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2025-12-08lib: sbi_domain: Allow MMIO access to non-MMIO rangesSamuel Holland
Currently, platforms do not provide complete memory region information to OpenSBI. Generally, memory regions are only created for the few MMIO devices that have M-mode drivers. As a result, most MMIO devices fall inside the default S-mode RWX memory region, which does _not_ have the MMIO flag set. In fact, OpenSBI relies on certain S-mode MMIO devices being inside non-MMIO memory regions. Both fdt_domain_based_fixup_one() and mpxy_rpmi_sysmis_xfer() call sbi_domain_check_addr() with the MMIO flag cleared, and that function currently requires an exact flag match. Those access checks will thus erroneously fail if the platform creates memory regions with the correct flags for these devices (or for a larger MMIO region containing these devices). We should not ignore the MMIO flag entirely, because sbi_domain_check_addr() is also used to check the permissions of S-mode shared memory buffers, and S-mode should not be using MMIO device addresses as memory buffers. But when checking if S-mode is allowed to do MMIO accesses, we need to recognize that MMIO devices appear in memory regions both with and without the MMIO flag set. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Yu-Chien Peter Lin <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-12-08lib: sbi: Enable Ssqosid Ext using mstateen0Chen Pei
The QoS Identifiers extension (Ssqosid) introduces the srmcfg register, which configures a hart with two identifiers: a Resource Control ID (RCID) and a Monitoring Counter ID (MCID). These identifiers accompany each request issued by the hart to shared resource controllers. If extension Smstateen is implemented together with Ssqosid, then Ssqosid also requires the SRMCFG bit in mstateen0 to be implemented. If mstateen0.SRMCFG is 0, attempts to access srmcfg in privilege modes less privileged than M-mode raise an illegal-instruction exception. If mstateen0.SRMCFG is 1 or if extension Smstateen is not implemented, attempts to access srmcfg when V=1 raise a virtual-instruction exception. This extension can be found in the RISC-V Instruction Set Manual: https://github.com/riscv/riscv-isa-manual Changes in v5: - Remove SBI_HART_EXT_SSQOSID dependency SBI_HART_PRIV_VER_1_12 Changes in v4: - Remove extraneous parentheses around SMSTATEEN0_SRMCFG Changes in v3: - Check SBI_HART_EXT_SSQOSID when swapping SRMCFG Changes in v2: - Remove trap-n-detect - Context switch CSR_SRMCFG Signed-off-by: Chen Pei <[email protected]> Reviewed-by: Radim Krčmář <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-12-02lib: sbi: Remove static variable root_memregs_countVladimir Kondratiev
Calculate number of used memory regions using helper function when needed. Signed-off-by: Vladimir Kondratiev <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-12-02lib: sbi: fix covered regions handling in sanitize_domain()Vladimir Kondratiev
In the sanitize_domain, code that checks for the case when one memory region covered by the other, was never executed. Quote: /* Sort the memory regions */ for (i = 0; i < (count - 1); i++) { <snip> } /* Remove covered regions */ while(i < (count - 1)) { Here "while" loop never executed because condition "i < (count - 1)" is always false after the "for" loop just above. In addition, when clearing region, "root_memregs_count" should be adjusted as well, otherwise code that adds memory region in the "root_add_memregion" will use wrong position: /* Append the memregion to root memregions */ nreg = &root.regions[root_memregs_count]; empty entry will be created in the middle of regions array, new regions will be added after this empty entry while sanitizing code will stop when reaching empty entry. Fixes: 3b03cdd60ce5 ("lib: sbi: Add regions merging when sanitizing domain region") Signed-off-by: Vladimir Kondratiev <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-12-01lib: sbi_pmu: Fix xINH bits configuringShifrin Dmitry
Before this patch sbi_pmu_ctr_start() ignores flags received in sbi_pmu_ctr_cfg_match() including inhibit ones. To prevent it, save flags together with event_data and use them both in sbi_pmu_ctr_start(). Fixes: 1db95da2997b ("lib: sbi: sbi_pmu: fixed hw counters start for hart") Signed-off-by: Shifrin Dmitry <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-11-02lib: sbi_domain_context: preserve firmware PMP entries during domain context ↵Yu-Chien Peter Lin
