by platform support code and FDT fixup code. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-04include: sbi: Add domains_init() platform operationAnup Patel1-0/+8
We introduce domains_init() platform operation which can be used by platform support to initialize/populate domains in the coldboot path. The domains_init() is called late in the coldboot sequence from the sbi_domain_finalize() so sbi_printf() can be used by platform support to print errors/warnings at time of populating domains. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-04lib: sbi: Add error prints in sbi_domain_finalize()Anup Patel1-11/+52
We add error prints in sbi_domain_finalize() and sanitize_domain() to help debug domain configuration issues. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-04lib: sbi: Override domain boot HART when coldboot HART assigned to itAnup Patel1-0/+11
If coldboot HART is assigned to a domain then we should use coldboot HART as the boot HART of the domain. This allows coldboot HART to continue boot sequence even when it is assigned to some non-root domain. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-04lib: sbi: Auto start domain only if boot HART within limitsAnup Patel1-0/+4
The sbi_domain_finalize() should auto start a domain only if the boot HART is withing limits (i.e. less than SBI_HARTMASK_MAX_BITS). Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-04lib: sbi: Fix domain_count check in sbi_domain_finalize()Anup Patel1-1/+1
The domain_count check in sbi_domain_finalize() for newly discovered domain is incorrect and should be reversed. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-04lib: sbi: Fix typo in sbi_domain_finalize()Anup Patel1-2/+2
There has been typo in automatic domain boot hart startup for non-root domains so this patch fixes it. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-04lib: sbi: Fix sbi_hart_switch_mode() for u-modeAnup Patel1-3/+5
We should check and access N-extension CSRs in sbi_hart_switch_mode() when next_mode is u-mode because N-extension is optional. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-01lib: sbi: Implement System Reset (SRST) SBI extensionAnup Patel2-0/+63
The SBI SRST extension has been accepted and merged in the latest SBI v0.3-draft specification. (Refer, https://github.com/riscv/riscv-sbi-doc) It allows to S-mode software to request system shutdown, cold reboot, and warm reboot. This patch implements SBI SRST extension as a replacement of the legacy sbi_shutdown() call of SBI v0.1 specification. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-01lib: sbi: Improve system reset platform operationsAnup Patel7-12/+49
To implement the SBI SRST extension, we need two platform operations for system reset: 1) system_reset_check() - This operation will check whether given reset type and reason are supported by the platform 2) system_reset() - This operation will do the actual platform system reset and it will not return if reset type and reason are supported by the platform This patch updates system reset related code everywhere as-per above. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-12-01include: sbi: Remove opensbi specific reset type definesAnup Patel3-6/+6
We can now use the standard SBI SRST extension reset types instead of the opensbi specific (SBI_PLATFORM_RESET_xyz) reset types hence remove related opensbi specific defines. The "platform_" prefix of the reset type parameter of sbi_system_reset() function should also be removed. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-11-10lib: sbi: Improve boot prints in cold boot sequenceAnup Patel1-21/+69
Currently, we have all boot prints at the end of cold boot sequence which means if there is any failure in cold boot sequence before boot prints then we don't get any print. This patch improves boot prints in cold boot sequence as follows: 1. We divide the boot prints into multiple parts and print it from different locations after sbi_console_init() 2. We throw an error print if there is any failure in cold boot sequence after sbi_console_init() Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-26lib: sbi: Improve boot time print with additional PMP informationAtish Patra1-14/+23
We know about pmp granularity and number of bits supported by PMP. Show those information in the boot time info print Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-10-26lib: sbi: Detect PMP granularity and number of address bitsAtish Patra1-4/+58
As per RISC-V privilege specification, a platform may choose to implement a coarser granularity scheme for PMP addresses. In that case, we shouldn't allow any pmp region size smaller than the platform supports. A platform may not also implement all the bits for a PMP address specified in the priv specification. The pmp range granularity and address bits should be detected dynamically before detecing PMP regions. Any pmp modification request beyond these detected value must not succeed. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-10-23lib: utils: Implement "ranges" property parsingAtish Patra1-2/+48
