Author: mcayland Date: Fri May 23 14:01:51 2014 New Revision: 1302 URL: http://tracker.coreboot.org/trac/openbios/changeset/1302
Log: SPARC64: preserve window state when invoking CIF functions
Members of the *BSD family have a restriction that no window spill/fill traps can occur in the short time between calling SUNW,set-trap-table in OF and returning back to the caller.
In order to ensure we minimise window spill/fill traps, preserve the entire window state across the CIF calls (probably similar to OBP) to ensure that we don't breach this restriction.
Signed-off-by: Mark Cave-Ayland mark.cave-ayland@ilande.co.uk
Modified: trunk/openbios-devel/arch/sparc64/call-client.S
Modified: trunk/openbios-devel/arch/sparc64/call-client.S ============================================================================== --- trunk/openbios-devel/arch/sparc64/call-client.S Fri May 23 14:01:43 2014 (r1301) +++ trunk/openbios-devel/arch/sparc64/call-client.S Fri May 23 14:01:51 2014 (r1302) @@ -1,5 +1,153 @@ .globl sparc64_of_client_interface, client_tba
+ +/* + * SAVE_WINDOW_STATE and RESTORE_WINDOW_STATE are used to ensure + * that the CPU window state is preserved across CIF calls. This is + * to workaround a *BSD restriction that window fill/spill traps must + * be minimised during trap table takeover, and likely emulates the + * behaviour of OBP. + */ + +#define SAVE_WINDOW_STATE(type) \ + setx client_window, %g6, %g1; \ + rdpr %cwp, %g7; \ + stx %g7, [%g1]; \ + rdpr %cansave, %g7; \ + stx %g7, [%g1 + 0x8]; \ + rdpr %canrestore, %g7; \ + stx %g7, [%g1 + 0x10]; \ + rdpr %otherwin, %g7; \ + stx %g7, [%g1 + 0x18]; \ + rdpr %wstate, %g7; \ + stx %g7, [%g1 + 0x20]; \ + rdpr %cleanwin, %g7; \ + stx %g7, [%g1 + 0x28]; \ + \ + stx %o0, [%g1 + 0x30]; \ + stx %o1, [%g1 + 0x38]; \ + stx %o2, [%g1 + 0x40]; \ + stx %o3, [%g1 + 0x48]; \ + stx %o4, [%g1 + 0x50]; \ + stx %o5, [%g1 + 0x58]; \ + stx %o6, [%g1 + 0x60]; \ + stx %o7, [%g1 + 0x68]; \ + \ + rdpr %pstate, %g7; \ + stx %g7, [%g1 + 0x70]; \ + rd %y, %g7; \ + stx %g7, [%g1 + 0x78]; \ + rd %fprs, %g7; \ + stx %g7, [%g1 + 0x80]; \ + \ + /* Now iterate through all of the windows saving all l and i registers */ \ + add %g1, 0x90, %g5; \ + \ + /* Get the number of windows in %g6 */ \ + rdpr %ver, %g6; \ + and %g6, 0xf, %g6; \ + inc %g6; \ + \ +save_cpu_window_##type: \ + deccc %g6; \ + wrpr %g6, %cwp; \ + stx %l0, [%g5]; \ + stx %l1, [%g5 + 0x8]; \ + stx %l2, [%g5 + 0x10]; \ + stx %l3, [%g5 + 0x18]; \ + stx %l4, [%g5 + 0x20]; \ + stx %l5, [%g5 + 0x28]; \ + stx %l6, [%g5 + 0x30]; \ + stx %l7, [%g5 + 0x38]; \ + stx %i0, [%g5 + 0x40]; \ + stx %i1, [%g5 + 0x48]; \ + stx %i2, [%g5 + 0x50]; \ + stx %i3, [%g5 + 0x58]; \ + stx %i4, [%g5 + 0x60]; \ + stx %i5, [%g5 + 0x68]; \ + stx %i6, [%g5 + 0x70]; \ + stx %i7, [%g5 + 0x78]; \ + bne save_cpu_window_##type; \ + add %g5, 0x80, %g5; \ + \ + /* For 8 windows