switch When SmePMP is enabled, clearing firmware PMP entries during a domain context switch can temporarily revoke access to OpenSBI’s own code and data, leading to faults. Keep firmware PMP entries enabled across switches so firmware regions remain accessible and executable. Signed-off-by: Yu-Chien Peter Lin <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-11-02lib: sbi: sbi_hart: track firmware PMP entries for SmePMPYu-Chien Peter Lin
Add fw_smepmp_ids bitmap to track PMP entries that protect firmware regions. Allow us to preserve these critical entries across domain transitions and check inconsistent firmware entry allocation. Also add sbi_hart_smepmp_is_fw_region() helper function to query whether a given SmePMP entry protects firmware regions. Signed-off-by: Yu-Chien Peter Lin <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-11-02lib: sbi_domain: ensure consistent firmware PMP entriesYu-Chien Peter Lin
During domain context switches, all PMP entries are reconfigured which can clear firmware access permissions, causing M-mode access faults under SmePMP. Sort domain regions to place firmware regions first, ensuring consistent firmware PMP entries so they won't be revoked during domain context switches. Signed-off-by: Yu-Chien Peter Lin <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-11-02lib: sbi_domain: add SBI_DOMAIN_MEMREGION_FW memregion flagYu-Chien Peter Lin
Add a new memregion flag, SBI_DOMAIN_MEMREGION_FW and mark the OpenSBI code and data regions. Signed-off-by: Yu-Chien Peter Lin <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-11-02lib: sbi_hart: return error when insufficient PMP entries availableYu-Chien Peter Lin
Previously, when memory regions exceed available PMP entries, some regions were silently ignored. If the last entry that covers the full 64-bit address space is not added to a domain, the next stage S-mode software won't have permission to access and fetch instructions from its memory. So return early with error message to catch such situation. Signed-off-by: Yu-Chien Peter Lin <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-11-02lib: sbi_domain: print unsupported SmePMP permissionsYu-Chien Peter Lin
The reg->flag is encoded with 6 bits to specify RWX permissions for M-mode and S-/U-mode. However, only 16 of the possible encodings are valid on SmePMP. Add a warning message when an unsupported permission encoding is detected. Signed-off-by: Yu-Chien Peter Lin <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-11-02lib: sbi_domain: allow specifying inaccessible regionYu-Chien Peter Lin
According to the RISC‑V Privileged Specification, SmePMP regions that grant no access in any privilege mode are valid. Allow such regions to be specified. Signed-off-by: Yu-Chien Peter Lin <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-11-02lib: sbi_hart: move sbi_hart_get_smepmp_flags() to sbi_domainYu-Chien Peter Lin
Move sbi_hart_get_smepmp_flags() from sbi_hart.c to sbi_domain.c and rename it to sbi_domain_get_smepmp_flags() to better reflect its purpose of converting domain memory region flags to PMP configuration. Also removes unused parameters (scratch and dom). Signed-off-by: Yu-Chien Peter Lin <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-28lib: sbi: Add system_resume callback for restoring the systemNick Hu
The last core who performs the system suspend is responsible for restoring the system after waking up. Add the system_resume callback for restoring the system from suspend. Suggested-by: Anup Patel <[email protected]> Signed-off-by: Nick Hu <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-28lib: sbi: Extends sbi_ipi_raw_send() to use all available IPI devicesNick Hu
A platform may contain multiple IPI devices. In certain use cases, such as power management, it may be necessary to send an IPI through a specific device to wake up a CPU. For example, if an IMSIC is powered down and reset, the core cannot receive IPIs from it, so the wake-up must instead be triggered through the CLINT. Suggested-by: Anup Patel <[email protected]> Signed-off-by: Nick Hu <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-28lib: sbi: Add SiFive proprietary xsfceaseNick Hu
Using ISA string "xsfcease" to detect the support of the custom instruction "CEASE". Reviewed-by: Cyan Yang <[email protected]> Reviewed-by: Anup Patel <[email protected]> Signed-off-by: Nick Hu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-28lib: sbi: Add SiFive proprietary xsfcflushdloneNick Hu
