[PATCH 4/5] MIPS: OCTEON: program L2C_CTL, not L2C_CFG, on OCTEON II
COOLING7d
From: Orgad Shaneh <hidden>
Date: 2026-09-15 07:13:21
Also in:
lkml
Subsystem:
mips, the rest · Maintainers:
Thomas Bogendoerfer, Linus Torvalds
cvmx_helper_initialize_packet_io_global() sets the L2 arbitration modes by rewriting L2C_CFG. That register (0x1180080000000) does not exist on OCTEON II; there the L2 controller is configured through L2C_CTL (0x1180080800000), whose corresponding fields are rsp_arb_mode and xmc_arb_mode. On a CN6335 the stray write hung the board hard when this function ran - no exception, no watchdog, just a dead console. Keep the L2C_CFG write for CN3XXX/CN5XXX and program L2C_CTL on CN6XXX with the values the vendor SDK uses there (rsp_arb_mode 1, xmc_arb_mode 0), which is the same trade the existing code makes for the older parts: keep IO blocks from being starved under high L2 load. Assisted-by: Claude:claude-opus-5 Signed-off-by: Orgad Shaneh <redacted> ---
diff --git a/arch/mips/cavium-octeon/executive/cvmx-helper.c b/arch/mips/cavium-octeon/executive/cvmx-helper.c
--- a/arch/mips/cavium-octeon/executive/cvmx-helper.c
+++ b/arch/mips/cavium-octeon/executive/cvmx-helper.c@@ -1014,7 +1014,6 @@ int cvmx_helper_initialize_packet_io_global(void) { int result = 0; int interface; - union cvmx_l2c_cfg l2c_cfg; const int num_interfaces = cvmx_helper_get_number_of_interfaces(); /*
@@ -1029,10 +1028,21 @@ int cvmx_helper_initialize_packet_io_global(void) * to the cores. This avoids conditions where IO blocks might * be starved under very high L2 loads. */ - l2c_cfg.u64 = cvmx_read_csr(CVMX_L2C_CFG); - l2c_cfg.s.lrf_arb_mode = 0; - l2c_cfg.s.rfb_arb_mode = 0; - cvmx_write_csr(CVMX_L2C_CFG, l2c_cfg.u64); + if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) { + union cvmx_l2c_ctl l2c_ctl; + + l2c_ctl.u64 = cvmx_read_csr(CVMX_L2C_CTL); + l2c_ctl.s.rsp_arb_mode = 1; + l2c_ctl.s.xmc_arb_mode = 0; + cvmx_write_csr(CVMX_L2C_CTL, l2c_ctl.u64); + } else { + union cvmx_l2c_cfg l2c_cfg; + + l2c_cfg.u64 = cvmx_read_csr(CVMX_L2C_CFG); + l2c_cfg.s.lrf_arb_mode = 0; + l2c_cfg.s.rfb_arb_mode = 0; + cvmx_write_csr(CVMX_L2C_CFG, l2c_cfg.u64); + } cvmx_pko_initialize_global(); for (interface = 0; interface < num_interfaces; interface++) {
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2.47.0