diff options
Diffstat (limited to 'arch/powerpc/platforms')
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-lpc.c | 59 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/dlpar.c | 4 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/lpar.c | 14 |
3 files changed, 73 insertions, 4 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-lpc.c b/arch/powerpc/platforms/powernv/opal-lpc.c index ad4b31df779a..e4169d68cb32 100644 --- a/arch/powerpc/platforms/powernv/opal-lpc.c +++ b/arch/powerpc/platforms/powernv/opal-lpc.c @@ -216,14 +216,54 @@ static ssize_t lpc_debug_read(struct file *filp, char __user *ubuf, &data, len); if (rc) return -ENXIO; + + /* + * Now there is some trickery with the data returned by OPAL + * as it's the desired data right justified in a 32-bit BE + * word. + * + * This is a very bad interface and I'm to blame for it :-( + * + * So we can't just apply a 32-bit swap to what comes from OPAL, + * because user space expects the *bytes* to be in their proper + * respective positions (ie, LPC position). + * + * So what we really want to do here is to shift data right + * appropriately on a LE kernel. + * + * IE. If the LPC transaction has bytes B0, B1, B2 and B3 in that + * order, we have in memory written to by OPAL at the "data" + * pointer: + * + * Bytes: OPAL "data" LE "data" + * 32-bit: B0 B1 B2 B3 B0B1B2B3 B3B2B1B0 + * 16-bit: B0 B1 0000B0B1 B1B00000 + * 8-bit: B0 000000B0 B0000000 + * + * So a BE kernel will have the leftmost of the above in the MSB + * and rightmost in the LSB and can just then "cast" the u32 "data" + * down to the appropriate quantity and write it. + * + * However, an LE kernel can't. It doesn't need to swap because a + * load from data followed by a store to user are going to preserve + * the byte ordering which is the wire byte order which is what the + * user wants, but in order to "crop" to the right size, we need to + * shift right first. + */ switch(len) { case 4: rc = __put_user((u32)data, (u32 __user *)ubuf); break; case 2: +#ifdef __LITTLE_ENDIAN__ + data >>= 16; +#endif rc = __put_user((u16)data, (u16 __user *)ubuf); break; default: +#ifdef __LITTLE_ENDIAN__ + data >>= 24; +#endif rc = __put_user((u8)data, (u8 __user *)ubuf); break; } @@ -263,12 +303,31 @@ static ssize_t lpc_debug_write(struct file *filp, const char __user *ubuf, else if (todo > 1 && (pos & 1) == 0) len = 2; } + + /* + * Similarly to the read case, we have some trickery here but + * it's different to handle. We need to pass the value to OPAL in + * a register whose layout depends on the access size. We want + * to reproduce the memory layout of the user, however we aren't + * doing a load from user and a store to another memory location + * which would achieve that. Here we pass the value to OPAL via + * a register which is expected to contain the "BE" interpretation + * of the byte sequence. IE: for a 32-bit access, byte 0 should be + * in the MSB. So here we *do* need to byteswap on LE. + * + * User bytes: LE "data" OPAL "data" + * 32-bit: B0 B1 B2 B3 B3B2B1B0 B0B1B2B3 + * 16-bit: B0 B1 0000B1B0 0000B0B1 + * 8-bit: B0 000000B0 000000B0 + */ switch(len) { case 4: rc = __get_user(data, (u32 __user *)ubuf); + data = cpu_to_be32(data); break; case 2: rc = __get_user(data, (u16 __user *)ubuf); + data = cpu_to_be16(data); break; default: rc = __get_user(data, (u8 __user *)ubuf); diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c index 6ad83bd11fe2..c22bb1b4beb8 100644 --- a/arch/powerpc/platforms/pseries/dlpar.c +++ b/arch/powerpc/platforms/pseries/dlpar.c @@ -382,7 +382,7 @@ static int dlpar_online_cpu(struct device_node *dn) BUG_ON(get_cpu_current_state(cpu) != CPU_STATE_OFFLINE); cpu_maps_update_done(); - rc = cpu_up(cpu); + rc = device_online(get_cpu_device(cpu)); if (rc) goto out; cpu_maps_update_begin(); @@ -467,7 +467,7 @@ static int dlpar_offline_cpu(struct device_node *dn) if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) { set_preferred_offline_state(cpu, CPU_STATE_OFFLINE); cpu_maps_update_done(); - rc = cpu_down(cpu); + rc = device_offline(get_cpu_device(cpu)); if (rc) goto out; cpu_maps_update_begin(); diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 8c509d5397c6..f6880d2a40fb 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -43,6 +43,7 @@ #include <asm/trace.h> #include <asm/firmware.h> #include <asm/plpar_wrappers.h> +#include <asm/fadump.h> #include "pseries.h" @@ -247,8 +248,17 @@ static void pSeries_lpar_hptab_clear(void) } #ifdef __LITTLE_ENDIAN__ - /* Reset exceptions to big endian */ - if (firmware_has_feature(FW_FEATURE_SET_MODE)) { + /* + * Reset exceptions to big endian. + * + * FIXME this is a hack for kexec, we need to reset the exception + * endian before starting the new kernel and this is a convenient place + * to do it. + * + * This is also called on boot when a fadump happens. In that case we + * must not change the exception endian mode. + */ + if (firmware_has_feature(FW_FEATURE_SET_MODE) && !is_fadump_active()) { long rc; rc = pseries_big_endian_exceptions(); |