Using ISA string "xsfcflushdlone" to detect the support of the SiFive L1D cache flush custom instruction. Reviewed-by: Cyan Yang <[email protected]> Reviewed-by: Anup Patel <[email protected]> Signed-off-by: Nick Hu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-27lib: sbi: sbi_pmu: added checks for ctr_idx in matchAlexander Chuprunov
Previously, in sbi_pmu_ctr_cfg_match() function, ctr_idx was used immediately after pmu_ctr_find_fw() or pmu_ctr_find_hw() calls. In first case, array index was (ctr_idx - num_hw_ctrs), in second - ctr_idx. But pmu_ctr_find_fw() and pmu_ctr_find_hw() functions can return negative value, in which case writing in arrays with such indexes would corrupt sbi_pmu_hart_state structure. To avoid this situation, direct ctr_idx value check added. Signed-off-by: Alexander Chuprunov <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-27lib: sbi: sbi_pmu: fixed alignmentAlexander Chuprunov
Deleted spaces before brace in pmu_ctr_start_fw() for correct alignment. Signed-off-by: Alexander Chuprunov <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-27lib: sbi: sbi_pmu: fixed hw counters start for hartAlexander Chuprunov
Generally, hardware performance counters can only be started, stopped, or configured from machine-mode using mcountinhibit and mhpmeventX CSRs. Also, in opensbi only sbi_pmu_ctr_cfg_match() managed mhpmeventX. But in generic Linux driver, when perf starts, Linux calls both sbi_pmu_ctr_cfg_match() and sbi_pmu_ctr_start(), while after hart suspend only sbi_pmu_ctr_start() command called through SBI interface. This doesn't work properly in case when suspend state resets HPM registers. In order to keep counter integrity, sbi_pmu_ctr_start() modified. First, we're saving hw_counters_data, and after hart suspend this value is restored if event is currently active. Signed-off-by: Alexander Chuprunov <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-21lib: Allow custom CSRs in csr_read_num() and csr_write_num()Anup Patel
Some of the platforms use platform specific CSR access functions for configuring implementation specific CSRs (such as PMA registers). Extend the common csr_read_num() and csr_write_num() to allow custom CSRs so that platform specific CSR access functions are not needed. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Andrew Jones <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-06lib: sbi: Prevent target domain same as the currentXiang W
Add error handling code to sbi_domain_context_enter to prevent the target domain from being the same as the current domain. Signed-off-by: Xiang W <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-06lib: sbi: Add hart context init when first call enterXiang W
When entering sbi_domain_context_enter for the first time, the hart context may not be initialized. Add initialization code. Signed-off-by: Xiang W <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-10-06lib: sbi: Add error handling to switch_to_next_domain_contextXiang W
Add error handling to switch_to_next_domain_context to ensure legal input. When switching contexts, ensure that the target to be switched is different from the current one. Signed-off-by: Xiang W <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-09-16lib: sbi_hsm: Use 64-bit CSR macro for menvcfgSamuel Holland
Simplify the code and remove preprocessor checks by treating menvcfg and menvcfgh together as one 64-bit value. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-09-16lib: sbi_hart: Do not call delegate_traps() in the resume flowSamuel Holland
The only purpose of this function is to program the initial values of mideleg and medeleg. However, both of these CSRs are now saved/restored across non-retentive suspend, so the values from this function are always overwritten by the restored values. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-09-16lib: sbi_hsm: Save mideleg across non-retentive suspendSamuel Holland
OpenSBI updates mideleg when registering or unregistering the PMU SSE event. The updated CSR value must be saved across non-retentive suspend, or PMU SSE events will not be delivered after the hart is resumed. Fixes: b31a0a24279d ("lib: sbi: pmu: Add SSE register/unregister() callbacks") Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-09-16include: sbi: Remove platform specific IPI initAnup Patel