with 16 registers to save in the window, memory required \ + is 16*8*8 = 0x400 bytes */ \ + \ + /* Now we should be in window 0 so update the other window registers */ \ + rdpr %ver, %g6; \ + and %g6, 0xf, %g6; \ + dec %g6; \ + wrpr %g6, %cansave; \ + \ + wrpr %g0, %cleanwin; \ + wrpr %g0, %canrestore; \ + wrpr %g0, %otherwin; + + +#define RESTORE_WINDOW_STATE(type) \ + setx client_window, %g6, %g1; \ + \ + /* Get the number of windows in %g6 */ \ + rdpr %ver, %g6; \ + and %g6, 0xf, %g6; \ + inc %g6; \ + \ + /* Now iterate through all of the windows restoring all l and i registers */ \ + add %g1, 0x90, %g5; \ + \ +restore_cpu_window_##type: \ + deccc %g6; \ + wrpr %g6, %cwp; \ + ldx [%g5], %l0; \ + ldx [%g5 + 0x8], %l1; \ + ldx [%g5 + 0x10], %l2; \ + ldx [%g5 + 0x18], %l3; \ + ldx [%g5 + 0x20], %l4; \ + ldx [%g5 + 0x28], %l5; \ + ldx [%g5 + 0x30], %l6; \ + ldx [%g5 + 0x38], %l7; \ + ldx [%g5 + 0x40], %i0; \ + ldx [%g5 + 0x48], %i1; \ + ldx [%g5 + 0x50], %i2; \ + ldx [%g5 + 0x58], %i3; \ + ldx [%g5 + 0x60], %i4; \ + ldx [%g5 + 0x68], %i5; \ + ldx [%g5 + 0x70], %i6; \ + ldx [%g5 + 0x78], %i7; \ + bne restore_cpu_window_##type; \ + add %g5, 0x80, %g5; \ + \ + /* Restore the window registers to their original value */ \ + ldx [%g1], %g7; \ + wrpr %g7, %cwp; \ + ldx [%g1 + 0x8], %g7; \ + wrpr %g7, %cansave; \ + ldx [%g1 + 0x10], %g7; \ + wrpr %g7, %canrestore; \ + ldx [%g1 + 0x18], %g7; \ + wrpr %g7, %otherwin; \ + ldx [%g1 + 0x20], %g7; \ + wrpr %g7, %wstate; \ + ldx [%g1 + 0x28], %g7; \ + wrpr %g7, %cleanwin; \ + \ + ldx [%g1 + 0x30], %o0; \ + ldx [%g1 + 0x38], %o1; \ + ldx [%g1 + 0x40], %o2; \ + ldx [%g1 + 0x48], %o3; \ + ldx [%g1 + 0x50], %o4; \ + ldx [%g1 + 0x58], %o5; \ + ldx [%g1 + 0x60], %o6; \ + ldx [%g1 + 0x68], %o7; \ + \ + ldx [%g1 + 0x70], %g7; \ + wrpr %g7, %pstate; \ + ldx [%g1 + 0x78], %g7; \ + wr %g7, 0, %y; \ + ldx [%g1 + 0x80], %g7; \ + wr %g7, 0, %fprs + + .data .align 8
@@ -10,6 +158,9 @@ .xword 0 client_tba: .xword 0 +client_window: + .skip 2048 +
.text .align 4 @@ -23,8 +174,6 @@ */
sparc64_of_client_interface: - /* make sure caller's windows are on caller's stack */ - flushw
/* Save globals on callers stack */ add %sp, -56, %sp @@ -42,20 +191,26 @@ rdpr %tba, %g6 stx %g6, [%g7]
- /* Save existing stack and move to openbios stack */ + /* Save existing stack */ setx client_stack, %g6, %g7 stx %sp, [%g7] + + /* Save windows */ + SAVE_WINDOW_STATE(cif) + + /* Move to OpenBIOS stack */ setx openbios_stack - 2047 - 192, %g6, %g7 mov %g7, %sp
/* Call client inteface */ - save %sp, -192, %sp - call of_client_interface - mov %i0, %o0 + ldx [%g1 + 0x30], %o0 + + setx client_window, %g6, %g1 + stx %o0, [%g1 + 0x30]
- mov %o0, %i0 - restore %sp, 192, %sp + /* Restore windows */ + RESTORE_WINDOW_STATE(cif)
/* Restore stack */ setx client_stack, %g6, %g7
-
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