The "reg" property in a device node may not be the correct address always. If a parent node defines a "ranges" property, the child address need to be translated with respect to parents address. If the ranges property is not present, it will just use 1:1 translation. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-10-21lib: sbi: Display domain details in boot printsAnup Patel3-46/+119
We extend boot prints to display details of each domain. In the process, we remove sbi_hart_pmp_dump() because it shows redundant information which domain details already show. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-20lib: sbi: Configure PMP based on domain memory regionsAnup Patel1-15/+22
The PMP configuration on each HART should be only based on the memory regions of the assigned domain because each domain includes a memory region to protect the underlying firmware. This patch updates the sbi_hart_pmp_configure() function accordingly. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-20lib: sbi: Remove redundant sbi_hart_pmp_xyz() functionsAnup Patel1-42/+0
The sbi_hart_pmp_get() and sbi_hart_pmp_check_addr() functions are not used anymore hence this patch removes these functions. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-20lib: utils: Update fdt_cpu_fixup() to use current domainAnup Patel1-5/+3
The fdt_cpu_fixup() should disable a HART in DT if the HART is not assigned to the current HART domain. This patch updates fdt_cpu_fixup() accordingly. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-20lib: utils: Update fdt_reserved_memory_fixup() to use current domainAnup Patel1-25/+22
Now that each HART is mapped to a domain having a set of memory regions, we update fdt_reserved_memory_fixup() to use domain memory regions for adding reserved memory nodes in device tree. We also change reserved memory node name prefix from "mmode_pmp" to "mmode_resv" because domain memory regions can impact other hardware configurations (such as IOPMP, etc) along with PMP. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-20lib: sbi: Extend sbi_system_reset() for domainsAnup Patel1-3/+4
The sbi_system_reset() should issue platform system reset only if domain of current HART is allowed to do system reset. This patch extends sbi_system_reset() as-per above. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-20lib: sbi: Optimize sbi_hsm_hart_started_mask() implementationAnup Patel1-12/+22
Instead of calling sbi_hsm_hart_get_state() in a loop, we can simply call a new inline __sbi_hsm_hart_get_state() which only takes "hartid" and enforce domain checks using sbi_domain_assigned_hartmask(). This patch optimizes sbi_hsm_hart_started_mask() as-per above. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-20lib: sbi: Extend sbi_hsm_hart_start() for domainsAnup Patel3-13/+16
The sbi_hsm_hart_start() should consider the domain under which we are trying to start the HART. This will help ensure that HART A can start HART B only if both HARTs A and B belong to the same domain. We also have a special case when we bring-up boot HART of non-root domains in sbi_domain_finalize() where we should skip domain checks in sbi_hsm_hart_start(). To achieve this, sbi_hsm_hart_start() should do domain checks only when domain parameter is non-NULL. This patch extends sbi_hsm_hart_start() as-per above. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-20lib: sbi: Extend sbi_hsm_hart_started_mask() for domainsAnup Patel5-12/+23
The sbi_hsm_hart_started_mask() API should take one more parameter to allow caller specify domain under which started_mask is being generated. Further, the sbi_hsm_hart_started_mask() depends on sbi_hsm_hart_get_state() which also should return HART state under specified domain. This patch updates both sbi_hsm_hart_started_mask() and sbi_hsm_hart_get_state() as-per above. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2020-10-20lib: sbi: Add initial domain supportAnup Patel3-0/+401
An OpenSBI domain is a logical entity representing a set of HARTs and a set of memory regions for these HARTs. The OpenSBI domains support will allow OpenSBI platforms and previous booting stage (i.e. U-Boot SPL, Coreboot, etc) to partition a system into multiple domains where each domain will run it's own software. For inter-domain isolation, OpenSBI will eventually use various HW features such as PMP, ePMP, IOPMP, SiFive shield, etc but initial implementation only use HW PMP support. This patch provides initial implementation of OpenSBI domains where we have a root/default domain and OpenSBI platforms can provide non-root/custom domains using domain_get() callback. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-10-20lib: sbi: Remove redundant hartid parameter from sbi_hart_init()Anup Patel2-9/+9
The hartid parameter of sbi_hart_init() is not used anywhere in sbi_hart_init() implementation so let's remove it. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2020-10-20lib: sbi: Configure PMP late in coldboot and warmboot pathAnup Patel2-2/+10
We factor-out PMP configuration from sbi_hart_init() as a separate sbi_hart_pmp_configure() function and do the PMP configuration very late in coldboot and warmboot path just before platform_final_init(). Eventually, this enable us to configure PMP totally based on OpenSBI domain where OpenSBI domains can be parsed from device-tree in any of the platform operations except platform_final_init(). Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2020-10-20include: sbi: Remove pmp_region callbacks from sbi_platform_operationsAnup Patel1-13/+1