The platform specfic IPI init is not need anymore because using IPI device rating multiple IPI devices can be registered in any order as part of the platform specific early init. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Samuel Holland <[email protected]> Tested-by: Nick Hu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-09-16lib: sbi: Introduce IPI device ratingAnup Patel
A platform can have multiple IPI devices (such as ACLINT MSWI, AIA IMSIC, etc). Currently, OpenSBI rely on platform calling the sbi_ipi_set_device() function in correct order and prefer the first avaiable IPI device which is fragile. Instead of the above, introduce IPI device rating and prefer the highest rated IPI device. This further allows extending the sbi_ipi_raw_clear() to clear all available IPI devices. Signed-off-by: Anup Patel <[email protected]> Tested-by: Nick Hu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-09-01lib: sbi_heap: Simplify allocation algorithmSamuel Holland
Now that the allocator cannot run out of nodes in the middle of an allocation, the code can be simplified greatly. First it moves bytes from the beginning and/or end of the node to new nodes in the free list as necessary. These new nodes are inserted into the free list in address order. Then it moves the original node to the used list. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]> Tested-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-09-01lib: sbi_heap: Allocate list nodes dynamicallySamuel Holland
Currently the heap has a fixed housekeeping factor of 16, which means 1/16 of the heap is reserved for list nodes. But this is not enough when there are many small allocations; in the worst case, 1/3 of the heap is needed for list nodes (32 byte heap_node for each 64 byte allocation). This has caused allocation failures on some platforms. Let's avoid trying to guess the best ratio. Instead, allocate more nodes as needed. To avoid recursion, the nodes are permanent allocations. So to minimize fragmentation, allocate them in small batches from the end of the last free space node. Bootstrap the free space list by embedding one node in the heap control struct. Some error paths are avoided because the nodes are allocated up front. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]> Tested-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-08-28dbtr: Fix sbi_dbtr_read_trig to read from CSRsJesse Taube
sbi_dbtr_read_trig returned the saved state of tdata{1-3}, when it should have returned the updated state read from CSRs. Update sbi_dbtr_read_trig to return updated state read from CSRs. Signed-off-by: Anup Patel <[email protected]> Signed-off-by: Jesse Taube <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-08-28dbtr: Add support for icount trigger typeJesse Taube
The linux kernel needs icount to implement hardware breakpoints. Signed-off-by: Jesse Taube <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-08-26lib: sbi: pmu: Improve loop in pmu_ctr_find_hwManuel Hernández Méndez
We do not need to iterate over all values in the loop, we can break the loop when we found a valid counter that is not started yet. Signed-off-by: Manuel Hernández Méndez <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-07-21lib: sbi: Only enable TM bit in scounterenAtish Patra
The S-mode should disable Cycle and instruction counter for user space to avoid side channel attacks. The Linux kernel already does this so that any random user space code shouldn't be able to monitor cycle/instruction without higher privilege mode involvement. Remove the CY/IR bits in scountern in OpenSBI. Reviewed-by: Anup Patel <[email protected]> Signed-off-by: Atish Patra <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-07-20lib: sbi: Remove redundant call to sbi_hart_expected_trap_addr()Alvin Chang
The variable "sbi_hart_expected_trap" has already been extern variable. Therefore, the program can directly refer to it instead of calling sbi_hart_expected_trap_addr(). Signed-off-by: Alvin Chang <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-06-17lib: sbi_platform: Add platform specific pmp_set() and pmp_disable()Chao-ying Fu
Allow platforms to implement platform specific PMP setup and PMP disable functions which are called before actual PMP CSRs are configured. Also, implement pmp_set() and pmp_disable() for MIPS P8700. Signed-off-by: Chao-ying Fu <[email protected]> Signed-off-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-06-16lib: sbi: dbtr: Fix update_triggers to match SBIJesse Taube
OpenSBI implements sbi_dbtr_update_trig as `sbi_dbtr_update_trig(unsigned long trig_idx_base, unsigned long trig_idx_mask)` yet SBI v3.0-rc7 Chapter 19. Debug Triggers Extension [0] declares it as `sbi_debug_update_triggers(unsigned long trig_count)` Change update_triggers to match SBI. [0] https://github.com/riscv-non-isa/riscv-sbi-doc/tree/v3.0-rc7/src/ext-debug-triggers.adoc Fixes: 97f234f15c96 ("lib: sbi: Introduce the SBI debug triggers extension support") Signed-off-by: Jesse Taube <[email protected]> Reviewed-by: Himanshu Chauhan <[email protected]> Tested-by: Charlie Jenkins <[email protected]> Reviewed-by: Charlie Jenkins <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-06-16lib: sbi: Optimize saddr mapping in sbi_dbtr.cXiang W
The original implementation mapped saddr individually for each entry. The updated code now maps saddr for all entries in a single operation. This change reduces the number of PMP (Physical Memory Protection) operations, improving efficiency and performance. Tested-by: Himanshu Chauhan <[email protected]> Reviewed-by: Himanshu Chauhan <[email protected]> Signed-off-by: Xiang W <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-06-16lib: sbi: dbtr: Fix shared memory layoutJesse Taube
The existing sbi_dbtr_shmem_entry has a size of 5 * XLEN with the final entry being idx. This is in contrast to the SBI v3.0-rc7 Chapter 19. Debug Triggers Extension [0] where idx and trig_state share the same offset (0) in shared memory, with a total size of 4 * XLEN for all the SBI calls. Replace struct with union to match memory layout described in SBI. [0] https://github.com/riscv-non-isa/riscv-sbi-doc/tree/v3.0-rc7/src/ext-debug-triggers.adoc Fixes: 97f234f15c96 ("lib: sbi: Introduce the SBI debug triggers extension support") Signed-off-by: Jesse Taube <[email protected]> Reviewed-by: Charlie Jenkins <[email protected]> Tested-by: Charlie Jenkins <[email protected]> Reviewed-by: Himanshu Chauhan <[email protected]> Tested-by: Himanshu Chauhan <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-06-16lib: sbi: Revert entry_count before doing hsm stop in hsm wait loopAnup Patel
Using hsm stop in hsm wait loop causes secondary harts to be stuck forever in OpenSBI on RISC-V platforms where HSM hart hotplug is available and all harts come-up at the same time during system power-on. For example, lets say we have two harts A and B on a RISC-V platform with HSM hart hotplug which come-up at the same time during system power-on. The hart A enters OpenSBI before hart B hence it becomes the primary (or cold-boot) hart whereas hart B becomes the secondary (or warm-boot) hart. The hart A follows the OpenSBI cold-boot path and registers hsm device before hart B enters OpenSBI. The hart B eventually enters OpenSBI and follows the OpenSBI warm-boot path so it will increment it's own entry_count before entering hsm wait loop where it sees hsm device and stops itself. Later as part of the Linux boot-up sequence, hart A issues SBI HSM start call to bring-up hart B but OpenSBI sees entry_count != init_count for hart B in sbi_hsm_hart_start() hence hsm_device_hart_start() is not called for hart B resulting in hart B stuck forever in OpenSBI. To fix the above issue, revert entry_count before doing hsm stop in hsm wait loop. Fixes: d844deadec94 ("lib: sbi: Use hsm stop for hsm wait") Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Nick Hu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-06-15lib: sbi: fwft: Use only the provided PMLEN valueSamuel Holland
As of riscv-sbi-doc commit c7d3d1f7dcaa ("ext-fwft: use the provided value in fwft_set(POINTER_MASKING_PMLEN)"), the SBI implementation must use only the provided PMLEN value or else fail. It may not fall back to a larger PMLEN value. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Radim Krčmář <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-06-15lib: sbi: pmu: Remove MIP clearing from pmu_sse_enable()Clément Léger
Clearing MIP at that point means that we can probably lose a pending interrupt. This should not happen, remove MIP clearing from there. Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Atish Patra <[email protected]> Reviewed-by: Samuel Holland <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-06-15lib: sbi: pmu: Add SSE register/unregister() callbacksClément Léger
As soon as the SSE event is registered, there is no reason not to delegate the interrupt. Split the PMU SSE enable/disable() callbacks by moving MIDELEG setting to register/unregister(). Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Atish Patra <[email protected]> Reviewed-by: Samuel Holland <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-05-20lib: sbi: pmu: Return SBI_EINVAL if cidx_mask is 0James Raphael Tiovalen