The pmp_region_xyz() callbacks are not required in sbi_platform_operations because we will be using OpenSBI domain memory regions to program the PMP CSRs. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2020-10-20include: sbi: Remove redundant includes from sbi_platform.hAnup Patel1-0/+1
The sbi_ecall.h and sbi_trap.h are not required to be included in sbi_platform.h hence we remove it. This way sources requiring these headers will have to explicitly include it thereby reducing implicit includes. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2020-09-25lib: sbi: Fix PMP CSR detectionPragnesh Patel1-1/+1
HiFive unleashed currently implements fewer than 56 bits of physical address so existing PMP CSR detection is broken. PMP address register encodes bits 55-2 of a 56-bit physical address, Not all physical address bits may be implemented, So just check minimum 1 bit. Fixes: 74d1db706293 ("lib: sbi: Improve PMP CSR detection and progamming") Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-09-16lib: sbi: Ensure coldboot HART supports next privilege modeAnup Patel1-1/+28
The coldboot HART jumps to the next booting stage at the end of init_coldboot() so it is absolutely necessary for coldboot HART to support the privilege mode expected by the next booting stage. We extend the coldboot HART selection in sbi_init() to ensure that the selected coldboot HART always supports privilege mode specified in scratch space (i.e. scratch->next_mode). This will further help us allow E-core (without MMU) on SiFive Unleashed and PolarFire ICICLE boards to proceed further and wait in HSM STOPPED state. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-09-16lib: utils: Improve fdt_cpu_fixup() implementationAnup Patel1-2/+11
The fdt_cpu_fixup() should work fine even if HARTs without MMU are not marked invalid by platform support code. In future, we plan to treat HARTs without MMU as valid in the generic platform support so that we can hold these HARTs in HSM STOPPED state. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-09-16lib: sbi: Allow specifying mode in sbi_hart_pmp_check_addr() APIAnup Patel3-18/+30
We extend sbi_hart_pmp_check_addr() API so that users can specify privilege mode of the address for checking PMP access permissions. To achieve this, we end-up converting "unsigned long *size" parameter to "unsigned long *log2len" for pmp_get() implementation so that we can deal with regions of "1UL << __riscv_xlen" size in a special case in sbi_hart_pmp_check_addr() implementation. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-09-16lib: sbi: Allow specifying start mode to sbi_hsm_hart_start() APIAnup Patel2-2/+10
The sbi_scratch already has provision to specify the next stage mode so we can leverage this to specify start mode to sbi_hsm_hart_start(). In future, this will be useful in providing SBI calls to U-mode on embedded cores where we M-mode and U-mode but no S-mode. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-09-09lib: sbi_trap: Allow M-mode to M-mode ECALLsAnup Patel1-0/+1
We should allow M-mode to M-mode ECALLs because: 1. No other mode can handle M-mode ECALLs 2. In future, we can allow M-mode baremetal application (not linked to OpenSBI) running independently and cooperatively without corrupting OpenSBI M-mode state (CSRs and memory). Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-09-09include: Rename ECALL defines to match latest RISC-V specAnup Patel2-2/+2
We rename CAUSE_HYPERVISOR_ECALL to CAUSE_SUPERVISOR_ECALL and CAUSE_SUPERVISOR_ECALL to CAUSE_VIRTUAL_SUPERVISOR_ECALL so that it matches latest RISC-V privilege spec. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-09-09lib: sbi: Don't handle VS-mode ecall in sbi_trap_handler()Anup Patel1-1/+0
The VS-mode ecall is supposed to be handled by HS-mode so sbi_trap_handler() should fallback to default case for VS-mode ecall trap. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-09-01lib: sbi: Improve HPM CSR read/write emulationAnup Patel1-72/+75
We improve HPM CSR read/write emulation as follows: 1. Fail for unimplemented counters so that trap is redirected to S-mode which can further help debugging S-mode software. 2. Check permissions in both MCOUNTEREN and SCOUNTEREN for HS-mode and U-mode. 3. Don't check permissions for TIME CSR because we emulate TIME CSR for both Host (HS/U-mode) and Guest (VS/VU-mode). Also, faster TIME CSR read is very helpful for good performance of S-mode software. 4. Don't emulate S-mode CSR read/write to M-mode HPM CSRs because these should not be accessible to S-mode software. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-09-01lib: sbi: Detect and print MHPM counters at boot-timeAnup Patel2-0/+18
A RISC-V platform can leave unimplemented MHPM counters hard-wired to zero. We extend hart_detect_features() to detect MHPM counters which are accessible and not hard-wired to zero. We also print number of available MHPM counters as part of boot prints. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>