Currently, when configuring a matching programmable HPM counter with Sscofpmf being present, cidx_base > 2, and cidx_mask == 0 to monitor either the CPU_CYCLES or INSTRUCTIONS hardware event, sbi_pmu_ctr_cfg_match will succeed but it will configure the corresponding fixed counter instead of the counter specified by the cidx_base parameter. During counter configuration, the following issues may arise: - If the SKIP_MATCH flag is set, an out-of-bounds memory read of the phs->active_events array would occur, which could lead to undefined behavior. - If the CLEAR_VALUE flag is set, the corresponding fixed counter will be reset, which could be considered unexpected behavior. - If the AUTO_START flag is set, pmu_ctr_start_hw will silently start the fixed counter, even though it has already started. From the supervisor's perspective, nothing has changed, which could be confusing. The supervisor will not see the SBI_ERR_ALREADY_STARTED error code since sbi_pmu_ctr_cfg_match does not return the error code of pmu_ctr_start_hw. The only way to detect these issues is to check the ctr_idx return value of sbi_pmu_ctr_cfg_match and compare it with cidx_base. Fix these issues by returning the SBI_ERR_INVALID_PARAM error code if the cidx_mask parameter value being passed in is 0 since an invalid parameter should not lead to a successful sbi_pmu_ctr_cfg_match but with unexpected side effects. Following a similar rationale, add the validation check to sbi_pmu_ctr_start and sbi_pmu_ctr_stop as well since sbi_fls is undefined when the mask is 0. This also aligns OpenSBI's behavior with KVM's. Signed-off-by: James Raphael Tiovalen <[email protected]> Reviewed-by: Atish Patra <[email protected]> Reviewed-by: Andrew Jones <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-05-20include: sbi: Change SBI spec version to 3.0Anup Patel
Now that SBI v3.0 specification is frozen, change runtime SBI version implemented by OpenSBI to v3.0. Also, mark extensions defined by the SBI v3.0 specification as non-experimental. Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Clément Léger <[email protected]> Reviewed-by: Atish Patra <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-05-20lib: sbi: hart: Detect existence of cycle and instret CSRs for ZicntrYao Zi
Zicntr extension specifies three read-only CSRs, time, cycle and instret. It isn't sufficient to report Zicntr is fully supported with only time CSR detected. This patch introduces a bitmap to sbi_hart_features to record availability of these CSRs, which are detected using traps. Zicntr is reported as present if and only if three CSRs are all available on the HARTs. Sites originally depending on SBI_HART_EXT_ZICNTR for detecting existence of time CSR are switched to detect SBI_HART_CSR_TIME instead. Suggested-by: Anup Patel <[email protected]> Signed-off-by: Yao Zi <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-05-20lib: Emulate AMO instructions when Zaamo is not availableChao-ying Fu
The AMO instructions are very critical for Linux so allow low-end RISC-V implementations without Zaamo to boot Linux by emulating AMO instructions using Zalrsc when OpenSBI is compiled without Zaamo. Signed-off-by: Chao-ying Fu <[email protected]> Signed-off-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-05-15lib: sbi: Use hsm stop for hsm waitNick Hu
If we hotplug a core and then perform a suspend-to-RAM operation on a multi-core platform, the hotplugged CPU may be woken up along with the rest of the system, particularly on platforms that wake all cores from the deepest sleep state. When this happens, the hotplugged CPU enters the sbi_hsm_wait WFI wait loop instead of transitioning into a platform-specific low-power state. To address this, we add a HSM stop call within the wait loop. This allows platforms that support HSM stop to enter a low-power state when the CPU is unexpectedly woken up. Signed-off-by: Nick Hu <[email protected]> Reviewed-by: Samuel Holland <[email protected]> Reviewed-by: Anup Patel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>
2025-04-30lib: sbi_hart: properly reset SsstateenRadim Krčmář
sstateen* and hstateen* CSRs must be zeroed by M-mode if the mstateen* registers are missing, to avoid security issues. Reviewed-by: Anup Patel <[email protected]> Signed-off-by: Radim Krčmář <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Anup Patel <[email protected]>